diff --git a/ChangeLog.d/fix_dh_genprime_error_reporting.txt b/ChangeLog.d/fix_dh_genprime_error_reporting.txt
new file mode 100644
index 0000000..1c98947
--- /dev/null
+++ b/ChangeLog.d/fix_dh_genprime_error_reporting.txt
@@ -0,0 +1,4 @@
+Bugfix
+   * Fix bug in error reporting in dh_genprime.c where upon failure,
+     the error code returned by mbedtls_mpi_write_file() is overwritten
+     and therefore not printed.
diff --git a/ChangeLog.d/negative-zero-from-add.txt b/ChangeLog.d/negative-zero-from-add.txt
new file mode 100644
index 0000000..107d858
--- /dev/null
+++ b/ChangeLog.d/negative-zero-from-add.txt
@@ -0,0 +1,6 @@
+Bugfix
+   * In the bignum module, operations of the form (-A) - (+A) or (-A) - (-A)
+     with A > 0 created an unintended representation of the value 0 which was
+     not processed correctly by some bignum operations. Fix this. This had no
+     consequence on cryptography code, but might affect applications that call
+     bignum directly and use negative numbers.
diff --git a/docs/architecture/psa-migration/outcome-analysis.sh b/docs/architecture/psa-migration/outcome-analysis.sh
index 81ab691..9084685 100755
--- a/docs/architecture/psa-migration/outcome-analysis.sh
+++ b/docs/architecture/psa-migration/outcome-analysis.sh
@@ -13,6 +13,7 @@
 # - the set of tests skipped in the driver-only build is the same as in an
 #   equivalent software-based configuration, or the difference is small enough,
 #   justified, and a github issue is created to track it.
+#   This part is verified by tests/scripts/analyze_outcomes.py
 #
 # WARNING: this script checks out a commit other than the head of the current
 # branch; it checks out the current branch again when running successfully,
@@ -26,30 +27,12 @@
 # re-running this script (for example "get numbers before this PR").
 
 # ----- BEGIN edit this -----
-# The component in all.sh that builds and tests with drivers.
-DRIVER_COMPONENT=test_psa_crypto_config_accel_hash_use_psa
-# A similar configuration to that of the component, except without drivers,
-# for comparison.
-reference_config () {
-    # start with full
-    scripts/config.py full
-    # use PSA config and disable driver-less algs as in the component
-    scripts/config.py set MBEDTLS_PSA_CRYPTO_CONFIG
-    scripts/config.py -f include/psa/crypto_config.h unset PSA_WANT_ALG_STREAM_CIPHER
-    scripts/config.py -f include/psa/crypto_config.h unset PSA_WANT_ALG_ECB_NO_PADDING
-    # disable options as in the component
-    # (no need to disable whole modules, we'll just skip their test suite)
-    scripts/config.py unset MBEDTLS_ECDSA_DETERMINISTIC
-    scripts/config.py -f include/psa/crypto_config.h unset PSA_WANT_ALG_DETERMINISTIC_ECDSA
-}
 # Space-separated list of test suites to ignore:
 # if SSS is in that list, test_suite_SSS and test_suite_SSS.* are ignored.
 IGNORE="md mdx shax" # accelerated
 IGNORE="$IGNORE entropy hmac_drbg random" # disabled (ext. RNG)
 IGNORE="$IGNORE psa_crypto_init" # needs internal RNG
 IGNORE="$IGNORE hkdf" # disabled in the all.sh component tested
-# Compare only "reference vs driver" or also "before vs after"?
-BEFORE_AFTER=1 # 0 or 1
 # ----- END edit this -----
 
 set -eu
@@ -65,38 +48,27 @@
     make check
 }
 
-if [ "$BEFORE_AFTER" -eq 1 ]; then
-    # save current HEAD
-    HEAD=$(git branch --show-current)
+# save current HEAD
+HEAD=$(git branch --show-current)
 
-    # get the numbers before this PR for default and full
-    cleanup
-    git checkout $(git merge-base HEAD development)
-    record "before-default"
-
-    cleanup
-    scripts/config.py full
-    record "before-full"
-
-    # get the numbers now for default and full
-    cleanup
-    git checkout $HEAD
-    record "after-default"
-
-    cleanup
-    scripts/config.py full
-    record "after-full"
-fi
-
-# get the numbers now for driver-only and reference
+# get the numbers before this PR for default and full
 cleanup
-reference_config
-record "reference"
+git checkout $(git merge-base HEAD development)
+record "before-default"
 
 cleanup
-export MBEDTLS_TEST_OUTCOME_FILE="$PWD/outcome-drivers.csv"
-export SKIP_SSL_OPT_COMPAT_SH=1
-tests/scripts/all.sh -k test_psa_crypto_config_accel_hash_use_psa
+scripts/config.py full
+record "before-full"
+
+# get the numbers now for default and full
+cleanup
+git checkout $HEAD
+record "after-default"
+
+cleanup
+scripts/config.py full
+record "after-full"
+
 
 # analysis
 
@@ -156,8 +128,5 @@
 }
 
 populate_suites
-if [ "$BEFORE_AFTER" -eq 1 ]; then
-    compare_builds before-default after-default
-    compare_builds before-full after-full
-fi
-compare_builds reference drivers
+compare_builds before-default after-default
+compare_builds before-full after-full
diff --git a/include/mbedtls/bignum.h b/include/mbedtls/bignum.h
index 9d15955..3bd1ca0 100644
--- a/include/mbedtls/bignum.h
+++ b/include/mbedtls/bignum.h
@@ -188,9 +188,27 @@
  */
 typedef struct mbedtls_mpi
 {
-    int MBEDTLS_PRIVATE(s);              /*!<  Sign: -1 if the mpi is negative, 1 otherwise */
-    size_t MBEDTLS_PRIVATE(n);           /*!<  total # of limbs  */
-    mbedtls_mpi_uint *MBEDTLS_PRIVATE(p);          /*!<  pointer to limbs  */
+    /** Sign: -1 if the mpi is negative, 1 otherwise.
+     *
+     * The number 0 must be represented with `s = +1`. Although many library
+     * functions treat all-limbs-zero as equivalent to a valid representation
+     * of 0 regardless of the sign bit, there are exceptions, so bignum
+     * functions and external callers must always set \c s to +1 for the
+     * number zero.
+     *
+     * Note that this implies that calloc() or `... = {0}` does not create
+     * a valid MPI representation. You must call mbedtls_mpi_init().
+     */
+    int MBEDTLS_PRIVATE(s);
+
+    /** Total number of limbs in \c p.  */
+    size_t MBEDTLS_PRIVATE(n);
+
+    /** Pointer to limbs.
+     *
+     * This may be \c NULL if \c n is 0.
+     */
+    mbedtls_mpi_uint *MBEDTLS_PRIVATE(p);
 }
 mbedtls_mpi;
 
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index d36db4a..3918639 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -842,10 +842,10 @@
         "but no key exchange methods defined with MBEDTLS_KEY_EXCHANGE_xxxx"
 #endif
 
-/* Early data requires PSK related mode defined */
 #if defined(MBEDTLS_SSL_EARLY_DATA) && \
-        ( !defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED) && \
-          !defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED))
+    ( !defined(MBEDTLS_SSL_SESSION_TICKETS) || \
+      ( !defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED) && \
+        !defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED) ) )
 #error "MBEDTLS_SSL_EARLY_DATA  defined, but not all prerequisites"
 #endif
 
diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index b4c8635..3f869b9 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -1637,7 +1637,8 @@
 *
 * Enable support for RFC 8446 TLS 1.3 early data.
 *
-* Requires: MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED or
+* Requires: MBEDTLS_SSL_SESSION_TICKETS and either
+*           MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED or
 *           MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED
 *
 * Comment this to disable support for early data. If MBEDTLS_SSL_PROTO_TLS1_3
@@ -1647,7 +1648,7 @@
 * production.
 *
 */
-//#define MBEDTLS_SSL_EARLY_DATA
+#define MBEDTLS_SSL_EARLY_DATA
 
 /**
  * \def MBEDTLS_SSL_PROTO_DTLS
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 01ede40..d055851 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -801,6 +801,29 @@
 typedef struct mbedtls_ssl_flight_item mbedtls_ssl_flight_item;
 #endif
 
+#if defined(MBEDTLS_SSL_EARLY_DATA) && defined(MBEDTLS_SSL_CLI_C)
+#define MBEDTLS_SSL_EARLY_DATA_STATUS_UNKNOWN           0
+#define MBEDTLS_SSL_EARLY_DATA_STATUS_NOT_SENT          1
+#define MBEDTLS_SSL_EARLY_DATA_STATUS_INDICATION_SENT   2
+#define MBEDTLS_SSL_EARLY_DATA_STATUS_REJECTED          3
+#define MBEDTLS_SSL_EARLY_DATA_STATUS_ACCEPTED          4
+#endif
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3) && defined(MBEDTLS_SSL_SESSION_TICKETS)
+typedef uint8_t mbedtls_ssl_tls13_ticket_flags;
+
+#define MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_PSK_RESUMPTION                          \
+            MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK                /* 1U << 0 */
+#define MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_PSK_EPHEMERAL_RESUMPTION                \
+            MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL      /* 1U << 2 */
+#define MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_EARLY_DATA                  ( 1U << 3 )
+
+#define MBEDTLS_SSL_TLS1_3_TICKET_FLAGS_MASK                                    \
+            ( MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_PSK_RESUMPTION             |      \
+              MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_PSK_EPHEMERAL_RESUMPTION   |      \
+              MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_EARLY_DATA )
+#endif /* MBEDTLS_SSL_PROTO_TLS1_3 && MBEDTLS_SSL_SESSION_TICKETS */
+
 /**
  * \brief          Callback type: server-side session cache getter
  *
@@ -1783,6 +1806,10 @@
                             *   and #MBEDTLS_SSL_CID_DISABLED. */
 #endif /* MBEDTLS_SSL_DTLS_CONNECTION_ID */
 
+#if defined(MBEDTLS_SSL_EARLY_DATA) && defined(MBEDTLS_SSL_CLI_C)
+    int MBEDTLS_PRIVATE(early_data_status);
+#endif /* MBEDTLS_SSL_EARLY_DATA && MBEDTLS_SSL_CLI_C */
+
     /** Callback to export key block and master secret                      */
     mbedtls_ssl_export_keys_t *MBEDTLS_PRIVATE(f_export_keys);
     void *MBEDTLS_PRIVATE(p_export_keys);            /*!< context for key export callback    */
diff --git a/library/bignum.c b/library/bignum.c
index 521787d..42be815 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -972,10 +972,12 @@
     return( ret );
 }
 
-/*
- * Signed addition: X = A + B
+/* Common function for signed addition and subtraction.
+ * Calculate A + B * flip_B where flip_B is 1 or -1.
  */
-int mbedtls_mpi_add_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B )
+static int add_sub_mpi( mbedtls_mpi *X,
+                        const mbedtls_mpi *A, const mbedtls_mpi *B,
+                        int flip_B )
 {
     int ret, s;
     MPI_VALIDATE_RET( X != NULL );
@@ -983,16 +985,21 @@
     MPI_VALIDATE_RET( B != NULL );
 
     s = A->s;
-    if( A->s * B->s < 0 )
+    if( A->s * B->s * flip_B < 0 )
     {
-        if( mbedtls_mpi_cmp_abs( A, B ) >= 0 )
+        int cmp = mbedtls_mpi_cmp_abs( A, B );
+        if( cmp >= 0 )
         {
             MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( X, A, B ) );
-            X->s =  s;
+            /* If |A| = |B|, the result is 0 and we must set the sign bit
+             * to +1 regardless of which of A or B was negative. Otherwise,
+             * since |A| > |B|, the sign is the sign of A. */
+            X->s = cmp == 0 ? 1 : s;
         }
         else
         {
             MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( X, B, A ) );
+            /* Since |A| < |B|, the sign is the opposite of A. */
             X->s = -s;
         }
     }
@@ -1008,38 +1015,19 @@
 }
 
 /*
+ * Signed addition: X = A + B
+ */
+int mbedtls_mpi_add_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B )
+{
+    return( add_sub_mpi( X, A, B, 1 ) );
+}
+
+/*
  * Signed subtraction: X = A - B
  */
 int mbedtls_mpi_sub_mpi( mbedtls_mpi *X, const mbedtls_mpi *A, const mbedtls_mpi *B )
 {
-    int ret, s;
-    MPI_VALIDATE_RET( X != NULL );
-    MPI_VALIDATE_RET( A != NULL );
-    MPI_VALIDATE_RET( B != NULL );
-
-    s = A->s;
-    if( A->s * B->s > 0 )
-    {
-        if( mbedtls_mpi_cmp_abs( A, B ) >= 0 )
-        {
-            MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( X, A, B ) );
-            X->s =  s;
-        }
-        else
-        {
-            MBEDTLS_MPI_CHK( mbedtls_mpi_sub_abs( X, B, A ) );
-            X->s = -s;
-        }
-    }
-    else
-    {
-        MBEDTLS_MPI_CHK( mbedtls_mpi_add_abs( X, A, B ) );
-        X->s = s;
-    }
-
-cleanup:
-
-    return( ret );
+    return( add_sub_mpi( X, A, B, -1 ) );
 }
 
 /*
diff --git a/library/bignum_mod_raw.c b/library/bignum_mod_raw.c
index a329e86..b43add7 100644
--- a/library/bignum_mod_raw.c
+++ b/library/bignum_mod_raw.c
@@ -127,7 +127,40 @@
 /* END MERGE SLOT 6 */
 
 /* BEGIN MERGE SLOT 7 */
+int mbedtls_mpi_mod_raw_to_mont_rep( mbedtls_mpi_uint *X,
+                                     const mbedtls_mpi_mod_modulus *m )
+{
+    mbedtls_mpi_uint *T;
+    const size_t t_limbs = m->limbs * 2 + 1;
 
+    if( ( T = (mbedtls_mpi_uint *) mbedtls_calloc( t_limbs, ciL ) ) == NULL )
+        return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
+
+    mbedtls_mpi_core_montmul( X, X, m->rep.mont.rr, m->limbs, m->p, m->limbs,
+                              m->rep.mont.mm, T );
+
+    mbedtls_platform_zeroize( T, t_limbs * ciL );
+    mbedtls_free( T );
+    return( 0 );
+}
+
+int mbedtls_mpi_mod_raw_from_mont_rep( mbedtls_mpi_uint *X,
+                                       const mbedtls_mpi_mod_modulus *m )
+{
+    const mbedtls_mpi_uint one = 1;
+    const size_t t_limbs = m->limbs * 2 + 1;
+    mbedtls_mpi_uint *T;
+
+    if( ( T = (mbedtls_mpi_uint *) mbedtls_calloc( t_limbs, ciL ) ) == NULL )
+        return( MBEDTLS_ERR_MPI_ALLOC_FAILED );
+
+    mbedtls_mpi_core_montmul( X, X, &one, 1, m->p, m->limbs,
+                              m->rep.mont.mm, T );
+
+    mbedtls_platform_zeroize( T, t_limbs * ciL );
+    mbedtls_free( T );
+    return( 0 );
+}
 /* END MERGE SLOT 7 */
 
 /* BEGIN MERGE SLOT 8 */
diff --git a/library/bignum_mod_raw.h b/library/bignum_mod_raw.h
index 30648d3..f738e91 100644
--- a/library/bignum_mod_raw.h
+++ b/library/bignum_mod_raw.h
@@ -163,7 +163,29 @@
 /* END MERGE SLOT 6 */
 
 /* BEGIN MERGE SLOT 7 */
+/** Convert an MPI into Montgomery form.
+ *
+ * \param X      The address of the MPI.
+ *               Must have the same number of limbs as \p m.
+ * \param m      The address of the modulus, which gives the size of
+ *               the base `R` = 2^(biL*m->limbs).
+ *
+ * \return       \c 0 if successful.
+ */
+int mbedtls_mpi_mod_raw_to_mont_rep( mbedtls_mpi_uint *X,
+                                     const mbedtls_mpi_mod_modulus *m );
 
+/** Convert an MPI back from Montgomery representation.
+ *
+ * \param X      The address of the MPI.
+ *               Must have the same number of limbs as \p m.
+ * \param m      The address of the modulus, which gives the size of
+ *               the base `R`= 2^(biL*m->limbs).
+ *
+ * \return       \c 0 if successful.
+ */
+int mbedtls_mpi_mod_raw_from_mont_rep( mbedtls_mpi_uint *X,
+                                       const mbedtls_mpi_mod_modulus *m );
 /* END MERGE SLOT 7 */
 
 /* BEGIN MERGE SLOT 8 */
diff --git a/library/ssl_client.c b/library/ssl_client.c
index d9c6781..0f0ea1d 100644
--- a/library/ssl_client.c
+++ b/library/ssl_client.c
@@ -106,6 +106,9 @@
 
     *olen = hostname_len + 9;
 
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_SERVERNAME );
+#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
     return( 0 );
 }
 #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
@@ -177,6 +180,9 @@
     /* Extension length = *out_len - 2 (ext_type) - 2 (ext_len) */
     MBEDTLS_PUT_UINT16_BE( *out_len - 4, buf, 2 );
 
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_ALPN );
+#endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
     return( 0 );
 }
 #endif /* MBEDTLS_SSL_ALPN */
@@ -296,7 +302,8 @@
     *out_len = p - buf;
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
-    ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_SUPPORTED_GROUPS;
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask(
+        ssl, MBEDTLS_TLS_EXT_SUPPORTED_GROUPS );
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
 
     return( 0 );
@@ -557,7 +564,7 @@
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
     /* Keeping track of the included extensions */
-    handshake->extensions_present = MBEDTLS_SSL_EXT_NONE;
+    handshake->sent_extensions = MBEDTLS_SSL_EXT_MASK_NONE;
 #endif
 
     /* First write extensions, then the total length */
@@ -667,6 +674,11 @@
                                   p_extensions_len, extensions_len );
     }
 
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
+    MBEDTLS_SSL_PRINT_EXTS(
+        3, MBEDTLS_SSL_HS_CLIENT_HELLO, handshake->sent_extensions );
+#endif
+
     *out_len = p - buf;
     return( 0 );
 }
diff --git a/library/ssl_debug_helpers.h b/library/ssl_debug_helpers.h
index 9f1df73..4412f8e 100644
--- a/library/ssl_debug_helpers.h
+++ b/library/ssl_debug_helpers.h
@@ -43,6 +43,32 @@
 
 const char *mbedtls_ssl_named_group_to_str( uint16_t in );
 
+const char *mbedtls_ssl_get_extension_name( unsigned int extension_type );
+
+void mbedtls_ssl_print_extensions( const mbedtls_ssl_context *ssl,
+                                   int level, const char *file, int line,
+                                   int hs_msg_type, uint32_t extensions_mask,
+                                   const char *extra );
+
+void mbedtls_ssl_print_extension( const mbedtls_ssl_context *ssl,
+                                  int level, const char *file, int line,
+                                  int hs_msg_type, unsigned int extension_type,
+                                  const char *extra_msg0, const char *extra_msg1 );
+
+#define MBEDTLS_SSL_PRINT_EXTS( level, hs_msg_type, extensions_mask )            \
+            mbedtls_ssl_print_extensions( ssl, level, __FILE__, __LINE__,       \
+                                          hs_msg_type, extensions_mask, NULL )
+
+#define MBEDTLS_SSL_PRINT_EXT( level, hs_msg_type, extension_type, extra )      \
+            mbedtls_ssl_print_extension( ssl, level, __FILE__, __LINE__,        \
+                                         hs_msg_type, extension_type,           \
+                                         extra, NULL )
+#else
+
+#define MBEDTLS_SSL_PRINT_EXTS( level, hs_msg_type, extension_mask )
+
+#define MBEDTLS_SSL_PRINT_EXT( level, hs_msg_type, extension_type, extra )
+
 #endif /* MBEDTLS_DEBUG_C */
 
-#endif /* SSL_DEBUG_HELPERS_H */
+#endif /* MBEDTLS_SSL_DEBUG_HELPERS_H */
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 41bb9c5..4d7f635 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -74,34 +74,147 @@
 #define MBEDTLS_SSL_RENEGOTIATION_DONE          2   /* Done or aborted */
 #define MBEDTLS_SSL_RENEGOTIATION_PENDING       3   /* Requested (server only) */
 
-/*
- * Mask of TLS 1.3 handshake extensions used in extensions_present
- * of mbedtls_ssl_handshake_params.
- */
-#define MBEDTLS_SSL_EXT_NONE                        0
+/* Faked handshake message identity for HelloRetryRequest. */
+#define MBEDTLS_SSL_TLS1_3_HS_HELLO_RETRY_REQUEST ( -MBEDTLS_SSL_HS_SERVER_HELLO )
 
