From d56ca658ab8bd49cbbde8790240ec4074c0a7622 Mon Sep 17 00:00:00 2001 From: Gilles Peskine Date: Wed, 12 Jun 2019 19:33:42 +0200 Subject: [PATCH] entropy_nv_seed: cope with SHA-256 This test case was only executed if the SHA-512 module was enabled and MBEDTLS_ENTROPY_FORCE_SHA256 was not enabled, so "config.pl full" didn't have a chance to reach it even if that enabled MBEDTLS_PLATFORM_NV_SEED_ALT. Now all it takes to enable this test is MBEDTLS_PLATFORM_NV_SEED_ALT and its requirements, and the near-ubiquitous MD module. --- tests/suites/test_suite_entropy.function | 63 +++++++++++++++--------- 1 file changed, 40 insertions(+), 23 deletions(-) diff --git a/tests/suites/test_suite_entropy.function b/tests/suites/test_suite_entropy.function index 18ad25e33..3b87244d0 100644 --- a/tests/suites/test_suite_entropy.function +++ b/tests/suites/test_suite_entropy.function @@ -300,10 +300,19 @@ void entropy_nv_seed_std_io() } /* END_CASE */ -/* BEGIN_CASE depends_on:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_PLATFORM_NV_SEED_ALT:MBEDTLS_ENTROPY_SHA512_ACCUMULATOR */ +/* BEGIN_CASE depends_on:MBEDTLS_MD_C:MBEDTLS_ENTROPY_NV_SEED:MBEDTLS_PLATFORM_NV_SEED_ALT */ void entropy_nv_seed( char *read_seed_str ) { - mbedtls_sha512_context accumulator; +#if defined(MBEDTLS_ENTROPY_SHA512_ACCUMULATOR) + const mbedtls_md_info_t *md_info = + mbedtls_md_info_from_type( MBEDTLS_MD_SHA512 ); +#elif defined(MBEDTLS_ENTROPY_SHA256_ACCUMULATOR) + const mbedtls_md_info_t *md_info = + mbedtls_md_info_from_type( MBEDTLS_MD_SHA256 ); +#else +#error "Unsupported entropy accumulator" +#endif + mbedtls_md_context_t accumulator; mbedtls_entropy_context ctx; int (*original_mbedtls_nv_seed_read)( unsigned char *buf, size_t buf_len ) = mbedtls_nv_seed_read; @@ -320,18 +329,14 @@ void entropy_nv_seed( char *read_seed_str ) memset( entropy, 0, MBEDTLS_ENTROPY_BLOCK_SIZE ); memset( buf, 0, MBEDTLS_ENTROPY_BLOCK_SIZE ); - memset( buffer_seed, 0, MBEDTLS_ENTROPY_BLOCK_SIZE ); memset( empty, 0, MBEDTLS_ENTROPY_BLOCK_SIZE ); memset( check_seed, 2, MBEDTLS_ENTROPY_BLOCK_SIZE ); memset( check_entropy, 3, MBEDTLS_ENTROPY_BLOCK_SIZE ); - // Set the initial NV seed to read - unhexify( read_seed, read_seed_str ); - memcpy( buffer_seed, read_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ); - // Make sure we read/write NV seed from our buffers mbedtls_platform_set_nv_seed( buffer_nv_seed_read, buffer_nv_seed_write ); + mbedtls_md_init( &accumulator ); mbedtls_entropy_init( &ctx ); entropy_clear_sources( &ctx ); @@ -339,45 +344,57 @@ void entropy_nv_seed( char *read_seed_str ) MBEDTLS_ENTROPY_BLOCK_SIZE, MBEDTLS_ENTROPY_SOURCE_STRONG ) == 0 ); + // Set the initial NV seed to read. + // Get exactly MBEDTLS_ENTROPY_BLOCK_SIZE bytes from read_str. + TEST_ASSERT( strlen( read_seed ) / 2 >= MBEDTLS_ENTROPY_BLOCK_SIZE ); + read_seed_str[MBEDTLS_ENTROPY_BLOCK_SIZE * 2] = '\0'; + unhexify( read_seed, read_seed_str ); + memcpy( buffer_seed, read_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ); + // Do