Merge pull request #8468 from daverodgman/mbedtls-3.5.1-pr

Mbed TLS 3.5.1
diff --git a/library/common.h b/library/common.h
index f392b7f..c20f6b2 100644
--- a/library/common.h
+++ b/library/common.h
@@ -294,18 +294,36 @@
 #define MBEDTLS_STATIC_ASSERT(expr, msg)
 #endif
 
-/* Define compiler branch hints */
 #if defined(__has_builtin)
-#if __has_builtin(__builtin_expect)
+#define MBEDTLS_HAS_BUILTIN(x) __has_builtin(x)
+#else
+#define MBEDTLS_HAS_BUILTIN(x) 0
+#endif
+
+/* Define compiler branch hints */
+#if MBEDTLS_HAS_BUILTIN(__builtin_expect)
 #define MBEDTLS_LIKELY(x)       __builtin_expect(!!(x), 1)
 #define MBEDTLS_UNLIKELY(x)     __builtin_expect(!!(x), 0)
-#endif
-#endif
-#if !defined(MBEDTLS_LIKELY)
+#else
 #define MBEDTLS_LIKELY(x)       x
 #define MBEDTLS_UNLIKELY(x)     x
 #endif
 
+/* MBEDTLS_ASSUME may be used to provide additional information to the compiler
+ * which can result in smaller code-size. */
+#if MBEDTLS_HAS_BUILTIN(__builtin_assume)
+/* clang provides __builtin_assume */
+#define MBEDTLS_ASSUME(x)       __builtin_assume(x)
+#elif MBEDTLS_HAS_BUILTIN(__builtin_unreachable)
+/* gcc and IAR can use __builtin_unreachable */
+#define MBEDTLS_ASSUME(x)       do { if (!(x)) __builtin_unreachable(); } while (0)
+#elif defined(_MSC_VER)
+/* Supported by MSVC since VS 2005 */
+#define MBEDTLS_ASSUME(x)       __assume(x)
+#else
+#define MBEDTLS_ASSUME(x)       do { } while (0)
+#endif
+
 #if defined(__GNUC__) && !defined(__ARMCC_VERSION) && !defined(__clang__) \
     && !defined(__llvm__) && !defined(__INTEL_COMPILER)
 /* Defined if the compiler really is gcc and not clang, etc */
diff --git a/library/psa_crypto_cipher.c b/library/psa_crypto_cipher.c
index f0bb3aa..3132854 100644
--- a/library/psa_crypto_cipher.c
+++ b/library/psa_crypto_cipher.c
@@ -30,45 +30,97 @@
     psa_algorithm_t alg,
     psa_key_type_t key_type)
 {
-    switch (alg) {
-        case PSA_ALG_STREAM_CIPHER:
-        case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CHACHA20_POLY1305, 0):
-            if (key_type != PSA_KEY_TYPE_CHACHA20) {
-                return PSA_ERROR_NOT_SUPPORTED;
-            }
-            break;
+    /* Reduce code size - hinting to the compiler about what it can assume allows the compiler to
+       eliminate bits of the logic below. */
+#if !defined(PSA_WANT_KEY_TYPE_AES)
+    MBEDTLS_ASSUME(key_type != PSA_KEY_TYPE_AES);
+#endif
+#if !defined(PSA_WANT_KEY_TYPE_ARIA)
+    MBEDTLS_ASSUME(key_type != PSA_KEY_TYPE_ARIA);
+#endif
+#if !defined(PSA_WANT_KEY_TYPE_CAMELLIA)
+    MBEDTLS_ASSUME(key_type != PSA_KEY_TYPE_CAMELLIA);
+#endif
+#if !defined(PSA_WANT_KEY_TYPE_CHACHA20)
+    MBEDTLS_ASSUME(key_type != PSA_KEY_TYPE_CHACHA20);
+#endif
+#if !defined(PSA_WANT_KEY_TYPE_DES)
+    MBEDTLS_ASSUME(key_type != PSA_KEY_TYPE_DES);
+#endif
+#if !defined(PSA_WANT_ALG_CCM)
+    MBEDTLS_ASSUME(alg != PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CCM, 0));
+#endif
+#if !defined(PSA_WANT_ALG_GCM)
+    MBEDTLS_ASSUME(alg != PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 0));
+#endif
+#if !defined(PSA_WANT_ALG_STREAM_CIPHER)
+    MBEDTLS_ASSUME(alg != PSA_ALG_STREAM_CIPHER);
+#endif
+#if !defined(PSA_WANT_ALG_CHACHA20_POLY1305)
+    MBEDTLS_ASSUME(alg != PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CHACHA20_POLY1305, 0));
+#endif
+#if !defined(PSA_WANT_ALG_CCM_STAR_NO_TAG)
+    MBEDTLS_ASSUME(alg != PSA_ALG_CCM_STAR_NO_TAG);
+#endif
+#if !defined(PSA_WANT_ALG_CTR)
+    MBEDTLS_ASSUME(alg != PSA_ALG_CTR);
+#endif
+#if !defined(PSA_WANT_ALG_CFB)
+    MBEDTLS_ASSUME(alg != PSA_ALG_CFB);
+#endif
+#if !defined(PSA_WANT_ALG_OFB)
+    MBEDTLS_ASSUME(alg != PSA_ALG_OFB);
+#endif
+#if !defined(PSA_WANT_ALG_XTS)
+    MBEDTLS_ASSUME(alg != PSA_ALG_XTS);
+#endif
+#if !defined(PSA_WANT_ALG_ECB_NO_PADDING)
+    MBEDTLS_ASSUME(alg != PSA_ALG_ECB_NO_PADDING);
+#endif
+#if !defined(PSA_WANT_ALG_CBC_NO_PADDING)
+    MBEDTLS_ASSUME(alg != PSA_ALG_CBC_NO_PADDING);
+#endif
+#if !defined(PSA_WANT_ALG_CBC_PKCS7)
+    MBEDTLS_ASSUME(alg != PSA_ALG_CBC_PKCS7);
+#endif
+#if !defined(PSA_WANT_ALG_CMAC)
+    MBEDTLS_ASSUME(alg != PSA_ALG_CMAC);
+#endif
 
