Merge pull request #8680 from mpg/ciphers-wrapup

Driver-only ciphers wrapup
diff --git a/include/mbedtls/config_adjust_legacy_crypto.h b/include/mbedtls/config_adjust_legacy_crypto.h
index c6b7f8e..696266c 100644
--- a/include/mbedtls/config_adjust_legacy_crypto.h
+++ b/include/mbedtls/config_adjust_legacy_crypto.h
@@ -22,6 +22,20 @@
 #ifndef MBEDTLS_CONFIG_ADJUST_LEGACY_CRYPTO_H
 #define MBEDTLS_CONFIG_ADJUST_LEGACY_CRYPTO_H
 
+/* Auto-enable CIPHER_C when any of the unauthenticated ciphers is builtin
+ * in PSA. */
+#if defined(MBEDTLS_PSA_CRYPTO_C) && \
+    (defined(MBEDTLS_PSA_BUILTIN_ALG_STREAM_CIPHER) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_CTR) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_CFB) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_OFB) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_ECB_NO_PADDING) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_CBC_NO_PADDING) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_CBC_PKCS7) || \
+    defined(MBEDTLS_PSA_BUILTIN_ALG_CCM_STAR_NO_TAG))
+#define MBEDTLS_CIPHER_C
+#endif
+
 /* Auto-enable MBEDTLS_MD_LIGHT based on MBEDTLS_MD_C.
  * This allows checking for MD_LIGHT rather than MD_LIGHT || MD_C.
  */
diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index 94e21e2..6a5828c 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -2579,6 +2579,8 @@
  *          library/ssl_ciphersuites.c
  *          library/ssl_msg.c
  *          library/ssl_ticket.c (unless MBEDTLS_USE_PSA_CRYPTO is enabled)
+ * Auto-enabled by: MBEDTLS_PSA_CRYPTO_C depending on which ciphers are enabled
+ *                  (see the documentation of that option for details).
  *
  * Uncomment to enable generic cipher wrappers.
  */
@@ -3168,7 +3170,9 @@
  * Requires: either MBEDTLS_CTR_DRBG_C and MBEDTLS_ENTROPY_C,
  *           or MBEDTLS_HMAC_DRBG_C and MBEDTLS_ENTROPY_C,
  *           or MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG.
- *
+ * Auto-enables: MBEDTLS_CIPHER_C if any unauthenticated (ie, non-AEAD) cipher
+ *               is enabled in PSA (unless it's fully accelerated, see
+ *               docs/driver-only-builds.md about that).
  */
 #define MBEDTLS_PSA_CRYPTO_C
 
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 043988f..3192e2a 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -1188,6 +1188,11 @@
     unsigned char MBEDTLS_PRIVATE(mfl_code);     /*!< MaxFragmentLength negotiated by peer */
 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
 
+/*!< RecordSizeLimit received from the peer */
+#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
+    uint16_t MBEDTLS_PRIVATE(record_size_limit);
+#endif /* MBEDTLS_SSL_RECORD_SIZE_LIMIT */
+
     unsigned char MBEDTLS_PRIVATE(exported);
 
     /** TLS version negotiated in the session. Used if and when renegotiating
diff --git a/include/psa/crypto_values.h b/include/psa/crypto_values.h
index 5e33f6b..8d30bf0 100644
--- a/include/psa/crypto_values.h
+++ b/include/psa/crypto_values.h
@@ -594,19 +594,23 @@
  * They are defined in _Standards for Efficient Cryptography_,
  * _SEC 2: Recommended Elliptic Curve Domain Parameters_.
  * https://www.secg.org/sec2-v2.pdf
+ *
+ * \note For secp224k1, the bit-size is 225 (size of a private value).
+ *
+ * \note Mbed TLS only supports secp192k1 and secp256k1.
  */
 #define PSA_ECC_FAMILY_SECP_K1           ((psa_ecc_family_t) 0x17)
 
 /** SEC random curves over prime fields.
  *
  * This family comprises the following curves:
- * secp192k1, secp224r1, secp256r1, secp384r1, secp521r1.
+ * secp192r1, secp224r1, secp256r1, secp384r1, secp521r1.
  * They are defined in _Standards for Efficient Cryptography_,
  * _SEC 2: Recommended Elliptic Curve Domain Parameters_.
  * https://www.secg.org/sec2-v2.pdf
  */
 #define PSA_ECC_FAMILY_SECP_R1           ((psa_ecc_family_t) 0x12)
-/* SECP160R2 (SEC2 v1, obsolete) */
+/* SECP160R2 (SEC2 v1, obsolete, not supported in Mbed TLS) */
 #define PSA_ECC_FAMILY_SECP_R2           ((psa_ecc_family_t) 0x1b)
 
