| /* BEGIN_HEADER */ |
| #include "mbedtls/entropy.h" |
| #include "mbedtls/ctr_drbg.h" |
| #include "string.h" |
| |
| /* Modes for ctr_drbg_validate */ |
| enum reseed_mode |
| { |
| RESEED_NEVER, /* never reseed */ |
| RESEED_FIRST, /* instantiate, reseed, generate, generate */ |
| RESEED_SECOND, /* instantiate, generate, reseed, generate */ |
| RESEED_ALWAYS /* prediction resistance, no explicit reseed */ |
| }; |
| |
| static size_t test_offset_idx = 0; |
| static size_t test_max_idx = 0; |
| static int mbedtls_test_entropy_func( void *data, unsigned char *buf, size_t len ) |
| { |
| const unsigned char *p = (unsigned char *) data; |
| if( test_offset_idx + len > test_max_idx ) |
| return( MBEDTLS_ERR_ENTROPY_SOURCE_FAILED ); |
| memcpy( buf, p + test_offset_idx, len ); |
| test_offset_idx += len; |
| return( 0 ); |
| } |
| |
| static void ctr_drbg_validate_internal( int reseed_mode, data_t * nonce, |
| int entropy_len_arg, data_t * entropy, |
| data_t * reseed, |
| data_t * add1, data_t * add2, |
| data_t * result ) |
| { |
| mbedtls_ctr_drbg_context ctx; |
| unsigned char buf[64]; |
| |
| size_t entropy_chunk_len = (size_t) entropy_len_arg; |
| |
| TEST_ASSERT( entropy_chunk_len <= sizeof( buf ) ); |
| |
| test_offset_idx = 0; |
| mbedtls_ctr_drbg_init( &ctx ); |
| |
| test_max_idx = entropy->len; |
| |
| /* CTR_DRBG_Instantiate(entropy[:entropy->len], nonce, perso, <ignored>) |
| * where nonce||perso = nonce[nonce->len] */ |
| mbedtls_ctr_drbg_set_entropy_len( &ctx, entropy_chunk_len ); |
| mbedtls_ctr_drbg_set_nonce_len( &ctx, 0 ); |
| TEST_ASSERT( mbedtls_ctr_drbg_seed( |
| &ctx, |
| mbedtls_test_entropy_func, entropy->x, |
| nonce->x, nonce->len ) == 0 ); |
| if( reseed_mode == RESEED_ALWAYS ) |
| mbedtls_ctr_drbg_set_prediction_resistance( |
| &ctx, |
| MBEDTLS_CTR_DRBG_PR_ON ); |
| |
| if( reseed_mode == RESEED_FIRST ) |
| { |
| /* CTR_DRBG_Reseed(entropy[idx:idx+entropy->len], |
| * reseed[:reseed->len]) */ |
| TEST_ASSERT( mbedtls_ctr_drbg_reseed( |
| &ctx, |
| reseed->x, reseed->len ) == 0 ); |
| } |
| |
| /* CTR_DRBG_Generate(result->len * 8 bits, add1[:add1->len]) -> buf */ |
| /* Then reseed if prediction resistance is enabled. */ |
| TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( |
| &ctx, |
| buf, result->len, |
| add1->x, add1->len ) == 0 ); |
| |
| |
| if( reseed_mode == RESEED_SECOND ) |
| { |
| /* CTR_DRBG_Reseed(entropy[idx:idx+entropy->len], |
| * reseed[:reseed->len]) */ |
| TEST_ASSERT( mbedtls_ctr_drbg_reseed( |
| &ctx, |
| reseed->x, reseed->len ) == 0 ); |
| } |
| |
| /* CTR_DRBG_Generate(result->len * 8 bits, add2->x[:add2->len]) -> buf */ |
| /* Then reseed if prediction resistance is enabled. */ |
| TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( |
| &ctx, |
| buf, result->len, |
| add2->x, add2->len ) == 0 ); |
| TEST_ASSERT( memcmp( buf, result->x, result->len ) == 0 ); |
| |
| exit: |
| mbedtls_ctr_drbg_free( &ctx ); |
| } |
| |
| /* END_HEADER */ |
| |
| /* BEGIN_DEPENDENCIES |
| * depends_on:MBEDTLS_CTR_DRBG_C |
| * END_DEPENDENCIES |
| */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_special_behaviours( ) |
| { |
| mbedtls_ctr_drbg_context ctx; |
| unsigned char output[512]; |
| unsigned char additional[512]; |
| |
| mbedtls_ctr_drbg_init( &ctx ); |
| memset( output, 0, sizeof( output ) ); |
| memset( additional, 0, sizeof( additional ) ); |
| |
| TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, |
| output, MBEDTLS_CTR_DRBG_MAX_REQUEST + 1, |
| additional, 16 ) == |
| MBEDTLS_ERR_CTR_DRBG_REQUEST_TOO_BIG ); |
| TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, |
| output, 16, |
| additional, MBEDTLS_CTR_DRBG_MAX_INPUT + 1 ) == |
| MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG ); |
| |
