Merge pull request #10575 from ronald-cron-arm/dtls-client-hello-defragmentation-prep

Some preparatory work for DTLS client hello defragmentation

library/ssl_debug_helpers.h

@@ -36,6 +36,8 @@ const char *mbedtls_ssl_named_group_to_str(uint16_t in);
 
 const char *mbedtls_ssl_get_extension_name(unsigned int extension_type);
 
+const char *mbedtls_ssl_get_hs_msg_name(int hs_msg_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,

library/ssl_msg.c

@@ -18,6 +18,7 @@
 
 #include "mbedtls/ssl.h"
 #include "debug_internal.h"
+#include "ssl_debug_helpers.h"
 #include "mbedtls/error.h"
 #include "mbedtls/platform_util.h"
 #include "mbedtls/version.h"
@@ -2325,7 +2326,8 @@ int mbedtls_ssl_flight_transmit(mbedtls_ssl_context *ssl)
                               max_hs_frag_len : rem_len;
 
             if (frag_off == 0 && cur_hs_frag_len != hs_len) {
-                MBEDTLS_SSL_DEBUG_MSG(2, ("fragmenting handshake message (%u > %u)",
+                MBEDTLS_SSL_DEBUG_MSG(2, ("fragmenting %s handshake message (%u > %u)",
+                                          mbedtls_ssl_get_hs_msg_name(cur->p[0]),
                                           (unsigned) cur_hs_frag_len,
                                           (unsigned) max_hs_frag_len));
             }
@@ -4157,7 +4159,9 @@ static int ssl_load_buffered_message(mbedtls_ssl_context *ssl)
             return MBEDTLS_ERR_SSL_INTERNAL_ERROR;
         }
 
-        MBEDTLS_SSL_DEBUG_MSG(2, ("Next handshake message has been buffered - load"));
+        MBEDTLS_SSL_DEBUG_MSG(2, ("%s handshake message has been buffered%s",
+                                  mbedtls_ssl_get_hs_msg_name(hs_buf->data[0]),
+                                  hs_buf->is_fragmented ? " and reassembled" : ""));
         MBEDTLS_SSL_DEBUG_BUF(3, "Buffered handshake message (incl. header)",
                               hs_buf->data, msg_len + 12);
 

library/ssl_tls.c

@@ -679,7 +679,7 @@ const char *mbedtls_ssl_get_extension_name(unsigned int extension_type)
         mbedtls_ssl_get_extension_id(extension_type)];
 }
 
-static const char *ssl_tls13_get_hs_msg_name(int hs_msg_type)
+const char *mbedtls_ssl_get_hs_msg_name(int hs_msg_type)
 {
     switch (hs_msg_type) {
         case MBEDTLS_SSL_HS_CLIENT_HELLO:
@@ -694,8 +694,16 @@ static const char *ssl_tls13_get_hs_msg_name(int hs_msg_type)
             return "EncryptedExtensions";
         case MBEDTLS_SSL_HS_CERTIFICATE:
             return "Certificate";
+        case MBEDTLS_SSL_HS_SERVER_KEY_EXCHANGE:
+            return "ServerKeyExchange";
         case MBEDTLS_SSL_HS_CERTIFICATE_REQUEST:
             return "CertificateRequest";
+        case MBEDTLS_SSL_HS_CERTIFICATE_VERIFY:
+            return "CertificateVerify";
+        case MBEDTLS_SSL_HS_CLIENT_KEY_EXCHANGE:
+            return "ClientKeyExchange";
+        case MBEDTLS_SSL_HS_FINISHED:
+            return "Finished";
     }
     return "Unknown";
 }
@@ -710,7 +718,7 @@ void mbedtls_ssl_print_extension(const mbedtls_ssl_context *ssl,
         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_hs_msg_name(hs_msg_type),
             mbedtls_ssl_get_extension_name(extension_type),
             extension_type,
             extra_msg0, extra_msg1);
@@ -721,7 +729,7 @@ void mbedtls_ssl_print_extension(const mbedtls_ssl_context *ssl,
     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),
+            "%s: %s(%u) extension %s.", mbedtls_ssl_get_hs_msg_name(hs_msg_type),
             mbedtls_ssl_get_extension_name(extension_type), extension_type,
             extra_msg);
         return;
@@ -729,7 +737,7 @@ void mbedtls_ssl_print_extension(const mbedtls_ssl_context *ssl,
 