 /** SEC Koblitz curves over binary fields.
@@ -616,6 +620,8 @@
  * They are defined in _Standards for Efficient Cryptography_,
  * _SEC 2: Recommended Elliptic Curve Domain Parameters_.
  * https://www.secg.org/sec2-v2.pdf
+ *
+ * \note Mbed TLS does not support any curve in this family.
  */
 #define PSA_ECC_FAMILY_SECT_K1           ((psa_ecc_family_t) 0x27)
 
@@ -626,6 +632,8 @@
  * They are defined in _Standards for Efficient Cryptography_,
  * _SEC 2: Recommended Elliptic Curve Domain Parameters_.
  * https://www.secg.org/sec2-v2.pdf
+ *
+ * \note Mbed TLS does not support any curve in this family.
  */
 #define PSA_ECC_FAMILY_SECT_R1           ((psa_ecc_family_t) 0x22)
 
@@ -636,6 +644,8 @@
  * It is defined in _Standards for Efficient Cryptography_,
  * _SEC 2: Recommended Elliptic Curve Domain Parameters_.
  * https://www.secg.org/sec2-v2.pdf
+ *
+ * \note Mbed TLS does not support any curve in this family.
  */
 #define PSA_ECC_FAMILY_SECT_R2           ((psa_ecc_family_t) 0x2b)
 
@@ -645,6 +655,9 @@
  * brainpoolP160r1, brainpoolP192r1, brainpoolP224r1, brainpoolP256r1,
  * brainpoolP320r1, brainpoolP384r1, brainpoolP512r1.
  * It is defined in RFC 5639.
+ *
+ * \note Mbed TLS only supports the 256-bit, 384-bit and 512-bit curves
+ *       in this family.
  */
 #define PSA_ECC_FAMILY_BRAINPOOL_P_R1    ((psa_ecc_family_t) 0x30)
 
@@ -673,6 +686,8 @@
  * - 448-bit: Edwards448, the twisted Edwards curve birationally equivalent
  *   to Curve448.
  *   Hamburg, _Ed448-Goldilocks, a new elliptic curve_, NIST ECC Workshop, 2015.
+ *
+ * \note Mbed TLS does not support Edwards curves yet.
  */
 #define PSA_ECC_FAMILY_TWISTED_EDWARDS   ((psa_ecc_family_t) 0x42)
 
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index b9801a0..a8afd42 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -439,6 +439,19 @@
 size_t mbedtls_ssl_get_input_max_frag_len(const mbedtls_ssl_context *ssl);
 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
 
+#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
+/**
+ * \brief    Get the size limit in bytes for the protected outgoing records
+ *           as defined in RFC 8449
+ *
+ * \param ssl      SSL context
+ *
+ * \return         The size limit in bytes for the protected outgoing
+ *                 records as defined in RFC 8449.
+ */
+size_t mbedtls_ssl_get_output_record_size_limit(const mbedtls_ssl_context *ssl);
+#endif /* MBEDTLS_SSL_RECORD_SIZE_LIMIT */
+
 #if defined(MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH)
 static inline size_t mbedtls_ssl_get_output_buflen(const mbedtls_ssl_context *ctx)
 {
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index e1fb128..f92e40a 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2455,6 +2455,7 @@
  *       uint8 ticket_flags;
  *       opaque resumption_key<0..255>;
  *       uint32 max_early_data_size;
+ *       uint16 record_size_limit;
  *       select ( endpoint ) {
  *            case client: ClientOnlyData;
  *            case server: uint64 ticket_creation_time;
@@ -2490,6 +2491,9 @@
 #if defined(MBEDTLS_SSL_EARLY_DATA)
     needed += 4;                            /* max_early_data_size */
 #endif
+#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
+    needed += 2;                            /* record_size_limit */
+#endif /* MBEDTLS_SSL_RECORD_SIZE_LIMIT */
 
 #if defined(MBEDTLS_HAVE_TIME)
     needed += 8; /* ticket_creation_time or ticket_reception_time */
@@ -2534,6 +2538,10 @@
     MBEDTLS_PUT_UINT32_BE(session->max_early_data_size, p, 0);
     p += 4;
 #endif
+#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
+    MBEDTLS_PUT_UINT16_BE(session->record_size_limit, p, 0);
+    p += 2;
+#endif /* MBEDTLS_SSL_RECORD_SIZE_LIMIT */
 
