Backport 2.28: Run ssl-opt.sh in more reduced configurations

ChangeLog.d/dtls-cid-null.txt

@@ -0,0 +1,5 @@
+Bugfix
+   * In configurations with MBEDTLS_SSL_DTLS_CONNECTION_ID enabled but none of
+     MBEDTLS_SSL_HW_RECORD_ACCEL, MBEDTLS_SSL_EXPORT_KEYS or MBEDTLS_DEBUG_C,
+     DTLS handshakes using CID would crash due to a null pointer dereference.
+     Fix this. Fixes #3998.

configs/config-ccm-psk-dtls1_2.h

@@ -0,0 +1,110 @@
+/**
+ * \file config-ccm-psk-dtls1_2.h
+ *
+ * \brief Small configuration for DTLS 1.2 with PSK and AES-CCM ciphersuites
+ */
+/*
+ *  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.
+ */
+/*
+ * Minimal configuration for DTLS 1.2 with PSK and AES-CCM ciphersuites
+ *
+ * Distinguishing features:
+ * - Optimized for small code size, low bandwidth (on an unreliable transport),
+ *   and low RAM usage.
+ * - No asymmetric cryptography (no certificates, no Diffie-Hellman key
+ *   exchange).
+ * - Fully modern and secure (provided the pre-shared keys are generated and
+ *   stored securely).
+ * - Very low record overhead with CCM-8.
+ * - Includes several optional DTLS features typically used in IoT.
+ *
+ * See README.txt for usage instructions.
+ */
+#ifndef MBEDTLS_CONFIG_H
+#define MBEDTLS_CONFIG_H
+
+/* System support */
+//#define MBEDTLS_HAVE_TIME /* Optionally used in Hello messages */
+/* Other MBEDTLS_HAVE_XXX flags irrelevant for this configuration */
+
+/* Mbed TLS modules */
+#define MBEDTLS_AES_C
+#define MBEDTLS_CCM_C
+#define MBEDTLS_CIPHER_C
+#define MBEDTLS_CTR_DRBG_C
+#define MBEDTLS_ENTROPY_C
+#define MBEDTLS_MD_C
+#define MBEDTLS_NET_C
+#define MBEDTLS_SHA256_C
+#define MBEDTLS_SSL_CLI_C
+#define MBEDTLS_SSL_COOKIE_C
+#define MBEDTLS_SSL_SRV_C
+#define MBEDTLS_SSL_TLS_C
+#define MBEDTLS_TIMING_C
+
+/* TLS protocol feature support */
+#define MBEDTLS_KEY_EXCHANGE_PSK_ENABLED
+#define MBEDTLS_SSL_PROTO_TLS1_2
+#define MBEDTLS_SSL_PROTO_DTLS
+#define MBEDTLS_SSL_DTLS_ANTI_REPLAY
+#define MBEDTLS_SSL_DTLS_BADMAC_LIMIT
+#define MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE
+#define MBEDTLS_SSL_DTLS_CONNECTION_ID
+#define MBEDTLS_SSL_DTLS_HELLO_VERIFY
+#define MBEDTLS_SSL_MAX_FRAGMENT_LENGTH
+
+/*
+ * Use only CCM_8 ciphersuites, and
+ * save ROM and a few bytes of RAM by specifying our own ciphersuite list
+ */
+#define MBEDTLS_SSL_CIPHERSUITES                        \
+        MBEDTLS_TLS_PSK_WITH_AES_256_CCM_8,             \
+        MBEDTLS_TLS_PSK_WITH_AES_128_CCM_8
+
+/*
+ * Save RAM at the expense of interoperability: do this only if you control
+ * both ends of the connection!  (See comments in "mbedtls/ssl.h".)
+ * The optimal size here depends on the typical size of records.
+ */
+#define MBEDTLS_SSL_MAX_CONTENT_LEN             256
+
+/* Save RAM at the expense of ROM */
+#define MBEDTLS_AES_ROM_TABLES
+
+/* Save some RAM by adjusting to your exact needs */
+#define MBEDTLS_PSK_MAX_LEN    16 /* 128-bits keys are generally enough */
+
+/*
+ * You should adjust this to the exact number of sources you're using: default
+ * is the "platform_entropy_poll" source plus a weak clock source, but you may
+ * want to add other ones. Minimum is 3 for the entropy test suite.
+ */
+#define MBEDTLS_ENTROPY_MAX_SOURCES 3
+
+/* These defines are present so that the config modifying scripts can enable
+ * them during tests/scripts/test-ref-configs.pl */
+//#define MBEDTLS_USE_PSA_CRYPTO
+//#define MBEDTLS_PSA_CRYPTO_C
+
+/* Error messages and TLS debugging traces
+ * (huge code size increase, needed for tests/ssl-opt.sh) */
+//#define MBEDTLS_DEBUG_C
+//#define MBEDTLS_ERROR_C
+
+#include "mbedtls/check_config.h"
+
+#endif /* MBEDTLS_CONFIG_H */