     mbedtls_debug_print_msg(
         ssl, level, file, line,
-        "%s: %s(%u) extension.", ssl_tls13_get_hs_msg_name(hs_msg_type),
+        "%s: %s(%u) extension.", mbedtls_ssl_get_hs_msg_name(hs_msg_type),
         mbedtls_ssl_get_extension_name(extension_type), extension_type);
 }
 

programs/ssl/ssl_server2.c

@@ -3490,6 +3490,7 @@ handshake:
      * 5. Verify the client certificate
      */
     mbedtls_printf("  . Verifying peer X.509 certificate...");
+    fflush(stdout);
 
     if ((flags = mbedtls_ssl_get_verify_result(&ssl)) != 0) {
         char vrfy_buf[512];
@@ -3507,6 +3508,7 @@ handshake:
         char crt_buf[512];
 
         mbedtls_printf("  . Peer certificate information    ...\n");
+        fflush(stdout);
         mbedtls_x509_crt_info(crt_buf, sizeof(crt_buf), "      ",
                               mbedtls_ssl_get_peer_cert(&ssl));
         mbedtls_printf("%s\n", crt_buf);
@@ -3959,6 +3961,7 @@ data_exchange:
         size_t buf_len;
 
         mbedtls_printf("  . Serializing live connection...");
+        fflush(stdout);
 
         ret = mbedtls_ssl_context_save(&ssl, NULL, 0, &buf_len);
         if (ret != MBEDTLS_ERR_SSL_BUFFER_TOO_SMALL) {
@@ -3993,6 +3996,7 @@ data_exchange:
             size_t b64_len;
 
             mbedtls_printf("  . Save serialized context to a file... ");
+            fflush(stdout);
 
             mbedtls_base64_encode(NULL, 0, &b64_len, context_buf, buf_len);
 
@@ -4041,6 +4045,7 @@ data_exchange:
         if (opt.serialize == 1) {
             /* nothing to do here, done by context_save() already */
             mbedtls_printf("  . Context has been reset... ok\n");
+            fflush(stdout);
         }
 
         /*
@@ -4053,6 +4058,7 @@ data_exchange:
          */
         if (opt.serialize == 2) {
             mbedtls_printf("  . Freeing and reinitializing context...");
+            fflush(stdout);
 
             mbedtls_ssl_free(&ssl);
 
@@ -4089,6 +4095,7 @@ data_exchange:
         }
 
         mbedtls_printf("  . Deserializing connection...");
+        fflush(stdout);
 
         if ((ret = mbedtls_ssl_context_load(&ssl, context_buf,
                                             buf_len)) != 0) {
@@ -4118,6 +4125,7 @@ data_exchange:
      */
 close_notify:
     mbedtls_printf("  . Closing the connection...");
+    fflush(stdout);
 
     /* No error checking, the connection might be closed already */
     do {

scripts/generate_tls_handshake_tests.py

@@ -0,0 +1,17 @@
+#!/usr/bin/env python3
+"""
+Generate miscellaneous TLS test cases relating to the handshake.
+"""
+
+# Copyright The Mbed TLS Contributors
+# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+
+import sys
+
+import framework_scripts_path # pylint: disable=unused-import
+
+from mbedtls_framework import tls_handshake_tests
+
+if __name__ == '__main__':
+    sys.argv[1:1] = ["--no-tls12-client-hello-defragmentation-support"]
+    tls_handshake_tests.main()

scripts/make_generated_files.bat

@@ -12,4 +12,4 @@ python framework\scripts\make_generated_files.py || exit /b 1
 cd ..
 
 @rem @@@@ mbedtls @@@@
-python framework\scripts\make_generated_files.py || exit /b 1
+python scripts\make_generated_files.py || exit /b 1