 #if defined(MBEDTLS_HAVE_TIME) && defined(MBEDTLS_SSL_SRV_C)
     if (session->endpoint == MBEDTLS_SSL_IS_SERVER) {
@@ -2610,6 +2618,13 @@
     session->max_early_data_size = MBEDTLS_GET_UINT32_BE(p, 0);
     p += 4;
 #endif
+#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
+    if (end - p < 2) {
+        return MBEDTLS_ERR_SSL_BAD_INPUT_DATA;
+    }
+    session->record_size_limit = MBEDTLS_GET_UINT16_BE(p, 0);
+    p += 2;
+#endif /* MBEDTLS_SSL_RECORD_SIZE_LIMIT */
 
 #if defined(MBEDTLS_HAVE_TIME) && defined(MBEDTLS_SSL_SRV_C)
     if (session->endpoint == MBEDTLS_SSL_IS_SERVER) {
@@ -3372,6 +3387,31 @@
     }
 }
 
+#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
+
+size_t mbedtls_ssl_get_output_record_size_limit(const mbedtls_ssl_context *ssl)
+{
+    const size_t max_len = MBEDTLS_SSL_OUT_CONTENT_LEN;
+    size_t record_size_limit = max_len;
+
+    if (ssl->session != NULL &&
+        ssl->session->record_size_limit >= MBEDTLS_SSL_RECORD_SIZE_LIMIT_MIN &&
+        ssl->session->record_size_limit < max_len) {
+        record_size_limit = ssl->session->record_size_limit;
+    }
+
+    // TODO: this is currently untested
+    /* During a handshake, use the value being negotiated */
+    if (ssl->session_negotiate != NULL &&
+        ssl->session_negotiate->record_size_limit >= MBEDTLS_SSL_RECORD_SIZE_LIMIT_MIN &&
+        ssl->session_negotiate->record_size_limit < max_len) {
+        record_size_limit = ssl->session_negotiate->record_size_limit;
+    }
+
+    return record_size_limit;
+}
+#endif /* MBEDTLS_SSL_RECORD_SIZE_LIMIT */
+
 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
 size_t mbedtls_ssl_get_input_max_frag_len(const mbedtls_ssl_context *ssl)
 {
@@ -3458,6 +3498,7 @@
     size_t max_len = MBEDTLS_SSL_OUT_CONTENT_LEN;
 
 #if !defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) && \
+    !defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT) && \
     !defined(MBEDTLS_SSL_PROTO_DTLS)
     (void) ssl;
 #endif
@@ -3470,6 +3511,30 @@
     }
 #endif
 
+#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
+    const size_t record_size_limit = mbedtls_ssl_get_output_record_size_limit(ssl);
+
+    if (max_len > record_size_limit) {
+        max_len = record_size_limit;
+    }
+#endif
+
+    if (ssl->transform_out != NULL &&
+        ssl->transform_out->tls_version == MBEDTLS_SSL_VERSION_TLS1_3) {
+        /* RFC 8449, section 4:
+         *
+         * This value [record_size_limit] is the length of the plaintext
+         * of a protected record.
+         * The value includes the content type and padding added in TLS 1.3
+         * (that is, the complete length of TLSInnerPlaintext).
+         *
+         * Thus, round down to a multiple of MBEDTLS_SSL_CID_TLS1_3_PADDING_GRANULARITY
+         * and subtract 1 (for the content type that will be added later)
+         */
+        max_len = ((max_len / MBEDTLS_SSL_CID_TLS1_3_PADDING_GRANULARITY) *
+                   MBEDTLS_SSL_CID_TLS1_3_PADDING_GRANULARITY) - 1;
+    }
+
 #if defined(MBEDTLS_SSL_PROTO_DTLS)
     if (mbedtls_ssl_get_current_mtu(ssl) != 0) {
         const size_t mtu = mbedtls_ssl_get_current_mtu(ssl);
@@ -3492,7 +3557,8 @@
 #endif /* MBEDTLS_SSL_PROTO_DTLS */
 
 #if !defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) &&        \
-    !defined(MBEDTLS_SSL_PROTO_DTLS)
+    !defined(MBEDTLS_SSL_PROTO_DTLS) &&                 \
+    !defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
     ((void) ssl);
 #endif
 
diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index ae11364..342ec52 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -2113,12 +2113,11 @@
 
                 ret = mbedtls_ssl_tls13_parse_record_size_limit_ext(
                     ssl, p, p + extension_data_len);
-
-                /* TODO: Return unconditionally here until we handle the record
-                 * size limit correctly. Once handled correctly, only return in
-                 * case of errors. */
-                return ret;
-
+                if (ret != 0) {
+                    MBEDTLS_SSL_DEBUG_RET(
+                        1, ("mbedtls_ssl_tls13_parse_record_size_limit_ext"), ret);
+                    return ret;
+                }
                 break;
 #endif /* MBEDTLS_SSL_RECORD_SIZE_LIMIT */
 
