ctr_drbg tests: unify validate functions

Unify the three existing validation functions (with prediction
resistance, with manual reseeding between generations, and with no
reseeding) into a single function that supports these three scenarios
plus a fourth one (reseed before the first generation).

The four supported scenarios cover the three scenarios from the
current CAVP test vectors (no reseed, reseed before generating,
prediction resistance) plus a fourth scenario used by the existing
test vectors (reseed after generating).

(cherry picked from commit cee9bedee6bc1a8e2b22fa8a31647b62ebb8a0a4)
This commit is contained in:
Gilles Peskine 2018-08-03 20:27:50 +02:00 committed by Nir Sonnenschein
parent 4c78665ccd
commit 5ef5a9aeb4

View file

@ -3,6 +3,15 @@
#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;
static size_t test_max_idx;
static int mbedtls_test_entropy_func( void *data, unsigned char *buf, size_t len )
@ -55,74 +64,107 @@ exit:
/* END_CASE */
/* BEGIN_CASE */
/* BEGIN_CASE */
void ctr_drbg_validate_no_reseed( char *add_init_string, char *entropy_string,
char *add1_string, char *add2_string,
char *result_string )
void ctr_drbg_validate( int reseed_mode, char *nonce_string,
int entropy_len_arg, char *entropy_string,
char *reseed_string,
char *add1_string, char *add2_string,
char *result_string )
{
unsigned char entropy[512];
unsigned char add_init[512];
unsigned char add1[512];
unsigned char add2[512];
unsigned char entropy[144];
unsigned char nonce[64];
unsigned char reseed[32];
unsigned char add1[48];
unsigned char add2[48];
mbedtls_ctr_drbg_context ctx;
unsigned char buf[512];
unsigned char result[512];
size_t entropy_len, add_init_len, add1_len, add2_len, result_len;
unsigned char buf[64];
unsigned char result[64];
size_t entropy_chunk_len = (size_t) entropy_len_arg;
size_t nonce_len, reseed_len, add1_len, add2_len, result_len;
test_offset_idx = 0;
mbedtls_ctr_drbg_init( &ctx );
entropy_len = unhexify( entropy, entropy_string );
add_init_len = unhexify( add_init, add_init_string );
test_max_idx = unhexify( entropy, entropy_string );
nonce_len = unhexify( nonce, nonce_string );
reseed_len = unhexify( reseed, reseed_string );
add1_len = unhexify( add1, add1_string );
add2_len = unhexify( add2, add2_string );
result_len = unhexify( result, result_string );
test_offset_idx = 0;
test_max_idx = entropy_len;
/* CTR_DRBG_Instantiate(entropy[:entropy_len], nonce, perso, <ignored>)
* where nonce||perso = add_init[add_init_len] */
TEST_ASSERT( mbedtls_ctr_drbg_seed_entropy_len( &ctx, mbedtls_test_entropy_func, entropy, add_init, add_init_len, entropy_len ) == 0 );
* where nonce||perso = nonce[nonce_len] */
TEST_ASSERT( mbedtls_ctr_drbg_seed_entropy_len(
&ctx,
mbedtls_test_entropy_func, entropy,
nonce, nonce_len,
entropy_chunk_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, reseed_len ) == 0 );
}
/* CTR_DRBG_Generate(result_len * 8 bits, add1[:add1_len]) -> buf */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, buf, result_len, add1, add1_len ) == 0 );
/* Then reseed if prediction resistance is enabled. */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add(
&ctx,
buf, result_len,
add1, 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, reseed_len ) == 0 );
}
/* CTR_DRBG_Generate(result_len * 8 bits, add2[:add2_len]) -> buf */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, buf, result_len, add2, add2_len ) == 0 );
/* Then reseed if prediction resistance is enabled. */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add(
&ctx,