-#define MBEDTLS_SSL_EXT_SERVERNAME                  ( 1 <<  0 )
-#define MBEDTLS_SSL_EXT_MAX_FRAGMENT_LENGTH         ( 1 <<  1 )
-#define MBEDTLS_SSL_EXT_STATUS_REQUEST              ( 1 <<  2 )
-#define MBEDTLS_SSL_EXT_SUPPORTED_GROUPS            ( 1 <<  3 )
-#define MBEDTLS_SSL_EXT_SIG_ALG                     ( 1 <<  4 )
-#define MBEDTLS_SSL_EXT_USE_SRTP                    ( 1 <<  5 )
-#define MBEDTLS_SSL_EXT_HEARTBEAT                   ( 1 <<  6 )
-#define MBEDTLS_SSL_EXT_ALPN                        ( 1 <<  7 )
-#define MBEDTLS_SSL_EXT_SCT                         ( 1 <<  8 )
-#define MBEDTLS_SSL_EXT_CLI_CERT_TYPE               ( 1 <<  9 )
-#define MBEDTLS_SSL_EXT_SERV_CERT_TYPE              ( 1 << 10 )
-#define MBEDTLS_SSL_EXT_PADDING                     ( 1 << 11 )
-#define MBEDTLS_SSL_EXT_PRE_SHARED_KEY              ( 1 << 12 )
-#define MBEDTLS_SSL_EXT_EARLY_DATA                  ( 1 << 13 )
-#define MBEDTLS_SSL_EXT_SUPPORTED_VERSIONS          ( 1 << 14 )
-#define MBEDTLS_SSL_EXT_COOKIE                      ( 1 << 15 )
-#define MBEDTLS_SSL_EXT_PSK_KEY_EXCHANGE_MODES      ( 1 << 16 )
-#define MBEDTLS_SSL_EXT_CERT_AUTH                   ( 1 << 17 )
-#define MBEDTLS_SSL_EXT_OID_FILTERS                 ( 1 << 18 )
-#define MBEDTLS_SSL_EXT_POST_HANDSHAKE_AUTH         ( 1 << 19 )
-#define MBEDTLS_SSL_EXT_SIG_ALG_CERT                ( 1 << 20 )
-#define MBEDTLS_SSL_EXT_KEY_SHARE                   ( 1 << 21 )
+/*
+ * Internal identity of handshake extensions
+ */
+#define MBEDTLS_SSL_EXT_ID_UNRECOGNIZED                0
+#define MBEDTLS_SSL_EXT_ID_SERVERNAME                  1
+#define MBEDTLS_SSL_EXT_ID_SERVERNAME_HOSTNAME         1
+#define MBEDTLS_SSL_EXT_ID_MAX_FRAGMENT_LENGTH         2
+#define MBEDTLS_SSL_EXT_ID_STATUS_REQUEST              3
+#define MBEDTLS_SSL_EXT_ID_SUPPORTED_GROUPS            4
+#define MBEDTLS_SSL_EXT_ID_SUPPORTED_ELLIPTIC_CURVES   4
+#define MBEDTLS_SSL_EXT_ID_SIG_ALG                     5
+#define MBEDTLS_SSL_EXT_ID_USE_SRTP                    6
+#define MBEDTLS_SSL_EXT_ID_HEARTBEAT                   7
+#define MBEDTLS_SSL_EXT_ID_ALPN                        8
+#define MBEDTLS_SSL_EXT_ID_SCT                         9
+#define MBEDTLS_SSL_EXT_ID_CLI_CERT_TYPE              10
+#define MBEDTLS_SSL_EXT_ID_SERV_CERT_TYPE             11
+#define MBEDTLS_SSL_EXT_ID_PADDING                    12
+#define MBEDTLS_SSL_EXT_ID_PRE_SHARED_KEY             13
+#define MBEDTLS_SSL_EXT_ID_EARLY_DATA                 14
+#define MBEDTLS_SSL_EXT_ID_SUPPORTED_VERSIONS         15
+#define MBEDTLS_SSL_EXT_ID_COOKIE                     16
+#define MBEDTLS_SSL_EXT_ID_PSK_KEY_EXCHANGE_MODES     17
+#define MBEDTLS_SSL_EXT_ID_CERT_AUTH                  18
+#define MBEDTLS_SSL_EXT_ID_OID_FILTERS                19
+#define MBEDTLS_SSL_EXT_ID_POST_HANDSHAKE_AUTH        20
+#define MBEDTLS_SSL_EXT_ID_SIG_ALG_CERT               21
+#define MBEDTLS_SSL_EXT_ID_KEY_SHARE                  22
+#define MBEDTLS_SSL_EXT_ID_TRUNCATED_HMAC             23
+#define MBEDTLS_SSL_EXT_ID_SUPPORTED_POINT_FORMATS    24
+#define MBEDTLS_SSL_EXT_ID_ENCRYPT_THEN_MAC           25
+#define MBEDTLS_SSL_EXT_ID_EXTENDED_MASTER_SECRET     26
+#define MBEDTLS_SSL_EXT_ID_SESSION_TICKET             27
+
+/* Utility for translating IANA extension type. */
+uint32_t mbedtls_ssl_get_extension_id( unsigned int extension_type );
+uint32_t mbedtls_ssl_get_extension_mask( unsigned int extension_type );
+/* Macros used to define mask constants */
+#define MBEDTLS_SSL_EXT_MASK( id )       ( 1ULL << ( MBEDTLS_SSL_EXT_ID_##id ) )
+/* Reset value of extension mask */
+#define MBEDTLS_SSL_EXT_MASK_NONE                                              0
+
+/* In messages containing extension requests, we should ignore unrecognized
+ * extensions. In messages containing extension responses, unrecognized
+ * extensions should result in handshake abortion. Messages containing
+ * extension requests include ClientHello, CertificateRequest and
+ * NewSessionTicket. Messages containing extension responses include
+ * ServerHello, HelloRetryRequest, EncryptedExtensions and Certificate.
+ *
+ * RFC 8446 section 4.1.3
+ *
+ * The ServerHello MUST only include extensions which are required to establish
+ * the cryptographic context and negotiate the protocol version.
+ *
+ * RFC 8446 section 4.2
+ *
+ * If an implementation receives an extension which it recognizes and which is
+ * not specified for the message in which it appears, it MUST abort the handshake
+ * with an "illegal_parameter" alert.
+ */
+
+/* Extensions that are not recognized by TLS 1.3 */
+#define MBEDTLS_SSL_TLS1_3_EXT_MASK_UNRECOGNIZED                               \
+            ( MBEDTLS_SSL_EXT_MASK( SUPPORTED_POINT_FORMATS )                | \
+              MBEDTLS_SSL_EXT_MASK( ENCRYPT_THEN_MAC )                       | \
+              MBEDTLS_SSL_EXT_MASK( EXTENDED_MASTER_SECRET )                 | \
+              MBEDTLS_SSL_EXT_MASK( SESSION_TICKET )                         | \
+              MBEDTLS_SSL_EXT_MASK( TRUNCATED_HMAC )                         | \
+              MBEDTLS_SSL_EXT_MASK( UNRECOGNIZED ) )
+
+/* RFC 8446 section 4.2. Allowed extensions for ClienHello */
+#define MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CH                                  \
+            ( MBEDTLS_SSL_EXT_MASK( SERVERNAME )                             | \
+              MBEDTLS_SSL_EXT_MASK( MAX_FRAGMENT_LENGTH )                    | \
+              MBEDTLS_SSL_EXT_MASK( STATUS_REQUEST )                         | \
+              MBEDTLS_SSL_EXT_MASK( SUPPORTED_GROUPS )                       | \
+              MBEDTLS_SSL_EXT_MASK( SIG_ALG )                                | \
+              MBEDTLS_SSL_EXT_MASK( USE_SRTP )                               | \
+              MBEDTLS_SSL_EXT_MASK( HEARTBEAT )                              | \
+              MBEDTLS_SSL_EXT_MASK( ALPN )                                   | \
+              MBEDTLS_SSL_EXT_MASK( SCT )                                    | \
+              MBEDTLS_SSL_EXT_MASK( CLI_CERT_TYPE )                          | \
+              MBEDTLS_SSL_EXT_MASK( SERV_CERT_TYPE )                         | \
+              MBEDTLS_SSL_EXT_MASK( PADDING )                                | \
+              MBEDTLS_SSL_EXT_MASK( KEY_SHARE )                              | \
+              MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY )                         | \
+              MBEDTLS_SSL_EXT_MASK( PSK_KEY_EXCHANGE_MODES )                 | \
+              MBEDTLS_SSL_EXT_MASK( EARLY_DATA )                             | \
+              MBEDTLS_SSL_EXT_MASK( COOKIE )                                 | \
+              MBEDTLS_SSL_EXT_MASK( SUPPORTED_VERSIONS )                     | \
+              MBEDTLS_SSL_EXT_MASK( CERT_AUTH )                              | \
+              MBEDTLS_SSL_EXT_MASK( POST_HANDSHAKE_AUTH )                    | \
+              MBEDTLS_SSL_EXT_MASK( SIG_ALG_CERT )                           | \
+              MBEDTLS_SSL_TLS1_3_EXT_MASK_UNRECOGNIZED )
+
+/* RFC 8446 section 4.2. Allowed extensions for EncryptedExtensions */
+#define MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_EE                                  \
+            ( MBEDTLS_SSL_EXT_MASK( SERVERNAME )                             | \
+              MBEDTLS_SSL_EXT_MASK( MAX_FRAGMENT_LENGTH )                    | \
+              MBEDTLS_SSL_EXT_MASK( SUPPORTED_GROUPS )                       | \
+              MBEDTLS_SSL_EXT_MASK( USE_SRTP )                               | \
+              MBEDTLS_SSL_EXT_MASK( HEARTBEAT )                              | \
+              MBEDTLS_SSL_EXT_MASK( ALPN )                                   | \
+              MBEDTLS_SSL_EXT_MASK( CLI_CERT_TYPE )                          | \
+              MBEDTLS_SSL_EXT_MASK( SERV_CERT_TYPE )                         | \
+              MBEDTLS_SSL_EXT_MASK( EARLY_DATA ) )
+
+/* RFC 8446 section 4.2. Allowed extensions for CertificateRequest */
+#define MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CR                                  \
+            ( MBEDTLS_SSL_EXT_MASK( STATUS_REQUEST )                         | \
+              MBEDTLS_SSL_EXT_MASK( SIG_ALG )                                | \
+              MBEDTLS_SSL_EXT_MASK( SCT )                                    | \
+              MBEDTLS_SSL_EXT_MASK( CERT_AUTH )                              | \
+              MBEDTLS_SSL_EXT_MASK( OID_FILTERS )                            | \
+              MBEDTLS_SSL_EXT_MASK( SIG_ALG_CERT )                           | \
+              MBEDTLS_SSL_TLS1_3_EXT_MASK_UNRECOGNIZED )
+
+/* RFC 8446 section 4.2. Allowed extensions for Certificate */
+#define MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CT                                  \
+            ( MBEDTLS_SSL_EXT_MASK( STATUS_REQUEST )                         | \
+              MBEDTLS_SSL_EXT_MASK( SCT ) )
+
+/* RFC 8446 section 4.2. Allowed extensions for ServerHello */
+#define MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_SH                                  \
+            ( MBEDTLS_SSL_EXT_MASK( KEY_SHARE )                              | \
+              MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY )                         | \
+              MBEDTLS_SSL_EXT_MASK( SUPPORTED_VERSIONS ) )
+
+/* RFC 8446 section 4.2. Allowed extensions for HelloRetryRequest */
+#define MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_HRR                                 \
+            ( MBEDTLS_SSL_EXT_MASK( KEY_SHARE )                              | \
+              MBEDTLS_SSL_EXT_MASK( COOKIE )                                 | \
+              MBEDTLS_SSL_EXT_MASK( SUPPORTED_VERSIONS ) )
+
+/* RFC 8446 section 4.2. Allowed extensions for NewSessionTicket */
+#define MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_NST                                 \
+            ( MBEDTLS_SSL_EXT_MASK( EARLY_DATA )                             | \
+              MBEDTLS_SSL_TLS1_3_EXT_MASK_UNRECOGNIZED )
 
 /*
  * Helper macros for function call with return check.
@@ -858,9 +971,8 @@
 #endif
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
-    int extensions_present;             /*!< extension presence; Each bitfield
-                                             represents an extension and defined
-                                             as \c MBEDTLS_SSL_EXT_XXX */
+    uint32_t sent_extensions;       /*!< extensions sent by endpoint */
+    uint32_t received_extensions;   /*!< extensions received by endpoint */
 
 #if defined(MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED)
     unsigned char certificate_request_context_len;
@@ -1839,6 +1951,24 @@
           MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */
 
 /*
+ * Helper functions for extensions checking.
+ */
+
+MBEDTLS_CHECK_RETURN_CRITICAL
+int mbedtls_ssl_tls13_check_received_extension(
+        mbedtls_ssl_context *ssl,
+        int hs_msg_type,
+        unsigned int received_extension_type,
+        uint32_t hs_msg_allowed_extensions_mask );
+
+static inline void mbedtls_ssl_tls13_set_hs_sent_ext_mask(
+                       mbedtls_ssl_context *ssl, unsigned int extension_type )
+{
+    ssl->handshake->sent_extensions |=
+        mbedtls_ssl_get_extension_mask( extension_type );
+}
+
+/*
  * Helper functions to check the selected key exchange mode.
  */
 static inline int mbedtls_ssl_tls13_key_exchange_mode_check(
@@ -1916,6 +2046,12 @@
                 size_t *out_len );
 #endif /* MBEDTLS_ECDH_C */
 
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+int mbedtls_ssl_tls13_write_early_data_ext( mbedtls_ssl_context *ssl,
+                                            unsigned char *buf,
+                                            const unsigned char *end,
+                                            size_t *out_len );
+#endif /* MBEDTLS_SSL_EARLY_DATA */
 
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
 
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index dbbd6f2..da90b23 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -521,6 +521,245 @@
 }
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
+uint32_t mbedtls_ssl_get_extension_id( unsigned int extension_type )
+{
+    switch( extension_type )
+    {
+        case MBEDTLS_TLS_EXT_SERVERNAME:
+            return( MBEDTLS_SSL_EXT_ID_SERVERNAME );
+
+        case MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH:
+            return( MBEDTLS_SSL_EXT_ID_MAX_FRAGMENT_LENGTH );
+
+        case MBEDTLS_TLS_EXT_STATUS_REQUEST:
+            return( MBEDTLS_SSL_EXT_ID_STATUS_REQUEST );
+
+        case MBEDTLS_TLS_EXT_SUPPORTED_GROUPS:
+            return( MBEDTLS_SSL_EXT_ID_SUPPORTED_GROUPS );
+
+        case MBEDTLS_TLS_EXT_SIG_ALG:
+            return( MBEDTLS_SSL_EXT_ID_SIG_ALG );
+
+        case MBEDTLS_TLS_EXT_USE_SRTP:
+            return( MBEDTLS_SSL_EXT_ID_USE_SRTP );
+
+        case MBEDTLS_TLS_EXT_HEARTBEAT:
+            return( MBEDTLS_SSL_EXT_ID_HEARTBEAT );
+
+        case MBEDTLS_TLS_EXT_ALPN:
+            return( MBEDTLS_SSL_EXT_ID_ALPN );
+
+        case MBEDTLS_TLS_EXT_SCT:
+            return( MBEDTLS_SSL_EXT_ID_SCT );
+
+        case MBEDTLS_TLS_EXT_CLI_CERT_TYPE:
+            return( MBEDTLS_SSL_EXT_ID_CLI_CERT_TYPE );
+
+        case MBEDTLS_TLS_EXT_SERV_CERT_TYPE:
+            return( MBEDTLS_SSL_EXT_ID_SERV_CERT_TYPE );
+
+        case MBEDTLS_TLS_EXT_PADDING:
+            return( MBEDTLS_SSL_EXT_ID_PADDING );
+
+        case MBEDTLS_TLS_EXT_PRE_SHARED_KEY:
+            return( MBEDTLS_SSL_EXT_ID_PRE_SHARED_KEY );
+
+        case MBEDTLS_TLS_EXT_EARLY_DATA:
+            return( MBEDTLS_SSL_EXT_ID_EARLY_DATA );
+
+        case MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS:
+            return( MBEDTLS_SSL_EXT_ID_SUPPORTED_VERSIONS );
+
+        case MBEDTLS_TLS_EXT_COOKIE:
+            return( MBEDTLS_SSL_EXT_ID_COOKIE );
+
+        case MBEDTLS_TLS_EXT_PSK_KEY_EXCHANGE_MODES:
+            return( MBEDTLS_SSL_EXT_ID_PSK_KEY_EXCHANGE_MODES );
+
+        case MBEDTLS_TLS_EXT_CERT_AUTH:
+            return( MBEDTLS_SSL_EXT_ID_CERT_AUTH );
+
+        case MBEDTLS_TLS_EXT_OID_FILTERS:
+            return( MBEDTLS_SSL_EXT_ID_OID_FILTERS );
+
+        case MBEDTLS_TLS_EXT_POST_HANDSHAKE_AUTH:
+            return( MBEDTLS_SSL_EXT_ID_POST_HANDSHAKE_AUTH );
+
+        case MBEDTLS_TLS_EXT_SIG_ALG_CERT:
+            return( MBEDTLS_SSL_EXT_ID_SIG_ALG_CERT );
+
+        case MBEDTLS_TLS_EXT_KEY_SHARE:
+            return( MBEDTLS_SSL_EXT_ID_KEY_SHARE );
+
+        case MBEDTLS_TLS_EXT_TRUNCATED_HMAC:
+            return( MBEDTLS_SSL_EXT_ID_TRUNCATED_HMAC );
+
+        case MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS:
+            return( MBEDTLS_SSL_EXT_ID_SUPPORTED_POINT_FORMATS );
+
+        case MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC:
+            return( MBEDTLS_SSL_EXT_ID_ENCRYPT_THEN_MAC );
+
+        case MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET:
+            return( MBEDTLS_SSL_EXT_ID_EXTENDED_MASTER_SECRET );
+
+        case MBEDTLS_TLS_EXT_SESSION_TICKET:
+            return( MBEDTLS_SSL_EXT_ID_SESSION_TICKET );
+
+    }
+
+    return( MBEDTLS_SSL_EXT_ID_UNRECOGNIZED );
+}
+
+uint32_t mbedtls_ssl_get_extension_mask( unsigned int extension_type )
+{
+    return( 1 << mbedtls_ssl_get_extension_id( extension_type ) );
+}
+
+#if defined(MBEDTLS_DEBUG_C)
+static const char *extension_name_table[] = {
+    [MBEDTLS_SSL_EXT_ID_UNRECOGNIZED] = "unrecognized",
+    [MBEDTLS_SSL_EXT_ID_SERVERNAME] = "server_name",
+    [MBEDTLS_SSL_EXT_ID_MAX_FRAGMENT_LENGTH] = "max_fragment_length",
+    [MBEDTLS_SSL_EXT_ID_STATUS_REQUEST] = "status_request",
+    [MBEDTLS_SSL_EXT_ID_SUPPORTED_GROUPS] = "supported_groups",
+    [MBEDTLS_SSL_EXT_ID_SIG_ALG] = "signature_algorithms",
+    [MBEDTLS_SSL_EXT_ID_USE_SRTP] = "use_srtp",
+    [MBEDTLS_SSL_EXT_ID_HEARTBEAT] = "heartbeat",
+    [MBEDTLS_SSL_EXT_ID_ALPN] = "application_layer_protocol_negotiation",
+    [MBEDTLS_SSL_EXT_ID_SCT] = "signed_certificate_timestamp",
+    [MBEDTLS_SSL_EXT_ID_CLI_CERT_TYPE] = "client_certificate_type",
+    [MBEDTLS_SSL_EXT_ID_SERV_CERT_TYPE] = "server_certificate_type",
+    [MBEDTLS_SSL_EXT_ID_PADDING] = "padding",
+    [MBEDTLS_SSL_EXT_ID_PRE_SHARED_KEY] = "pre_shared_key",
+    [MBEDTLS_SSL_EXT_ID_EARLY_DATA] = "early_data",
+    [MBEDTLS_SSL_EXT_ID_SUPPORTED_VERSIONS] = "supported_versions",
+    [MBEDTLS_SSL_EXT_ID_COOKIE] = "cookie",
+    [MBEDTLS_SSL_EXT_ID_PSK_KEY_EXCHANGE_MODES] = "psk_key_exchange_modes",
+    [MBEDTLS_SSL_EXT_ID_CERT_AUTH] = "certificate_authorities",
+    [MBEDTLS_SSL_EXT_ID_OID_FILTERS] = "oid_filters",
+    [MBEDTLS_SSL_EXT_ID_POST_HANDSHAKE_AUTH] = "post_handshake_auth",
+    [MBEDTLS_SSL_EXT_ID_SIG_ALG_CERT] = "signature_algorithms_cert",
+    [MBEDTLS_SSL_EXT_ID_KEY_SHARE] = "key_share",
+    [MBEDTLS_SSL_EXT_ID_TRUNCATED_HMAC] = "truncated_hmac",
+    [MBEDTLS_SSL_EXT_ID_SUPPORTED_POINT_FORMATS] = "supported_point_formats",
+    [MBEDTLS_SSL_EXT_ID_ENCRYPT_THEN_MAC] = "encrypt_then_mac",
+    [MBEDTLS_SSL_EXT_ID_EXTENDED_MASTER_SECRET] = "extended_master_secret",
+    [MBEDTLS_SSL_EXT_ID_SESSION_TICKET] = "session_ticket"
+};
+
+static unsigned int extension_type_table[]={
+    [MBEDTLS_SSL_EXT_ID_UNRECOGNIZED] = 0xff,
+    [MBEDTLS_SSL_EXT_ID_SERVERNAME] = MBEDTLS_TLS_EXT_SERVERNAME,
+    [MBEDTLS_SSL_EXT_ID_MAX_FRAGMENT_LENGTH] = MBEDTLS_TLS_EXT_MAX_FRAGMENT_LENGTH,
+    [MBEDTLS_SSL_EXT_ID_STATUS_REQUEST] = MBEDTLS_TLS_EXT_STATUS_REQUEST,
+    [MBEDTLS_SSL_EXT_ID_SUPPORTED_GROUPS] = MBEDTLS_TLS_EXT_SUPPORTED_GROUPS,
+    [MBEDTLS_SSL_EXT_ID_SIG_ALG] = MBEDTLS_TLS_EXT_SIG_ALG,
+    [MBEDTLS_SSL_EXT_ID_USE_SRTP] = MBEDTLS_TLS_EXT_USE_SRTP,
+    [MBEDTLS_SSL_EXT_ID_HEARTBEAT] = MBEDTLS_TLS_EXT_HEARTBEAT,
+    [MBEDTLS_SSL_EXT_ID_ALPN] = MBEDTLS_TLS_EXT_ALPN,
+    [MBEDTLS_SSL_EXT_ID_SCT] = MBEDTLS_TLS_EXT_SCT,
+    [MBEDTLS_SSL_EXT_ID_CLI_CERT_TYPE] = MBEDTLS_TLS_EXT_CLI_CERT_TYPE,
+    [MBEDTLS_SSL_EXT_ID_SERV_CERT_TYPE] = MBEDTLS_TLS_EXT_SERV_CERT_TYPE,
+    [MBEDTLS_SSL_EXT_ID_PADDING] = MBEDTLS_TLS_EXT_PADDING,
+    [MBEDTLS_SSL_EXT_ID_PRE_SHARED_KEY] = MBEDTLS_TLS_EXT_PRE_SHARED_KEY,
+    [MBEDTLS_SSL_EXT_ID_EARLY_DATA] = MBEDTLS_TLS_EXT_EARLY_DATA,
+    [MBEDTLS_SSL_EXT_ID_SUPPORTED_VERSIONS] = MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS,
+    [MBEDTLS_SSL_EXT_ID_COOKIE] = MBEDTLS_TLS_EXT_COOKIE,
+    [MBEDTLS_SSL_EXT_ID_PSK_KEY_EXCHANGE_MODES] = MBEDTLS_TLS_EXT_PSK_KEY_EXCHANGE_MODES,
+    [MBEDTLS_SSL_EXT_ID_CERT_AUTH] = MBEDTLS_TLS_EXT_CERT_AUTH,
+    [MBEDTLS_SSL_EXT_ID_OID_FILTERS] = MBEDTLS_TLS_EXT_OID_FILTERS,
+    [MBEDTLS_SSL_EXT_ID_POST_HANDSHAKE_AUTH] = MBEDTLS_TLS_EXT_POST_HANDSHAKE_AUTH,
+    [MBEDTLS_SSL_EXT_ID_SIG_ALG_CERT] = MBEDTLS_TLS_EXT_SIG_ALG_CERT,
+    [MBEDTLS_SSL_EXT_ID_KEY_SHARE] = MBEDTLS_TLS_EXT_KEY_SHARE,
+    [MBEDTLS_SSL_EXT_ID_TRUNCATED_HMAC] = MBEDTLS_TLS_EXT_TRUNCATED_HMAC,
+    [MBEDTLS_SSL_EXT_ID_SUPPORTED_POINT_FORMATS] = MBEDTLS_TLS_EXT_SUPPORTED_POINT_FORMATS,
+    [MBEDTLS_SSL_EXT_ID_ENCRYPT_THEN_MAC] = MBEDTLS_TLS_EXT_ENCRYPT_THEN_MAC,
+    [MBEDTLS_SSL_EXT_ID_EXTENDED_MASTER_SECRET] = MBEDTLS_TLS_EXT_EXTENDED_MASTER_SECRET,
+    [MBEDTLS_SSL_EXT_ID_SESSION_TICKET] = MBEDTLS_TLS_EXT_SESSION_TICKET
+};
+
+const char *mbedtls_ssl_get_extension_name( unsigned int extension_type )
+{
+    return( extension_name_table[
+                mbedtls_ssl_get_extension_id( extension_type ) ] );
+}
+
+static const char *ssl_tls13_get_hs_msg_name( int hs_msg_type )
+{
+    switch( hs_msg_type )
+    {
+        case MBEDTLS_SSL_HS_CLIENT_HELLO:
+            return( "ClientHello" );
+        case MBEDTLS_SSL_HS_SERVER_HELLO:
+            return( "ServerHello" );
+        case MBEDTLS_SSL_TLS1_3_HS_HELLO_RETRY_REQUEST:
+            return( "HelloRetryRequest" );
+        case MBEDTLS_SSL_HS_NEW_SESSION_TICKET:
+            return( "NewSessionTicket" );
+        case MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS:
+            return( "EncryptedExtensions" );
+        case MBEDTLS_SSL_HS_CERTIFICATE:
+            return( "Certificate" );
+        case MBEDTLS_SSL_HS_CERTIFICATE_REQUEST:
+            return( "CertificateRequest" );
+    }
+    return( "Unknown" );
+}
+
+void mbedtls_ssl_print_extension( const mbedtls_ssl_context *ssl,
+                                  int level, const char *file, int line,
+                                  int hs_msg_type, unsigned int extension_type,
+                                  const char *extra_msg0, const char *extra_msg1 )
+{
+    const char *extra_msg;
+    if( extra_msg0 && extra_msg1 )
+    {
+        mbedtls_debug_print_msg(
+            ssl, level, file, line,
+            "%s: %s(%u) extension %s %s.",
+            ssl_tls13_get_hs_msg_name( hs_msg_type ),
+            mbedtls_ssl_get_extension_name( extension_type ),
+            extension_type,
+            extra_msg0, extra_msg1 );
+        return;
+    }
+
+    extra_msg = extra_msg0 ? extra_msg0 : extra_msg1;
+    if( extra_msg )
+    {
+        mbedtls_debug_print_msg(
+            ssl, level, file, line,
+            "%s: %s(%u) extension %s.", ssl_tls13_get_hs_msg_name( hs_msg_type ),
+            mbedtls_ssl_get_extension_name( extension_type ), extension_type,
+            extra_msg );
+        return;
+    }
+
+    mbedtls_debug_print_msg(
+        ssl, level, file, line,
+        "%s: %s(%u) extension.", ssl_tls13_get_hs_msg_name( hs_msg_type ),
+        mbedtls_ssl_get_extension_name( extension_type ), extension_type );
+}
+
+void mbedtls_ssl_print_extensions( const mbedtls_ssl_context *ssl,
+                                   int level, const char *file, int line,
+                                   int hs_msg_type, uint32_t extensions_mask,
+                                   const char *extra )
+{
+
+    for( unsigned i = 0;
+         i < sizeof( extension_name_table ) / sizeof( extension_name_table[0] );
+         i++ )
+    {
+        mbedtls_ssl_print_extension(
+            ssl, level, file, line, hs_msg_type, extension_type_table[i],
+            extensions_mask & ( 1 << i ) ? "exists" : "does not exist", extra );
+    }
+}
+
+#endif /* MBEDTLS_DEBUG_C */
+
 void mbedtls_ssl_optimize_checksum( mbedtls_ssl_context *ssl,
                             const mbedtls_ssl_ciphersuite_t *ciphersuite_info )
 {
@@ -8744,8 +8983,9 @@
     *out_len = p - buf;
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
-    ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_SIG_ALG;
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_SIG_ALG );
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
+
     return( 0 );
 }
 #endif /* MBEDTLS_SSL_HANDSHAKE_WITH_CERT_ENABLED */
@@ -8944,6 +9184,11 @@
     p[6] = MBEDTLS_BYTE_0( protocol_name_len );
 