scripts/make_generated_files.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+"""Generate, check and list the generated files
+"""
+
+# Copyright The Mbed TLS Contributors
+# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
+
+import sys
+from pathlib import Path
+
+import framework_scripts_path # pylint: disable=unused-import
+
+from mbedtls_framework import build_tree
+from mbedtls_framework import generated_files
+from mbedtls_framework.generated_files import GenerationScript, get_generation_script_files
+
+GENERATION_SCRIPTS = [
+    GenerationScript(
+        Path("scripts/generate_errors.pl"),
+        [Path("library/error.c")],
+        None, "tf-psa-crypto/drivers/builtin/include/mbedtls \
+               include/mbedtls/ \
+               scripts/data_files"
+    ),
+    GenerationScript(
+        Path("scripts/generate_features.pl"),
+        [Path("library/version_features.c")],
+        None, "include/mbedtls/ scripts/data_files"
+    ),
+    GenerationScript(
+        Path("framework/scripts/generate_ssl_debug_helpers.py"),
+        [Path("library/ssl_debug_helpers_generated.c")],
+        "", None
+    ),
+    GenerationScript(
+        Path("framework/scripts/generate_test_keys.py"),
+        [Path("tests/include/test/test_keys.h")],
+        None, "--output"
+    ),
+    GenerationScript(
+        Path("framework/scripts/generate_test_cert_macros.py"),
+        [Path("tests/include/test/test_certs.h")],
+        None, "--output"
+    ),
+    GenerationScript(
+        Path("scripts/generate_query_config.pl"),
+        [Path("programs/test/query_config.c")],
+        None, "include/mbedtls/mbedtls_config.h \
+               tf-psa-crypto/include/psa/crypto_config.h \
+               scripts/data_files/query_config.fmt"
+    ),
+    GenerationScript(
+        Path("framework/scripts/generate_config_tests.py"),
+        get_generation_script_files("framework/scripts/generate_config_tests.py"),
+        "--directory", None
+    ),
+    GenerationScript(
+        Path("framework/scripts/generate_tls13_compat_tests.py"),
+        [Path("tests/opt-testcases/tls13-compat.sh")],
+        None, "--output"
+    ),
+    GenerationScript(
+        Path("scripts/generate_tls_handshake_tests.py"),
+        [Path("tests/opt-testcases/handshake-generated.sh")],
+        None, "--output"
+    ),
+    GenerationScript(
+        Path("scripts/generate_config_checks.py"),
+        get_generation_script_files("scripts/generate_config_checks.py"),
+        output_dir_option="",
+        optional=True)
+]
+
+def main() -> int:
+    if not build_tree.looks_like_mbedtls_root("."):
+        raise RuntimeError("This script must be run from Mbed TLS.")
+
+    return generated_files.main(GENERATION_SCRIPTS)
+
+if __name__ == "__main__":
+    sys.exit(main())

tests/CMakeLists.txt

@@ -58,10 +58,10 @@ if(GEN_FILES)
             ${CMAKE_CURRENT_SOURCE_DIR}/..
         COMMAND
             "${MBEDTLS_PYTHON_EXECUTABLE}"
-            "${CMAKE_CURRENT_SOURCE_DIR}/../framework/scripts/generate_tls_handshake_tests.py"
+            "${PROJECT_SOURCE_DIR}/scripts/generate_tls_handshake_tests.py"
         DEPENDS
             ${CMAKE_CURRENT_SOURCE_DIR}/../framework/scripts/mbedtls_framework/tls_test_case.py
-            ${CMAKE_CURRENT_SOURCE_DIR}/../framework/scripts/generate_tls_handshake_tests.py
+            ${PROJECT_SOURCE_DIR}/scripts/generate_tls_handshake_tests.py
     )
     add_custom_target(handshake-generated.sh
         DEPENDS ${CMAKE_CURRENT_SOURCE_DIR}/opt-testcases/handshake-generated.sh)

tests/Makefile

@@ -45,9 +45,9 @@ GENERATED_FILES = \
 .PHONY: ssl-opt
 
 opt-testcases/handshake-generated.sh: ../framework/scripts/mbedtls_framework/tls_test_case.py
-opt-testcases/handshake-generated.sh: ../framework/scripts/generate_tls_handshake_tests.py
+opt-testcases/handshake-generated.sh: ../scripts/generate_tls_handshake_tests.py
 	echo "  Gen   $@"
-	$(PYTHON) ../framework/scripts/generate_tls_handshake_tests.py -o $@
+	$(PYTHON) ../scripts/generate_tls_handshake_tests.py -o $@
 GENERATED_FILES += opt-testcases/handshake-generated.sh
 ssl-opt: opt-testcases/handshake-generated.sh
 