-        case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CCM, 0):
-        case PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 0):
-        case PSA_ALG_CCM_STAR_NO_TAG:
-            if ((key_type != PSA_KEY_TYPE_AES) &&
-                (key_type != PSA_KEY_TYPE_ARIA) &&
-                (key_type != PSA_KEY_TYPE_CAMELLIA)) {
-                return PSA_ERROR_NOT_SUPPORTED;
-            }
-            break;
-
-        case PSA_ALG_CTR:
-        case PSA_ALG_CFB:
-        case PSA_ALG_OFB:
-        case PSA_ALG_XTS:
-        case PSA_ALG_ECB_NO_PADDING:
-        case PSA_ALG_CBC_NO_PADDING:
-        case PSA_ALG_CBC_PKCS7:
-        case PSA_ALG_CMAC:
-            if ((key_type != PSA_KEY_TYPE_AES) &&
-                (key_type != PSA_KEY_TYPE_ARIA) &&
-                (key_type != PSA_KEY_TYPE_DES) &&
-                (key_type != PSA_KEY_TYPE_CAMELLIA)) {
-                return PSA_ERROR_NOT_SUPPORTED;
-            }
-            break;
-
-        default:
-            return PSA_ERROR_NOT_SUPPORTED;
+    if (alg == PSA_ALG_STREAM_CIPHER ||
+        alg == PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CHACHA20_POLY1305, 0)) {
+        if (key_type == PSA_KEY_TYPE_CHACHA20) {
+            return PSA_SUCCESS;
+        }
     }
 