     memcpy( p + 7, ssl->alpn_chosen, protocol_name_len );
+
+#if defined(MBEDTLS_SSL_PROTO_TLS1_3)
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_ALPN );
+#endif
+
     return ( 0 );
 }
 #endif /* MBEDTLS_SSL_ALPN */
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index ac19f63..0372f2d 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -32,6 +32,7 @@
 #include "ssl_misc.h"
 #include "ssl_client.h"
 #include "ssl_tls13_keys.h"
+#include "ssl_debug_helpers.h"
 
 /* Write extensions */
 
@@ -89,6 +90,9 @@
 
     *out_len = 5 + versions_len;
 
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask(
+        ssl, MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS );
+
     return( 0 );
 }
 
@@ -359,7 +363,7 @@
 
     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, key_share extension", buf, *out_len );
 
-    ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_KEY_SHARE;
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_KEY_SHARE );
 
 cleanup:
 
@@ -512,7 +516,6 @@
     else
         return( MBEDTLS_ERR_SSL_INTERNAL_ERROR );
 
-    ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_KEY_SHARE;
     return( ret );
 }
 
@@ -600,6 +603,8 @@
 
     *out_len = handshake->hrr_cookie_len + 6;
 
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_COOKIE );
+
     return( 0 );
 }
 
@@ -669,7 +674,10 @@
     buf[4] = ke_modes_len;
 
     *out_len = p - buf;
-    ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_PSK_KEY_EXCHANGE_MODES;
+
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask(
+        ssl, MBEDTLS_TLS_EXT_PSK_KEY_EXCHANGE_MODES );
+
     return ( 0 );
 }
 
@@ -692,6 +700,19 @@
             session != NULL && session->ticket != NULL );
 }
 
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+static int ssl_tls13_early_data_has_valid_ticket( mbedtls_ssl_context *ssl )
+{
+    mbedtls_ssl_session *session = ssl->session_negotiate;
+    return( ssl->handshake->resume &&
+            session->tls_version == MBEDTLS_SSL_VERSION_TLS1_3 &&
+            ( session->ticket_flags &
+              MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_EARLY_DATA ) &&
+            mbedtls_ssl_tls13_cipher_suite_is_offered(
+                ssl, session->ciphersuite ) );
+}
+#endif
+
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_ticket_get_identity( mbedtls_ssl_context *ssl,
                                           psa_algorithm_t *hash_alg,
@@ -981,8 +1002,6 @@
 
     MBEDTLS_SSL_DEBUG_BUF( 3, "pre_shared_key identities", buf, p - buf );
 
-    ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_PRE_SHARED_KEY;
-
     return( 0 );
 }
 
@@ -1037,6 +1056,9 @@
 
     MBEDTLS_SSL_DEBUG_BUF( 3, "pre_shared_key binders", buf, p - buf );
 
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask(
+        ssl, MBEDTLS_TLS_EXT_PRE_SHARED_KEY );
+
     return( 0 );
 }
 
@@ -1109,8 +1131,6 @@
         return( ret );
     }
 
-    ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_PRE_SHARED_KEY;
-
     return( 0 );
 }
 #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */
@@ -1153,6 +1173,29 @@
     }
 #endif
 
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+    if( mbedtls_ssl_conf_tls13_some_psk_enabled( ssl ) &&
+        ssl_tls13_early_data_has_valid_ticket( ssl ) &&
+        ssl->conf->early_data_enabled == MBEDTLS_SSL_EARLY_DATA_ENABLED )
+    {
+        ret = mbedtls_ssl_tls13_write_early_data_ext( ssl, p, end, &ext_len );
+        if( ret != 0 )
+            return( ret );
+        p += ext_len;
+
+        /* Initializes the status to `indication sent`. It will be updated to
+         * `accepted` or `rejected` depending on whether the EncryptedExtension
+         * message will contain an early data indication extension or not.
+         */
+        ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_INDICATION_SENT;
+    }
+    else
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip write early_data extension" ) );
+        ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_NOT_SENT;
+    }
+#endif /* MBEDTLS_SSL_EARLY_DATA */
+
 #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
     /* For PSK-based key exchange we need the pre_shared_key extension
      * and the psk_key_exchange_modes extension.
@@ -1388,7 +1431,7 @@
     ssl->session_negotiate->tls_version = ssl->tls_version;
 #endif /* MBEDTLS_SSL_SESSION_TICKETS */
 
-    handshake->extensions_present = MBEDTLS_SSL_EXT_NONE;
+    handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE;
 
     ret = ssl_server_hello_is_hrr( ssl, buf, end );
     switch( ret )
@@ -1498,6 +1541,9 @@
     uint16_t cipher_suite;
     const mbedtls_ssl_ciphersuite_t *ciphersuite_info;
     int fatal_alert = 0;
+    uint32_t allowed_extensions_mask;
+    int hs_msg_type = is_hrr ? MBEDTLS_SSL_TLS1_3_HS_HELLO_RETRY_REQUEST :
+                               MBEDTLS_SSL_HS_SERVER_HELLO;
 
     /*
      * Check there is space for minimal fields
@@ -1640,6 +1686,11 @@
 
     MBEDTLS_SSL_DEBUG_BUF( 3, "server hello extensions", p, extensions_len );
 
+    handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE;
+    allowed_extensions_mask = is_hrr ?
+                                  MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_HRR :
+                                  MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_SH;
+
     while( p < extensions_end )
     {
         unsigned int extension_type;
@@ -1654,16 +1705,15 @@
         MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
         extension_data_end = p + extension_data_len;
 
+        ret = mbedtls_ssl_tls13_check_received_extension(
+                  ssl, hs_msg_type, extension_type, allowed_extensions_mask );
+        if( ret != 0 )
+            return( ret );
+
         switch( extension_type )
         {
             case MBEDTLS_TLS_EXT_COOKIE:
 
-                if( !is_hrr )
-                {
-                    fatal_alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT;
-                    goto cleanup;
-                }
-
                 ret = ssl_tls13_parse_cookie_ext( ssl,
                                                   p, extension_data_end );
                 if( ret != 0 )
@@ -1686,11 +1736,6 @@
 #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
             case MBEDTLS_TLS_EXT_PRE_SHARED_KEY:
                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found pre_shared_key extension" ) );
-                if( is_hrr )
-                {
-                    fatal_alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT;
-                    goto cleanup;
-                }
 
                 if( ( ret = ssl_tls13_parse_server_pre_shared_key_ext(
                                 ssl, p, extension_data_end ) ) != 0 )
@@ -1726,18 +1771,15 @@
                 break;
 
             default:
-                MBEDTLS_SSL_DEBUG_MSG(
-                    3,
-                    ( "unknown extension found: %u ( ignoring )",
-                      extension_type ) );
-
-                fatal_alert = MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT;
+                ret = MBEDTLS_ERR_SSL_INTERNAL_ERROR;
                 goto cleanup;
         }
 
         p += extension_data_len;
     }
 
+    MBEDTLS_SSL_PRINT_EXTS( 3, hs_msg_type, handshake->received_extensions );
+
 cleanup:
 
     if( fatal_alert == MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT )
@@ -1786,21 +1828,21 @@
      * 3) If only the key_share extension was received then the key
      *    exchange mode is EPHEMERAL-only.
      */
-    switch( handshake->extensions_present &
-            ( MBEDTLS_SSL_EXT_PRE_SHARED_KEY | MBEDTLS_SSL_EXT_KEY_SHARE ) )
+    switch( handshake->received_extensions &
+            ( MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY ) | MBEDTLS_SSL_EXT_MASK( KEY_SHARE ) ) )
     {
         /* Only the pre_shared_key extension was received */
-        case MBEDTLS_SSL_EXT_PRE_SHARED_KEY:
+        case MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY ):
             handshake->key_exchange_mode = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK;
             break;
 
         /* Only the key_share extension was received */
-        case MBEDTLS_SSL_EXT_KEY_SHARE:
+        case MBEDTLS_SSL_EXT_MASK( KEY_SHARE ):
             handshake->key_exchange_mode = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL;
             break;
 
         /* Both the pre_shared_key and key_share extensions were received */
-        case ( MBEDTLS_SSL_EXT_PRE_SHARED_KEY | MBEDTLS_SSL_EXT_KEY_SHARE ):
+        case ( MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY ) | MBEDTLS_SSL_EXT_MASK( KEY_SHARE ) ):
             handshake->key_exchange_mode = MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL;
             break;
 
@@ -1969,6 +2011,7 @@
     size_t extensions_len;
     const unsigned char *p = buf;
     const unsigned char *extensions_end;
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
 
     MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 2 );
     extensions_len = MBEDTLS_GET_UINT16_BE( p, 0 );
@@ -1978,6 +2021,8 @@
     MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extensions_len );
     extensions_end = p + extensions_len;
 
+    handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE;
+
     while( p < extensions_end )
     {
         unsigned int extension_type;
@@ -1996,22 +2041,14 @@
 
         MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
 
-        /* The client MUST check EncryptedExtensions for the
-         * presence of any forbidden extensions and if any are found MUST abort
-         * the handshake with an "unsupported_extension" alert.
-         */
+        ret = mbedtls_ssl_tls13_check_received_extension(
+                  ssl, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, extension_type,
+                  MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_EE );
+        if( ret != 0 )
+            return( ret );
+
         switch( extension_type )
         {
-            case MBEDTLS_TLS_EXT_SERVERNAME:
-                MBEDTLS_SSL_DEBUG_MSG( 3, ( "found server_name extension" ) );
-
-                /* The server_name extension should be an empty extension */
-
-                break;
-            case MBEDTLS_TLS_EXT_SUPPORTED_GROUPS:
-                MBEDTLS_SSL_DEBUG_MSG( 3, ( "found extensions supported groups" ) );
-                break;
-
 #if defined(MBEDTLS_SSL_ALPN)
             case MBEDTLS_TLS_EXT_ALPN:
                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found alpn extension" ) );
@@ -2024,17 +2061,18 @@
                 break;
 #endif /* MBEDTLS_SSL_ALPN */
             default:
-                MBEDTLS_SSL_DEBUG_MSG(
-                    3, ( "unsupported extension found: %u ", extension_type) );
-                MBEDTLS_SSL_PEND_FATAL_ALERT(
-                    MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT,
-                    MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
-                return ( MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
+                MBEDTLS_SSL_PRINT_EXT(
+                    3, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS,
+                    extension_type, "( ignored )" );
+                break;
         }
 
         p += extension_data_len;
     }
 
+    MBEDTLS_SSL_PRINT_EXTS( 3, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS,
+                            handshake->received_extensions );
+
     /* Check that we consumed all the message. */
     if( p != end )
     {
@@ -2140,7 +2178,7 @@
     size_t certificate_request_context_len = 0;
     size_t extensions_len = 0;
     const unsigned char *extensions_end;
-    unsigned char sig_alg_ext_found = 0;
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
 
     /* ...
      * opaque certificate_request_context<0..2^8-1>
@@ -2156,7 +2194,6 @@
         MBEDTLS_SSL_DEBUG_BUF( 3, "Certificate Request Context",
                                p, certificate_request_context_len );
 
-        mbedtls_ssl_handshake_params *handshake = ssl->handshake;
         handshake->certificate_request_context =
                 mbedtls_calloc( 1, certificate_request_context_len );
         if( handshake->certificate_request_context == NULL )
@@ -2180,6 +2217,8 @@
     MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extensions_len );
     extensions_end = p + extensions_len;
 
+    handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE;
+
     while( p < extensions_end )
     {
         unsigned int extension_type;
@@ -2192,6 +2231,12 @@
 
         MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
 
+        ret = mbedtls_ssl_tls13_check_received_extension(
+                  ssl, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, extension_type,
+                  MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CR );
+        if( ret != 0 )
+            return( ret );
+
         switch( extension_type )
         {
             case MBEDTLS_TLS_EXT_SIG_ALG:
@@ -2201,25 +2246,22 @@
                                                      p + extension_data_len );
                 if( ret != 0 )
                     return( ret );
-                if( ! sig_alg_ext_found )
-                    sig_alg_ext_found = 1;
-                else
-                {
-                    MBEDTLS_SSL_DEBUG_MSG( 3,
-                        ( "Duplicate signature algorithms extensions found" ) );
-                    goto decode_error;
-                }
+
                 break;
 
             default:
-                MBEDTLS_SSL_DEBUG_MSG(
-                    3,
-                    ( "unknown extension found: %u ( ignoring )",
-                    extension_type ) );
+                MBEDTLS_SSL_PRINT_EXT(
+                    3, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST,
+                    extension_type, "( ignored )" );
                 break;
         }
+
         p += extension_data_len;
     }
+
+    MBEDTLS_SSL_PRINT_EXTS( 3, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST,
+                            handshake->received_extensions );
+
     /* Check that we consumed all the message. */
     if( p != end )
     {
@@ -2227,8 +2269,12 @@
             ( "CertificateRequest misaligned" ) );
         goto decode_error;
     }
-    /* Check that we found signature algorithms extension */
-    if( ! sig_alg_ext_found )
+
+    /* RFC 8446 section 4.3.2
+     *
+     * The "signature_algorithms" extension MUST be specified
+     */
+    if( ( handshake->received_extensions & MBEDTLS_SSL_EXT_MASK( SIG_ALG ) ) == 0 )
     {
         MBEDTLS_SSL_DEBUG_MSG( 3,
             ( "no signature algorithms extension found" ) );
@@ -2468,14 +2514,17 @@
                                                     const unsigned char *buf,
                                                     const unsigned char *end )
 {
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
     const unsigned char *p = buf;
 
-    ((void) ssl);
+
+    handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE;
 
     while( p < end )
     {
         unsigned int extension_type;
         size_t extension_data_len;
+        int ret;
 
         MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 4 );
         extension_type = MBEDTLS_GET_UINT16_BE( p, 0 );
@@ -2484,18 +2533,44 @@
 
         MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, extension_data_len );
 
+        ret = mbedtls_ssl_tls13_check_received_extension(
+                  ssl, MBEDTLS_SSL_HS_NEW_SESSION_TICKET, extension_type,
+                  MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_NST );
+        if( ret != 0 )
+            return( ret );
+
         switch( extension_type )
         {
+#if defined(MBEDTLS_SSL_EARLY_DATA)
             case MBEDTLS_TLS_EXT_EARLY_DATA:
-                MBEDTLS_SSL_DEBUG_MSG( 4, ( "early_data extension received" ) );
+                if( extension_data_len != 4 )
+                {
+                    MBEDTLS_SSL_PEND_FATAL_ALERT(
+                        MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
+                        MBEDTLS_ERR_SSL_DECODE_ERROR );
+                    return( MBEDTLS_ERR_SSL_DECODE_ERROR );
+                }
+                if( ssl->session != NULL )
+                {
+                    ssl->session->ticket_flags |=
+                            MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_EARLY_DATA;
+                }
                 break;
+#endif /* MBEDTLS_SSL_EARLY_DATA */
 
             default:
+                MBEDTLS_SSL_PRINT_EXT(
+                    3, MBEDTLS_SSL_HS_NEW_SESSION_TICKET,
+                    extension_type, "( ignored )" );
                 break;
         }
+
         p +=  extension_data_len;
     }
 
