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mirror of https://github.com/Mbed-TLS/mbedtls.git synced 2025-08-30 17:41:11 +03:00

Support set *_drbg reseed interval before seed

mbedtls_ctr_drbg_set_reseed_interval() and
mbedtls_hmac_drbg_set_reseed_interval() can now be called before
their seed functions and the reseed_interval value will persist.
Previously it would be overwritten with the default value.

*_drbg_reseed_interval is now set in init() and free().

mbedtls_ctr_drbg_free() and mbedtls_hmac_drbg_free() now
reset the drbg context to the state immediately after init().

Tests:
- Added test to check that DRBG reseeds when reseed_counter
reaches reseed_interval, if reseed_interval set before seed
and reseed_interval is less than MBEDTLS_CTR_DRBG_RESEED_INTERVAL.

Signed-off-by: gacquroff <gavina352@gmail.com>
This commit is contained in:
Gavin Acquroff
2020-03-01 17:06:11 -08:00
committed by gacquroff
parent 662deb38d6
commit 6aceb51e43
6 changed files with 54 additions and 21 deletions

View File

@@ -55,11 +55,17 @@ void mbedtls_ctr_drbg_init( mbedtls_ctr_drbg_context *ctx )
* See mbedtls_ctr_drbg_set_nonce_len(). */
ctx->reseed_counter = -1;
ctx->reseed_interval = MBEDTLS_CTR_DRBG_RESEED_INTERVAL;
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_init( &ctx->mutex );
#endif
}
/*
* This function resets CTR_DRBG context to the state immediately
* after initial call of mbedtls_ctr_drbg_init().
*/
void mbedtls_ctr_drbg_free( mbedtls_ctr_drbg_context *ctx )
{
if( ctx == NULL )
@@ -70,6 +76,11 @@ void mbedtls_ctr_drbg_free( mbedtls_ctr_drbg_context *ctx )
#endif
mbedtls_aes_free( &ctx->aes_ctx );
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_ctr_drbg_context ) );
ctx->reseed_interval = MBEDTLS_CTR_DRBG_RESEED_INTERVAL;
ctx->reseed_counter = -1;
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_init( &ctx->mutex );
#endif
}
void mbedtls_ctr_drbg_set_prediction_resistance( mbedtls_ctr_drbg_context *ctx,
@@ -468,8 +479,6 @@ int mbedtls_ctr_drbg_seed( mbedtls_ctr_drbg_context *ctx,
(size_t) ctx->reseed_counter :
good_nonce_len( ctx->entropy_len ) );
ctx->reseed_interval = MBEDTLS_CTR_DRBG_RESEED_INTERVAL;
/* Initialize with an empty key. */
if( ( ret = mbedtls_aes_setkey_enc( &ctx->aes_ctx, key,
MBEDTLS_CTR_DRBG_KEYBITS ) ) != 0 )

View File

@@ -53,6 +53,8 @@ void mbedtls_hmac_drbg_init( mbedtls_hmac_drbg_context *ctx )
{
memset( ctx, 0, sizeof( mbedtls_hmac_drbg_context ) );
ctx->reseed_interval = MBEDTLS_HMAC_DRBG_RESEED_INTERVAL;
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_init( &ctx->mutex );
#endif
@@ -266,8 +268,6 @@ int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
ctx->f_entropy = f_entropy;
ctx->p_entropy = p_entropy;
ctx->reseed_interval = MBEDTLS_HMAC_DRBG_RESEED_INTERVAL;
if( ctx->entropy_len == 0 )
{
/*
@@ -412,7 +412,8 @@ int mbedtls_hmac_drbg_random( void *p_rng, unsigned char *output, size_t out_len
}
/*
* Free an HMAC_DRBG context
* This function resets HMAC_DRBG context to the state immediately
* after initial call of mbedtls_hmac_drbg_init().
*/
void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx )
{
@@ -424,6 +425,10 @@ void mbedtls_hmac_drbg_free( mbedtls_hmac_drbg_context *ctx )
#endif
mbedtls_md_free( &ctx->md_ctx );
mbedtls_platform_zeroize( ctx, sizeof( mbedtls_hmac_drbg_context ) );
ctx->reseed_interval = MBEDTLS_HMAC_DRBG_RESEED_INTERVAL;
#if defined(MBEDTLS_THREADING_C)
mbedtls_mutex_init( &ctx->mutex );
#endif
}
#if defined(MBEDTLS_FS_IO)