buf, result_len,
add2, add2_len ) == 0 );
TEST_ASSERT( memcmp( buf, result, result_len ) == 0 );
exit:
mbedtls_ctr_drbg_free( &ctx );
}
/* END_CASE */
/* BEGIN_CASE */
void ctr_drbg_validate_no_reseed( char *add_init_string, char *entropy_string,
char *add1_string, char *add2_string,
char *result_string )
{
test_suite_ctr_drbg_validate( RESEED_NEVER, add_init_string,
strlen( entropy_string ) / 2, entropy_string,
"", add1_string, add2_string,
result_string );
goto exit;
}
/* END_CASE */
/* BEGIN_CASE */
void ctr_drbg_validate_pr( char *add_init_string, char *entropy_string,
char *add1_string, char *add2_string,
char *result_string )
{
mbedtls_ctr_drbg_context ctx;
unsigned char buf[512];
unsigned char result[512];
size_t entropy_len, add_init_len, add1_len, add2_len, result_len;
mbedtls_ctr_drbg_init( &ctx );
entropy_len = unhexify( entropy, entropy_string );
result_len = unhexify( result, result_string );
test_offset_idx = 0;
test_max_idx = entropy_len;
/* CTR_DRBG_Instantiate(entropy[:entropy_len/3], nonce, perso, <ignored>)
* where nonce||perso = add_init[add_init_len] */
TEST_ASSERT( mbedtls_ctr_drbg_seed_entropy_len( &ctx, mbedtls_test_entropy_func, entropy, add_init, add_init_len, entropy_len / 3 ) == 0 );
mbedtls_ctr_drbg_set_prediction_resistance( &ctx, MBEDTLS_CTR_DRBG_PR_ON );
/* CTR_DRBG_Generate(result_len * 8 bits, add1[:add1_len]) -> buf */
/* Then reseed because of prediction resistance. */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, buf, result_len, add1, add1_len ) == 0 );
/* CTR_DRBG_Generate(result_len * 8 bits, add2[:add2_len]) -> buf */
/* Then reseed because of prediction resistance. */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, buf, result_len, add2, add2_len ) == 0 );
TEST_ASSERT( memcmp( buf, result, result_len ) == 0 );
exit:
mbedtls_ctr_drbg_free( &ctx );
test_suite_ctr_drbg_validate( RESEED_ALWAYS, add_init_string,
strlen( entropy_string ) / 6, entropy_string,
"", add1_string, add2_string,
result_string );
goto exit;
}
/* END_CASE */
@ -131,32 +173,11 @@ void ctr_drbg_validate_nopr( data_t * add_init, data_t * entropy,
data_t * add1, data_t * add_reseed,
char *add2_string, char *result_string )
{
mbedtls_ctr_drbg_context ctx;
unsigned char buf[512];
unsigned char result[512];
size_t entropy_len, add_init_len, add1_len, add_reseed_len, add2_len, result_len;
mbedtls_ctr_drbg_init( &ctx );
entropy_len = unhexify( entropy, entropy_string );
result_len = unhexify( result, result_string );
test_offset_idx = 0;
test_max_idx = entropy_len;
/* CTR_DRBG_Instantiate(entropy[:entropy_len/2], nonce, perso, <ignored>)
* where nonce||perso = add_init[add_init_len] */
TEST_ASSERT( mbedtls_ctr_drbg_seed_entropy_len( &ctx, mbedtls_test_entropy_func, entropy, add_init, add_init_len, entropy_len / 2 ) == 0 );
/* CTR_DRBG_Generate(16 * 8 bits, add1[:add1_len]) -> buf */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, buf, result_len, add1, add1_len ) == 0 );
/* CTR_DRBG_Reseed(entropy[entropy_len/2:entropy_len], add_reseed[:add_reseed_len]) */
TEST_ASSERT( hexcmp( buf, result_str->x, 16, result_str->len ) == 0 );
/* CTR_DRBG_Generate(16 * 8 bits, add2[:add2_len]) -> buf */
TEST_ASSERT( mbedtls_ctr_drbg_random_with_add( &ctx, buf, result_len, add2, add2_len ) == 0 );
TEST_ASSERT( memcmp( buf, result, result_len ) == 0 );
exit:
mbedtls_ctr_drbg_free( &ctx );
test_suite_ctr_drbg_validate( RESEED_SECOND, add_init_string,
strlen( entropy_string ) / 4, entropy_string,
add_reseed_string, add1_string, add2_string,
result_string );
goto exit;
}
/* END_CASE */