+    MBEDTLS_SSL_PRINT_EXTS( 3, MBEDTLS_SSL_HS_NEW_SESSION_TICKET,
+                            handshake->received_extensions );
+
     return( 0 );
 }
 
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index 48e3675..761c00e 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -398,6 +398,7 @@
     size_t certificate_list_len = 0;
     const unsigned char *p = buf;
     const unsigned char *certificate_list_end;
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
 
     MBEDTLS_SSL_CHK_BUF_READ_PTR( p, end, 4 );
     certificate_request_context_len = p[0];
@@ -447,6 +448,7 @@
     while( p < certificate_list_end )
     {
         size_t cert_data_len, extensions_len;
+        const unsigned char *extensions_end;
 
         MBEDTLS_SSL_CHK_BUF_READ_PTR( p, certificate_list_end, 3 );
         cert_data_len = MBEDTLS_GET_UINT24_BE( p, 0 );
@@ -504,7 +506,48 @@
         extensions_len = MBEDTLS_GET_UINT16_BE( p, 0 );
         p += 2;
         MBEDTLS_SSL_CHK_BUF_READ_PTR( p, certificate_list_end, extensions_len );
-        p += extensions_len;
+
+        extensions_end = p + extensions_len;
+        handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE;
+
+        while( p < extensions_end )
+        {
+            unsigned int extension_type;
+            size_t extension_data_len;
+
+            /*
+            * struct {
+            *     ExtensionType extension_type; (2 bytes)
+            *     opaque extension_data<0..2^16-1>;
+            * } Extension;
+            */
+            MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, 4 );
+            extension_type = MBEDTLS_GET_UINT16_BE( p, 0 );
+            extension_data_len = MBEDTLS_GET_UINT16_BE( p, 2 );
+            p += 4;
+
+            MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
+
+            ret = mbedtls_ssl_tls13_check_received_extension(
+                      ssl, MBEDTLS_SSL_HS_CERTIFICATE, extension_type,
+                      MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CT );
+            if( ret != 0 )
+                return( ret );
+
+            switch( extension_type )
+            {
+                default:
+                    MBEDTLS_SSL_PRINT_EXT(
+                        3, MBEDTLS_SSL_HS_CERTIFICATE,
+                        extension_type, "( ignored )" );
+                    break;
+            }
+
+            p += extension_data_len;
+        }
+
+        MBEDTLS_SSL_PRINT_EXTS( 3, MBEDTLS_SSL_HS_CERTIFICATE,
+                                handshake->received_extensions );
     }
 
 exit:
@@ -512,7 +555,7 @@
     if( p != end )
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "bad Certificate message" ) );
-        MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR, \
+        MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_DECODE_ERROR,
                                       MBEDTLS_ERR_SSL_DECODE_ERROR );
         return( MBEDTLS_ERR_SSL_DECODE_ERROR );
     }
@@ -843,6 +886,9 @@
 
     *out_len = p - buf;
 
+    MBEDTLS_SSL_PRINT_EXTS(
+        3, MBEDTLS_SSL_HS_CERTIFICATE, ssl->handshake->sent_extensions );
+
     return( 0 );
 }
 
@@ -1328,6 +1374,39 @@
 
 #endif /* MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE */
 
+/* Early Data Indication Extension
+ *
+ * struct {
+ *   select ( Handshake.msg_type ) {
+ *     ...
+ *     case client_hello:         Empty;
+ *     case encrypted_extensions: Empty;
+ *   };
+ * } EarlyDataIndication;
+ */
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+int mbedtls_ssl_tls13_write_early_data_ext( mbedtls_ssl_context *ssl,
+                                            unsigned char *buf,
+                                            const unsigned char *end,
+                                            size_t *out_len )
+{
+    unsigned char *p = buf;
+    *out_len = 0;
+    ((void) ssl);
+
+    MBEDTLS_SSL_CHK_BUF_PTR( p, end, 4 );
+
+    MBEDTLS_PUT_UINT16_BE( MBEDTLS_TLS_EXT_EARLY_DATA, p, 0 );
+    MBEDTLS_PUT_UINT16_BE( 0, p, 2 );
+
+    *out_len = 4;
+
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_EARLY_DATA );
+
+    return( 0 );
+}
+#endif /* MBEDTLS_SSL_EARLY_DATA */
+
 /* Reset SSL context and update hash for handling HRR.
  *
  * Replace Transcript-Hash(X) by
@@ -1485,4 +1564,61 @@
 }
 #endif /* MBEDTLS_ECDH_C */
 
+/* RFC 8446 section 4.2
+ *
+ * If an implementation receives an extension which it recognizes and which is
+ * not specified for the message in which it appears, it MUST abort the handshake
+ * with an "illegal_parameter" alert.
+ *
+ */
+int mbedtls_ssl_tls13_check_received_extension(
+        mbedtls_ssl_context *ssl,
+        int hs_msg_type,
+        unsigned int received_extension_type,
+        uint32_t hs_msg_allowed_extensions_mask )
+{
+    uint32_t extension_mask = mbedtls_ssl_get_extension_mask(
+                                  received_extension_type );
+
+    MBEDTLS_SSL_PRINT_EXT(
+        3, hs_msg_type, received_extension_type, "received" );
+
+    if( ( extension_mask & hs_msg_allowed_extensions_mask ) == 0 )
+    {
+        MBEDTLS_SSL_PRINT_EXT(
+            3, hs_msg_type, received_extension_type, "is illegal" );
+        MBEDTLS_SSL_PEND_FATAL_ALERT(
+            MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
+            MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+        return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+    }
+
+    ssl->handshake->received_extensions |= extension_mask;
+    /*
+     * If it is a message containing extension responses, check that we
+     * previously sent the extension.
+     */
+    switch( hs_msg_type )
+    {
+        case MBEDTLS_SSL_HS_SERVER_HELLO:
+        case MBEDTLS_SSL_TLS1_3_HS_HELLO_RETRY_REQUEST:
+        case MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS:
+        case MBEDTLS_SSL_HS_CERTIFICATE:
+            /* Check if the received extension is sent by peer message.*/
+            if( ( ssl->handshake->sent_extensions & extension_mask ) != 0 )
+                return( 0 );
+            break;
+        default:
+            return( 0 );
+    }
+
+    MBEDTLS_SSL_PRINT_EXT(
+            3, hs_msg_type, received_extension_type, "is unsupported" );
+    MBEDTLS_SSL_PEND_FATAL_ALERT(
+        MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT,
+        MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
+    return( MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION );
+}
+
 #endif /* MBEDTLS_SSL_TLS_C && MBEDTLS_SSL_PROTO_TLS1_3 */
+
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 3762393..3cd0310 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -700,6 +700,8 @@
     MBEDTLS_SSL_DEBUG_MSG( 4, ( "sent selected_identity: %u",
                                 ssl->handshake->selected_identity ) );
 
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_PRE_SHARED_KEY );
+
     return( 0 );
 }
 
@@ -926,110 +928,69 @@
 }
 #endif /* MBEDTLS_ECDH_C */
 
-#if defined(MBEDTLS_DEBUG_C)
-static void ssl_tls13_debug_print_client_hello_exts( mbedtls_ssl_context *ssl )
-{
-    ((void) ssl);
-
-    MBEDTLS_SSL_DEBUG_MSG( 3, ( "Supported Extensions:" ) );
-    MBEDTLS_SSL_DEBUG_MSG( 3,
-            ( "- KEY_SHARE_EXTENSION ( %s )",
-            ( ( ssl->handshake->extensions_present
-                & MBEDTLS_SSL_EXT_KEY_SHARE ) > 0 ) ? "TRUE" : "FALSE" ) );
-    MBEDTLS_SSL_DEBUG_MSG( 3,
-            ( "- PSK_KEY_EXCHANGE_MODES_EXTENSION ( %s )",
-            ( ( ssl->handshake->extensions_present
-                & MBEDTLS_SSL_EXT_PSK_KEY_EXCHANGE_MODES ) > 0 ) ?
-                "TRUE" : "FALSE" ) );
-    MBEDTLS_SSL_DEBUG_MSG( 3,
-            ( "- PRE_SHARED_KEY_EXTENSION ( %s )",
-            ( ( ssl->handshake->extensions_present
-                & MBEDTLS_SSL_EXT_PRE_SHARED_KEY ) > 0 ) ? "TRUE" : "FALSE" ) );
-    MBEDTLS_SSL_DEBUG_MSG( 3,
-            ( "- SIGNATURE_ALGORITHM_EXTENSION ( %s )",
-            ( ( ssl->handshake->extensions_present
-                & MBEDTLS_SSL_EXT_SIG_ALG ) > 0 ) ? "TRUE" : "FALSE" ) );
-    MBEDTLS_SSL_DEBUG_MSG( 3,
-            ( "- SUPPORTED_GROUPS_EXTENSION ( %s )",
-            ( ( ssl->handshake->extensions_present
-                & MBEDTLS_SSL_EXT_SUPPORTED_GROUPS ) >0 ) ?
-                "TRUE" : "FALSE" ) );
-    MBEDTLS_SSL_DEBUG_MSG( 3,
-            ( "- SUPPORTED_VERSION_EXTENSION ( %s )",
-            ( ( ssl->handshake->extensions_present
-                & MBEDTLS_SSL_EXT_SUPPORTED_VERSIONS ) > 0 ) ?
-                "TRUE" : "FALSE" ) );
-#if defined ( MBEDTLS_SSL_SERVER_NAME_INDICATION )
-    MBEDTLS_SSL_DEBUG_MSG( 3,
-            ( "- SERVERNAME_EXTENSION    ( %s )",
-            ( ( ssl->handshake->extensions_present
-                & MBEDTLS_SSL_EXT_SERVERNAME ) > 0 ) ?
-                "TRUE" : "FALSE" ) );
-#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
-#if defined ( MBEDTLS_SSL_ALPN )
-    MBEDTLS_SSL_DEBUG_MSG( 3,
-            ( "- ALPN_EXTENSION   ( %s )",
-            ( ( ssl->handshake->extensions_present
-                & MBEDTLS_SSL_EXT_ALPN ) > 0 ) ?
-                "TRUE" : "FALSE" ) );
-#endif /* MBEDTLS_SSL_ALPN */
-}
-#endif /* MBEDTLS_DEBUG_C */
-
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_client_hello_has_exts( mbedtls_ssl_context *ssl,
                                             int exts_mask )
 {
-    int masked = ssl->handshake->extensions_present & exts_mask;
+    int masked = ssl->handshake->received_extensions & exts_mask;
     return( masked == exts_mask );
 }
 
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED)
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_client_hello_has_exts_for_ephemeral_key_exchange(
         mbedtls_ssl_context *ssl )
 {
     return( ssl_tls13_client_hello_has_exts(
                 ssl,
-                MBEDTLS_SSL_EXT_SUPPORTED_GROUPS |
-                MBEDTLS_SSL_EXT_KEY_SHARE        |
-                MBEDTLS_SSL_EXT_SIG_ALG ) );
+                MBEDTLS_SSL_EXT_MASK( SUPPORTED_GROUPS ) |
+                MBEDTLS_SSL_EXT_MASK( KEY_SHARE )        |
+                MBEDTLS_SSL_EXT_MASK( SIG_ALG ) ) );
 }
+#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */
 
-#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED)
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_client_hello_has_exts_for_psk_key_exchange(
                mbedtls_ssl_context *ssl )
 {
     return( ssl_tls13_client_hello_has_exts(
                 ssl,
-                MBEDTLS_SSL_EXT_PRE_SHARED_KEY          |
-                MBEDTLS_SSL_EXT_PSK_KEY_EXCHANGE_MODES ) );
+                MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY )          |
+                MBEDTLS_SSL_EXT_MASK( PSK_KEY_EXCHANGE_MODES ) ) );
 }
+#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED */
 
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED)
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_client_hello_has_exts_for_psk_ephemeral_key_exchange(
                mbedtls_ssl_context *ssl )
 {
     return( ssl_tls13_client_hello_has_exts(
                 ssl,
-                MBEDTLS_SSL_EXT_SUPPORTED_GROUPS        |
-                MBEDTLS_SSL_EXT_KEY_SHARE               |
-                MBEDTLS_SSL_EXT_PRE_SHARED_KEY          |
-                MBEDTLS_SSL_EXT_PSK_KEY_EXCHANGE_MODES ) );
+                MBEDTLS_SSL_EXT_MASK( SUPPORTED_GROUPS )        |
+                MBEDTLS_SSL_EXT_MASK( KEY_SHARE )               |
+                MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY )          |
+                MBEDTLS_SSL_EXT_MASK( PSK_KEY_EXCHANGE_MODES ) ) );
 }
-#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */
+#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED */
 
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_check_ephemeral_key_exchange( mbedtls_ssl_context *ssl )
 {
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED)
     return( mbedtls_ssl_conf_tls13_ephemeral_enabled( ssl ) &&
             ssl_tls13_client_hello_has_exts_for_ephemeral_key_exchange( ssl ) );
+#else
+    ((void) ssl);
+    return( 0 );
+#endif
 }
 
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_check_psk_key_exchange( mbedtls_ssl_context *ssl )
 {
-#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED)
     return( mbedtls_ssl_conf_tls13_psk_enabled( ssl ) &&
             mbedtls_ssl_tls13_psk_enabled( ssl ) &&
             ssl_tls13_client_hello_has_exts_for_psk_key_exchange( ssl ) );
@@ -1042,7 +1003,7 @@
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_check_psk_ephemeral_key_exchange( mbedtls_ssl_context *ssl )
 {
-#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED)
     return( mbedtls_ssl_conf_tls13_psk_ephemeral_enabled( ssl ) &&
             mbedtls_ssl_tls13_psk_ephemeral_enabled( ssl ) &&
             ssl_tls13_client_hello_has_exts_for_psk_ephemeral_key_exchange( ssl ) );
@@ -1289,6 +1250,7 @@
     const unsigned char *cipher_suites_end;
     size_t extensions_len;
     const unsigned char *extensions_end;
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
     int hrr_required = 0;
 
 #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
@@ -1297,8 +1259,6 @@
     const unsigned char *pre_shared_key_ext_end = NULL;
 #endif
 
-    ssl->handshake->extensions_present = MBEDTLS_SSL_EXT_NONE;
-
     /*
      * ClientHello layout:
      *     0  .   1   protocol version
@@ -1356,7 +1316,7 @@
     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello, random bytes",
                            p, MBEDTLS_CLIENT_HELLO_RANDOM_LEN );
 
-    memcpy( &ssl->handshake->randbytes[0], p, MBEDTLS_CLIENT_HELLO_RANDOM_LEN );
+    memcpy( &handshake->randbytes[0], p, MBEDTLS_CLIENT_HELLO_RANDOM_LEN );
     p += MBEDTLS_CLIENT_HELLO_RANDOM_LEN;
 
     /* ...
@@ -1426,13 +1386,13 @@
             continue;
 
         ssl->session_negotiate->ciphersuite = cipher_suite;
-        ssl->handshake->ciphersuite_info = ciphersuite_info;
+        handshake->ciphersuite_info = ciphersuite_info;
         MBEDTLS_SSL_DEBUG_MSG( 2, ( "selected ciphersuite: %04x - %s",
                                     cipher_suite,
                                     ciphersuite_info->name ) );
     }
 
-    if( ssl->handshake->ciphersuite_info == NULL )
+    if( handshake->ciphersuite_info == NULL )
     {
         MBEDTLS_SSL_PEND_FATAL_ALERT( MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
                                       MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
@@ -1468,27 +1428,29 @@
 
     MBEDTLS_SSL_DEBUG_BUF( 3, "client hello extensions", p, extensions_len );
 
+    handshake->received_extensions = MBEDTLS_SSL_EXT_MASK_NONE;
+
     while( p < extensions_end )
     {
         unsigned int extension_type;
         size_t extension_data_len;
         const unsigned char *extension_data_end;
 
-        /* RFC 8446, page 57
+        /* RFC 8446, section 4.2.11
          *
          * The "pre_shared_key" extension MUST be the last extension in the
          * ClientHello (this facilitates implementation as described below).
          * Servers MUST check that it is the last extension and otherwise fail
          * the handshake with an "illegal_parameter" alert.
          */
-        if( ssl->handshake->extensions_present & MBEDTLS_SSL_EXT_PRE_SHARED_KEY )
+        if( handshake->received_extensions & MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY ) )
         {
             MBEDTLS_SSL_DEBUG_MSG(
                 3, ( "pre_shared_key is not last extension." ) );
             MBEDTLS_SSL_PEND_FATAL_ALERT(
                 MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
-                MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
-            return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+                MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+            return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
         }
 
         MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, 4 );
@@ -1499,6 +1461,12 @@
         MBEDTLS_SSL_CHK_BUF_READ_PTR( p, extensions_end, extension_data_len );
         extension_data_end = p + extension_data_len;
 
+        ret = mbedtls_ssl_tls13_check_received_extension(
+                  ssl, MBEDTLS_SSL_HS_CLIENT_HELLO, extension_type,
+                  MBEDTLS_SSL_TLS1_3_ALLOWED_EXTS_OF_CH );
+        if( ret != 0 )
+            return( ret );
+
         switch( extension_type )
         {
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
@@ -1512,7 +1480,6 @@
                             1, "mbedtls_ssl_parse_servername_ext", ret );
                     return( ret );
                 }
-                ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_SERVERNAME;
                 break;
 #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
 
@@ -1535,7 +1502,6 @@
                     return( ret );
                 }
 
-                ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_SUPPORTED_GROUPS;
                 break;
 #endif /* MBEDTLS_ECDH_C */
 
@@ -1565,7 +1531,6 @@
                     return( ret );
                 }
 
-                ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_KEY_SHARE;
                 break;
 #endif /* MBEDTLS_ECDH_C */
 
@@ -1580,7 +1545,6 @@
                                 ( "ssl_tls13_parse_supported_versions_ext" ), ret );
                     return( ret );
                 }
-                ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_SUPPORTED_VERSIONS;
                 break;
 
 #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
@@ -1596,19 +1560,18 @@
                     return( ret );
                 }
 
-                ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_PSK_KEY_EXCHANGE_MODES;
                 break;
 #endif
 
             case MBEDTLS_TLS_EXT_PRE_SHARED_KEY:
                 MBEDTLS_SSL_DEBUG_MSG( 3, ( "found pre_shared_key extension" ) );
-                if( ( ssl->handshake->extensions_present &
-                      MBEDTLS_SSL_EXT_PSK_KEY_EXCHANGE_MODES ) == 0 )
+                if( ( handshake->received_extensions &
+                      MBEDTLS_SSL_EXT_MASK( PSK_KEY_EXCHANGE_MODES ) ) == 0 )
                 {
                     MBEDTLS_SSL_PEND_FATAL_ALERT(
                         MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
-                        MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
-                    return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
+                        MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+                    return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
                 }
 #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
                 /* Delay processing of the PSK identity once we have
@@ -1617,8 +1580,7 @@
                  */
                 pre_shared_key_ext = p;
                 pre_shared_key_ext_end = extension_data_end;
-#endif
-                ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_PRE_SHARED_KEY;
+#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */
                 break;
 
 #if defined(MBEDTLS_SSL_ALPN)
@@ -1632,7 +1594,6 @@
                             1, ( "mbedtls_ssl_parse_alpn_ext" ), ret );
                     return( ret );
                 }
-                ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_ALPN;
                 break;
 #endif /* MBEDTLS_SSL_ALPN */
 
@@ -1649,23 +1610,21 @@
                       ret ) );
                     return( ret );
                 }
-                ssl->handshake->extensions_present |= MBEDTLS_SSL_EXT_SIG_ALG;
                 break;
 #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED */
 
             default:
-                MBEDTLS_SSL_DEBUG_MSG( 3,
-                        ( "unknown extension found: %ud ( ignoring )",
-                          extension_type ) );
+                MBEDTLS_SSL_PRINT_EXT(
+                    3, MBEDTLS_SSL_HS_CLIENT_HELLO,
+                    extension_type, "( ignored )" );
+                break;
         }
 
         p += extension_data_len;
     }
 
-#if defined(MBEDTLS_DEBUG_C)
-    /* List all the extensions we have received */
-    ssl_tls13_debug_print_client_hello_exts( ssl );
-#endif /* MBEDTLS_DEBUG_C */
+    MBEDTLS_SSL_PRINT_EXTS( 3, MBEDTLS_SSL_HS_CLIENT_HELLO,
+                            handshake->received_extensions );
 
     mbedtls_ssl_add_hs_hdr_to_checksum( ssl,
                                         MBEDTLS_SSL_HS_CLIENT_HELLO,
@@ -1679,9 +1638,9 @@
     /* If we've settled on a PSK-based exchange, parse PSK identity ext */
     if( mbedtls_ssl_tls13_some_psk_enabled( ssl ) &&
         mbedtls_ssl_conf_tls13_some_psk_enabled( ssl ) &&
-        ( ssl->handshake->extensions_present & MBEDTLS_SSL_EXT_PRE_SHARED_KEY ) )
+        ( handshake->received_extensions & MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY ) ) )
     {
-        ssl->handshake->update_checksum( ssl, buf,
+        handshake->update_checksum( ssl, buf,
                                          pre_shared_key_ext - buf );
         ret = ssl_tls13_parse_pre_shared_key_ext( ssl,
                                                   pre_shared_key_ext,
@@ -1690,26 +1649,26 @@
                                                   cipher_suites_end );
         if( ret == MBEDTLS_ERR_SSL_UNKNOWN_IDENTITY )
         {
-            ssl->handshake->extensions_present &= ~MBEDTLS_SSL_EXT_PRE_SHARED_KEY;
+            handshake->received_extensions &= ~MBEDTLS_SSL_EXT_MASK( PRE_SHARED_KEY );
         }
         else if( ret != 0 )
         {
-            MBEDTLS_SSL_DEBUG_RET( 1, ( "ssl_tls13_parse_pre_shared_key_ext" ),
-                                   ret );
+            MBEDTLS_SSL_DEBUG_RET(
+                1, "ssl_tls13_parse_pre_shared_key_ext" , ret );
             return( ret );
         }
     }
     else
 #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */
     {
-        ssl->handshake->update_checksum( ssl, buf, p - buf );
+        handshake->update_checksum( ssl, buf, p - buf );
     }
 
     ret = ssl_tls13_determine_key_exchange_mode( ssl );
     if( ret < 0 )
         return( ret );
 