| TEST_ASSERT( mbedtls_ctr_drbg_reseed( &ctx, additional, |
| MBEDTLS_CTR_DRBG_MAX_SEED_INPUT + 1 ) == |
| MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG ); |
| |
| mbedtls_ctr_drbg_set_entropy_len( &ctx, ~0 ); |
| TEST_ASSERT( mbedtls_ctr_drbg_reseed( &ctx, additional, |
| MBEDTLS_CTR_DRBG_MAX_SEED_INPUT ) == |
| MBEDTLS_ERR_CTR_DRBG_INPUT_TOO_BIG ); |
| exit: |
| mbedtls_ctr_drbg_free( &ctx ); |
| } |
| /* END_CASE */ |
| |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_validate_no_reseed( data_t * add_init, data_t * entropy, |
| data_t * add1, data_t * add2, |
| data_t * result_string ) |
| { |
| data_t empty = { 0, 0 }; |
| ctr_drbg_validate_internal( RESEED_NEVER, add_init, |
| entropy->len, entropy, |
| &empty, add1, add2, |
| result_string ); |
| goto exit; // goto is needed to avoid warning ( no test assertions in func) |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_validate_pr( data_t * add_init, data_t * entropy, |
| data_t * add1, data_t * add2, |
| data_t * result_string ) |
| { |
| data_t empty = { 0, 0 }; |
| ctr_drbg_validate_internal( RESEED_ALWAYS, add_init, |
| entropy->len / 3, entropy, |
| &empty, add1, add2, |
| result_string ); |
| goto exit; // goto is needed to avoid warning ( no test assertions in func) |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_validate_reseed_between( data_t * add_init, data_t * entropy, |
| data_t * add1, data_t * add_reseed, |
| data_t * add2, data_t * result_string ) |
| { |
| ctr_drbg_validate_internal( RESEED_SECOND, add_init, |
| entropy->len / 2, entropy, |
| add_reseed, add1, add2, |
| result_string ); |
| goto exit; // goto is needed to avoid warning ( no test assertions in func) |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_validate_reseed_first( data_t * add_init, data_t * entropy, |
| data_t * add1, data_t * add_reseed, |
| data_t * add2, data_t * result_string ) |
| { |
| ctr_drbg_validate_internal( RESEED_FIRST, add_init, |
| entropy->len / 2, entropy, |
| add_reseed, add1, add2, |
| result_string ); |
| goto exit; // goto is needed to avoid warning ( no test assertions in func) |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_entropy_strength( int expected_bit_strength ) |
| { |
| unsigned char entropy[/*initial entropy*/ MBEDTLS_CTR_DRBG_ENTROPY_LEN + |
| /*nonce*/ MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN + |
| /*reseed*/ MBEDTLS_CTR_DRBG_ENTROPY_LEN]; |
| mbedtls_ctr_drbg_context ctx; |
| size_t last_idx; |
| size_t byte_strength = expected_bit_strength / 8; |
| |
| mbedtls_ctr_drbg_init( &ctx ); |
| test_offset_idx = 0; |
| test_max_idx = sizeof( entropy ); |
| memset( entropy, 0, sizeof( entropy ) ); |
| |
| /* The initial seeding must grab at least byte_strength bytes of entropy |
| * for the entropy input and byte_strength/2 bytes for a nonce. */ |
| TEST_ASSERT( mbedtls_ctr_drbg_seed( &ctx, |
| mbedtls_test_entropy_func, entropy, |
| NULL, 0 ) == 0 ); |
| TEST_ASSERT( test_offset_idx >= ( byte_strength * 3 + 1 ) / 2 ); |
| last_idx = test_offset_idx; |
| |
| /* A reseed must grab at least byte_strength bytes of entropy. */ |
| TEST_ASSERT( mbedtls_ctr_drbg_reseed( &ctx, NULL, 0 ) == 0 ); |
| TEST_ASSERT( test_offset_idx - last_idx >= byte_strength ); |
| |
| exit: |
| mbedtls_ctr_drbg_free( &ctx ); |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE */ |
| void ctr_drbg_entropy_usage( int entropy_nonce_len ) |
| { |
| unsigned char out[16]; |
| unsigned char add[16]; |
| unsigned char entropy[1024]; |
| mbedtls_ctr_drbg_context ctx; |
| size_t i, reps = 10; |
| size_t expected_idx = 0; |
| |
| mbedtls_ctr_drbg_init( &ctx ); |
| test_offset_idx = 0; |
| test_max_idx = sizeof( entropy ); |
| memset( entropy, 0, sizeof( entropy ) ); |
| memset( out, 0, sizeof( out ) ); |
| memset( add, 0, sizeof( add ) ); |