an entropy run TEST_ASSERT( mbedtls_entropy_func( &ctx, entropy, sizeof( entropy ) ) == 0 ); - // Determine what should have happened with manual entropy internal logic - // Only use the SHA-512 version to check // Init accumulator header[1] = MBEDTLS_ENTROPY_BLOCK_SIZE; - mbedtls_sha512_starts( &accumulator, 0 ); + TEST_ASSERT( mbedtls_md_setup( &accumulator, md_info, 0 ) == 0 ); // First run for updating write_seed header[0] = 0; - mbedtls_sha512_update( &accumulator, header, 2 ); - mbedtls_sha512_update( &accumulator, read_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ); - mbedtls_sha512_finish( &accumulator, buf ); + TEST_ASSERT( mbedtls_md_starts( &accumulator ) == 0 ); + TEST_ASSERT( mbedtls_md_update( &accumulator, header, 2 ) == 0 ); + TEST_ASSERT( mbedtls_md_update( &accumulator, + read_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 ); + TEST_ASSERT( mbedtls_md_finish( &accumulator, buf ) == 0 ); - memset( &accumulator, 0, sizeof( mbedtls_sha512_context ) ); - mbedtls_sha512_starts( &accumulator, 0 ); - mbedtls_sha512_update( &accumulator, buf, MBEDTLS_ENTROPY_BLOCK_SIZE ); + TEST_ASSERT( mbedtls_md_starts( &accumulator ) == 0 ); + TEST_ASSERT( mbedtls_md_update( &accumulator, + buf, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 ); - mbedtls_sha512( buf, MBEDTLS_ENTROPY_BLOCK_SIZE, check_seed, 0 ); + TEST_ASSERT( mbedtls_md( md_info, buf, MBEDTLS_ENTROPY_BLOCK_SIZE, + check_seed ) == 0 ); // Second run for actual entropy (triggers mbedtls_entropy_update_nv_seed) header[0] = MBEDTLS_ENTROPY_SOURCE_MANUAL; - mbedtls_sha512_update( &accumulator, header, 2 ); - mbedtls_sha512_update( &accumulator, empty, MBEDTLS_ENTROPY_BLOCK_SIZE ); + TEST_ASSERT( mbedtls_md_update( &accumulator, header, 2 ) == 0 ); + TEST_ASSERT( mbedtls_md_update( &accumulator, + empty, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 ); header[0] = 0; - mbedtls_sha512_update( &accumulator, header, 2 ); - mbedtls_sha512_update( &accumulator, check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ); - mbedtls_sha512_finish( &accumulator, buf ); + TEST_ASSERT( mbedtls_md_update( &accumulator, header, 2 ) == 0 ); + TEST_ASSERT( mbedtls_md_update( &accumulator, + check_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 ); + TEST_ASSERT( mbedtls_md_finish( &accumulator, buf ) == 0 ); - mbedtls_sha512( buf, MBEDTLS_ENTROPY_BLOCK_SIZE, check_entropy, 0 ); + TEST_ASSERT( mbedtls_md( md_info, buf, MBEDTLS_ENTROPY_BLOCK_SIZE, + check_entropy ) == 0 ); // Check result of both NV file and entropy received with the manual calculations TEST_ASSERT( memcmp( check_seed, buffer_seed, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 ); TEST_ASSERT( memcmp( check_entropy, entropy, MBEDTLS_ENTROPY_BLOCK_SIZE ) == 0 ); exit: + mbedtls_md_free( &accumulator ); mbedtls_entropy_free( &ctx ); mbedtls_nv_seed_read = original_mbedtls_nv_seed_read; mbedtls_nv_seed_write = original_mbedtls_nv_seed_write;