-    mbedtls_ssl_optimize_checksum( ssl, ssl->handshake->ciphersuite_info );
+    mbedtls_ssl_optimize_checksum( ssl, handshake->ciphersuite_info );
 
     return( hrr_required ? SSL_CLIENT_HELLO_HRR_REQUIRED : SSL_CLIENT_HELLO_OK );
 }
@@ -1856,6 +1815,9 @@
 
     *out_len = 6;
 
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask(
+        ssl, MBEDTLS_TLS_EXT_SUPPORTED_VERSIONS );
+
     return( 0 );
 }
 
@@ -1962,6 +1924,8 @@
 
     *out_len = p - buf;
 
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_KEY_SHARE );
+
     return( 0 );
 }
 
@@ -2026,6 +1990,8 @@
 
     *out_len = 6;
 
+    mbedtls_ssl_tls13_set_hs_sent_ext_mask( ssl, MBEDTLS_TLS_EXT_KEY_SHARE );
+
     return( 0 );
 }
 
@@ -2054,6 +2020,7 @@
     size_t output_len;
 
     *out_len = 0;
+    ssl->handshake->sent_extensions = MBEDTLS_SSL_EXT_MASK_NONE;
 
     /* ...
      * ProtocolVersion legacy_version = 0x0303; // TLS 1.2
@@ -2179,6 +2146,11 @@
 
     MBEDTLS_SSL_DEBUG_BUF( 3, "server hello", buf, *out_len );
 
+    MBEDTLS_SSL_PRINT_EXTS(
+        3, is_hrr ? MBEDTLS_SSL_TLS1_3_HS_HELLO_RETRY_REQUEST :
+                    MBEDTLS_SSL_HS_SERVER_HELLO,
+        ssl->handshake->sent_extensions );
+
     return( ret );
 }
 
@@ -2363,6 +2335,9 @@
 
     MBEDTLS_SSL_DEBUG_BUF( 4, "encrypted extensions", buf, *out_len );
 
+    MBEDTLS_SSL_PRINT_EXTS(
+        3, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, ssl->handshake->sent_extensions );
+
     return( 0 );
 }
 
@@ -2492,6 +2467,9 @@
 
     *out_len = p - buf;
 
+    MBEDTLS_SSL_PRINT_EXTS(
+        3, MBEDTLS_SSL_HS_CERTIFICATE_REQUEST, ssl->handshake->sent_extensions );
+
     return( 0 );
 }
 
@@ -2877,6 +2855,8 @@
      * Note: We currently don't have any extensions.
      * Set length to zero.
      */
+    ssl->handshake->sent_extensions = MBEDTLS_SSL_EXT_MASK_NONE;
+
     MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
     MBEDTLS_PUT_UINT16_BE( 0, p, 0 );
     p += 2;
@@ -2885,6 +2865,9 @@
     MBEDTLS_SSL_DEBUG_BUF( 4, "ticket", buf, *out_len );
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write new session ticket" ) );
 
+    MBEDTLS_SSL_PRINT_EXTS(
+        3, MBEDTLS_SSL_HS_NEW_SESSION_TICKET, ssl->handshake->sent_extensions );
+
     return( 0 );
 }
 
diff --git a/programs/pkey/dh_genprime.c b/programs/pkey/dh_genprime.c
index 2e696e5..331838b 100644
--- a/programs/pkey/dh_genprime.c
+++ b/programs/pkey/dh_genprime.c
@@ -157,8 +157,8 @@
         goto exit;
     }
 
-    if( ( ret = mbedtls_mpi_write_file( "P = ", &P, 16, fout ) != 0 ) ||
-        ( ret = mbedtls_mpi_write_file( "G = ", &G, 16, fout ) != 0 ) )
+    if( ( ( ret = mbedtls_mpi_write_file( "P = ", &P, 16, fout ) ) != 0 ) ||
+        ( ( ret = mbedtls_mpi_write_file( "G = ", &G, 16, fout ) ) != 0 ) )
     {
         mbedtls_printf( " failed\n  ! mbedtls_mpi_write_file returned %d\n\n", ret );
         fclose( fout );
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 56efb3c..6aa295d 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -64,6 +64,7 @@
 #define DFL_KEY_OPAQUE          0
 #define DFL_KEY_PWD             ""
 #define DFL_PSK                 ""
+#define DFL_EARLY_DATA          MBEDTLS_SSL_EARLY_DATA_DISABLED
 #define DFL_PSK_OPAQUE          0
 #define DFL_PSK_IDENTITY        "Client_identity"
 #define DFL_ECJPAKE_PW          NULL
@@ -344,6 +345,14 @@
 #define USAGE_SERIALIZATION ""
 #endif
 
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+#define USAGE_EARLY_DATA \
+    "    early_data=%%d        default: 0 (disabled)\n"      \
+    "                        options: 0 (disabled), 1 (enabled)\n"
+#else
+#define USAGE_EARLY_DATA ""
+#endif /* MBEDTLS_SSL_EARLY_DATA && MBEDTLS_SSL_PROTO_TLS1_3 */
+
 #define USAGE_KEY_OPAQUE_ALGS \
     "    key_opaque_algs=%%s  Allowed opaque key algorithms.\n"                      \
     "                        comma-separated pair of values among the following:\n"    \
@@ -422,6 +431,7 @@
     USAGE_REPRODUCIBLE                                      \
     USAGE_CURVES                                            \
     USAGE_SIG_ALGS                                          \
+    USAGE_EARLY_DATA                                        \
     USAGE_DHMLEN                                            \
     USAGE_KEY_OPAQUE_ALGS                                   \
     "\n"
@@ -533,6 +543,9 @@
                                  * after renegotiation                      */
     int reproducible;           /* make communication reproducible          */
     int skip_close_notify;      /* skip sending the close_notify alert      */
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+    int early_data;             /* support for early data                   */
+#endif
     int query_config_mode;      /* whether to read config                   */
     int use_srtp;               /* Support SRTP                             */
     int force_srtp_profile;     /* SRTP protection profile to use or all    */
@@ -932,6 +945,9 @@
     opt.alpn_string         = DFL_ALPN_STRING;
     opt.curves              = DFL_CURVES;
     opt.sig_algs            = DFL_SIG_ALGS;
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+    opt.early_data          = DFL_EARLY_DATA;
+#endif
     opt.transport           = DFL_TRANSPORT;
     opt.hs_to_min           = DFL_HS_TO_MIN;
     opt.hs_to_max           = DFL_HS_TO_MAX;
@@ -1189,7 +1205,24 @@
                 default: goto usage;
             }
         }
+
 #if defined(MBEDTLS_SSL_PROTO_TLS1_3)
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+        else if( strcmp( p, "early_data" ) == 0 )
+        {
+            switch( atoi( q ) )
+            {
+                case 0:
+                    opt.early_data = MBEDTLS_SSL_EARLY_DATA_DISABLED;
+                    break;
+                case 1:
+                    opt.early_data = MBEDTLS_SSL_EARLY_DATA_ENABLED;
+                    break;
+                default: goto usage;
+            }
+        }
+#endif /* MBEDTLS_SSL_EARLY_DATA */
+
         else if( strcmp( p, "tls13_kex_modes" ) == 0 )
         {
             if( strcmp( q, "psk" ) == 0 )
@@ -2091,6 +2124,10 @@
     if( opt.max_version != DFL_MAX_VERSION )
         mbedtls_ssl_conf_max_tls_version( &conf, opt.max_version );
 
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+    mbedtls_ssl_tls13_conf_early_data( &conf, opt.early_data );
+#endif /* MBEDTLS_SSL_EARLY_DATA */
+
     if( ( ret = mbedtls_ssl_setup( &ssl, &conf ) ) != 0 )
     {
         mbedtls_printf( " failed\n  ! mbedtls_ssl_setup returned -0x%x\n\n",
diff --git a/scripts/mbedtls_dev/bignum_common.py b/scripts/mbedtls_dev/bignum_common.py
index 279668f..8b11bc2 100644
--- a/scripts/mbedtls_dev/bignum_common.py
+++ b/scripts/mbedtls_dev/bignum_common.py
@@ -14,9 +14,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import itertools
-import typing
-
 from abc import abstractmethod
 from typing import Iterator, List, Tuple, TypeVar
 
@@ -38,7 +35,13 @@
     raise ValueError("Not invertible")
 
 def hex_to_int(val: str) -> int:
-    return int(val, 16) if val else 0
+    """Implement the syntax accepted by mbedtls_test_read_mpi().
+
+    This is a superset of what is accepted by mbedtls_test_read_mpi_core().
+    """
+    if val in ['', '-']:
+        return 0
+    return int(val, 16)
 
 def quote_str(val) -> str:
     return "\"{}\"".format(val)
@@ -57,15 +60,8 @@
     return (val.bit_length() + bits_in_limb - 1) // bits_in_limb
 
 def combination_pairs(values: List[T]) -> List[Tuple[T, T]]:
-    """Return all pair combinations from input values.
-
-    The return value is cast, as older versions of mypy are unable to derive
-    the specific type returned by itertools.combinations_with_replacement.
-    """
-    return typing.cast(
-        List[Tuple[T, T]],
-        list(itertools.combinations_with_replacement(values, 2))
-    )
+    """Return all pair combinations from input values."""
+    return [(x, y) for x in values for y in values]
 
 
 class OperationCommon:
diff --git a/scripts/mbedtls_dev/bignum_mod_raw.py b/scripts/mbedtls_dev/bignum_mod_raw.py
index 1465e3e..bd694a6 100644
--- a/scripts/mbedtls_dev/bignum_mod_raw.py
+++ b/scripts/mbedtls_dev/bignum_mod_raw.py
@@ -122,7 +122,126 @@
 # END MERGE SLOT 6
 
 # BEGIN MERGE SLOT 7
+class BignumModRawConvertToMont(BignumModRawOperationArchSplit):
+    """ Test cases for mpi_mod_raw_to_mont_rep(). """
 
+    test_function = "mpi_mod_raw_to_mont_rep"
+    test_name = "Convert into Mont: "
+
+    test_data_moduli = ["b",
+                        "fd",
+                        "eeff99aa37",
+                        "eeff99aa11",
+                        "800000000005",
+                        "7fffffffffffffff",
+                        "80fe000a10000001",
+                        "25a55a46e5da99c71c7",
+                        "1058ad82120c3a10196bb36229c1",
+                        "7e35b84cb19ea5bc57ec37f5e431462fa962d98c1e63738d4657f"
+                        "18ad6532e6adc3eafe67f1e5fa262af94cee8d3e7268593942a2a"
+                        "98df75154f8c914a282f8b",
+                        "8335616aed761f1f7f44e6bd49e807b82e3bf2bf11bfa63",
+                        "ffcece570f2f991013f26dd5b03c4c5b65f97be5905f36cb4664f"
+                        "2c78ff80aa8135a4aaf57ccb8a0aca2f394909a74cef1ef6758a6"
+                        "4d11e2c149c393659d124bfc94196f0ce88f7d7d567efa5a649e2"
+                        "deefaa6e10fdc3deac60d606bf63fc540ac95294347031aefd73d"
+                        "6a9ee10188aaeb7a90d920894553cb196881691cadc51808715a0"
+                        "7e8b24fcb1a63df047c7cdf084dd177ba368c806f3d51ddb5d389"
+                        "8c863e687ecaf7d649a57a46264a582f94d3c8f2edaf59f77a7f6"
+                        "bdaf83c991e8f06abe220ec8507386fce8c3da84c6c3903ab8f3a"
+                        "d4630a204196a7dbcbd9bcca4e40ec5cc5c09938d49f5e1e6181d"
+                        "b8896f33bb12e6ef73f12ec5c5ea7a8a337"
+                        ]
+
+    test_input_numbers = ["0",
+                          "1",
+                          "97",
+                          "f5",
+                          "6f5c3",
+                          "745bfe50f7",
+                          "ffa1f9924123",
+                          "334a8b983c79bd",
+                          "5b84f632b58f3461",
+                          "19acd15bc38008e1",
+                          "ffffffffffffffff",
+                          "54ce6a6bb8247fa0427cfc75a6b0599",
+                          "fecafe8eca052f154ce6a6bb8247fa019558bfeecce9bb9",
+                          "a87d7a56fa4bfdc7da42ef798b9cf6843d4c54794698cb14d72"
+                          "851dec9586a319f4bb6d5695acbd7c92e7a42a5ede6972adcbc"
+                          "f68425265887f2d721f462b7f1b91531bac29fa648facb8e3c6"
+                          "1bd5ae42d5a59ba1c89a95897bfe541a8ce1d633b98f379c481"
+                          "6f25e21f6ac49286b261adb4b78274fe5f61c187581f213e84b"
+                          "2a821e341ef956ecd5de89e6c1a35418cd74a549379d2d4594a"
+                          "577543147f8e35b3514e62cf3e89d1156cdc91ab5f4c928fbd6"
+                          "9148c35df5962fed381f4d8a62852a36823d5425f7487c13a12"
+                          "523473fb823aa9d6ea5f42e794e15f2c1a8785cf6b7d51a4617"
+                          "947fb3baf674f74a673cf1d38126983a19ed52c7439fab42c2185"
+                          ]
+
+    descr_tpl = '{} #{} N: \"{}\" A: \"{}\".'
+
+    def result(self) -> List[str]:
+        return [self.hex_x]
+
+    def arguments(self) -> List[str]:
+        return [bignum_common.quote_str(n) for n in [self.hex_n,
+                                                     self.hex_a,
+                                                     self.hex_x]]
+
+    def description(self) -> str:
+        return self.descr_tpl.format(self.test_name,
+                                     self.count,
+                                     self.int_n,
+                                     self.int_a)
+
+    @classmethod
+    def generate_function_tests(cls) -> Iterator[test_case.TestCase]:
+        for bil in [32, 64]:
+            for n in cls.test_data_moduli:
+                for i in cls.test_input_numbers:
+                    # Skip invalid combinations where A.limbs > N.limbs
+                    if bignum_common.hex_to_int(i) > bignum_common.hex_to_int(n):
+                        continue
+                    yield cls(n, i, bits_in_limb=bil).create_test_case()
+
+    @property
+    def x(self) -> int: # pylint: disable=invalid-name
+        return (self.int_a * self.r) % self.int_n
+
+    @property
+    def hex_x(self) -> str:
+        return "{:x}".format(self.x).zfill(self.hex_digits)
+
+class BignumModRawConvertFromMont(BignumModRawConvertToMont):
+    """ Test cases for mpi_mod_raw_from_mont_rep(). """
+
+    test_function = "mpi_mod_raw_from_mont_rep"
+    test_name = "Convert from Mont: "
+
+    test_input_numbers = ["0",
+                          "1",
+                          "3ca",
+                          "539ed428",
+                          "7dfe5c6beb35a2d6",
+                          "dca8de1c2adfc6d7aafb9b48e",
+                          "a7d17b6c4be72f3d5c16bf9c1af6fc933",
+                          "2fec97beec546f9553142ed52f147845463f579",
+                          "378dc83b8bc5a7b62cba495af4919578dce6d4f175cadc4f",
+                          "b6415f2a1a8e48a518345db11f56db3829c8f2c6415ab4a395a"
+                          "b3ac2ea4cbef4af86eb18a84eb6ded4c6ecbfc4b59c2879a675"
+                          "487f687adea9d197a84a5242a5cf6125ce19a6ad2e7341f1c57"
+                          "d43ea4f4c852a51cb63dabcd1c9de2b827a3146a3d175b35bea"
+                          "41ae75d2a286a3e9d43623152ac513dcdea1d72a7da846a8ab3"
+                          "58d9be4926c79cfb287cf1cf25b689de3b912176be5dcaf4d4c"
+                          "6e7cb839a4a3243a6c47c1e2c99d65c59d6fa3672575c2f1ca8"
+                          "de6a32e854ec9d8ec635c96af7679fce26d7d159e4a9da3bd74"
+                          "e1272c376cd926d74fe3fb164a5935cff3d5cdb92b35fe2cea32"
+                          "138a7e6bfbc319ebd1725dacb9a359cbf693f2ecb785efb9d627"
+                         ]
+
+    @property
+    def x(self): # pylint: disable=invalid-name
+        return (self.int_a * self.r_inv) % self.int_n
 # END MERGE SLOT 7
 
 # BEGIN MERGE SLOT 8
diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index 09a0689..d4f2011 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -884,6 +884,11 @@
 	$(MBEDTLS_CERT_REQ) output_file=$@ filename=$< subject_name="C=NL,O=PolarSSL,CN=PolarSSL Server 1" md=SHA256
 all_final += server1.req.sha256
 
+server1.req.sha256.ext: server1.key
+	# Generating this with OpenSSL as a comparison point to test we're getting the same result
+	openssl req -new -out $@ -key $< -subj '/C=NL/O=PolarSSL/CN=PolarSSL Server 1' -sha256 -addext "extendedKeyUsage=serverAuth"
+all_final += server1.req.sha256.ext
+
 server1.req.sha384: server1.key
 	$(MBEDTLS_CERT_REQ) output_file=$@ filename=$< subject_name="C=NL,O=PolarSSL,CN=PolarSSL Server 1" md=SHA384
 all_final += server1.req.sha384
diff --git a/tests/data_files/server1.req.sha256.ext b/tests/data_files/server1.req.sha256.ext
new file mode 100644
index 0000000..3f26f09
--- /dev/null
+++ b/tests/data_files/server1.req.sha256.ext
@@ -0,0 +1,17 @@
+-----BEGIN CERTIFICATE REQUEST-----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+-----END CERTIFICATE REQUEST-----
diff --git a/tests/include/test/helpers.h b/tests/include/test/helpers.h
index e0e6fd2..5f9bde6 100644
--- a/tests/include/test/helpers.h
+++ b/tests/include/test/helpers.h
@@ -295,13 +295,19 @@
 
 /** Read an MPI from a hexadecimal string.
  *
- * Like mbedtls_mpi_read_string(), but size the resulting bignum based
- * on the number of digits in the string. In particular, construct a
- * bignum with 0 limbs for an empty string, and a bignum with leading 0
- * limbs if the string has sufficiently many leading 0 digits.
+ * Like mbedtls_mpi_read_string(), but with tighter guarantees around
+ * edge cases.
  *
- * This is important so that the "0 (null)" and "0 (1 limb)" and
- * "leading zeros" test cases do what they claim.
+ * - This function guarantees that if \p s begins with '-' then the sign
+ *   bit of the result will be negative, even if the value is 0.
+ *   When this function encounters such a "negative 0", it
+ *   increments #mbedtls_test_case_uses_negative_0.
+ * - The size of the result is exactly the minimum number of limbs needed
+ *   to fit the digits in the input. In particular, this function constructs
+ *   a bignum with 0 limbs for an empty string, and a bignum with leading 0
+ *   limbs if the string has sufficiently many leading 0 digits.
+ *   This is important so that the "0 (null)" and "0 (1 limb)" and
+ *   "leading zeros" test cases do what they claim.
  *
  * \param[out] X        The MPI object to populate. It must be initialized.
  * \param[in] s         The null-terminated hexadecimal string to read from.
@@ -309,6 +315,14 @@
  * \return \c 0 on success, an \c MBEDTLS_ERR_MPI_xxx error code otherwise.
  */
 int mbedtls_test_read_mpi( mbedtls_mpi *X, const char *s );
+
+/** Nonzero if the current test case had an input parsed with
+ * mbedtls_test_read_mpi() that is a negative 0 (`"-"`, `"-0"`, `"-00"`, etc.,
+ * constructing a result with the sign bit set to -1 and the value being
+ * all-limbs-0, which is not a valid representation in #mbedtls_mpi but is
+ * tested for robustness).
+ */
+extern unsigned mbedtls_test_case_uses_negative_0;
 #endif /* MBEDTLS_BIGNUM_C */
 
 #endif /* TEST_HELPERS_H */
diff --git a/tests/opt-testcases/tls13-kex-modes.sh b/tests/opt-testcases/tls13-kex-modes.sh
index 4f62ed6..974d513 100755
--- a/tests/opt-testcases/tls13-kex-modes.sh
+++ b/tests/opt-testcases/tls13-kex-modes.sh
@@ -18,228 +18,8 @@
 # limitations under the License.
 #
 
