mirror of
https://github.com/yuzu-emu/mbedtls.git
synced 2024-10-19 02:21:27 +00:00
69971662bf
The default entropy nonce length is either zero or nonzero depending on the desired security strength and the entropy length. The implementation calculates the actual entropy nonce length from the actual entropy length, and therefore it doesn't need a constant that indicates the default entropy nonce length. A portable application may be interested in this constant, however. And our test code could definitely use it. Define a constant MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN and use it in test code. Previously, test_suite_ctr_drbg had knowledge about the default entropy nonce length built in and test_suite_psa_crypto_init failed. Now both use MBEDTLS_CTR_DRBG_ENTROPY_NONCE_LEN. This change means that the test ctr_drbg_entropy_usage no longer validates that the default entropy nonce length is sensible. So add a new test that checks that the default entropy length and the default entropy nonce length are sufficient to ensure the expected security strength.
334 lines
12 KiB
Plaintext
334 lines
12 KiB
Plaintext
/* 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 );
|
|
|
|
/* 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 is large,
|
|
* 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 );
|
|
|
|
/* Set reseed_interval to the number of calls done,
|
|
* so the next call should reseed */
|
|
mbedtls_ctr_drbg_set_reseed_interval( &ctx, 2 * reps );
|
|
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 );
|
|
|
|
/* The new few calls should not reseed */
|
|
for( i = 0; i < reps / 2; 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_ret(
|
|
&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, 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 */
|