-    return PSA_SUCCESS;
+    if (alg == PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CCM, 0) ||
+        alg == PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 0) ||
+        alg == PSA_ALG_CCM_STAR_NO_TAG) {
+        if (key_type == PSA_KEY_TYPE_AES ||
+            key_type == PSA_KEY_TYPE_ARIA ||
+            key_type == PSA_KEY_TYPE_CAMELLIA) {
+            return PSA_SUCCESS;
+        }
+    }
+
+    if (alg == PSA_ALG_CTR ||
+        alg == PSA_ALG_CFB ||
+        alg == PSA_ALG_OFB ||
+        alg == PSA_ALG_XTS ||
+        alg == PSA_ALG_ECB_NO_PADDING ||
+        alg == PSA_ALG_CBC_NO_PADDING ||
+        alg == PSA_ALG_CBC_PKCS7 ||
+        alg == PSA_ALG_CMAC) {
+        if (key_type == PSA_KEY_TYPE_AES ||
+            key_type == PSA_KEY_TYPE_ARIA ||
+            key_type == PSA_KEY_TYPE_DES ||
+            key_type == PSA_KEY_TYPE_CAMELLIA) {
+            return PSA_SUCCESS;
+        }
+    }
+
+    return PSA_ERROR_NOT_SUPPORTED;
 }
 
 psa_status_t mbedtls_cipher_values_from_psa(
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 57f5f89..be0b77b 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -2800,6 +2800,26 @@
            (flags & MBEDTLS_SSL_TLS1_3_TICKET_FLAGS_MASK);
 }
 
+static inline unsigned int mbedtls_ssl_session_check_ticket_flags(
+    mbedtls_ssl_session *session, unsigned int flags)
+{
+    return mbedtls_ssl_session_get_ticket_flags(session, flags) == 0;
+}
+
+static inline unsigned int mbedtls_ssl_session_ticket_allow_psk(
+    mbedtls_ssl_session *session)
+{
+    return !mbedtls_ssl_session_check_ticket_flags(session,
+                                                   MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_PSK_RESUMPTION);
+}
+
+static inline unsigned int mbedtls_ssl_session_ticket_allow_psk_ephemeral(
+    mbedtls_ssl_session *session)
+{
+    return !mbedtls_ssl_session_check_ticket_flags(session,
+                                                   MBEDTLS_SSL_TLS1_3_TICKET_ALLOW_PSK_EPHEMERAL_RESUMPTION);
+}
+
 static inline void mbedtls_ssl_session_set_ticket_flags(
     mbedtls_ssl_session *session, unsigned int flags)
 {
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index 97ae51c..eac6326 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1892,36 +1892,6 @@
             ret = MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE;
             goto cleanup;
     }
-#if defined(MBEDTLS_SSL_EARLY_DATA)
-    if (handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(EARLY_DATA) &&
-        (handshake->selected_identity != 0 ||
-         handshake->ciphersuite_info->id !=
-         ssl->session_negotiate->ciphersuite)) {
-        /* RFC8446 4.2.11
-         * If the server supplies an "early_data" extension, the
-         * client MUST verify that the server's selected_identity
-         * is 0. If any other value is returned, the client MUST
-         * abort the handshake with an "illegal_parameter" alert.
-         *
-         * RFC 8446 4.2.10
-         * In order to accept early data, the server MUST have accepted a PSK
-         * cipher suite and selected the first key offered in the client's
-         * "pre_shared_key" extension. In addition, it MUST verify that the
-         * following values are the same as those associated with the
-         * selected PSK:
-         * - The TLS version number
-         * - The selected cipher suite
-         * - The selected ALPN [RFC7301] protocol, if any
-         *
-         * We check here that when early data is involved the server
-         * selected the cipher suite associated to the pre-shared key
-         * as it must have.
-         */
-        MBEDTLS_SSL_PEND_FATAL_ALERT(MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
-                                     MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER);
-        return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER;
-    }
-#endif
 
     if (!mbedtls_ssl_conf_tls13_check_kex_modes(
             ssl, handshake->key_exchange_mode)) {
@@ -2197,6 +2167,9 @@
     int ret;
     unsigned char *buf;
     size_t buf_len;
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
+#endif
 
     MBEDTLS_SSL_DEBUG_MSG(2, ("=> parse encrypted extensions"));
 