tests/scripts/components-basic-checks.sh

@@ -19,14 +19,14 @@ component_check_recursion () {
 component_check_generated_files () {
     msg "Check make_generated_files.py consistency"
     $MAKE_COMMAND neat
-    $FRAMEWORK/scripts/make_generated_files.py
+    scripts/make_generated_files.py
-    $FRAMEWORK/scripts/make_generated_files.py --check
+    scripts/make_generated_files.py --check
     $MAKE_COMMAND neat
 
     msg "Check files generated with make"
     MBEDTLS_ROOT_DIR="$PWD"
     $MAKE_COMMAND generated_files
-    $FRAMEWORK/scripts/make_generated_files.py --check
+    scripts/make_generated_files.py --check
 
     cd $TF_PSA_CRYPTO_ROOT_DIR
     ./framework/scripts/make_generated_files.py --check
@@ -39,7 +39,7 @@ component_check_generated_files () {
     make
     cd "$MBEDTLS_ROOT_DIR"
 
-    $FRAMEWORK/scripts/make_generated_files.py --root "$OUT_OF_SOURCE_DIR" --check
+    scripts/make_generated_files.py --root "$OUT_OF_SOURCE_DIR" --check
 
     cd $TF_PSA_CRYPTO_ROOT_DIR
     ./framework/scripts/make_generated_files.py --root "$OUT_OF_SOURCE_DIR/tf-psa-crypto" --check

tests/ssl-opt.sh

@@ -9914,6 +9914,7 @@ run_test    "DTLS reassembly: some fragmentation (gnutls server)" \
             "$P_CLI dtls=1 debug_level=2" \
             0 \
             -c "found fragmented DTLS handshake message" \
+            -c "Certificate handshake message has been buffered and reassembled" \
             -C "error"
 
 requires_gnutls
@@ -9923,6 +9924,8 @@ run_test    "DTLS reassembly: more fragmentation (gnutls server)" \
             "$P_CLI dtls=1 debug_level=2" \
             0 \
             -c "found fragmented DTLS handshake message" \
+            -c "Certificate handshake message has been buffered and reassembled" \
+            -c "ServerKeyExchange handshake message has been buffered and reassembled" \
             -C "error"
 
 requires_gnutls
@@ -9932,6 +9935,8 @@ run_test    "DTLS reassembly: more fragmentation, nbio (gnutls server)" \
             "$P_CLI dtls=1 nbio=2 debug_level=2" \
             0 \
             -c "found fragmented DTLS handshake message" \
+            -c "Certificate handshake message has been buffered and reassembled" \
+            -c "ServerKeyExchange handshake message has been buffered and reassembled" \
             -C "error"
 
 requires_gnutls
@@ -9942,6 +9947,7 @@ run_test    "DTLS reassembly: fragmentation, renego (gnutls server)" \
             "$P_CLI debug_level=3 dtls=1 renegotiation=1 renegotiate=1" \
             0 \
             -c "found fragmented DTLS handshake message" \
+            -c "Certificate handshake message has been buffered and reassembled" \
             -c "client hello, adding renegotiation extension" \
             -c "found renegotiation extension" \
             -c "=> renegotiate" \
@@ -9957,6 +9963,7 @@ run_test    "DTLS reassembly: fragmentation, nbio, renego (gnutls server)" \
             "$P_CLI debug_level=3 nbio=2 dtls=1 renegotiation=1 renegotiate=1" \
             0 \
             -c "found fragmented DTLS handshake message" \
+            -c "Certificate handshake message has been buffered and reassembled" \
             -c "client hello, adding renegotiation extension" \
             -c "found renegotiation extension" \
             -c "=> renegotiate" \
@@ -9972,20 +9979,17 @@ run_test    "DTLS reassembly: no fragmentation (openssl server)" \
             -C "found fragmented DTLS handshake message" \
             -C "error"
 
+# Minimum possible MTU for OpenSSL server: 256 bytes.
+# We expect the server Certificate handshake to be fragmented and verify that
+# this is the case. Depending on the configuration, other handshake messages may
+# also be fragmented.
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
-run_test    "DTLS reassembly: some fragmentation (openssl server)" \
+run_test    "DTLS reassembly: fragmentation (openssl server)" \
-            "$O_SRV -dtls -mtu 256" \
-            "$P_CLI dtls=1 debug_level=2" \
-            0 \
-            -c "found fragmented DTLS handshake message" \
-            -C "error"
-
-requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
-run_test    "DTLS reassembly: more fragmentation (openssl server)" \
             "$O_SRV -dtls -mtu 256" \
             "$P_CLI dtls=1 debug_level=2" \
             0 \
             -c "found fragmented DTLS handshake message" \
+            -c "Certificate handshake message has been buffered and reassembled" \
             -C "error"
 