configs/config-ccm-psk-tls1_2.h

@@ -21,11 +21,15 @@
  */
 /*
  * Minimal configuration for TLS 1.2 with PSK and AES-CCM ciphersuites
+ *
  * Distinguishing features:
- * - no bignum, no PK, no X509
- * - fully modern and secure (provided the pre-shared keys have high entropy)
- * - very low record overhead with CCM-8
- * - optimized for low RAM usage
+ * - Optimized for small code size, low bandwidth (on a reliable transport),
+ *   and low RAM usage.
+ * - No asymmetric cryptography (no certificates, no Diffie-Hellman key
+ *   exchange).
+ * - Fully modern and secure (provided the pre-shared keys are generated and
+ *   stored securely).
+ * - Very low record overhead with CCM-8.
  *
  * See README.txt for usage instructions.
  */
@@ -36,11 +40,7 @@
 //#define MBEDTLS_HAVE_TIME /* Optionally used in Hello messages */
 /* Other MBEDTLS_HAVE_XXX flags irrelevant for this configuration */
 
-/* mbed TLS feature support */
-#define MBEDTLS_KEY_EXCHANGE_PSK_ENABLED
-#define MBEDTLS_SSL_PROTO_TLS1_2
-
-/* mbed TLS modules */
+/* Mbed TLS modules */
 #define MBEDTLS_AES_C
 #define MBEDTLS_CCM_C
 #define MBEDTLS_CIPHER_C
@@ -53,18 +53,9 @@
 #define MBEDTLS_SSL_SRV_C
 #define MBEDTLS_SSL_TLS_C
 
-/* Save RAM at the expense of ROM */
-#define MBEDTLS_AES_ROM_TABLES
-
-/* Save some RAM by adjusting to your exact needs */
-#define MBEDTLS_PSK_MAX_LEN    16 /* 128-bits keys are generally enough */
-
-/*
- * You should adjust this to the exact number of sources you're using: default
- * is the "platform_entropy_poll" source, but you may want to add other ones
- * Minimum is 2 for the entropy test suite.
- */
-#define MBEDTLS_ENTROPY_MAX_SOURCES 2
+/* TLS protocol feature support */
+#define MBEDTLS_KEY_EXCHANGE_PSK_ENABLED
+#define MBEDTLS_SSL_PROTO_TLS1_2
 
 /*
  * Use only CCM_8 ciphersuites, and
@@ -81,11 +72,29 @@
  */
 #define MBEDTLS_SSL_MAX_CONTENT_LEN             1024
 
+/* Save RAM at the expense of ROM */
+#define MBEDTLS_AES_ROM_TABLES
+
+/* Save some RAM by adjusting to your exact needs */
+#define MBEDTLS_PSK_MAX_LEN    16 /* 128-bits keys are generally enough */
+
+/*
+ * You should adjust this to the exact number of sources you're using: default
+ * is the "platform_entropy_poll" source, but you may want to add other ones
+ * Minimum is 2 for the entropy test suite.
+ */
+#define MBEDTLS_ENTROPY_MAX_SOURCES 2
+
 /* These defines are present so that the config modifying scripts can enable
  * them during tests/scripts/test-ref-configs.pl */
 //#define MBEDTLS_USE_PSA_CRYPTO
 //#define MBEDTLS_PSA_CRYPTO_C
 
+/* Error messages and TLS debugging traces
+ * (huge code size increase, needed for tests/ssl-opt.sh) */
+//#define MBEDTLS_DEBUG_C
+//#define MBEDTLS_ERROR_C
+
 #include "mbedtls/check_config.h"
 
 #endif /* MBEDTLS_CONFIG_H */

configs/config-mini-tls1_1.h

@@ -82,4 +82,9 @@
 #endif
 #include "mbedtls/check_config.h"
 
+/* Error messages and TLS debugging traces
+ * (huge code size increase, needed for tests/ssl-opt.sh) */
+//#define MBEDTLS_DEBUG_C
+//#define MBEDTLS_ERROR_C
+
 #endif /* MBEDTLS_CONFIG_H */

configs/config-suite-b.h

@@ -119,6 +119,11 @@
 #define MBEDTLS_PK_WRITE_C
 #endif
 
+/* Error messages and TLS debugging traces
+ * (huge code size increase, needed for tests/ssl-opt.sh) */
+//#define MBEDTLS_DEBUG_C
+//#define MBEDTLS_ERROR_C
+
 #include "mbedtls/check_config.h"
 