@@ -2209,8 +2182,37 @@
         ssl_tls13_parse_encrypted_extensions(ssl, buf, buf + buf_len));
 
 #if defined(MBEDTLS_SSL_EARLY_DATA)
-    if (ssl->handshake->received_extensions &
-        MBEDTLS_SSL_EXT_MASK(EARLY_DATA)) {
+    if (handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(EARLY_DATA)) {
+        /* RFC8446 4.2.11
+         * If the server supplies an "early_data" extension, the
+         * client MUST verify that the server's selected_identity
+         * is 0. If any other value is returned, the client MUST
+         * abort the handshake with an "illegal_parameter" alert.
+         *
+         * RFC 8446 4.2.10
+         * In order to accept early data, the server MUST have accepted a PSK
+         * cipher suite and selected the first key offered in the client's
+         * "pre_shared_key" extension. In addition, it MUST verify that the
+         * following values are the same as those associated with the
+         * selected PSK:
+         * - The TLS version number
+         * - The selected cipher suite
+         * - The selected ALPN [RFC7301] protocol, if any
+         *
+         * We check here that when early data is involved the server
+         * selected the cipher suite associated to the pre-shared key
+         * as it must have.
+         */
+        if (handshake->selected_identity != 0 ||
+            handshake->ciphersuite_info->id !=
+            ssl->session_negotiate->ciphersuite) {
+
+            MBEDTLS_SSL_PEND_FATAL_ALERT(
+                MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
+                MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER);
+            return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER;
+        }
+
         ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_ACCEPTED;
     }
 #endif
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 815c0a9..061dcf7 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -94,6 +94,10 @@
 #define SSL_TLS1_3_OFFERED_PSK_MATCH       0
 
 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_check_psk_key_exchange(mbedtls_ssl_context *ssl);
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_check_psk_ephemeral_key_exchange(mbedtls_ssl_context *ssl);
 
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_offered_psks_check_identity_match_ticket(
@@ -105,6 +109,7 @@
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char *ticket_buffer;
+    unsigned int key_exchanges;
 #if defined(MBEDTLS_HAVE_TIME)
     mbedtls_time_t now;
     uint64_t age_in_s;
@@ -147,6 +152,12 @@
     /* We delete the temporary buffer */
     mbedtls_free(ticket_buffer);
 
+    if (ret == 0 && session->tls_version != MBEDTLS_SSL_VERSION_TLS1_3) {
+        MBEDTLS_SSL_DEBUG_MSG(3, ("Ticket TLS version is not 1.3."));
+        /* TODO: Define new return value for this case. */
+        ret = MBEDTLS_ERR_SSL_BAD_PROTOCOL_VERSION;
+    }
+
     if (ret != 0) {
         goto exit;
     }
@@ -160,13 +171,19 @@
      * We regard the ticket with incompatible key exchange modes as not match.
      */
     ret = MBEDTLS_ERR_ERROR_GENERIC_ERROR;
-    MBEDTLS_SSL_PRINT_TICKET_FLAGS(4,
-                                   session->ticket_flags);
-    if (mbedtls_ssl_tls13_check_kex_modes(
-            ssl,
-            mbedtls_ssl_session_get_ticket_flags(
-                session,
-                MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ALL))) {
+    MBEDTLS_SSL_PRINT_TICKET_FLAGS(4, session->ticket_flags);
+
+    key_exchanges = 0;
+    if (mbedtls_ssl_session_ticket_allow_psk_ephemeral(session) &&
+        ssl_tls13_check_psk_ephemeral_key_exchange(ssl)) {
+        key_exchanges |= MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL;
+    }
+    if (mbedtls_ssl_session_ticket_allow_psk(session) &&
+        ssl_tls13_check_psk_key_exchange(ssl)) {
+        key_exchanges |= MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK;
+    }
+
+    if (key_exchanges == 0) {
         MBEDTLS_SSL_DEBUG_MSG(3, ("No suitable key exchange mode"));
         goto exit;
     }
@@ -979,6 +996,26 @@
 }
 #endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED */
 