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
@@ -9994,6 +9998,7 @@ run_test    "DTLS reassembly: fragmentation, nbio (openssl server)" \
             "$P_CLI dtls=1 nbio=2 debug_level=2" \
             0 \
             -c "found fragmented DTLS handshake message" \
+            -c "Certificate handshake message has been buffered and reassembled" \
             -C "error"
 
 # Tests for sending fragmented handshake messages with DTLS
@@ -10662,7 +10667,7 @@ run_test    "DTLS fragmenting: gnutls server, DTLS 1.2" \
              key_file=$DATA_FILES_PATH/server8.key \
              mtu=512 force_version=dtls12" \
             0 \
-            -c "fragmenting handshake message" \
+            -c "fragmenting Certificate handshake message" \
             -C "error"
 
 # We use --insecure for the GnuTLS client because it expects
@@ -10684,7 +10689,7 @@ run_test    "DTLS fragmenting: gnutls client, DTLS 1.2" \
              mtu=512 force_version=dtls12" \
             "$G_CLI -u --insecure 127.0.0.1" \
             0 \
-            -s "fragmenting handshake message"
+            -s "fragmenting Certificate handshake message"
 
 requires_config_enabled MBEDTLS_SSL_PROTO_DTLS
 requires_config_enabled PSA_WANT_KEY_TYPE_RSA_KEY_PAIR_BASIC
@@ -10696,7 +10701,7 @@ run_test    "DTLS fragmenting: openssl server, DTLS 1.2" \
              key_file=$DATA_FILES_PATH/server8.key \
              mtu=512 force_version=dtls12" \
             0 \
-            -c "fragmenting handshake message" \
+            -c "fragmenting Certificate handshake message" \
             -C "error"
 
 requires_config_enabled MBEDTLS_SSL_PROTO_DTLS
@@ -10709,7 +10714,7 @@ run_test    "DTLS fragmenting: openssl client, DTLS 1.2" \
              mtu=512 force_version=dtls12" \
             "$O_CLI -dtls1_2" \
             0 \
-            -s "fragmenting handshake message"
+            -s "fragmenting Certificate handshake message"
 
 # interop tests for DTLS fragmentating with unreliable connection
 #
@@ -10728,7 +10733,7 @@ run_test    "DTLS fragmenting: 3d, gnutls server, DTLS 1.2" \
              key_file=$DATA_FILES_PATH/server8.key \
              hs_timeout=250-60000 mtu=512 force_version=dtls12" \
             0 \
-            -c "fragmenting handshake message" \
+            -c "fragmenting Certificate handshake message" \
             -C "error"
 
 requires_gnutls_next
@@ -10744,7 +10749,7 @@ run_test    "DTLS fragmenting: 3d, gnutls client, DTLS 1.2" \
              hs_timeout=250-60000 mtu=512 force_version=dtls12" \
            "$G_NEXT_CLI -u --insecure 127.0.0.1" \
             0 \
-            -s "fragmenting handshake message"
+            -s "fragmenting Certificate handshake message"
 
 ## The test below requires 1.1.1a or higher version of openssl, otherwise
 ## it might trigger a bug due to openssl server (https://github.com/openssl/openssl/issues/6902)
@@ -10761,7 +10766,7 @@ run_test    "DTLS fragmenting: 3d, openssl server, DTLS 1.2" \
              key_file=$DATA_FILES_PATH/server8.key \
              hs_timeout=250-60000 mtu=512 force_version=dtls12" \
             0 \
-            -c "fragmenting handshake message" \
+            -c "fragmenting Certificate handshake message" \
             -C "error"
 
 ## the test below will time out with certain seed.
@@ -10779,7 +10784,7 @@ run_test    "DTLS fragmenting: 3d, openssl client, DTLS 1.2" \
              hs_timeout=250-60000 mtu=512 force_version=dtls12" \
             "$O_CLI -dtls1_2" \
             0 \
-            -s "fragmenting handshake message"
+            -s "fragmenting Certificate handshake message"
 