-get_srv_psk_list ()
-{
-    case $(( TESTS % 3 )) in
-        0) echo "psk_list=abc,dead,def,beef,Client_identity,6162636465666768696a6b6c6d6e6f70";;
-        1) echo "psk_list=abc,dead,Client_identity,6162636465666768696a6b6c6d6e6f70,def,beef";;
-        2) echo "psk_list=Client_identity,6162636465666768696a6b6c6d6e6f70,abc,dead,def,beef";;
-    esac
-}
-
-requires_gnutls_tls1_3
-requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_3
-requires_config_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE
-requires_config_enabled MBEDTLS_SSL_SRV_C
-requires_config_enabled MBEDTLS_DEBUG_C
-requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
-
-run_test    "TLS 1.3: PSK: No valid ciphersuite. G->m" \
-            "$P_SRV force_version=tls13 tls13_kex_modes=all debug_level=5 $(get_srv_psk_list)" \
-            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-CIPHER-ALL:+AES-256-GCM:+AEAD:+SHA384:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK:+VERS-TLS1.3 \
-                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
-                         localhost" \
-            1 \
-            -s "found psk key exchange modes extension" \
-            -s "found pre_shared_key extension" \
-            -s "Found PSK_EPHEMERAL KEX MODE" \
-            -s "Found PSK KEX MODE" \
-            -s "No matched ciphersuite"
-
-requires_openssl_tls1_3
-requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_3
-requires_config_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE
-requires_config_enabled MBEDTLS_SSL_SRV_C
-requires_config_enabled MBEDTLS_DEBUG_C
-requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
-
-run_test    "TLS 1.3: PSK: No valid ciphersuite. O->m" \
-            "$P_SRV force_version=tls13 tls13_kex_modes=all debug_level=5 $(get_srv_psk_list)" \
-            "$O_NEXT_CLI -tls1_3 -msg -allow_no_dhe_kex -ciphersuites TLS_AES_256_GCM_SHA384\
-                         -psk_identity Client_identity -psk 6162636465666768696a6b6c6d6e6f70" \
-            1 \
-            -s "found psk key exchange modes extension" \
-            -s "found pre_shared_key extension" \
-            -s "Found PSK_EPHEMERAL KEX MODE" \
-            -s "Found PSK KEX MODE" \
-            -s "No matched ciphersuite"
-
-requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
-                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-run_test "TLS 1.3 m->m: Multiple PSKs: valid ticket, reconnect with ticket" \
-         "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70 tickets=8" \
-         "$P_CLI force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70 reco_mode=1 reconnect=1" \
-         0 \
-         -c "Pre-configured PSK number = 2" \
-         -s "sent selected_identity: 0" \
-         -s "key exchange mode: psk_ephemeral" \
-         -S "key exchange mode: psk$" \
-         -S "key exchange mode: ephemeral$" \
-         -S "ticket is not authentic"
-
-requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
-                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-run_test "TLS 1.3 m->m: Multiple PSKs: invalid ticket, reconnect with PSK" \
-         "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70 tickets=8 dummy_ticket=1" \
-         "$P_CLI force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70 reco_mode=1 reconnect=1" \
-         0 \
-         -c "Pre-configured PSK number = 2" \
-         -s "sent selected_identity: 1" \
-         -s "key exchange mode: psk_ephemeral" \
-         -S "key exchange mode: psk$" \
-         -S "key exchange mode: ephemeral$" \
-         -s "ticket is not authentic"
-
-requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
-                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-run_test "TLS 1.3 m->m: Session resumption failure, ticket authentication failed." \
-         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=1" \
-         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
-         0 \
-         -c "Pre-configured PSK number = 1" \
-         -S "sent selected_identity:" \
-         -s "key exchange mode: ephemeral" \
-         -S "key exchange mode: psk_ephemeral" \
-         -S "key exchange mode: psk$" \
-         -s "ticket is not authentic" \
-         -S "ticket is expired" \
-         -S "Invalid ticket start time" \
-         -S "Ticket age exceeds limitation" \
-         -S "Ticket age outside tolerance window"
-
-requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
-                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-run_test "TLS 1.3 m->m: Session resumption failure, ticket expired." \
-         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=2" \
-         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
-         0 \
-         -c "Pre-configured PSK number = 1" \
-         -S "sent selected_identity:" \
-         -s "key exchange mode: ephemeral" \
-         -S "key exchange mode: psk_ephemeral" \
-         -S "key exchange mode: psk$" \
-         -S "ticket is not authentic" \
-         -s "ticket is expired" \
-         -S "Invalid ticket start time" \
-         -S "Ticket age exceeds limitation" \
-         -S "Ticket age outside tolerance window"
-
-requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
-                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-run_test "TLS 1.3 m->m: Session resumption failure, invalid start time." \
-         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=3" \
-         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
-         0 \
-         -c "Pre-configured PSK number = 1" \
-         -S "sent selected_identity:" \
-         -s "key exchange mode: ephemeral" \
-         -S "key exchange mode: psk_ephemeral" \
-         -S "key exchange mode: psk$" \
-         -S "ticket is not authentic" \
-         -S "ticket is expired" \
-         -s "Invalid ticket start time" \
-         -S "Ticket age exceeds limitation" \
-         -S "Ticket age outside tolerance window"
-
-requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
-                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-run_test "TLS 1.3 m->m: Session resumption failure, ticket expired. too old" \
-         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=4" \
-         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
-         0 \
-         -c "Pre-configured PSK number = 1" \
-         -S "sent selected_identity:" \
-         -s "key exchange mode: ephemeral" \
-         -S "key exchange mode: psk_ephemeral" \
-         -S "key exchange mode: psk$" \
-         -S "ticket is not authentic" \
-         -S "ticket is expired" \
-         -S "Invalid ticket start time" \
-         -s "Ticket age exceeds limitation" \
-         -S "Ticket age outside tolerance window"
-
-requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
-                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-run_test "TLS 1.3 m->m: Session resumption failure, age outside tolerance window, too young." \
-         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=5" \
-         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
-         0 \
-         -c "Pre-configured PSK number = 1" \
-         -S "sent selected_identity:" \
-         -s "key exchange mode: ephemeral" \
-         -S "key exchange mode: psk_ephemeral" \
-         -S "key exchange mode: psk$" \
-         -S "ticket is not authentic" \
-         -S "ticket is expired" \
-         -S "Invalid ticket start time" \
-         -S "Ticket age exceeds limitation" \
-         -s "Ticket age outside tolerance window"
-
-requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
-                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
-                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
-run_test "TLS 1.3 m->m: Session resumption failure, age outside tolerance window, too old." \
-         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=6" \
-         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
-         0 \
-         -c "Pre-configured PSK number = 1" \
-         -S "sent selected_identity:" \
-         -s "key exchange mode: ephemeral" \
-         -S "key exchange mode: psk_ephemeral" \
-         -S "key exchange mode: psk$" \
-         -S "ticket is not authentic" \
-         -S "ticket is expired" \
-         -S "Invalid ticket start time" \
-         -S "Ticket age exceeds limitation" \
-         -s "Ticket age outside tolerance window"
-
-requires_gnutls_tls1_3
-requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
-requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
-run_test    "TLS 1.3: G->m: ephemeral_all/psk, fail, no common kex mode" \
-            "$P_SRV force_version=tls13 tls13_kex_modes=psk debug_level=5 $(get_srv_psk_list)" \
-            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:-PSK:+VERS-TLS1.3 \
-                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
-                         localhost" \
-            1 \
-            -s "found psk key exchange modes extension" \
-            -s "found pre_shared_key extension" \
-            -s "Found PSK_EPHEMERAL KEX MODE" \
-            -S "Found PSK KEX MODE" \
-            -S "key exchange mode: psk$"  \
-            -S "key exchange mode: psk_ephemeral"  \
-            -S "key exchange mode: ephemeral"
+# DO NOT ADD NEW TEST CASES INTO THIS FILE. The left cases will be generated by
+# scripts in future(#6280)
 
 requires_gnutls_tls1_3
 requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
diff --git a/tests/opt-testcases/tls13-misc.sh b/tests/opt-testcases/tls13-misc.sh
new file mode 100755
index 0000000..edece45
--- /dev/null
+++ b/tests/opt-testcases/tls13-misc.sh
@@ -0,0 +1,346 @@
+#!/bin/sh
+
+# tls13-misc.sh
+#
+# Copyright The Mbed TLS Contributors
+# SPDX-License-Identifier: Apache-2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+requires_gnutls_tls1_3
+requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_3
+requires_config_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE
+requires_config_enabled MBEDTLS_SSL_SRV_C
+requires_config_enabled MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
+
+run_test    "TLS 1.3: PSK: No valid ciphersuite. G->m" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=all debug_level=5 $(get_srv_psk_list)" \
+            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-CIPHER-ALL:+AES-256-GCM:+AEAD:+SHA384:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK:+VERS-TLS1.3 \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
+                         localhost" \
+            1 \
+            -s "found psk key exchange modes extension" \
+            -s "found pre_shared_key extension" \
+            -s "Found PSK_EPHEMERAL KEX MODE" \
+            -s "Found PSK KEX MODE" \
+            -s "No matched ciphersuite"
+
+requires_openssl_tls1_3
+requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_3
+requires_config_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE
+requires_config_enabled MBEDTLS_SSL_SRV_C
+requires_config_enabled MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
+
+run_test    "TLS 1.3: PSK: No valid ciphersuite. O->m" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=all debug_level=5 $(get_srv_psk_list)" \
+            "$O_NEXT_CLI -tls1_3 -msg -allow_no_dhe_kex -ciphersuites TLS_AES_256_GCM_SHA384\
+                         -psk_identity Client_identity -psk 6162636465666768696a6b6c6d6e6f70" \
+            1 \
+            -s "found psk key exchange modes extension" \
+            -s "found pre_shared_key extension" \
+            -s "Found PSK_EPHEMERAL KEX MODE" \
+            -s "Found PSK KEX MODE" \
+            -s "No matched ciphersuite"
+
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
+                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test "TLS 1.3 m->m: Multiple PSKs: valid ticket, reconnect with ticket" \
+         "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70 tickets=8" \
+         "$P_CLI force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70 reco_mode=1 reconnect=1" \
+         0 \
+         -c "Pre-configured PSK number = 2" \
+         -s "sent selected_identity: 0" \
+         -s "key exchange mode: psk_ephemeral" \
+         -S "key exchange mode: psk$" \
+         -S "key exchange mode: ephemeral$" \
+         -S "ticket is not authentic"
+
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
+                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test "TLS 1.3 m->m: Multiple PSKs: invalid ticket, reconnect with PSK" \
+         "$P_SRV force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70 tickets=8 dummy_ticket=1" \
+         "$P_CLI force_version=tls13 tls13_kex_modes=psk_ephemeral debug_level=5 psk_identity=Client_identity psk=6162636465666768696a6b6c6d6e6f70 reco_mode=1 reconnect=1" \
+         0 \
+         -c "Pre-configured PSK number = 2" \
+         -s "sent selected_identity: 1" \
+         -s "key exchange mode: psk_ephemeral" \
+         -S "key exchange mode: psk$" \
+         -S "key exchange mode: ephemeral$" \
+         -s "ticket is not authentic"
+
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
+                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test "TLS 1.3 m->m: Session resumption failure, ticket authentication failed." \
+         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=1" \
+         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
+         0 \
+         -c "Pre-configured PSK number = 1" \
+         -S "sent selected_identity:" \
+         -s "key exchange mode: ephemeral" \
+         -S "key exchange mode: psk_ephemeral" \
+         -S "key exchange mode: psk$" \
+         -s "ticket is not authentic" \
+         -S "ticket is expired" \
+         -S "Invalid ticket start time" \
+         -S "Ticket age exceeds limitation" \
+         -S "Ticket age outside tolerance window"
+
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
+                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test "TLS 1.3 m->m: Session resumption failure, ticket expired." \
+         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=2" \
+         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
+         0 \
+         -c "Pre-configured PSK number = 1" \
+         -S "sent selected_identity:" \
+         -s "key exchange mode: ephemeral" \
+         -S "key exchange mode: psk_ephemeral" \
+         -S "key exchange mode: psk$" \
+         -S "ticket is not authentic" \
+         -s "ticket is expired" \
+         -S "Invalid ticket start time" \
+         -S "Ticket age exceeds limitation" \
+         -S "Ticket age outside tolerance window"
+
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
+                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test "TLS 1.3 m->m: Session resumption failure, invalid start time." \
+         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=3" \
+         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
+         0 \
+         -c "Pre-configured PSK number = 1" \
+         -S "sent selected_identity:" \
+         -s "key exchange mode: ephemeral" \
+         -S "key exchange mode: psk_ephemeral" \
+         -S "key exchange mode: psk$" \
+         -S "ticket is not authentic" \
+         -S "ticket is expired" \
+         -s "Invalid ticket start time" \
+         -S "Ticket age exceeds limitation" \
+         -S "Ticket age outside tolerance window"
+
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
+                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test "TLS 1.3 m->m: Session resumption failure, ticket expired. too old" \
+         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=4" \
+         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
+         0 \
+         -c "Pre-configured PSK number = 1" \
+         -S "sent selected_identity:" \
+         -s "key exchange mode: ephemeral" \
+         -S "key exchange mode: psk_ephemeral" \
+         -S "key exchange mode: psk$" \
+         -S "ticket is not authentic" \
+         -S "ticket is expired" \
+         -S "Invalid ticket start time" \
+         -s "Ticket age exceeds limitation" \
+         -S "Ticket age outside tolerance window"
+
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
+                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test "TLS 1.3 m->m: Session resumption failure, age outside tolerance window, too young." \
+         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=5" \
+         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
+         0 \
+         -c "Pre-configured PSK number = 1" \
+         -S "sent selected_identity:" \
+         -s "key exchange mode: ephemeral" \
+         -S "key exchange mode: psk_ephemeral" \
+         -S "key exchange mode: psk$" \
+         -S "ticket is not authentic" \
+         -S "ticket is expired" \
+         -S "Invalid ticket start time" \
+         -S "Ticket age exceeds limitation" \
+         -s "Ticket age outside tolerance window"
+
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SESSION_TICKETS MBEDTLS_SSL_SRV_C \
+                             MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_RSA_PSK_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_DHE_PSK_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+requires_any_configs_enabled MBEDTLS_KEY_EXCHANGE_ECDHE_ECDSA_ENABLED MBEDTLS_KEY_EXCHANGE_ECDHE_RSA_ENABLED \
+                             MBEDTLS_KEY_EXCHANGE_ECDHE_PSK_ENABLED
+run_test "TLS 1.3 m->m: Session resumption failure, age outside tolerance window, too old." \
+         "$P_SRV debug_level=4 crt_file=data_files/server5.crt key_file=data_files/server5.key force_version=tls13 tickets=8 dummy_ticket=6" \
+         "$P_CLI debug_level=4 reco_mode=1 reconnect=1" \
+         0 \
+         -c "Pre-configured PSK number = 1" \
+         -S "sent selected_identity:" \
+         -s "key exchange mode: ephemeral" \
+         -S "key exchange mode: psk_ephemeral" \
+         -S "key exchange mode: psk$" \
+         -S "ticket is not authentic" \
+         -S "ticket is expired" \
+         -S "Invalid ticket start time" \
+         -S "Ticket age exceeds limitation" \
+         -s "Ticket age outside tolerance window"
+
+requires_gnutls_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
+run_test    "TLS 1.3: G->m: ephemeral_all/psk, fail, no common kex mode" \
+            "$P_SRV force_version=tls13 tls13_kex_modes=psk debug_level=5 $(get_srv_psk_list)" \
+            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:-PSK:+VERS-TLS1.3 \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
+                         localhost" \
+            1 \
+            -s "found psk key exchange modes extension" \
+            -s "found pre_shared_key extension" \
+            -s "Found PSK_EPHEMERAL KEX MODE" \
+            -S "Found PSK KEX MODE" \
+            -S "key exchange mode: psk$"  \
+            -S "key exchange mode: psk_ephemeral"  \
+            -S "key exchange mode: ephemeral"
+
+requires_gnutls_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C \
+                             MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE \
+                             MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
+requires_all_configs_disabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED \
+                              MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
+run_test    "TLS 1.3: G->m: PSK: configured psk only, good." \
+            "$P_SRV force_version=tls13 tls13_kex_modes=all debug_level=5 $(get_srv_psk_list)" \
+            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK:+VERS-TLS1.3:+GROUP-ALL \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
+                         localhost" \
+            0 \
+            -s "found psk key exchange modes extension" \
+            -s "found pre_shared_key extension"         \
+            -s "Found PSK_EPHEMERAL KEX MODE"           \
+            -s "Found PSK KEX MODE"                     \
+            -s "key exchange mode: psk$"
+
+requires_gnutls_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C \
+                             MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE \
+                             MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED
+requires_all_configs_disabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED \
+                              MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
+run_test    "TLS 1.3: G->m: PSK: configured psk_ephemeral only, good." \
+            "$P_SRV force_version=tls13 tls13_kex_modes=all debug_level=5 $(get_srv_psk_list)" \
+            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK:+VERS-TLS1.3:+GROUP-ALL \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
+                         localhost" \
+            0 \
+            -s "found psk key exchange modes extension" \
+            -s "found pre_shared_key extension"         \
+            -s "Found PSK_EPHEMERAL KEX MODE"           \
+            -s "Found PSK KEX MODE"                     \
+            -s "key exchange mode: psk_ephemeral$"
+
+requires_gnutls_tls1_3
+requires_all_configs_enabled MBEDTLS_SSL_PROTO_TLS1_3 MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C \
+                             MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE \
+                             MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
+requires_all_configs_disabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED \
+                              MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED
+run_test    "TLS 1.3: G->m: PSK: configured ephemeral only, good." \
+            "$P_SRV force_version=tls13 tls13_kex_modes=all debug_level=5 $(get_srv_psk_list)" \
+            "$G_NEXT_CLI -d 10 --priority NORMAL:-VERS-ALL:-KX-ALL:+ECDHE-PSK:+DHE-PSK:+PSK:+VERS-TLS1.3:+GROUP-ALL \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70 \
+                         localhost" \
+            0 \
+            -s "key exchange mode: ephemeral$"
+
+# skip the basic check now cause it will randomly trigger the anti-replay protection in gnutls_server
+# Add it back once we fix the issue
+skip_next_test
+requires_gnutls_tls1_3
+requires_config_enabled MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_CLI_C
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE \
+                             MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED \
+                             MBEDTLS_SSL_EARLY_DATA
+requires_any_configs_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED \
+                             MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
+run_test    "TLS 1.3 m->G: EarlyData: basic check, good" \
+            "$G_NEXT_SRV -d 10 --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3:+CIPHER-ALL:+ECDHE-PSK:+PSK --earlydata --disable-client-cert" \
+            "$P_CLI debug_level=4 early_data=1 reco_mode=1 reconnect=1 reco_delay=2" \
+            1 \
+            -c "Reconnecting with saved session" \
+            -c "NewSessionTicket: early_data(42) extension received." \
+            -c "ClientHello: early_data(42) extension exists." \
+            -c "EncryptedExtensions: early_data(42) extension received." \
+            -c "EncryptedExtensions: early_data(42) extension ( ignored )." \
+            -s "Parsing extension 'Early Data/42' (0 bytes)" \
+            -s "Sending extension Early Data/42 (0 bytes)" \
+            -s "early data accepted"
+
+requires_gnutls_tls1_3
+requires_config_enabled MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_CLI_C
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE \
+                             MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED \
+                             MBEDTLS_SSL_EARLY_DATA
+requires_any_configs_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED \
+                             MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
+run_test    "TLS 1.3 m->G: EarlyData: no early_data in NewSessionTicket, good" \
+            "$G_NEXT_SRV -d 10 --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3:+CIPHER-ALL:+ECDHE-PSK:+PSK --disable-client-cert" \
+            "$P_CLI debug_level=4 early_data=1 reco_mode=1 reconnect=1 reco_delay=2" \
+            0 \
+            -c "Reconnecting with saved session" \
+            -C "NewSessionTicket: early_data(42) extension received." \
+            -c "ClientHello: early_data(42) extension does not exist." \
+            -C "EncryptedExtensions: early_data(42) extension received." \
+            -C "EncryptedExtensions: early_data(42) extension ( ignored )."
+
+#TODO: OpenSSL tests don't work now. It might be openssl options issue, cause GnuTLS has worked.
+skip_next_test
+requires_openssl_tls1_3
+requires_config_enabled MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_CLI_C
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE \
+                             MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED \
+                             MBEDTLS_SSL_EARLY_DATA
+requires_any_configs_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED \
+                             MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
+run_test    "TLS 1.3, ext PSK, early data" \
+            "$O_NEXT_SRV_EARLY_DATA -msg -debug -tls1_3 -psk_identity 0a0b0c -psk 010203 -allow_no_dhe_kex -nocert" \
+            "$P_CLI debug_level=5 force_version=tls13 tls13_kex_modes=psk early_data=1 psk=010203 psk_identity=0a0b0c" \
+             1 \
+            -c "Reconnecting with saved session" \
+            -c "NewSessionTicket: early_data(42) extension received." \
+            -c "ClientHello: early_data(42) extension exists." \
+            -c "EncryptedExtensions: early_data(42) extension received." \
+            -c "EncryptedExtensions: early_data(42) extension ( ignored )."
+
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 9295c9d..8272dcc 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -2065,6 +2065,47 @@
     make test
 }
 