+#if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED)
+MBEDTLS_CHECK_RETURN_CRITICAL
+static int ssl_tls13_ticket_permission_check(mbedtls_ssl_context *ssl,
+                                             unsigned int kex_mode)
+{
+#if defined(MBEDTLS_SSL_SESSION_TICKETS)
+    if (ssl->handshake->resume) {
+        if (mbedtls_ssl_session_check_ticket_flags(
+                ssl->session_negotiate, kex_mode)) {
+            return 0;
+        }
+    }
+#else
+    ((void) ssl);
+    ((void) kex_mode);
+#endif
+    return 1;
+}
+#endif /* MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_SOME_PSK_ENABLED */
+
 MBEDTLS_CHECK_RETURN_CRITICAL
 static int ssl_tls13_check_ephemeral_key_exchange(mbedtls_ssl_context *ssl)
 {
@@ -995,7 +1032,9 @@
 static int ssl_tls13_check_psk_key_exchange(mbedtls_ssl_context *ssl)
 {
 #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED)
-    return mbedtls_ssl_conf_tls13_psk_enabled(ssl) &&
+    return ssl_tls13_ticket_permission_check(
+        ssl, MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK) &&
+           mbedtls_ssl_conf_tls13_psk_enabled(ssl) &&
            mbedtls_ssl_tls13_psk_enabled(ssl) &&
            ssl_tls13_client_hello_has_exts_for_psk_key_exchange(ssl);
 #else
@@ -1008,7 +1047,9 @@
 static int ssl_tls13_check_psk_ephemeral_key_exchange(mbedtls_ssl_context *ssl)
 {
 #if defined(MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL_ENABLED)
-    return mbedtls_ssl_conf_tls13_psk_ephemeral_enabled(ssl) &&
+    return ssl_tls13_ticket_permission_check(
+        ssl, MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_EPHEMERAL) &&
+           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);
 #else
@@ -1691,9 +1732,8 @@
      * - The content up to but excluding the PSK extension, if present.
      */
     /* 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) &&
-        (handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(PRE_SHARED_KEY))) {
+    if (ssl_tls13_check_psk_key_exchange(ssl) ||
+        ssl_tls13_check_psk_ephemeral_key_exchange(ssl)) {
         ret = handshake->update_checksum(ssl, buf,
                                          pre_shared_key_ext - buf);
         if (0 != ret) {
@@ -1750,9 +1790,59 @@
         return;
     }
 
-    /* We do not accept early data for the time being */
     ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_REJECTED;
 
+    if (ssl->conf->early_data_enabled == MBEDTLS_SSL_EARLY_DATA_DISABLED) {
+        MBEDTLS_SSL_DEBUG_MSG(
+            1,
+            ("EarlyData: rejected, feature disabled in server configuration."));
+        return;
+    }
+
+    if (!handshake->resume) {
+        /* We currently support early data only in the case of PSKs established
+           via a NewSessionTicket message thus in the case of a session
+           resumption. */
+        MBEDTLS_SSL_DEBUG_MSG(
+            1, ("EarlyData: rejected, not a session resumption."));
+        return;
+    }
+
+    /* RFC 8446 4.2.10
+     *
+     * In order to accept early data, the server MUST have accepted a PSK cipher
+     * suite and selected the first key offered in the client's "pre_shared_key"
+     * extension. In addition, it MUST verify that the following values are the
+     * same as those associated with the selected PSK:
+     * - The TLS version number
+     * - The selected cipher suite
+     * - The selected ALPN [RFC7301] protocol, if any
+     *
+     * NOTE:
+     *  - The TLS version number is checked in
+     *    ssl_tls13_offered_psks_check_identity_match_ticket().
+     *  - ALPN is not checked for the time being (TODO).
+     */
+
+    if (handshake->selected_identity != 0) {
+        MBEDTLS_SSL_DEBUG_MSG(
+            1, ("EarlyData: rejected, the selected key in "
+                "`pre_shared_key` is not the first one."));
+        return;
+    }
+
+    if (handshake->ciphersuite_info->id !=
+        ssl->session_negotiate->ciphersuite) {
+        MBEDTLS_SSL_DEBUG_MSG(
+            1, ("EarlyData: rejected, the selected ciphersuite is not the one "
+                "of the selected pre-shared key."));
+        return;
+
+    }
+
+
+    ssl->early_data_status = MBEDTLS_SSL_EARLY_DATA_STATUS_ACCEPTED;
+
 }
 #endif /* MBEDTLS_SSL_EARLY_DATA */
 