 # Tests for DTLS-SRTP (RFC 5764)
 requires_config_enabled MBEDTLS_SSL_DTLS_SRTP
@@ -11496,9 +11501,9 @@ run_test    "DTLS reordering: Buffer out-of-order handshake message on client" \
             hs_timeout=2500-60000" \
             0 \
             -c "Buffering HS message" \
-            -c "Next handshake message has been buffered - load"\
+            -c "Certificate handshake message has been buffered$"\
             -S "Buffering HS message" \
-            -S "Next handshake message has been buffered - load"\
+            -S "handshake message has been buffered"\
             -C "Injecting buffered CCS message" \
             -C "Remember CCS message" \
             -S "Injecting buffered CCS message" \
@@ -11516,9 +11521,9 @@ run_test    "DTLS reordering: Buffer out-of-order handshake message fragment on
             -c "Buffering HS message" \
             -c "found fragmented DTLS handshake message"\
             -c "Next handshake message 1 not or only partially buffered" \
-            -c "Next handshake message has been buffered - load"\
+            -c "Certificate handshake message has been buffered and reassembled"\
             -S "Buffering HS message" \
-            -S "Next handshake message has been buffered - load"\
+            -S "handshake message has been buffered" \
             -C "Injecting buffered CCS message" \
             -C "Remember CCS message" \
             -S "Injecting buffered CCS message" \
@@ -11539,10 +11544,11 @@ run_test    "DTLS reordering: Buffer out-of-order hs msg before reassembling nex
             hs_timeout=2500-60000" \
             0 \
             -c "Buffering HS message" \
-            -c "Next handshake message has been buffered - load"\
+            -c "Certificate handshake message has been buffered and reassembled"\
+            -c "ServerKeyExchange handshake message has been buffered$"\
             -C "attempt to make space by freeing buffered messages" \
             -S "Buffering HS message" \
-            -S "Next handshake message has been buffered - load"\
+            -S "handshake message has been buffered" \
             -C "Injecting buffered CCS message" \
             -C "Remember CCS message" \
             -S "Injecting buffered CCS message" \
@@ -11566,7 +11572,7 @@ run_test    "DTLS reordering: Buffer out-of-order hs msg before reassembling nex
             -c "attempt to make space by freeing buffered future messages" \
             -c "Enough space available after freeing buffered HS messages" \
             -S "Buffering HS message" \
-            -S "Next handshake message has been buffered - load"\
+            -S "handshake message has been buffered" \
             -C "Injecting buffered CCS message" \
             -C "Remember CCS message" \
             -S "Injecting buffered CCS message" \
@@ -11582,9 +11588,9 @@ run_test    "DTLS reordering: Buffer out-of-order handshake message on server" \
             hs_timeout=2500-60000" \
             0 \
             -C "Buffering HS message" \
-            -C "Next handshake message has been buffered - load"\
+            -C "handshake message has been buffered" \
             -s "Buffering HS message" \
-            -s "Next handshake message has been buffered - load" \
+            -s "ClientKeyExchange handshake message has been buffered$" \
             -C "Injecting buffered CCS message" \
             -C "Remember CCS message" \
             -S "Injecting buffered CCS message" \
@@ -11601,9 +11607,9 @@ run_test    "DTLS reordering: Buffer out-of-order CCS message on client"\
             hs_timeout=2500-60000" \
             0 \
             -C "Buffering HS message" \
-            -C "Next handshake message has been buffered - load"\
+            -C "handshake message has been buffered" \
             -S "Buffering HS message" \
-            -S "Next handshake message has been buffered - load" \
+            -S "handshake message has been buffered" \
             -c "Injecting buffered CCS message" \
             -c "Remember CCS message" \
             -S "Injecting buffered CCS message" \
@@ -11619,9 +11625,9 @@ run_test    "DTLS reordering: Buffer out-of-order CCS message on server"\
             hs_timeout=2500-60000" \
             0 \
             -C "Buffering HS message" \
-            -C "Next handshake message has been buffered - load"\
+            -C "handshake message has been buffered" \
             -S "Buffering HS message" \
-            -S "Next handshake message has been buffered - load" \
+            -S "handshake message has been buffered" \
             -C "Injecting buffered CCS message" \
             -C "Remember CCS message" \
             -s "Injecting buffered CCS message" \
@@ -11857,10 +11863,11 @@ not_with_valgrind # risk of non-mbedtls peer timing out
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
 run_test    "DTLS proxy: 3d, openssl server, fragmentation" \
             -p "$P_PXY drop=5 delay=5 duplicate=5 protect_hvr=1" \
-            "$O_NEXT_SRV -dtls1_2 -mtu 768" \
+            "$O_NEXT_SRV -dtls1_2 -mtu 256" \
-            "$P_CLI dgram_packing=0 dtls=1 hs_timeout=500-60000 tickets=0" \
+            "$P_CLI dgram_packing=0 dtls=1 debug_level=2 hs_timeout=500-60000 tickets=0" \
             0 \
-            -c "HTTP/1.0 200 OK"
+            -c "HTTP/1.0 200 OK" \
+            -c "Certificate handshake message has been buffered and reassembled"
 