| |
| if( entropy_nonce_len >= 0 ) |
| TEST_ASSERT( mbedtls_ctr_drbg_set_nonce_len( &ctx, entropy_nonce_len ) == 0 ); |
| |
| /* Set reseed interval before seed */ |
| mbedtls_ctr_drbg_set_reseed_interval( &ctx, 2 * reps ); |
| |
| /* Init must use entropy */ |
| TEST_ASSERT( mbedtls_ctr_drbg_seed( &ctx, mbedtls_test_entropy_func, entropy, NULL, 0 ) == 0 ); |
| expected_idx += MBEDTLS_CTR_DRBG_ENTROPY_LEN; |
| if( entropy_nonce_len >= 0 ) |
| expected_idx += entropy_nonce_len; |
| else |
| expected_idx += MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN; |
| TEST_EQUAL( test_offset_idx, expected_idx ); |
| |
| /* By default, PR is off, and reseed interval was set to |
| * 2 * reps so the next few calls should not use entropy */ |
| for( i = 0; i < reps; i++ ) |
| { |
| TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) - 4 ) == 0 ); |
| TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, out, sizeof( out ) - 4, |
| add, sizeof( add ) ) == 0 ); |
| } |
| TEST_EQUAL( test_offset_idx, expected_idx ); |
| |
| /* While at it, make sure we didn't write past the requested length */ |
| TEST_ASSERT( out[sizeof( out ) - 4] == 0 ); |
| TEST_ASSERT( out[sizeof( out ) - 3] == 0 ); |
| TEST_ASSERT( out[sizeof( out ) - 2] == 0 ); |
| TEST_ASSERT( out[sizeof( out ) - 1] == 0 ); |
| |
| /* There have been 2 * reps calls to random. The next call should reseed */ |
| TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 ); |
| expected_idx += MBEDTLS_CTR_DRBG_ENTROPY_LEN; |
| TEST_EQUAL( test_offset_idx, expected_idx ); |
| |
| /* Set reseed interval after seed */ |
| mbedtls_ctr_drbg_set_reseed_interval( &ctx, 4 * reps + 1 ); |
| |
| /* The next few calls should not reseed */ |
| for( i = 0; i < (2 * reps); i++ ) |
| { |
| TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 ); |
| TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, out, sizeof( out ) , |
| add, sizeof( add ) ) == 0 ); |
| } |
| TEST_EQUAL( test_offset_idx, expected_idx ); |
| |
| /* Call update with too much data (sizeof entropy > MAX(_SEED)_INPUT). |
| * Make sure it's detected as an error and doesn't cause memory |
| * corruption. */ |
| TEST_ASSERT( mbedtls_ctr_drbg_update( |
| &ctx, entropy, sizeof( entropy ) ) != 0 ); |
| |
| /* Now enable PR, so the next few calls should all reseed */ |
| mbedtls_ctr_drbg_set_prediction_resistance( &ctx, MBEDTLS_CTR_DRBG_PR_ON ); |
| TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 ); |
| expected_idx += MBEDTLS_CTR_DRBG_ENTROPY_LEN; |
| TEST_EQUAL( test_offset_idx, expected_idx ); |
| |
| /* Finally, check setting entropy_len */ |
| mbedtls_ctr_drbg_set_entropy_len( &ctx, 42 ); |
| TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 ); |
| expected_idx += 42; |
| TEST_EQUAL( test_offset_idx, expected_idx ); |
| |
| mbedtls_ctr_drbg_set_entropy_len( &ctx, 13 ); |
| TEST_ASSERT( mbedtls_ctr_drbg_random( &ctx, out, sizeof( out ) ) == 0 ); |
| expected_idx += 13; |
| TEST_EQUAL( test_offset_idx, expected_idx ); |
| |
| exit: |
| mbedtls_ctr_drbg_free( &ctx ); |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE depends_on:MBEDTLS_FS_IO */ |
| void ctr_drbg_seed_file( char * path, int ret ) |
| { |
| mbedtls_ctr_drbg_context ctx; |
| |
| mbedtls_ctr_drbg_init( &ctx ); |
| |
| TEST_ASSERT( mbedtls_ctr_drbg_seed( &ctx, mbedtls_test_rnd_std_rand, |
| NULL, NULL, 0 ) == 0 ); |
| TEST_ASSERT( mbedtls_ctr_drbg_write_seed_file( &ctx, path ) == ret ); |
| TEST_ASSERT( mbedtls_ctr_drbg_update_seed_file( &ctx, path ) == ret ); |
| |
| exit: |
| mbedtls_ctr_drbg_free( &ctx ); |
| } |
| /* END_CASE */ |
| |
| /* BEGIN_CASE depends_on:MBEDTLS_SELF_TEST */ |
| void ctr_drbg_selftest( ) |
| { |
| TEST_ASSERT( mbedtls_ctr_drbg_self_test( 1 ) == 0 ); |
| } |
| /* END_CASE */ |