@@ -2412,6 +2502,16 @@
     p += output_len;
 #endif /* MBEDTLS_SSL_ALPN */
 
+#if defined(MBEDTLS_SSL_EARLY_DATA)
+    if (ssl->early_data_status == MBEDTLS_SSL_EARLY_DATA_STATUS_ACCEPTED) {
+        ret = mbedtls_ssl_tls13_write_early_data_ext(ssl, p, end, &output_len);
+        if (ret != 0) {
+            return ret;
+        }
+        p += output_len;
+    }
+#endif /* MBEDTLS_SSL_EARLY_DATA */
+
     extensions_len = (p - p_extensions_len) - 2;
     MBEDTLS_PUT_UINT16_BE(extensions_len, p_extensions_len, 0);
 
diff --git a/tests/opt-testcases/tls13-kex-modes.sh b/tests/opt-testcases/tls13-kex-modes.sh
index 6556cd4..4581bc5 100755
--- a/tests/opt-testcases/tls13-kex-modes.sh
+++ b/tests/opt-testcases/tls13-kex-modes.sh
@@ -550,7 +550,7 @@
             -s "found pre_shared_key extension" \
             -S "Found PSK_EPHEMERAL KEX MODE" \
             -s "Found PSK KEX MODE" \
-            -s "Pre shared key found" \
+            -S "Pre shared key found" \
             -S "No matched PSK or ticket" \
             -S "key exchange mode: psk$"  \
             -S "key exchange mode: psk_ephemeral"  \
@@ -733,7 +733,7 @@
             -s "found pre_shared_key extension" \
             -s "Found PSK_EPHEMERAL KEX MODE" \
             -S "Found PSK KEX MODE" \
-            -s "Pre shared key found" \
+            -S "Pre shared key found" \
             -S "No matched PSK or ticket" \
             -S "key exchange mode: psk$"  \
             -S "key exchange mode: psk_ephemeral"  \
@@ -1413,7 +1413,7 @@
             -s "found pre_shared_key extension" \
             -s "Found PSK_EPHEMERAL KEX MODE" \
             -S "Found PSK KEX MODE" \
-            -s "Pre shared key found" \
+            -S "Pre shared key found" \
             -S "No matched PSK or ticket" \
             -S "key exchange mode: psk$"  \
             -S "key exchange mode: psk_ephemeral"  \
diff --git a/tests/opt-testcases/tls13-misc.sh b/tests/opt-testcases/tls13-misc.sh
index 3182b48..3816a2b 100755
--- a/tests/opt-testcases/tls13-misc.sh
+++ b/tests/opt-testcases/tls13-misc.sh
@@ -411,7 +411,8 @@
          0 \
          -c "Pre-configured PSK number = 1" \
          -S "No suitable key exchange mode" \
-         -s "found matched identity"
+         -s "found matched identity" \
+         -s "key exchange mode: psk_ephemeral"
 
 requires_all_configs_enabled MBEDTLS_SSL_SESSION_TICKETS \
                              MBEDTLS_SSL_SRV_C MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C \
@@ -423,7 +424,8 @@
          0 \
          -c "Pre-configured PSK number = 1" \
          -S "No suitable key exchange mode" \
-         -s "found matched identity"
+         -s "found matched identity" \
+         -s "key exchange mode: psk_ephemeral"
 