 requires_openssl_next
 client_needs_more_time 8
@@ -11868,10 +11875,11 @@ not_with_valgrind # risk of non-mbedtls peer timing out
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
 run_test    "DTLS proxy: 3d, openssl server, fragmentation, nbio" \
             -p "$P_PXY drop=5 delay=5 duplicate=5 protect_hvr=1" \
-            "$O_NEXT_SRV -dtls1_2 -mtu 768" \
+            "$O_NEXT_SRV -dtls1_2 -mtu 256" \
-            "$P_CLI dgram_packing=0 dtls=1 hs_timeout=500-60000 nbio=2 tickets=0" \
+            "$P_CLI dgram_packing=0 dtls=1 debug_level=2 hs_timeout=500-60000 nbio=2 tickets=0" \
             0 \
-            -c "HTTP/1.0 200 OK"
+            -c "HTTP/1.0 200 OK" \
+            -c "Certificate handshake message has been buffered and reassembled"
 
 requires_gnutls
 client_needs_more_time 6
@@ -11892,10 +11900,11 @@ requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
 run_test    "DTLS proxy: 3d, gnutls server, fragmentation" \
             -p "$P_PXY drop=5 delay=5 duplicate=5" \
             "$G_NEXT_SRV -u --mtu 512" \
-            "$P_CLI dgram_packing=0 dtls=1 hs_timeout=500-60000" \
+            "$P_CLI dgram_packing=0 dtls=1 debug_level=2 hs_timeout=500-60000" \
             0 \
             -s "Extra-header:" \
-            -c "Extra-header:"
+            -c "Extra-header:" \
+            -c "Certificate handshake message has been buffered and reassembled"
 
 requires_gnutls_next
 client_needs_more_time 8
@@ -11904,10 +11913,11 @@ requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
 run_test    "DTLS proxy: 3d, gnutls server, fragmentation, nbio" \
             -p "$P_PXY drop=5 delay=5 duplicate=5" \
             "$G_NEXT_SRV -u --mtu 512" \
-            "$P_CLI dgram_packing=0 dtls=1 hs_timeout=500-60000 nbio=2" \
+            "$P_CLI dgram_packing=0 dtls=1 debug_level=2 hs_timeout=500-60000 nbio=2" \
             0 \
             -s "Extra-header:" \
-            -c "Extra-header:"
+            -c "Extra-header:" \
+            -c "Certificate handshake message has been buffered and reassembled"
 
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
 run_test    "export keys functionality" \
@@ -13766,16 +13776,6 @@ run_test    "TLS 1.2 ClientHello indicating support for deflate compression meth
 
 # Most test cases are in opt-testcases/handshake-generated.sh
 
-requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
-requires_certificate_authentication
-run_test    "Handshake defragmentation on server: len=32, TLS 1.2 ClientHello (unsupported)" \
-            "$P_SRV debug_level=4 force_version=tls12 auth_mode=required" \
-            "$O_NEXT_CLI -tls1_2 -split_send_frag 32 -cert $DATA_FILES_PATH/server5.crt -key $DATA_FILES_PATH/server5.key" \
-            1 \
-            -s "The SSL configuration is tls12 only" \
-            -s "bad client hello message" \
-            -s "SSL - A message could not be parsed due to a syntactic error"
-
 # Test server-side buffer resizing with fragmented handshake on TLS1.2
 requires_config_enabled MBEDTLS_SSL_PROTO_TLS1_2
 requires_config_enabled MBEDTLS_SSL_MAX_FRAGMENT_LENGTH