@@ -2132,6 +2131,17 @@
         p += extension_data_len;
     }
 
+    if ((handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(RECORD_SIZE_LIMIT)) &&
+        (handshake->received_extensions & MBEDTLS_SSL_EXT_MASK(MAX_FRAGMENT_LENGTH))) {
+        MBEDTLS_SSL_DEBUG_MSG(3,
+                              (
+                                  "Record size limit extension cannot be used with max fragment length extension"));
+        MBEDTLS_SSL_PEND_FATAL_ALERT(
+            MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER,
+            MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER);
+        return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER;
+    }
+
     MBEDTLS_SSL_PRINT_EXTS(3, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS,
                            handshake->received_extensions);
 
diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index fe2a2eb..ecfaf8a 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -1731,7 +1731,7 @@
 
     MBEDTLS_SSL_DEBUG_MSG(2, ("RecordSizeLimit: %u Bytes", record_size_limit));
 
-    /* RFC 8449, section 4
+    /* RFC 8449, section 4:
      *
      * Endpoints MUST NOT send a "record_size_limit" extension with a value
      * smaller than 64.  An endpoint MUST treat receipt of a smaller value
@@ -1744,14 +1744,11 @@
         return MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER;
     }
 
-    MBEDTLS_SSL_DEBUG_MSG(
-        2, ("record_size_limit extension is still in development. Aborting handshake."));
+    ssl->session_negotiate->record_size_limit = record_size_limit;
 
-    MBEDTLS_SSL_PEND_FATAL_ALERT(
-        MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT,
-        MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION);
-    return MBEDTLS_ERR_SSL_UNSUPPORTED_EXTENSION;
+    return 0;
 }
+
 #endif /* MBEDTLS_SSL_RECORD_SIZE_LIMIT */
 
 #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 fe7a674..a7c266b 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -1699,14 +1699,11 @@
 
                 ret = mbedtls_ssl_tls13_parse_record_size_limit_ext(
                     ssl, p, extension_data_end);
-
-                /*
-                 * TODO: Return unconditionally here until we handle the record
-                 *       size limit correctly.
-                 *       Once handled correctly, only return in case of errors.
-                 */
-                return ret;
-
+                if (ret != 0) {
+                    MBEDTLS_SSL_DEBUG_RET(
+                        1, ("mbedtls_ssl_tls13_parse_record_size_limit_ext"), ret);
+                    return ret;
+                }
                 break;
 #endif /* MBEDTLS_SSL_RECORD_SIZE_LIMIT */
 
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index e6ebd8e..598d38c 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -3521,7 +3521,7 @@
         mbedtls_printf("    [ Record expansion is unknown ]\n");
     }
 