 requires_all_configs_enabled MBEDTLS_SSL_SESSION_TICKETS \
                              MBEDTLS_SSL_SRV_C MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C \
@@ -466,7 +468,8 @@
          0 \
          -c "Pre-configured PSK number = 1" \
          -S "No suitable key exchange mode" \
-         -s "found matched identity"
+         -s "found matched identity" \
+         -s "key exchange mode: psk_ephemeral"
 
 requires_all_configs_enabled MBEDTLS_SSL_SESSION_TICKETS \
                              MBEDTLS_SSL_SRV_C MBEDTLS_SSL_CLI_C MBEDTLS_DEBUG_C \
@@ -479,7 +482,11 @@
          0 \
          -c "Pre-configured PSK number = 1" \
          -S "No suitable key exchange mode" \
-         -s "found matched identity"
+         -s "found matched identity" \
+         -s "key exchange mode: psk_ephemeral"
+
+EARLY_DATA_INPUT_LEN_BLOCKS=$(( ( $( cat $EARLY_DATA_INPUT | wc -c ) + 31 ) / 32 ))
+EARLY_DATA_INPUT_LEN=$(( $EARLY_DATA_INPUT_LEN_BLOCKS * 32 ))
 
 requires_gnutls_next
 requires_all_configs_enabled MBEDTLS_SSL_EARLY_DATA MBEDTLS_SSL_SESSION_TICKETS     \
@@ -496,3 +503,20 @@
          -s "EncryptedExtensions: early_data(42) extension does not exist."    \
          -s "NewSessionTicket: early_data(42) extension does not exist."        \
          -s "Last error was: -29056 - SSL - Verification of the message MAC failed"
+
+requires_gnutls_next
+requires_all_configs_enabled MBEDTLS_SSL_EARLY_DATA MBEDTLS_SSL_SESSION_TICKETS \
+                             MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C MBEDTLS_HAVE_TIME \
+                             MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED \
+                             MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE
+requires_any_configs_enabled 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: EarlyData: feature is enabled, fail." \
+         "$P_SRV force_version=tls13 debug_level=4 max_early_data_size=$EARLY_DATA_INPUT_LEN" \
+         "$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3:+GROUP-ALL:+KX-ALL \
+                      -d 10 -r --earlydata $EARLY_DATA_INPUT " \
+         1 \
+         -s "ClientHello: early_data(42) extension exists."                 \
+         -s "EncryptedExtensions: early_data(42) extension exists."         \
+         -s "NewSessionTicket: early_data(42) extension does not exist."    \
+         -s "Last error was: -29056 - SSL - Verification of the message MAC failed"
diff --git a/tests/scripts/check_files.py b/tests/scripts/check_files.py
index 68871ef..a2a9dfa 100755
--- a/tests/scripts/check_files.py
+++ b/tests/scripts/check_files.py
@@ -10,10 +10,11 @@
 Note: requires python 3, must be run from Mbed TLS root.
 """
 
-import os
 import argparse
-import logging
 import codecs
+import inspect
+import logging
+import os
 import re
 import subprocess
 import sys
@@ -345,6 +346,100 @@
         return False
 
