From 2de07f1dd1b771c19d22aa58e083c0c69ca270aa Mon Sep 17 00:00:00 2001 From: Jaeden Amero Date: Wed, 5 Jun 2019 13:32:08 +0100 Subject: [PATCH] ssl: Don't access non-existent encrypt_then_mac field When MBEDTLS_SSL_ENCRYPT_THEN_MAC is enabled, but not MBEDTLS_SSL_SOME_MODES_USE_MAC, mbedtls_ssl_derive_keys() and build_transforms() will attempt to use a non-existent `encrypt_then_mac` field in the ssl_transform. Compile [ 93.7%]: ssl_tls.c [Error] ssl_tls.c@865,14: 'mbedtls_ssl_transform {aka struct mbedtls_ssl_transform}' ha s no member named 'encrypt_then_mac' [ERROR] ./mbed-os/features/mbedtls/src/ssl_tls.c: In function 'mbedtls_ssl_derive_keys' : ./mbed-os/features/mbedtls/src/ssl_tls.c:865:14: error: 'mbedtls_ssl_transform {aka str uct mbedtls_ssl_transform}' has no member named 'encrypt_then_mac' transform->encrypt_then_mac = session->encrypt_then_mac; ^~ Change mbedtls_ssl_derive_keys() and build_transforms() to only access `encrypt_then_mac` if `encrypt_then_mac` is actually present. Add a regression test to detect when we have regressions with configurations that do not include any MAC ciphersuites. Fixes d56ed2491be9 ("Reduce size of `ssl_transform` if no MAC ciphersuite is enabled") --- library/ssl_tls.c | 3 ++- tests/scripts/all.sh | 14 ++++++++++++++ tests/suites/test_suite_ssl.function | 3 ++- 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/library/ssl_tls.c b/library/ssl_tls.c index 56e9c8b446..d9e777d8a7 100644 --- a/library/ssl_tls.c +++ b/library/ssl_tls.c @@ -953,7 +953,8 @@ int mbedtls_ssl_derive_keys( mbedtls_ssl_context *ssl ) MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> derive keys" ) ); -#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) +#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) && \ + defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) transform->encrypt_then_mac = session->encrypt_then_mac; #endif transform->minor_ver = ssl->minor_ver; diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh index 86c0ce5cf3..51053d7fff 100755 --- a/tests/scripts/all.sh +++ b/tests/scripts/all.sh @@ -953,6 +953,20 @@ component_test_no_max_fragment_length_small_ssl_out_content_len () { if_build_succeeded tests/ssl-opt.sh -f "Max fragment length\|Large buffer" } +component_test_when_no_ciphersuites_have_mac () { + msg "build: when no ciphersuites have MAC" + scripts/config.pl unset MBEDTLS_CIPHER_NULL_CIPHER + scripts/config.pl unset MBEDTLS_ARC4_C + scripts/config.pl unset MBEDTLS_CIPHER_MODE_CBC + make + + msg "test: !MBEDTLS_SSL_SOME_MODES_USE_MAC" + make test + + msg "test ssl-opt.sh: !MBEDTLS_SSL_SOME_MODES_USE_MAC" + if_build_succeeded tests/ssl-opt.sh +} + component_test_null_entropy () { msg "build: default config with MBEDTLS_TEST_NULL_ENTROPY (ASan build)" scripts/config.pl set MBEDTLS_TEST_NULL_ENTROPY diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function index cc7d8dcea6..104a52f229 100644 --- a/tests/suites/test_suite_ssl.function +++ b/tests/suites/test_suite_ssl.function @@ -159,7 +159,8 @@ static int build_transforms( mbedtls_ssl_transform *t_in, * Setup transforms */ -#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) +#if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC) && \ + defined(MBEDTLS_SSL_SOME_MODES_USE_MAC) t_out->encrypt_then_mac = etm; t_in->encrypt_then_mac = etm; #else