-#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
+#if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH) || defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
     mbedtls_printf("    [ Maximum incoming record payload length is %u ]\n",
                    (unsigned int) mbedtls_ssl_get_max_in_record_payload(&ssl));
     mbedtls_printf("    [ Maximum outgoing record payload length is %u ]\n",
diff --git a/scripts/mbedtls_dev/asymmetric_key_data.py b/scripts/mbedtls_dev/asymmetric_key_data.py
index ef3e3a0..8ca6758 100644
--- a/scripts/mbedtls_dev/asymmetric_key_data.py
+++ b/scripts/mbedtls_dev/asymmetric_key_data.py
@@ -41,13 +41,15 @@
     'ECC(PSA_ECC_FAMILY_SECP_K1)': {
         192: ("297ac1722ccac7589ecb240dc719842538ca974beb79f228",
               "0426b7bb38da649ac2138fc050c6548b32553dab68afebc36105d325b75538c12323cb0764789ecb992671beb2b6bef2f5"),
-        224: ("0024122bf020fa113f6c0ac978dfbd41f749257a9468febdbe0dc9f7e8",
+        225: ("0024122bf020fa113f6c0ac978dfbd41f749257a9468febdbe0dc9f7e8",
               "042cc7335f4b76042bed44ef45959a62aa215f7a5ff0c8111b8c44ed654ee71c1918326ad485b2d599fe2a6eab096ee26d977334d2bac6d61d"),
         256: ("7fa06fa02d0e911b9a47fdc17d2d962ca01e2f31d60c6212d0ed7e3bba23a7b9",
               "045c39154579efd667adc73a81015a797d2c8682cdfbd3c3553c4a185d481cdc50e42a0e1cbc3ca29a32a645e927f54beaed14c9dbbf8279d725f5495ca924b24d"),
     },
     'ECC(PSA_ECC_FAMILY_SECP_R1)': {
-        225: ("872f203b3ad35b7f2ecc803c3a0e1e0b1ed61cc1afe71b189cd4c995",
+        192: ("d83b57a59c51358d9c8bbb898aff507f44dd14cf16917190",
+              "04e35fcbee11cec3154f80a1a61df7d7612de4f2fd70c5608d0ee3a4a1a5719471adb33966dd9b035fdb774feeba94b04c"),
+        224: ("872f203b3ad35b7f2ecc803c3a0e1e0b1ed61cc1afe71b189cd4c995",
               "046f00eadaa949fee3e9e1c7fa1247eecec86a0dce46418b9bd3117b981d4bd0ae7a990de912f9d060d6cb531a42d22e394ac29e81804bf160"),
         256: ("49c9a8c18c4b885638c431cf1df1c994131609b580d4fd43a0cab17db2f13eee",
               "047772656f814b399279d5e1f1781fac6f099a3c5ca1b0e35351834b08b65e0b572590cdaf8f769361bcf34acfc11e5e074e8426bdde04be6e653945449617de45"),
diff --git a/scripts/mbedtls_dev/crypto_knowledge.py b/scripts/mbedtls_dev/crypto_knowledge.py
index 285d6c6..ebfd55c 100644
--- a/scripts/mbedtls_dev/crypto_knowledge.py
+++ b/scripts/mbedtls_dev/crypto_knowledge.py
@@ -131,8 +131,8 @@
         'PSA_DH_FAMILY_RFC7919': (2048, 3072, 4096, 6144, 8192),
     } # type: Dict[str, Tuple[int, ...]]
     ECC_KEY_SIZES = {
-        'PSA_ECC_FAMILY_SECP_K1': (192, 224, 256),
-        'PSA_ECC_FAMILY_SECP_R1': (225, 256, 384, 521),
+        'PSA_ECC_FAMILY_SECP_K1': (192, 225, 256),
+        'PSA_ECC_FAMILY_SECP_R1': (224, 256, 384, 521),
         'PSA_ECC_FAMILY_SECP_R2': (160,),
         'PSA_ECC_FAMILY_SECT_K1': (163, 233, 239, 283, 409, 571),
         'PSA_ECC_FAMILY_SECT_R1': (163, 233, 283, 409, 571),
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index b37973a..f1b9cc2 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -5815,11 +5815,8 @@
     msg "test_suite_ssl: TLS 1.3 only, record size limit extension enabled"
     cd tests; ./test_suite_ssl; cd ..
 
-    msg "ssl-opt.sh: (TLS 1.3 only, record size limit extension tests only)"
-    # Both the server and the client will currently abort the handshake when they encounter the
-    # record size limit extension. There is no way to prevent gnutls-cli from sending the extension
-    # which makes all G_NEXT_CLI + P_SRV tests fail. Thus, run only the tests for the this extension.
-    tests/ssl-opt.sh -f "Record Size Limit"
+    msg "ssl-opt.sh: (TLS 1.3 only, record size limit extension enabled)"
+    tests/ssl-opt.sh
 }
 
 component_build_mingw () {
diff --git a/tests/src/test_helpers/ssl_helpers.c b/tests/src/test_helpers/ssl_helpers.c
index d02d305..3d8937d 100644
--- a/tests/src/test_helpers/ssl_helpers.c
+++ b/tests/src/test_helpers/ssl_helpers.c
@@ -1776,6 +1776,10 @@
     }
 #endif /* MBEDTLS_SSL_CLI_C */
 