 
+def this_location():
+    frame = inspect.currentframe()
+    assert frame is not None
+    info = inspect.getframeinfo(frame)
+    return os.path.basename(info.filename), info.lineno
+THIS_FILE_BASE_NAME, LINE_NUMBER_BEFORE_LICENSE_ISSUE_TRACKER = this_location()
+
+class LicenseIssueTracker(LineIssueTracker):
+    """Check copyright statements and license indications.
+
+    This class only checks that statements are correct if present. It does
+    not enforce the presence of statements in each file.
+    """
+
+    heading = "License issue:"
+
+    LICENSE_EXEMPTION_RE_LIST = [
+        # Third-party code, other than whitelisted third-party modules,
+        # may be under a different license.
+        r'3rdparty/(?!(p256-m)/.*)',
+        # Documentation explaining the license may have accidental
+        # false positives.
+        r'(ChangeLog|LICENSE|[-0-9A-Z_a-z]+\.md)\Z',
+        # Files imported from TF-M, and not used except in test builds,
+        # may be under a different license.
+        r'configs/crypto_config_profile_medium\.h\Z',
+        r'configs/tfm_mbedcrypto_config_profile_medium\.h\Z',
+        # Third-party file.
+        r'dco\.txt\Z',
+    ]
+    path_exemptions = re.compile('|'.join(BINARY_FILE_PATH_RE_LIST +
+                                          LICENSE_EXEMPTION_RE_LIST))
+
+    COPYRIGHT_HOLDER = rb'The Mbed TLS Contributors'
+    # Catch "Copyright foo", "Copyright (C) foo", "Copyright © foo", etc.
+    COPYRIGHT_RE = re.compile(rb'.*\bcopyright\s+((?:\w|\s|[()]|[^ -~])*\w)', re.I)
+
+    SPDX_HEADER_KEY = b'SPDX-License-Identifier'
+    LICENSE_IDENTIFIER = b'Apache-2.0 OR GPL-2.0-or-later'
+    SPDX_RE = re.compile(br'.*?(' +
+                         re.escape(SPDX_HEADER_KEY) +
+                         br')(:\s*(.*?)\W*\Z|.*)', re.I)
+
+    LICENSE_MENTION_RE = re.compile(rb'.*(?:' + rb'|'.join([
+        rb'Apache License',
+        rb'General Public License',
+    ]) + rb')', re.I)
+
+    def __init__(self):
+        super().__init__()
+        # Record what problem was caused. We can't easily report it due to
+        # the structure of the script. To be fixed after
+        # https://github.com/Mbed-TLS/mbedtls/pull/2506
+        self.problem = None
+
+    def issue_with_line(self, line, filepath, line_number):
+        #pylint: disable=too-many-return-statements
+
+        # Use endswith() rather than the more correct os.path.basename()
+        # because experimentally, it makes a significant difference to
+        # the running time.
+        if filepath.endswith(THIS_FILE_BASE_NAME) and \
+           line_number > LINE_NUMBER_BEFORE_LICENSE_ISSUE_TRACKER:
+            # Avoid false positives from the code in this class.
+            # Also skip the rest of this file, which is highly unlikely to
+            # contain any problematic statements since we put those near the
+            # top of files.
+            return False
+
+        m = self.COPYRIGHT_RE.match(line)
+        if m and m.group(1) != self.COPYRIGHT_HOLDER:
+            self.problem = 'Invalid copyright line'
+            return True
+
+        m = self.SPDX_RE.match(line)
+        if m:
+            if m.group(1) != self.SPDX_HEADER_KEY:
+                self.problem = 'Misspelled ' + self.SPDX_HEADER_KEY.decode()
+                return True
+            if not m.group(3):
+                self.problem = 'Improperly formatted SPDX license identifier'
+                return True
+            if m.group(3) != self.LICENSE_IDENTIFIER:
+                self.problem = 'Wrong SPDX license identifier'
+                return True
+
+        m = self.LICENSE_MENTION_RE.match(line)
+        if m:
+            self.problem = 'Suspicious license mention'
+            return True
+
+        return False
+
+
 class IntegrityChecker:
     """Sanity-check files under the current directory."""
 
@@ -365,6 +460,7 @@
             TrailingWhitespaceIssueTracker(),
             TabIssueTracker(),
             MergeArtifactIssueTracker(),
+            LicenseIssueTracker(),
         ]
 
     def setup_logger(self, log_file, level=logging.INFO):
diff --git a/tests/suites/test_suite_constant_time_hmac.function b/tests/suites/test_suite_constant_time_hmac.function
index 435e4b9..9d9aa3c 100644
--- a/tests/suites/test_suite_constant_time_hmac.function
+++ b/tests/suites/test_suite_constant_time_hmac.function
@@ -4,6 +4,7 @@
 #include <mbedtls/md.h>
 #include <constant_time_internal.h>
 #include "md_psa.h"
+#include <ssl_misc.h>
 
 #include <test/constant_flow.h>
 /* END_HEADER */