 #endif /* MBEDTLS_CONFIG_H */

library/ssl_tls.c

@@ -990,6 +990,7 @@ static int ssl_populate_transform( mbedtls_ssl_transform *transform,
 
 #if !defined(MBEDTLS_SSL_HW_RECORD_ACCEL) && \
     !defined(MBEDTLS_SSL_EXPORT_KEYS) && \
+    !defined(MBEDTLS_SSL_DTLS_CONNECTION_ID) && \
     !defined(MBEDTLS_DEBUG_C)
     ssl = NULL; /* make sure we don't use it except for those cases */
     (void) ssl;

programs/ssl/ssl_server2.c

@@ -164,9 +164,6 @@ int main( void )
 
 /*
  * Size of the basic I/O buffer. Able to hold our default response.
- *
- * You will need to adapt the mbedtls_ssl_get_bytes_avail() test in ssl-opt.sh
- * if you change this value to something outside the range <= 100 or > 500
  */
 #define DFL_IO_BUF_LEN      200
 
@@ -2032,10 +2029,26 @@ int main( int argc, char *argv[] )
 #if defined(MBEDTLS_DEBUG_C)
     mbedtls_debug_set_threshold( opt.debug_level );
 #endif
-    buf = mbedtls_calloc( 1, opt.buffer_size + 1 );
+
+    /* buf will alternatively contain the input read from the client and the
+     * response that's about to be sent, plus a null byte in each case. */
+    size_t buf_content_size = opt.buffer_size;
+    /* The default response contains the ciphersuite name. Leave enough
+     * room for that plus some margin. */
+    if( buf_content_size < strlen( HTTP_RESPONSE ) + 80 )
+    {
+        buf_content_size = strlen( HTTP_RESPONSE ) + 80;
+    }
+    if( opt.response_size != DFL_RESPONSE_SIZE &&
+        buf_content_size < (size_t) opt.response_size )
+    {
+        buf_content_size = opt.response_size;
+    }
+    buf = mbedtls_calloc( 1, buf_content_size + 1 );
     if( buf == NULL )
     {
-        mbedtls_printf( "Could not allocate %u bytes\n", opt.buffer_size );
+        mbedtls_printf( "Could not allocate %lu bytes\n",
+                        (unsigned long) buf_content_size + 1 );
         ret = 3;
         goto exit;
     }
@@ -3451,7 +3464,7 @@ int main( int argc, char *argv[] )
         do
         {
             int terminated = 0;
-            len = opt.buffer_size - 1;
+            len = opt.buffer_size;
             memset( buf, 0, opt.buffer_size );
             ret = mbedtls_ssl_read( &ssl, buf, len );
 
@@ -3552,7 +3565,7 @@ int main( int argc, char *argv[] )
     }
     else /* Not stream, so datagram */
     {
-        len = opt.buffer_size - 1;
+        len = opt.buffer_size;
         memset( buf, 0, opt.buffer_size );
 
         do
@@ -3654,6 +3667,8 @@ int main( int argc, char *argv[] )
     mbedtls_printf( "  > Write to client:" );
     fflush( stdout );
 
+    /* If the format of the response changes, make sure there is enough
+     * room in buf (buf_content_size calculation above). */
     len = sprintf( (char *) buf, HTTP_RESPONSE,
                    mbedtls_ssl_get_ciphersuite( &ssl ) );
 

programs/test/dlopen.c

@@ -23,8 +23,9 @@
 #include MBEDTLS_CONFIG_FILE
 #endif
 
+#if defined(MBEDTLS_PLATFORM_C)
 #include "mbedtls/platform.h"
-#if !defined(MBEDTLS_PLATFORM_C)
+#else
 #include <stdio.h>
 #include <stdlib.h>
 #define mbedtls_fprintf    fprintf

tests/scripts/all.sh

@@ -2983,11 +2983,12 @@ component_test_cmake_out_of_source () {
     # "No such file or directory", which would indicate that some required
     # file is missing (ssl-opt.sh tolerates the absence of some files so
     # may exit with status 0 but emit errors).
-    ./tests/ssl-opt.sh -f 'Fallback SCSV: beginning of list' 2>ssl-opt.err
+    ./tests/ssl-opt.sh -f 'Fallback SCSV: beginning of list' >ssl-opt.out 2>ssl-opt.err
+    grep PASS ssl-opt.out
     cat ssl-opt.err >&2
     # If ssl-opt.err is non-empty, record an error and keep going.
     [ ! -s ssl-opt.err ]
-    rm ssl-opt.err
+    rm ssl-opt.out ssl-opt.err
     cd "$MBEDTLS_ROOT_DIR"
     rm -rf "$OUT_OF_SOURCE_DIR"
 }