+#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
+    session->record_size_limit = 2048;
+#endif
+
     return 0;
 }
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 4762285..92b3e17 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -4481,7 +4481,7 @@
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
 run_test    "Max fragment length: enabled, default" \
-            "$P_SRV debug_level=3" \
+            "$P_SRV debug_level=3 force_version=tls12" \
             "$P_CLI debug_level=3" \
             0 \
             -c "Maximum incoming record payload length is $MAX_CONTENT_LEN" \
@@ -4496,7 +4496,7 @@
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
 run_test    "Max fragment length: enabled, default, larger message" \
-            "$P_SRV debug_level=3" \
+            "$P_SRV debug_level=3 force_version=tls12" \
             "$P_CLI debug_level=3 request_size=$(( $MAX_CONTENT_LEN + 1))" \
             0 \
             -c "Maximum incoming record payload length is $MAX_CONTENT_LEN" \
@@ -4534,7 +4534,7 @@
 requires_config_disabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
 run_test    "Max fragment length: disabled, larger message" \
-            "$P_SRV debug_level=3" \
+            "$P_SRV debug_level=3 force_version=tls12" \
             "$P_CLI debug_level=3 request_size=$(( $MAX_CONTENT_LEN + 1))" \
             0 \
             -C "Maximum incoming record payload length is 16384" \
@@ -4548,7 +4548,7 @@
 requires_config_disabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
 run_test    "Max fragment length, DTLS: disabled, larger message" \
-            "$P_SRV debug_level=3 dtls=1" \
+            "$P_SRV debug_level=3 dtls=1 force_version=tls12" \
             "$P_CLI debug_level=3 dtls=1 request_size=$(( $MAX_CONTENT_LEN + 1))" \
             1 \
             -C "Maximum incoming record payload length is 16384" \
@@ -4837,34 +4837,177 @@
 requires_gnutls_tls1_3
 requires_gnutls_record_size_limit
 requires_config_enabled MBEDTLS_SSL_RECORD_SIZE_LIMIT
-run_test    "Record Size Limit: TLS 1.3: Server-side parsing, debug output and fatal alert" \
+requires_config_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE
+run_test    "Record Size Limit: TLS 1.3: Server-side parsing and debug output" \
             "$P_SRV debug_level=3 force_version=tls13" \
             "$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3 -V -d 4" \
-            1 \
-            -c "Preparing extension (Record Size Limit/28) for 'client hello'" \
-            -c "Sending extension Record Size Limit/28 (2 bytes)" \
-            -s "ClientHello: record_size_limit(28) extension received."\
-            -s "found record_size_limit extension" \
+            0 \
             -s "RecordSizeLimit: 16385 Bytes" \
-            -c "Received alert \[110]: An unsupported extension was sent"
+            -s "ClientHello: record_size_limit(28) extension exists." \
+            -s "Maximum outgoing record payload length is 16383" \
+            -s "bytes written in 1 fragments"
 