+# Auxiliary function to build config for hashes with and without drivers
+config_psa_crypto_hash_use_psa () {
+    DRIVER_ONLY="$1"
+    # start with config full for maximum coverage (also enables USE_PSA)
+    scripts/config.py full
+    # enable support for drivers and configuring PSA-only algorithms
+    scripts/config.py set MBEDTLS_PSA_CRYPTO_CONFIG
+    scripts/config.py set MBEDTLS_PSA_CRYPTO_DRIVERS
+    if [ "$DRIVER_ONLY" -eq 1 ]; then
+        # disable the built-in implementation of hashes
+        scripts/config.py unset MBEDTLS_MD5_C
+        scripts/config.py unset MBEDTLS_RIPEMD160_C
+        scripts/config.py unset MBEDTLS_SHA1_C
+        scripts/config.py unset MBEDTLS_SHA224_C
+        scripts/config.py unset MBEDTLS_SHA256_C # see external RNG below
+        scripts/config.py unset MBEDTLS_SHA256_USE_A64_CRYPTO_IF_PRESENT
+        scripts/config.py unset MBEDTLS_SHA384_C
+        scripts/config.py unset MBEDTLS_SHA512_C
+        scripts/config.py unset MBEDTLS_SHA512_USE_A64_CRYPTO_IF_PRESENT
+    fi
+    # Use an external RNG as currently internal RNGs depend on entropy.c
+    # which in turn hard-depends on SHA256_C (or SHA512_C).
+    # See component_test_psa_external_rng_no_drbg_use_psa.
+    scripts/config.py set MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG
+    scripts/config.py unset MBEDTLS_ENTROPY_C
+    scripts/config.py unset MBEDTLS_ENTROPY_NV_SEED # depends on ENTROPY_C
+    scripts/config.py unset MBEDTLS_PLATFORM_NV_SEED_ALT # depends on former
+    # Also unset MD_C and things that depend on it;
+    # see component_test_crypto_full_no_md.
+    if [ "$DRIVER_ONLY" -eq 1 ]; then
+        scripts/config.py unset MBEDTLS_MD_C
+    fi
+    scripts/config.py unset MBEDTLS_HKDF_C # has independent PSA implementation
+    scripts/config.py unset MBEDTLS_HMAC_DRBG_C
+    scripts/config.py unset MBEDTLS_ECDSA_DETERMINISTIC
+    scripts/config.py -f include/psa/crypto_config.h unset PSA_WANT_ALG_DETERMINISTIC_ECDSA
+}
+
+# Note that component_test_psa_crypto_config_reference_hash_use_psa
+# is related to this component and both components need to be kept in sync.
+# For details please see comments for component_test_psa_crypto_config_reference_hash_use_psa.
 component_test_psa_crypto_config_accel_hash_use_psa () {
     msg "test: MBEDTLS_PSA_CRYPTO_CONFIG with accelerated hash and USE_PSA"
 
@@ -2077,35 +2118,7 @@
     loc_accel_flags=$( echo "$loc_accel_list" | sed 's/[^ ]* */-DLIBTESTDRIVER1_MBEDTLS_PSA_ACCEL_&/g' )
     make -C tests libtestdriver1.a CFLAGS="$ASAN_CFLAGS $loc_accel_flags" LDFLAGS="$ASAN_CFLAGS"
 
-    # start with config full for maximum coverage (also enables USE_PSA)
-    scripts/config.py full
-    # enable support for drivers and configuring PSA-only algorithms
-    scripts/config.py set MBEDTLS_PSA_CRYPTO_DRIVERS
-    scripts/config.py set MBEDTLS_PSA_CRYPTO_CONFIG
-    # disable the built-in implementation of hashes
-    scripts/config.py unset MBEDTLS_MD5_C
-    scripts/config.py unset MBEDTLS_RIPEMD160_C
-    scripts/config.py unset MBEDTLS_SHA1_C
-    scripts/config.py unset MBEDTLS_SHA224_C
-    scripts/config.py unset MBEDTLS_SHA256_C # see external RNG below
-    scripts/config.py unset MBEDTLS_SHA256_USE_A64_CRYPTO_IF_PRESENT
-    scripts/config.py unset MBEDTLS_SHA384_C
-    scripts/config.py unset MBEDTLS_SHA512_C
-    scripts/config.py unset MBEDTLS_SHA512_USE_A64_CRYPTO_IF_PRESENT
-    # Use an external RNG as currently internal RNGs depend on entropy.c
-    # which in turn hard-depends on SHA256_C (or SHA512_C).
-    # See component_test_psa_external_rng_no_drbg_use_psa.
-    scripts/config.py set MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG
-    scripts/config.py unset MBEDTLS_ENTROPY_C
-    scripts/config.py unset MBEDTLS_ENTROPY_NV_SEED # depends on ENTROPY_C
-    scripts/config.py unset MBEDTLS_PLATFORM_NV_SEED_ALT # depends on former
-    # Also unset MD_C and things that depend on it;
-    # see component_test_crypto_full_no_md.
-    scripts/config.py unset MBEDTLS_MD_C
-    scripts/config.py unset MBEDTLS_HKDF_C # has independent PSA implementation
-    scripts/config.py unset MBEDTLS_HMAC_DRBG_C
-    scripts/config.py unset MBEDTLS_ECDSA_DETERMINISTIC
-    scripts/config.py -f include/psa/crypto_config.h unset PSA_WANT_ALG_DETERMINISTIC_ECDSA
+    config_psa_crypto_hash_use_psa 1
 
     loc_accel_flags="$loc_accel_flags $( echo "$loc_accel_list" | sed 's/[^ ]* */-DMBEDTLS_PSA_ACCEL_&/g' )"
     make CFLAGS="$ASAN_CFLAGS -Werror -I../tests/include -I../tests -I../../tests -DPSA_CRYPTO_DRIVER_TEST -DMBEDTLS_TEST_LIBTESTDRIVER1 $loc_accel_flags" LDFLAGS="-ltestdriver1 $ASAN_CFLAGS" all
@@ -2122,16 +2135,32 @@
     msg "test: MBEDTLS_PSA_CRYPTO_CONFIG with accelerated hash and USE_PSA"
     make test
 
-    # hidden option: when running outcome-analysis.sh, we can skip this
-    if [ "${SKIP_SSL_OPT_COMPAT_SH-unset}" = "unset" ]; then
-        msg "test: ssl-opt.sh, MBEDTLS_PSA_CRYPTO_CONFIG with accelerated hash and USE_PSA"
-        tests/ssl-opt.sh
+    msg "test: ssl-opt.sh, MBEDTLS_PSA_CRYPTO_CONFIG with accelerated hash and USE_PSA"
+    tests/ssl-opt.sh
 
-        msg "test: compat.sh, MBEDTLS_PSA_CRYPTO_CONFIG with accelerated hash and USE_PSA"
-        tests/compat.sh
-    else
-        echo "skip ssl-opt.sh and compat.sh"
-    fi
+    msg "test: compat.sh, MBEDTLS_PSA_CRYPTO_CONFIG without accelerated hash and USE_PSA"
+    tests/compat.sh
+}
+
+# This component provides reference configuration for test_psa_crypto_config_accel_hash_use_psa
+# without accelerated hash. The outcome from both components are used by the analyze_outcomes.py
+# script to find regression in test coverage when accelerated hash is used (tests and ssl-opt).
+# Both components need to be kept in sync.
+component_test_psa_crypto_config_reference_hash_use_psa() {
+    msg "test: MBEDTLS_PSA_CRYPTO_CONFIG without accelerated hash and USE_PSA"
+
+    scripts/config.py -f include/psa/crypto_config.h unset PSA_WANT_ALG_STREAM_CIPHER
+    scripts/config.py -f include/psa/crypto_config.h unset PSA_WANT_ALG_ECB_NO_PADDING
+
+    config_psa_crypto_hash_use_psa 0
+
+    make
+
+    msg "test: MBEDTLS_PSA_CRYPTO_CONFIG without accelerated hash and USE_PSA"
+    make test
+
+    msg "test: ssl-opt.sh, MBEDTLS_PSA_CRYPTO_CONFIG without accelerated hash and USE_PSA"
+    tests/ssl-opt.sh
 }
 
 component_test_psa_crypto_config_accel_cipher () {
@@ -3253,6 +3282,7 @@
     msg "build: TLS 1.3 only from default, only ephemeral key exchange mode"
     scripts/config.py unset MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
     scripts/config.py unset MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED
+    scripts/config.py unset MBEDTLS_SSL_EARLY_DATA
     make CFLAGS="'-DMBEDTLS_USER_CONFIG_FILE=\"../tests/configs/tls13-only.h\"'"
 
     msg "test_suite_ssl: TLS 1.3 only, only ephemeral key exchange mode"
diff --git a/tests/scripts/analyze_outcomes.py b/tests/scripts/analyze_outcomes.py
index d06a059..bb44396 100755
--- a/tests/scripts/analyze_outcomes.py
+++ b/tests/scripts/analyze_outcomes.py
@@ -9,6 +9,7 @@
 import argparse
 import sys
 import traceback
+import re
 
 import check_test_cases
 
@@ -60,6 +61,37 @@
             # fixed this branch to have full coverage of test cases.
             results.warning('Test case not executed: {}', key)
 
+def analyze_driver_vs_reference(outcomes, component_ref, component_driver, ignored_tests):
+    """Check that all tests executed in the reference component are also
+    executed in the corresponding driver component.
+    Skip test suites provided in ignored_tests list.
+    """
+    available = check_test_cases.collect_available_test_cases()
+    result = True
+
+    for key in available:
+        # Skip ignored test suites
+        test_suite = key.split(';')[0] # retrieve test suit name
+        test_suite = test_suite.split('.')[0] # retrieve main part of test suit name
+        if test_suite in ignored_tests:
+            continue
+        # Continue if test was not executed by any component
+        hits = outcomes[key].hits() if key in outcomes else 0
+        if hits == 0:
+            continue
+        # Search for tests that run in reference component and not in driver component
+        driver_test_passed = False
+        reference_test_passed = False
+        for entry in outcomes[key].successes:
+            if component_driver in entry:
+                driver_test_passed = True
+            if component_ref in entry:
+                reference_test_passed = True
+        if(driver_test_passed is False and reference_test_passed is True):
+            print('{}: driver: skipped/failed; reference: passed'.format(key))
+            result = False
+    return result
+
 def analyze_outcomes(outcomes):
     """Run all analyses on the given outcome collection."""
     results = Results()
@@ -87,20 +119,75 @@
                 outcomes[key].failures.append(setup)
     return outcomes
 
-def analyze_outcome_file(outcome_file):
-    """Analyze the given outcome file."""
+def do_analyze_coverage(outcome_file, args):
+    """Perform coverage analysis."""
+    del args # unused
     outcomes = read_outcome_file(outcome_file)
-    return analyze_outcomes(outcomes)
+    results = analyze_outcomes(outcomes)
+    return results.error_count == 0
+
+def do_analyze_driver_vs_reference(outcome_file, args):
+    """Perform driver vs reference analyze."""
+    ignored_tests = ['test_suite_' + x for x in args['ignored_suites']]
+
+    outcomes = read_outcome_file(outcome_file)
+    return analyze_driver_vs_reference(outcomes, args['component_ref'],
+                                       args['component_driver'], ignored_tests)
+
+# List of tasks with a function that can handle this task and additional arguments if required
+TASKS = {
+    'analyze_coverage':                 {
+        'test_function': do_analyze_coverage,
+        'args': {}},
+    'analyze_driver_vs_reference_hash': {
+        'test_function': do_analyze_driver_vs_reference,
+        'args': {
+            'component_ref': 'test_psa_crypto_config_reference_hash_use_psa',
+            'component_driver': 'test_psa_crypto_config_accel_hash_use_psa',
+            'ignored_suites': ['shax', 'mdx', # the software implementations that are being excluded
+                               'md',  # the legacy abstraction layer that's being excluded
+                              ]}}
+}
 
 def main():
     try:
         parser = argparse.ArgumentParser(description=__doc__)
         parser.add_argument('outcomes', metavar='OUTCOMES.CSV',
                             help='Outcome file to analyze')
+        parser.add_argument('task', default='all', nargs='?',
+                            help='Analysis to be done. By default, run all tasks. '
+                                 'With one or more TASK, run only those. '
+                                 'TASK can be the name of a single task or '
+                                 'comma/space-separated list of tasks. ')
+        parser.add_argument('--list', action='store_true',
+                            help='List all available tasks and exit.')
         options = parser.parse_args()
-        results = analyze_outcome_file(options.outcomes)
-        if results.error_count > 0:
+
+        if options.list:
+            for task in TASKS:
+                print(task)
+            sys.exit(0)
+
+        result = True
+
+        if options.task == 'all':
+            tasks = TASKS.keys()
+        else:
+            tasks = re.split(r'[, ]+', options.task)
+
+            for task in tasks:
+                if task not in TASKS:
+                    print('Error: invalid task: {}'.format(task))
+                    sys.exit(1)
+
+        for task in TASKS:
+            if task in tasks:
+                if not TASKS[task]['test_function'](options.outcomes, TASKS[task]['args']):
+                    result = False
+
+        if result is False:
             sys.exit(1)
+        print("SUCCESS :-)")
     except Exception: # pylint: disable=broad-except
         # Print the backtrace and exit explicitly with our chosen status.
         traceback.print_exc()
diff --git a/tests/scripts/generate_bignum_tests.py b/tests/scripts/generate_bignum_tests.py
index a105203..eee2f65 100755
--- a/tests/scripts/generate_bignum_tests.py
+++ b/tests/scripts/generate_bignum_tests.py
@@ -78,11 +78,17 @@
     #pylint: disable=abstract-method
     """Common features for bignum operations in legacy tests."""
     input_values = [
-        "", "0", "7b", "-7b",
+        "", "0", "-", "-0",
+        "7b", "-7b",
         "0000000000000000123", "-0000000000000000123",
         "1230000000000000000", "-1230000000000000000"
     ]
 
+    def description_suffix(self) -> str:
+        #pylint: disable=no-self-use # derived classes need self
+        """Text to add at the end of the test case description."""
+        return ""
+
     def description(self) -> str:
         """Generate a description for the test case.
 
@@ -96,6 +102,9 @@
                 self.symbol,
                 self.value_description(self.arg_b)
             )
+            description_suffix = self.description_suffix()
+            if description_suffix:
+                self.case_description += " " + description_suffix
         return super().description()
 
     @staticmethod
@@ -107,6 +116,8 @@
         """
         if val == "":
             return "0 (null)"
+        if val == "-":
+            return "negative 0 (null)"
         if val == "0":
             return "0 (1 limb)"
 
@@ -171,9 +182,21 @@
         ]
     )
 
-    def result(self) -> List[str]:
-        return [bignum_common.quote_str("{:x}").format(self.int_a + self.int_b)]
+    def __init__(self, val_a: str, val_b: str) -> None:
+        super().__init__(val_a, val_b)
+        self._result = self.int_a + self.int_b
 
+    def description_suffix(self) -> str:
+        if (self.int_a >= 0 and self.int_b >= 0):
+            return "" # obviously positive result or 0
+        if (self.int_a <= 0 and self.int_b <= 0):
+            return "" # obviously negative result or 0
+        # The sign of the result is not obvious, so indicate it
+        return ", result{}0".format('>' if self._result > 0 else
+                                    '<' if self._result < 0 else '=')
+
+    def result(self) -> List[str]:
+        return [bignum_common.quote_str("{:x}".format(self._result))]
 
 if __name__ == '__main__':
     # Use the section of the docstring relevant to the CLI as description
diff --git a/tests/src/helpers.c b/tests/src/helpers.c
index cc23fd7..7c83714 100644
--- a/tests/src/helpers.c
+++ b/tests/src/helpers.c
@@ -89,6 +89,10 @@
     mbedtls_test_info.step = step;
 }
 
+#if defined(MBEDTLS_BIGNUM_C)
+unsigned mbedtls_test_case_uses_negative_0 = 0;
+#endif
+
 void mbedtls_test_info_reset( void )
 {
     mbedtls_test_info.result = MBEDTLS_TEST_RESULT_SUCCESS;
@@ -98,6 +102,9 @@
     mbedtls_test_info.filename = 0;
     memset( mbedtls_test_info.line1, 0, sizeof( mbedtls_test_info.line1 ) );
     memset( mbedtls_test_info.line2, 0, sizeof( mbedtls_test_info.line2 ) );
+#if defined(MBEDTLS_BIGNUM_C)
+    mbedtls_test_case_uses_negative_0 = 0;
+#endif
 }
 
 int mbedtls_test_equal( const char *test, int line_no, const char* filename,
@@ -396,6 +403,15 @@
 
 int mbedtls_test_read_mpi( mbedtls_mpi *X, const char *s )
 {
+    int negative = 0;
+    /* Always set the sign bit to -1 if the input has a minus sign, even for 0.
+     * This creates an invalid representation, which mbedtls_mpi_read_string()
+     * avoids but we want to be able to create that in test data. */
+    if( s[0] == '-' )
+    {
+        ++s;
+        negative = 1;
+    }
     /* mbedtls_mpi_read_string() currently retains leading zeros.
      * It always allocates at least one limb for the value 0. */
     if( s[0] == 0 )
@@ -403,7 +419,15 @@
         mbedtls_mpi_free( X );
         return( 0 );
     }
-    else
-        return( mbedtls_mpi_read_string( X, 16, s ) );
+    int ret = mbedtls_mpi_read_string( X, 16, s );
+    if( ret != 0 )
+        return( ret );
+    if( negative )
+    {
+        if( mbedtls_mpi_cmp_int( X, 0 ) == 0 )
+            ++mbedtls_test_case_uses_negative_0;
+        X->s = -1;
+    }
+    return( 0 );
 }
 #endif
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index f2e3f0c..6220527 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -80,12 +80,14 @@
 
 if [ -n "${OPENSSL_NEXT:-}" ]; then
     O_NEXT_SRV="$OPENSSL_NEXT s_server -www -cert data_files/server5.crt -key data_files/server5.key"
+    O_NEXT_SRV_EARLY_DATA="$OPENSSL_NEXT s_server -early_data -cert data_files/server5.crt -key data_files/server5.key"
     O_NEXT_SRV_NO_CERT="$OPENSSL_NEXT s_server -www "
     O_NEXT_CLI="echo 'GET / HTTP/1.0' | $OPENSSL_NEXT s_client -CAfile data_files/test-ca_cat12.crt"
     O_NEXT_CLI_NO_CERT="echo 'GET / HTTP/1.0' | $OPENSSL_NEXT s_client"
 else
     O_NEXT_SRV=false
     O_NEXT_SRV_NO_CERT=false
+    O_NEXT_SRV_EARLY_DATA=false
     O_NEXT_CLI_NO_CERT=false
     O_NEXT_CLI=false
 fi
@@ -1024,6 +1026,16 @@
     esac
 }
 
+# Generate random psk_list argument for ssl_server2
+get_srv_psk_list ()
+{
+    case $(( TESTS % 3 )) in
+        0) echo "psk_list=abc,dead,def,beef,Client_identity,6162636465666768696a6b6c6d6e6f70";;
+        1) echo "psk_list=abc,dead,Client_identity,6162636465666768696a6b6c6d6e6f70,def,beef";;
+        2) echo "psk_list=Client_identity,6162636465666768696a6b6c6d6e6f70,abc,dead,def,beef";;
+    esac
+}
+
 # Determine what calc_verify trace is to be expected, if any.
 #
 # calc_verify is only called for two things: to calculate the
@@ -1680,6 +1692,7 @@
 if [ -n "${OPENSSL_NEXT:-}" ]; then
     O_NEXT_SRV="$O_NEXT_SRV -accept $SRV_PORT"
     O_NEXT_SRV_NO_CERT="$O_NEXT_SRV_NO_CERT -accept $SRV_PORT"
+    O_NEXT_SRV_EARLY_DATA="$O_NEXT_SRV_EARLY_DATA -accept $SRV_PORT"
     O_NEXT_CLI="$O_NEXT_CLI -connect 127.0.0.1:+SRV_PORT"
     O_NEXT_CLI_NO_CERT="$O_NEXT_CLI_NO_CERT -connect 127.0.0.1:+SRV_PORT"
 fi
diff --git a/tests/suites/test_suite_bignum.function b/tests/suites/test_suite_bignum.function
index 4cec0a7..b75f534 100644
--- a/tests/suites/test_suite_bignum.function
+++ b/tests/suites/test_suite_bignum.function
@@ -13,10 +13,21 @@
  * constructing the value. */
 static int sign_is_valid( const mbedtls_mpi *X )
 {
+    /* Only +1 and -1 are valid sign bits, not e.g. 0 */
     if( X->s != 1 && X->s != -1 )
-        return( 0 ); // invalid sign bit, e.g. 0
-    if( mbedtls_mpi_bitlen( X ) == 0 && X->s != 1 )
-        return( 0 ); // negative zero
+        return( 0 );
+
+    /* The value 0 must be represented with the sign +1. A "negative zero"
+     * with s=-1 is an invalid representation. Forbid that. As an exception,
+     * we sometimes test the robustness of library functions when given
+     * a negative zero input. If a test case has a negative zero as input,
+     * we don't mind if the function has a negative zero output. */
+    if( ! mbedtls_test_case_uses_negative_0 &&
+        mbedtls_mpi_bitlen( X ) == 0 && X->s != 1 )
+    {
+        return( 0 );
+    }
+
     return( 1 );
 }
 
@@ -959,24 +970,57 @@
 /* END_CASE */
 
 /* BEGIN_CASE */
-void mpi_mod_int( char * input_X, int input_Y,
-                  int input_A, int div_result )
+void mpi_mod_int( char * input_X, char * input_Y,
+                  char * input_A, int mod_result )
 {
     mbedtls_mpi X;
+    mbedtls_mpi Y;
+    mbedtls_mpi A;
     int res;
     mbedtls_mpi_uint r;
-    mbedtls_mpi_init( &X );
 
