From 73afa37507dbb6ec76fbed2e21a9305fbb1d6c09 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= Date: Wed, 19 Aug 2020 10:27:38 +0200 Subject: [PATCH] Add option to test constant-flow with valgrind MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently the new component in all.sh fails because mbedtls_ssl_cf_memcpy_offset() is not actually constant flow - this is on purpose to be able to verify that the new test works. Signed-off-by: Manuel Pégourié-Gonnard --- include/mbedtls/config.h | 17 ++++++++++++++ library/version_features.c | 3 +++ programs/test/query_config.c | 8 +++++++ scripts/config.py | 1 + tests/include/test/constant_flow.h | 36 ++++++++++++++++++++++++++++-- tests/scripts/all.sh | 22 ++++++++++++++++++ 6 files changed, 85 insertions(+), 2 deletions(-) diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h index 5eceea1bc..6337258dc 100644 --- a/include/mbedtls/config.h +++ b/include/mbedtls/config.h @@ -1924,6 +1924,23 @@ */ //#define MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN +/** + * \def MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND + * + * Enable testing of the constant-flow nature of some sensitive functions with + * valgrind's memcheck tool. This causes some existing tests to also test + * non-functional properties of the code under test. + * + * This setting requires valgrind headers for building, and is only useful for + * testing if the tests suites are run with valgrind's memcheck. + * + * \warning This macro is only used for extended testing; it is not considered + * part of the library's API, so it may change or disappear at any time. + * + * Uncomment to enable testing of the constant-flow nature of selected code. + */ +//#define MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND + /** * \def MBEDTLS_TEST_HOOKS * diff --git a/library/version_features.c b/library/version_features.c index 2470d8d1d..16719a6eb 100644 --- a/library/version_features.c +++ b/library/version_features.c @@ -560,6 +560,9 @@ static const char * const features[] = { #if defined(MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN) "MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN", #endif /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN */ +#if defined(MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND) + "MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND", +#endif /* MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND */ #if defined(MBEDTLS_TEST_HOOKS) "MBEDTLS_TEST_HOOKS", #endif /* MBEDTLS_TEST_HOOKS */ diff --git a/programs/test/query_config.c b/programs/test/query_config.c index 23dc51512..c242ab511 100644 --- a/programs/test/query_config.c +++ b/programs/test/query_config.c @@ -1546,6 +1546,14 @@ int query_config( const char *config ) } #endif /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN */ +#if defined(MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND) + if( strcmp( "MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND", config ) == 0 ) + { + MACRO_EXPANSION_TO_STR( MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND ); + return( 0 ); + } +#endif /* MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND */ + #if defined(MBEDTLS_TEST_HOOKS) if( strcmp( "MBEDTLS_TEST_HOOKS", config ) == 0 ) { diff --git a/scripts/config.py b/scripts/config.py index 793e9dfa7..37a2475e6 100755 --- a/scripts/config.py +++ b/scripts/config.py @@ -195,6 +195,7 @@ EXCLUDE_FROM_FULL = frozenset([ 'MBEDTLS_SHA512_NO_SHA384', # removes a feature 'MBEDTLS_SSL_HW_RECORD_ACCEL', # build dependency (hook functions) 'MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN', # build dependency (clang+memsan) + 'MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND', # build dependency (valgrind headers) 'MBEDTLS_TEST_NULL_ENTROPY', # removes a feature 'MBEDTLS_X509_ALLOW_UNSUPPORTED_CRITICAL_EXTENSION', # influences the use of X.509 in TLS 'MBEDTLS_ZLIB_SUPPORT', # build dependency (libz) diff --git a/tests/include/test/constant_flow.h b/tests/include/test/constant_flow.h index 98bee7e48..9307a2513 100644 --- a/tests/include/test/constant_flow.h +++ b/tests/include/test/constant_flow.h @@ -32,6 +32,28 @@ #include MBEDTLS_CONFIG_FILE #endif +/* + * This file defines the two macros + * + * #define TEST_CF_SECRET(ptr, size) + * #define TEST_CF_PUBLIC(ptr, size) + * + * that can be used in tests to mark a memory area as secret (no branch or + * memory access should depend on it) or public (default, only needs to be + * marked explicitly when it was derived from secret data). + * + * Arguments: + * - ptr: a pointer to the memory area to be marked + * - size: the size in bytes of the memory area + * + * Implementation: + * The basic idea is that of ctgrind : we can + * re-use tools that were designed for checking use of uninitialized memory. + * This file contains two implementations: one based on MemorySanitizer, the + * other on valgrind's memcheck. If none of them is enabled, dummy macros that + * do nothing are defined for convenience. + */ + #if defined(MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN) #include @@ -41,11 +63,21 @@ #define TEST_CF_PUBLIC __msan_unpoison // void __msan_unpoison(const volatile void *a, size_t size); -#else /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN */ +#elif defined(MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND) +#include + +#define TEST_CF_SECRET VALGRIND_MAKE_MEM_UNDEFINED +// VALGRIND_MAKE_MEM_UNDEFINED(_qzz_addr, _qzz_len) +#define TEST_CF_PUBLIC VALGRIND_MAKE_MEM_DEFINED +// VALGRIND_MAKE_MEM_DEFINED(_qzz_addr, _qzz_len) + +#else /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN || + MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND */ #define TEST_CF_SECRET(ptr, size) #define TEST_CF_PUBLIC(ptr, size) -#endif /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN */ +#endif /* MBEDTLS_TEST_CONSTANT_FLOW_MEMSAN || + MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND */ #endif /* TEST_CONSTANT_FLOW_H */ diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh index 6cc0cf806..caeb2fe79 100755 --- a/tests/scripts/all.sh +++ b/tests/scripts/all.sh @@ -1111,6 +1111,28 @@ component_test_memsan_constant_flow () { make test } +component_test_valgrind_constant_flow () { + # This tests both (1) everything that valgrind's memcheck usually checks + # (heap buffer overflows, use of uninitialized memory, use-after-free, + # etc.) and (2) branches or memory access depending on secret values, + # which will be reported as uninitialized memory. To distinguish between + # secret and actually uninitialized: + # - unset MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND - does the failure persist? + # - or alternatively, build with debug info and manually run the offending + # test suite with valgrind --track-origins=yes, then check if the origin + # was TEST_CF_SECRET() or something else. + msg "build: cmake release GCC, full config with constant flow testing" + scripts/config.py full + scripts/config.py set MBEDTLS_TEST_CONSTANT_FLOW_VALGRIND + cmake -D CMAKE_BUILD_TYPE:String=Release . + make + + # this only shows a summary of the results (how many of each type) + # details are left in Testing//DynamicAnalysis.xml + msg "test: main suites (valgrind + constant flow)" + make memcheck +} + component_test_default_no_deprecated () { # Test that removing the deprecated features from the default # configuration leaves something consistent.