 requires_gnutls_tls1_3
 requires_gnutls_record_size_limit
 requires_gnutls_next_disable_tls13_compat
 requires_config_enabled MBEDTLS_SSL_RECORD_SIZE_LIMIT
-run_test    "Record Size Limit: TLS 1.3: Client-side parsing, debug output and fatal alert" \
+requires_config_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE
+run_test    "Record Size Limit: TLS 1.3: Client-side parsing and debug output" \
             "$G_NEXT_SRV --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3:+CIPHER-ALL:%DISABLE_TLS13_COMPAT_MODE --disable-client-cert -d 4" \
             "$P_CLI debug_level=4 force_version=tls13" \
             0 \
             -s "Preparing extension (Record Size Limit/28) for 'encrypted extensions'"
 # The P_CLI can not yet send the Record Size Limit extension. Thus, the G_NEXT_SRV does not send
 # a response in its EncryptedExtensions record.
-#            -s "Parsing extension 'Record Size Limit/28 (2 bytes)" \
-#            -s "Sending extension Record Size Limit/28 (2 bytes)" \
-#            -c "EncryptedExtensions: record_size_limit(28) extension received."\
-#            -c "found record_size_limit extension" \
-#            -c "RecordSizeLimit: 16385 Bytes" \
-#            -s "Received alert \[110]: An unsupported extension was sent"
+#            -c "RecordSizeLimit: 16385 Bytes"
+
+# In the following (9) tests, --recordsize is the value used by the G_NEXT_CLI (3.7.2) to configure the
+# maximum record size using "https://gnutls.org/reference/gnutls-gnutls.html#gnutls-record-set-max-size".
+# There is currently a lower limit of 512, caused by this function not respecting the
+# "%ALLOW_SMALL_RECORDS" priority string and not using the more recent function
+# https://gnutls.org/reference/gnutls-gnutls.html#gnutls-record-set-max-recv-size.
+# There is currently an upper limit of 4096, caused by the cli arg parser:
+# https://gitlab.com/gnutls/gnutls/-/blob/3.7.2/src/cli-args.def#L395.
+# Thus, these tests are currently limit to that value range.
+# Moreover, the value sent in the extension is expected to be larger by one compared
+# to the value passed on the cli:
+# https://gitlab.com/gnutls/gnutls/-/blob/3.7.2/lib/ext/record_size_limit.c#L142
+
+# Currently test certificates being used do not fit in 513 record size limit
+# so for 513 record size limit tests we use preshared key to avoid sending
+# the certificate.
+
+requires_gnutls_tls1_3
+requires_gnutls_record_size_limit
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_RECORD_SIZE_LIMIT
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
+run_test    "Record Size Limit: TLS 1.3: Server complies with record size limit (513), 1 fragment" \
+            "$P_SRV debug_level=3 force_version=tls13 tls13_kex_modes=psk \
+                    psk_list=Client_identity,6162636465666768696a6b6c6d6e6f70 \
+                    response_size=256" \
+                    "$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3:+PSK --recordsize 512 \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70" \
+            0 \
+            -s "RecordSizeLimit: 513 Bytes" \
+            -s "Maximum outgoing record payload length is 511" \
+            -s "256 bytes written in 1 fragments"
+
+requires_gnutls_tls1_3
+requires_gnutls_record_size_limit
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_RECORD_SIZE_LIMIT
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
+run_test    "Record Size Limit: TLS 1.3: Server complies with record size limit (513), 2 fragments" \
+            "$P_SRV debug_level=3 force_version=tls13 tls13_kex_modes=psk \
+                    psk_list=Client_identity,6162636465666768696a6b6c6d6e6f70 \
+                    response_size=768" \
+            "$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3:+PSK --recordsize 512 \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70" \
+            0 \
+            -s "RecordSizeLimit: 513 Bytes" \
+            -s "Maximum outgoing record payload length is 511" \
+            -s "768 bytes written in 2 fragments"
+
+requires_gnutls_tls1_3
+requires_gnutls_record_size_limit
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_RECORD_SIZE_LIMIT
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_PSK_ENABLED
+run_test    "Record Size Limit: TLS 1.3: Server complies with record size limit (513), 3 fragments" \
+            "$P_SRV debug_level=3 force_version=tls13 tls13_kex_modes=psk \
+                    psk_list=Client_identity,6162636465666768696a6b6c6d6e6f70 \
+                    response_size=1280" \
+            "$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3:+PSK --recordsize 512 \
+                         --pskusername Client_identity --pskkey=6162636465666768696a6b6c6d6e6f70" \
+            0 \
+            -s "RecordSizeLimit: 513 Bytes" \
+            -s "Maximum outgoing record payload length is 511" \
+            -s "1280 bytes written in 3 fragments"
+
+requires_gnutls_tls1_3
+requires_gnutls_record_size_limit
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_RECORD_SIZE_LIMIT
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
+run_test    "Record Size Limit: TLS 1.3: Server complies with record size limit (1024), 1 fragment" \
+            "$P_SRV debug_level=3 force_version=tls13 response_size=512" \
+            "$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3 -V -d 4 --recordsize 1023" \
+            0 \
+            -s "RecordSizeLimit: 1024 Bytes" \
+            -s "ClientHello: record_size_limit(28) extension exists." \
+            -s "Maximum outgoing record payload length is 1023" \
+            -s "512 bytes written in 1 fragments"
+
+requires_gnutls_tls1_3
+requires_gnutls_record_size_limit
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_RECORD_SIZE_LIMIT
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
+run_test    "Record Size Limit: TLS 1.3: Server complies with record size limit (1024), 2 fragments" \
+            "$P_SRV debug_level=3 force_version=tls13 response_size=1536" \
+            "$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3 -V -d 4 --recordsize 1023" \
+            0 \
+            -s "RecordSizeLimit: 1024 Bytes" \
+            -s "ClientHello: record_size_limit(28) extension exists." \
+            -s "Maximum outgoing record payload length is 1023" \
+            -s "1536 bytes written in 2 fragments"
+
+requires_gnutls_tls1_3
+requires_gnutls_record_size_limit
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_RECORD_SIZE_LIMIT
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
+run_test    "Record Size Limit: TLS 1.3: Server complies with record size limit (1024), 3 fragments" \
+            "$P_SRV debug_level=3 force_version=tls13 response_size=2560" \
+            "$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3 -V -d 4 --recordsize 1023" \
+            0 \
+            -s "RecordSizeLimit: 1024 Bytes" \
+            -s "ClientHello: record_size_limit(28) extension exists." \
+            -s "Maximum outgoing record payload length is 1023" \
+            -s "2560 bytes written in 3 fragments"
+
+requires_gnutls_tls1_3
+requires_gnutls_record_size_limit
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_RECORD_SIZE_LIMIT
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
+run_test    "Record Size Limit: TLS 1.3: Server complies with record size limit (4096), 1 fragment" \
+            "$P_SRV debug_level=3 force_version=tls13 response_size=2048" \
+            "$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3 -V -d 4 --recordsize 4095" \
+            0 \
+            -s "RecordSizeLimit: 4096 Bytes" \
+            -s "ClientHello: record_size_limit(28) extension exists." \
+            -s "Maximum outgoing record payload length is 4095" \
+            -s "2048 bytes written in 1 fragments"
+
+requires_gnutls_tls1_3
+requires_gnutls_record_size_limit
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_RECORD_SIZE_LIMIT
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
+run_test    "Record Size Limit: TLS 1.3: Server complies with record size limit (4096), 2 fragments" \
+            "$P_SRV debug_level=3 force_version=tls13 response_size=6144" \
+            "$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3 -V -d 4 --recordsize 4095" \
+            0 \
+            -s "RecordSizeLimit: 4096 Bytes" \
+            -s "ClientHello: record_size_limit(28) extension exists." \
+            -s "Maximum outgoing record payload length is 4095" \
+            -s "6144 bytes written in 2 fragments"
+
+requires_gnutls_tls1_3
+requires_gnutls_record_size_limit
+requires_all_configs_enabled MBEDTLS_SSL_TLS1_3_COMPATIBILITY_MODE MBEDTLS_SSL_SRV_C MBEDTLS_DEBUG_C
+requires_config_enabled MBEDTLS_SSL_RECORD_SIZE_LIMIT
+requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
+run_test    "Record Size Limit: TLS 1.3: Server complies with record size limit (4096), 3 fragments" \
+            "$P_SRV debug_level=3 force_version=tls13 response_size=10240" \
+            "$G_NEXT_CLI localhost --priority=NORMAL:-VERS-ALL:+VERS-TLS1.3 -V -d 4 --recordsize 4095" \
+            0 \
+            -s "RecordSizeLimit: 4096 Bytes" \
+            -s "ClientHello: record_size_limit(28) extension exists." \
+            -s "Maximum outgoing record payload length is 4095" \
+            -s "10240 bytes written in 3 fragments"
 