-    TEST_ASSERT( mbedtls_test_read_mpi( &X, input_X ) == 0 );
-    res = mbedtls_mpi_mod_int( &r, &X, input_Y );
-    TEST_ASSERT( res == div_result );
+    mbedtls_mpi_init( &X );
+    mbedtls_mpi_init( &Y );
+    mbedtls_mpi_init( &A );
+
+    /* We use MPIs to read Y and A since the test framework limits us to
+     * ints, so we can't have 64-bit values */
+    TEST_EQUAL( mbedtls_test_read_mpi( &X, input_X ), 0 );
+    TEST_EQUAL( mbedtls_test_read_mpi( &Y, input_Y ), 0 );
+    TEST_EQUAL( mbedtls_test_read_mpi( &A, input_A ), 0 );
+
+    TEST_EQUAL( Y.n, 1 );
+    TEST_EQUAL( A.n, 1 );
+
+    /* Convert the MPIs for Y and A to (signed) mbedtls_mpi_sints */
+
+    /* Since we're converting sign+magnitude to two's complement, we lose one
+     * bit of value in the output. This means there are some values we can't
+     * represent, e.g. (hex) -A0000000 on 32-bit systems. These are technically
+     * invalid test cases, so could be considered "won't happen", but they are
+     * easy to test for, and this helps guard against human error. */
+
+    mbedtls_mpi_sint y = (mbedtls_mpi_sint) Y.p[0];
+    TEST_ASSERT( y >= 0 );      /* If y < 0 here, we can't make negative y */
+    if( Y.s == -1 )
+        y = -y;
+
+    mbedtls_mpi_sint a = (mbedtls_mpi_sint) A.p[0];
+    TEST_ASSERT( a >= 0 );      /* Same goes for a */
+    if( A.s == -1 )
+        a = -a;
+
+    res = mbedtls_mpi_mod_int( &r, &X, y );
+    TEST_EQUAL( res, mod_result );
     if( res == 0 )
     {
-        TEST_ASSERT( r == (mbedtls_mpi_uint) input_A );
+        TEST_EQUAL( r, a );
     }
 
 exit:
     mbedtls_mpi_free( &X );
+    mbedtls_mpi_free( &Y );
+    mbedtls_mpi_free( &A );
 }
 /* END_CASE */
 
diff --git a/tests/suites/test_suite_bignum.misc.data b/tests/suites/test_suite_bignum.misc.data
index 29ba4ab..818f361 100644
--- a/tests/suites/test_suite_bignum.misc.data
+++ b/tests/suites/test_suite_bignum.misc.data
@@ -1144,6 +1144,18 @@
 Test mbedtls_mpi_div_mpi: 0 (null) / -1
 mpi_div_mpi:"":"-1":"":"":0
 
+Test mbedtls_mpi_div_mpi: -0 (null) / 1
+mpi_div_mpi:"-":"1":"":"":0
+
+Test mbedtls_mpi_div_mpi: -0 (null) / -1
+mpi_div_mpi:"-":"-1":"":"":0
+
+Test mbedtls_mpi_div_mpi: -0 (null) / 42
+mpi_div_mpi:"-":"2a":"":"":0
+
+Test mbedtls_mpi_div_mpi: -0 (null) / -42
+mpi_div_mpi:"-":"-2a":"":"":0
+
 Test mbedtls_mpi_div_mpi #1
 mpi_div_mpi:"9e22d6da18a33d1ef28d2a82242b3f6e9c9742f63e5d440f58a190bfaf23a7866e67589adb80":"22":"4a6abf75b13dc268ea9cc8b5b6aaf0ac85ecd437a4e0987fb13cf8d2acc57c0306c738c1583":"1a":0
 
@@ -1204,41 +1216,85 @@
 Test mbedtls_mpi_mod_mpi: 0 (null) % -1
 mpi_mod_mpi:"":"-1":"":MBEDTLS_ERR_MPI_NEGATIVE_VALUE
 
+Test mbedtls_mpi_mod_mpi: -0 (null) % 1
+mpi_mod_mpi:"-":"1":"":0
+
+Test mbedtls_mpi_mod_mpi: -0 (null) % -1
+mpi_mod_mpi:"-":"-1":"":MBEDTLS_ERR_MPI_NEGATIVE_VALUE
+
+Test mbedtls_mpi_mod_mpi: -0 (null) % 42
+mpi_mod_mpi:"-":"2a":"":0
+
+Test mbedtls_mpi_mod_mpi: -0 (null) % -42
+mpi_mod_mpi:"-":"-2a":"":MBEDTLS_ERR_MPI_NEGATIVE_VALUE
+
 Base test mbedtls_mpi_mod_int #1
-mpi_mod_int:"3e8":13:12:0
+mpi_mod_int:"3e8":"d":"c":0
 
 Base test mbedtls_mpi_mod_int #2 (Divide by zero)
-mpi_mod_int:"3e8":0:0:MBEDTLS_ERR_MPI_DIVISION_BY_ZERO
+mpi_mod_int:"3e8":"0":"0":MBEDTLS_ERR_MPI_DIVISION_BY_ZERO
 
 Base test mbedtls_mpi_mod_int #3
-mpi_mod_int:"-3e8":13:1:0
+mpi_mod_int:"-3e8":"d":"1":0
 
 Base test mbedtls_mpi_mod_int #4 (Negative modulo)
-mpi_mod_int:"3e8":-13:0:MBEDTLS_ERR_MPI_NEGATIVE_VALUE
+mpi_mod_int:"3e8":"-d":"0":MBEDTLS_ERR_MPI_NEGATIVE_VALUE
 
 Base test mbedtls_mpi_mod_int #5 (Negative modulo)
-mpi_mod_int:"-3e8":-13:0:MBEDTLS_ERR_MPI_NEGATIVE_VALUE
+mpi_mod_int:"-3e8":"-d":"0":MBEDTLS_ERR_MPI_NEGATIVE_VALUE
 
 Base test mbedtls_mpi_mod_int #6 (By 1)
-mpi_mod_int:"3e8":1:0:0
+mpi_mod_int:"3e8":"1":"0":0
 
 Base test mbedtls_mpi_mod_int #7 (By 2)
-mpi_mod_int:"3e9":2:1:0
+mpi_mod_int:"3e9":"2":"1":0
 
 Base test mbedtls_mpi_mod_int #8 (By 2)
-mpi_mod_int:"3e8":2:0:0
+mpi_mod_int:"3e8":"2":"0":0
 
 Test mbedtls_mpi_mod_int: 0 (null) % 1
-mpi_mod_int:"":1:0:0
+mpi_mod_int:"":"1":"0":0
 
 Test mbedtls_mpi_mod_int: 0 (null) % 2
-mpi_mod_int:"":2:0:0
+mpi_mod_int:"":"2":"0":0
 
 Test mbedtls_mpi_mod_int: 0 (null) % -1
-mpi_mod_int:"":-1:0:MBEDTLS_ERR_MPI_NEGATIVE_VALUE
+mpi_mod_int:"":"-1":"0":MBEDTLS_ERR_MPI_NEGATIVE_VALUE
 
 Test mbedtls_mpi_mod_int: 0 (null) % -2
-mpi_mod_int:"":-2:0:MBEDTLS_ERR_MPI_NEGATIVE_VALUE
+mpi_mod_int:"":"-2":"0":MBEDTLS_ERR_MPI_NEGATIVE_VALUE
+
+# CURRENTLY FAILS - SEE GITHUB ISSUE #6540
+#Test mbedtls_mpi_mod_int: 230772460340063000000100500000300000010 % 5178236083361335880 -> 3386266129388798810
+#depends_on:MBEDTLS_HAVE_INT64
+#mpi_mod_int:"AD9D28BF6C4E98FDF156BF0980CEE30A":"47DCCA4847DCCA48":"2EFE6F1A7D28035A":0
+
+Test mbedtls_mpi_mod_mpi: 230772460340063000000100500000300000010 % 5178236083361335880 -> 3386266129388798810
+mpi_mod_mpi:"AD9D28BF6C4E98FDF156BF0980CEE30A":"47DCCA4847DCCA48":"2EFE6F1A7D28035A":0
+
+# CURRENTLY FAILS - SEE GITHUB ISSUE #6540
+#Test mbedtls_mpi_mod_int: 230772460340062999996714233870911201200 % 5178236083361335880 -> 0
+#depends_on:MBEDTLS_HAVE_INT64
+#mpi_mod_int:"AD9D28BF6C4E98FDC2584FEF03A6DFB0":"47DCCA4847DCCA48":"0":0
+
+Test mbedtls_mpi_mod_mpi: 230772460340062999996714233870911201200 % 5178236083361335880 -> 0
+mpi_mod_mpi:"AD9D28BF6C4E98FDC2584FEF03A6DFB0":"47DCCA4847DCCA48":"0":0
+
+# CURRENTLY FAILS WHEN MPIS ARE 32-BIT (ISSUE #6450): WHEN FIXED, REMOVE "depends_on" LINE
+Test mbedtls_mpi_mod_int: 230772460340063000000100500000300000010 % 1205652040 -> 3644370
+depends_on:MBEDTLS_HAVE_INT64
+mpi_mod_int:"AD9D28BF6C4E98FDF156BF0980CEE30A":"47DCCA48":"379BD2":0
+
+Test mbedtls_mpi_mod_mpi: 230772460340063000000100500000300000010 % 1205652040 -> 3644370
+mpi_mod_mpi:"AD9D28BF6C4E98FDF156BF0980CEE30A":"47DCCA48":"379BD2":0
+
+# CURRENTLY FAILS WHEN MPIS ARE 32-BIT (ISSUE #6450): WHEN FIXED, REMOVE "depends_on" LINE
+Test mbedtls_mpi_mod_int: 230772460340063000000100500000296355640 % 1205652040 -> 0
+depends_on:MBEDTLS_HAVE_INT64
+mpi_mod_int:"AD9D28BF6C4E98FDF156BF0980974738":"47DCCA48":"0":0
+
+Test mbedtls_mpi_mod_mpi: 230772460340063000000100500000296355640 % 1205652040 -> 0
+mpi_mod_mpi:"AD9D28BF6C4E98FDF156BF0980974738":"47DCCA48":"0":0
 
 Base test mbedtls_mpi_exp_mod #1
 mpi_exp_mod:"17":"d":"1d":"18":0
diff --git a/tests/suites/test_suite_bignum_mod_raw.function b/tests/suites/test_suite_bignum_mod_raw.function
index 4b90675..ff766b9 100644
--- a/tests/suites/test_suite_bignum_mod_raw.function
+++ b/tests/suites/test_suite_bignum_mod_raw.function
@@ -294,7 +294,77 @@
 /* END MERGE SLOT 6 */
 
 /* BEGIN MERGE SLOT 7 */
+/* BEGIN_CASE */
+void mpi_mod_raw_to_mont_rep( char * input_N, char * input_A, char * input_X )
+{
+    mbedtls_mpi_uint *N = NULL;
+    mbedtls_mpi_uint *A = NULL;
+    mbedtls_mpi_uint *X = NULL;
+    size_t n_limbs, a_limbs, x_limbs, x_bytes;
 
+    mbedtls_mpi_mod_modulus m;
+    mbedtls_mpi_mod_modulus_init( &m );
+
+    /* Read inputs */
+    TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &N, &n_limbs, input_N ) );
+    TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &A, &a_limbs, input_A ) );
+    TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &X, &x_limbs, input_X ) );
+    x_bytes = x_limbs * sizeof(mbedtls_mpi_uint);
+
+    /* Test that input does not require more limbs than modulo */
+    TEST_LE_U(a_limbs, n_limbs);
+
+    TEST_EQUAL( 0, mbedtls_mpi_mod_modulus_setup( &m, N, n_limbs,
+                MBEDTLS_MPI_MOD_EXT_REP_BE, MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
+
+    /* Convert from cannonical into Montgomery representation */
+    TEST_EQUAL(0, mbedtls_mpi_mod_raw_to_mont_rep( A, &m ) );
+
+    /* The result matches expected value */
+    ASSERT_COMPARE( A, x_bytes, X, x_bytes );
+exit:
+    mbedtls_mpi_mod_modulus_free( &m );
+    mbedtls_free( N );
+    mbedtls_free( A );
+    mbedtls_free( X );
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void mpi_mod_raw_from_mont_rep( char * input_N, char * input_A, char * input_X )
+{
+    mbedtls_mpi_uint *N = NULL;
+    mbedtls_mpi_uint *A = NULL;
+    mbedtls_mpi_uint *X = NULL;
+    size_t n_limbs, a_limbs, x_limbs, x_bytes;
+
+    mbedtls_mpi_mod_modulus m;
+    mbedtls_mpi_mod_modulus_init( &m );
+
+    /* Read inputs */
+    TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &N, &n_limbs, input_N ) );
+    TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &A, &a_limbs, input_A ) );
+    TEST_EQUAL( 0, mbedtls_test_read_mpi_core( &X, &x_limbs, input_X ) );
+    x_bytes = x_limbs * sizeof(mbedtls_mpi_uint);
+
+    /* Test that input does not require more limbs than modulo */
+    TEST_LE_U(a_limbs, n_limbs);
+
+    TEST_EQUAL( 0, mbedtls_mpi_mod_modulus_setup( &m, N, n_limbs,
+                MBEDTLS_MPI_MOD_EXT_REP_BE, MBEDTLS_MPI_MOD_REP_MONTGOMERY ) );
+
+    /* Convert from Montgomery into cannonical representation */
+    TEST_EQUAL(0, mbedtls_mpi_mod_raw_from_mont_rep( A, &m ) );
+
+    /* The result matches expected value */
+    ASSERT_COMPARE( A, x_bytes, X, x_bytes );
+exit:
+    mbedtls_mpi_mod_modulus_free( &m );
+    mbedtls_free( N );
+    mbedtls_free( A );
+    mbedtls_free( X );
+}
+/* END_CASE */
 /* END MERGE SLOT 7 */
 
 /* BEGIN MERGE SLOT 8 */
diff --git a/tests/suites/test_suite_x509write.data b/tests/suites/test_suite_x509write.data
index 8411557..c55c9d1 100644
--- a/tests/suites/test_suite_x509write.data
+++ b/tests/suites/test_suite_x509write.data
@@ -1,30 +1,30 @@
 Certificate Request check Server1 SHA1
 depends_on:MBEDTLS_HAS_ALG_SHA_1_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha1":MBEDTLS_MD_SHA1:0:0:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha1":MBEDTLS_MD_SHA1:0:0:0:0:0
 
 Certificate Request check Server1 SHA224
 depends_on:MBEDTLS_HAS_ALG_SHA_224_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha224":MBEDTLS_MD_SHA224:0:0:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha224":MBEDTLS_MD_SHA224:0:0:0:0:0
 
 Certificate Request check Server1 SHA256
 depends_on:MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha256":MBEDTLS_MD_SHA256:0:0:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha256":MBEDTLS_MD_SHA256:0:0:0:0:0
 
 Certificate Request check Server1 SHA384
 depends_on:MBEDTLS_HAS_ALG_SHA_384_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha384":MBEDTLS_MD_SHA384:0:0:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha384":MBEDTLS_MD_SHA384:0:0:0:0:0
 
 Certificate Request check Server1 SHA512
 depends_on:MBEDTLS_HAS_ALG_SHA_512_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha512":MBEDTLS_MD_SHA512:0:0:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha512":MBEDTLS_MD_SHA512:0:0:0:0:0
 
 Certificate Request check Server1 MD5
 depends_on:MBEDTLS_HAS_ALG_MD5_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.md5":MBEDTLS_MD_MD5:0:0:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.md5":MBEDTLS_MD_MD5:0:0:0:0:0
 
 Certificate Request check Server1 key_usage
 depends_on:MBEDTLS_HAS_ALG_SHA_1_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.key_usage":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:1:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.key_usage":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:1:0:0:0
 
 Certificate Request check opaque Server1 key_usage
 depends_on:MBEDTLS_HAS_ALG_SHA_1_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
@@ -32,23 +32,27 @@
 
 Certificate Request check Server1 key_usage empty
 depends_on:MBEDTLS_HAS_ALG_SHA_1_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.key_usage_empty":MBEDTLS_MD_SHA1:0:1:0:0
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.key_usage_empty":MBEDTLS_MD_SHA1:0:1:0:0:0
 
 Certificate Request check Server1 ns_cert_type
 depends_on:MBEDTLS_HAS_ALG_SHA_1_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.cert_type":MBEDTLS_MD_SHA1:0:0:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER:1
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.cert_type":MBEDTLS_MD_SHA1:0:0:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER:1:0
 
 Certificate Request check Server1 ns_cert_type empty
 depends_on:MBEDTLS_HAS_ALG_SHA_1_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.cert_type_empty":MBEDTLS_MD_SHA1:0:0:0:1
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.cert_type_empty":MBEDTLS_MD_SHA1:0:0:0:1:0
 
 Certificate Request check Server1 key_usage + ns_cert_type
 depends_on:MBEDTLS_HAS_ALG_SHA_1_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
-x509_csr_check:"data_files/server1.key":"data_files/server1.req.ku-ct":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:1:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER:1
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.ku-ct":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION | MBEDTLS_X509_KU_KEY_ENCIPHERMENT:1:MBEDTLS_X509_NS_CERT_TYPE_SSL_SERVER:1:0
 
 Certificate Request check Server5 ECDSA, key_usage
 depends_on:MBEDTLS_HAS_ALG_SHA_1_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_ECDSA_C:MBEDTLS_ECDSA_DETERMINISTIC:MBEDTLS_ECP_DP_SECP256R1_ENABLED
-x509_csr_check:"data_files/server5.key":"data_files/server5.req.ku.sha1":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION:1:0:0
+x509_csr_check:"data_files/server5.key":"data_files/server5.req.ku.sha1":MBEDTLS_MD_SHA1:MBEDTLS_X509_KU_DIGITAL_SIGNATURE | MBEDTLS_X509_KU_NON_REPUDIATION:1:0:0:0
+
+Certificate Request check Server1, set_extension
+depends_on:MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
+x509_csr_check:"data_files/server1.key":"data_files/server1.req.sha256.ext":MBEDTLS_MD_SHA256:0:0:0:0:1
 
 Certificate Request check opaque Server5 ECDSA, key_usage
 depends_on:MBEDTLS_HAS_ALG_SHA_256_VIA_MD_OR_PSA_BASED_ON_USE_PSA:MBEDTLS_ECDSA_C:MBEDTLS_ECP_DP_SECP256R1_ENABLED
diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index aa54072..5bd814a 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -5,6 +5,7 @@
 #include "mbedtls/pem.h"
 #include "mbedtls/oid.h"
 #include "mbedtls/rsa.h"
+#include "mbedtls/asn1write.h"
 
 #include "hash_info.h"
 #include "mbedtls/legacy_or_psa.h"
@@ -74,6 +75,56 @@
 }
 #endif /* MBEDTLS_USE_PSA_CRYPTO && MBEDTLS_PEM_WRITE_C && MBEDTLS_X509_CSR_WRITE_C */
 
+#if defined(MBEDTLS_X509_CSR_WRITE_C)
+
+/*
+ * The size of this temporary buffer is given by the sequence of functions
+ * called hereinafter:
+ * - mbedtls_asn1_write_oid()
+ *     - 8 bytes for MBEDTLS_OID_EXTENDED_KEY_USAGE raw value
+ *     - 1 byte for MBEDTLS_OID_EXTENDED_KEY_USAGE length
+ *     - 1 byte for MBEDTLS_ASN1_OID tag
+ * - mbedtls_asn1_write_len()
+ *     - 1 byte since we're dealing with sizes which are less than 0x80
+ * - mbedtls_asn1_write_tag()
+ *     - 1 byte
+ *
+ * This length is fine as long as this function is called using the
+ * MBEDTLS_OID_SERVER_AUTH OID. If this is changed in the future, then this
+ * buffer's length should be adjusted accordingly.
+ * Unfortunately there's no predefined max size for OIDs which can be used
+ * to set an overall upper boundary which is always guaranteed.
+ */
+#define EXT_KEY_USAGE_TMP_BUF_MAX_LENGTH    12
+
+static int csr_set_extended_key_usage( mbedtls_x509write_csr *ctx,
+                        const char *oid, size_t oid_len )
+{
+    unsigned char buf[EXT_KEY_USAGE_TMP_BUF_MAX_LENGTH] = { 0 };
+    unsigned char *p = buf + sizeof( buf );
+    int ret;
+    size_t len = 0;
+
+    /*
+     * Following functions fail anyway if the temporary buffer is not large,
+     * but we set an extra check here to emphasize a possible source of errors
+     */
+    if ( oid_len > EXT_KEY_USAGE_TMP_BUF_MAX_LENGTH )
+    {
+        return MBEDTLS_ERR_X509_BAD_INPUT_DATA;
+    }
+
+    MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_oid( &p, buf, oid, oid_len ) );
+    MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, buf, ret ) );
+    MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, buf,
+                        MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
+
+    ret = mbedtls_x509write_csr_set_extension( ctx, MBEDTLS_OID_EXTENDED_KEY_USAGE,
+              MBEDTLS_OID_SIZE( MBEDTLS_OID_EXTENDED_KEY_USAGE ), 0, p, len );
+
+    return ret;
+}
+#endif  /* MBEDTLS_X509_CSR_WRITE_C */
 /* END_HEADER */
 
 /* BEGIN_DEPENDENCIES
@@ -84,7 +135,7 @@
 /* BEGIN_CASE depends_on:MBEDTLS_PEM_WRITE_C:MBEDTLS_X509_CSR_WRITE_C */
 void x509_csr_check( char * key_file, char * cert_req_check_file, int md_type,
                      int key_usage, int set_key_usage, int cert_type,
-                     int set_cert_type )
+                     int set_cert_type, int set_extension )
 {
     mbedtls_pk_context key;
     mbedtls_x509write_csr req;
@@ -117,6 +168,9 @@
         TEST_ASSERT( mbedtls_x509write_csr_set_key_usage( &req, key_usage ) == 0 );
     if( set_cert_type != 0 )
         TEST_ASSERT( mbedtls_x509write_csr_set_ns_cert_type( &req, cert_type ) == 0 );
+    if ( set_extension != 0 )
+        TEST_ASSERT( csr_set_extended_key_usage( &req, MBEDTLS_OID_SERVER_AUTH,
+                            MBEDTLS_OID_SIZE( MBEDTLS_OID_SERVER_AUTH ) ) == 0 );
 
     ret = mbedtls_x509write_csr_pem( &req, buf, sizeof( buf ),
                                      mbedtls_test_rnd_pseudo_rand, &rnd_info );