 # Tests for renegotiation
 
@@ -8263,7 +8406,7 @@
 
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
 run_test    "mbedtls_ssl_get_bytes_avail: extra data (max)" \
-            "$P_SRV buffer_size=100" \
+            "$P_SRV buffer_size=100 force_version=tls12" \
             "$P_CLI request_size=$MAX_CONTENT_LEN" \
             0 \
             -s "Read from client: $MAX_CONTENT_LEN bytes read (100 + $((MAX_CONTENT_LEN - 100)))"
@@ -8452,20 +8595,20 @@
 requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
 run_test    "Large client packet TLS 1.3 AEAD" \
             "$P_SRV" \
-            "$P_CLI request_size=16384 \
+            "$P_CLI request_size=16383 \
              force_ciphersuite=TLS1-3-AES-128-CCM-SHA256" \
             0 \
-            -c "16384 bytes written in $(fragments_for_write 16384) fragments" \
-            -s "Read from client: $MAX_CONTENT_LEN bytes read"
+            -c "16383 bytes written in $(fragments_for_write 16383) fragments" \
+            -s "Read from client: 16383 bytes read"
 
 requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
 run_test    "Large client packet TLS 1.3 AEAD shorter tag" \
             "$P_SRV" \
-            "$P_CLI request_size=16384 \
+            "$P_CLI request_size=16383 \
              force_ciphersuite=TLS1-3-AES-128-CCM-8-SHA256" \
             0 \
-            -c "16384 bytes written in $(fragments_for_write 16384) fragments" \
-            -s "Read from client: $MAX_CONTENT_LEN bytes read"
+            -c "16383 bytes written in $(fragments_for_write 16383) fragments" \
+            -s "Read from client: 16383 bytes read"
 
 # The tests below fail when the server's OUT_CONTENT_LEN is less than 16384.
 run_test    "Large server packet TLS 1.2 BlockCipher" \
@@ -8508,17 +8651,17 @@
 
 requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
 run_test    "Large server packet TLS 1.3 AEAD" \
-            "$P_SRV response_size=16384" \
+            "$P_SRV response_size=16383" \
             "$P_CLI force_ciphersuite=TLS1-3-AES-128-CCM-SHA256" \
             0 \
-            -c "Read from server: 16384 bytes read"
+            -c "Read from server: 16383 bytes read"
 
 requires_config_enabled MBEDTLS_SSL_TLS1_3_KEY_EXCHANGE_MODE_EPHEMERAL_ENABLED
 run_test    "Large server packet TLS 1.3 AEAD shorter tag" \
-            "$P_SRV response_size=16384" \
+            "$P_SRV response_size=16383" \
             "$P_CLI force_ciphersuite=TLS1-3-AES-128-CCM-8-SHA256" \
             0 \
-            -c "Read from server: 16384 bytes read"
+            -c "Read from server: 16383 bytes read"
 
 # Tests for restartable ECC
 
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index 05571a1..8a03d1b 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -2096,6 +2096,10 @@
     }
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
 
+#if defined(MBEDTLS_SSL_RECORD_SIZE_LIMIT)
+    TEST_ASSERT(original.record_size_limit == restored.record_size_limit);
+#endif
+
 exit:
     mbedtls_ssl_session_free(&original);
     mbedtls_ssl_session_free(&restored);