[MBEDTLS] Update to version 2.7.12. CORE-16440

This commit is contained in:
Thomas Faber 2019-10-20 12:44:34 +02:00
parent e02cdcce68
commit c1eccaffaa
No known key found for this signature in database
GPG key ID: 076E7C3D44720826
29 changed files with 434 additions and 136 deletions

View file

@ -72,9 +72,14 @@ cleanup:
* Compute ECDSA signature of a hashed message (SEC1 4.1.3)
* Obviously, compared to SEC1 4.1.3, we skip step 4 (hash message)
*/
int mbedtls_ecdsa_sign( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
static int ecdsa_sign_internal( mbedtls_ecp_group *grp, mbedtls_mpi *r,
mbedtls_mpi *s, const mbedtls_mpi *d,
const unsigned char *buf, size_t blen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
int (*f_rng_blind)(void *, unsigned char *,
size_t),
void *p_rng_blind )
{
int ret, key_tries, sign_tries, blind_tries;
mbedtls_ecp_point R;
@ -101,7 +106,10 @@ int mbedtls_ecdsa_sign( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
key_tries = 0;
do
{
MBEDTLS_MPI_CHK( mbedtls_ecp_gen_keypair( grp, &k, &R, f_rng, p_rng ) );
MBEDTLS_MPI_CHK( mbedtls_ecp_gen_privkey( grp, &k, f_rng, p_rng ) );
MBEDTLS_MPI_CHK( mbedtls_ecp_mul( grp, &R, &k, &grp->G,
f_rng_blind, p_rng_blind ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_mod_mpi( r, &R.X, &grp->N ) );
if( key_tries++ > 10 )
@ -120,15 +128,20 @@ int mbedtls_ecdsa_sign( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
/*
* Generate a random value to blind inv_mod in next step,
* avoiding a potential timing leak.
*
* This loop does the same job as mbedtls_ecp_gen_privkey() and it is
* replaced by a call to it in the mainline. This change is not
* necessary to backport the fix separating the blinding and ephemeral
* key generating RNGs, therefore the original code is kept.
*/
blind_tries = 0;
do
{
size_t n_size = ( grp->nbits + 7 ) / 8;
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &t, n_size, f_rng, p_rng ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_fill_random( &t, n_size, f_rng_blind,
p_rng_blind ) );
MBEDTLS_MPI_CHK( mbedtls_mpi_shift_r( &t, 8 * n_size - grp->nbits ) );
/* See mbedtls_ecp_gen_keypair() */
if( ++blind_tries > 30 )
return( MBEDTLS_ERR_ECP_RANDOM_FAILED );
}
@ -160,15 +173,27 @@ cleanup:
return( ret );
}
int mbedtls_ecdsa_sign( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
const mbedtls_mpi *d, const unsigned char *buf,
size_t blen,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng )
{
/* Use the same RNG for both blinding and ephemeral key generation */
return( ecdsa_sign_internal( grp, r, s, d, buf, blen, f_rng, p_rng,
f_rng, p_rng ) );
}
#endif /* MBEDTLS_ECDSA_SIGN_ALT */
#if defined(MBEDTLS_ECDSA_DETERMINISTIC)
/*
* Deterministic signature wrapper
*/
int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
mbedtls_md_type_t md_alg )
static int ecdsa_sign_det_internal( mbedtls_ecp_group *grp, mbedtls_mpi *r,
mbedtls_mpi *s, const mbedtls_mpi *d,
const unsigned char *buf, size_t blen,
mbedtls_md_type_t md_alg,
int (*f_rng_blind)(void *, unsigned char *,
size_t),
void *p_rng_blind )
{
int ret;
mbedtls_hmac_drbg_context rng_ctx;
@ -176,12 +201,16 @@ int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi
size_t grp_len = ( grp->nbits + 7 ) / 8;
const mbedtls_md_info_t *md_info;
mbedtls_mpi h;
/* Variables for deterministic blinding fallback */
const char* blind_label = "BLINDING CONTEXT";
mbedtls_hmac_drbg_context rng_ctx_blind;
if( ( md_info = mbedtls_md_info_from_type( md_alg ) ) == NULL )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
mbedtls_mpi_init( &h );
mbedtls_hmac_drbg_init( &rng_ctx );
mbedtls_hmac_drbg_init( &rng_ctx_blind );
/* Use private key and message hash (reduced) to initialize HMAC_DRBG */
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( d, data, grp_len ) );
@ -189,15 +218,71 @@ int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi
MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &h, data + grp_len, grp_len ) );
mbedtls_hmac_drbg_seed_buf( &rng_ctx, md_info, data, 2 * grp_len );
ret = mbedtls_ecdsa_sign( grp, r, s, d, buf, blen,
mbedtls_hmac_drbg_random, &rng_ctx );
if( f_rng_blind != NULL )
ret = ecdsa_sign_internal( grp, r, s, d, buf, blen,
mbedtls_hmac_drbg_random, &rng_ctx,
f_rng_blind, p_rng_blind );
else
{
/*
* To avoid reusing rng_ctx and risking incorrect behavior we seed a
* second HMAC-DRBG with the same seed. We also apply a label to avoid
* reusing the bits of the ephemeral key for blinding and eliminate the
* risk that they leak this way.
*/
mbedtls_hmac_drbg_seed_buf( &rng_ctx_blind, md_info,
data, 2 * grp_len );
ret = mbedtls_hmac_drbg_update_ret( &rng_ctx_blind,
(const unsigned char*) blind_label,
strlen( blind_label ) );
if( ret != 0 )
goto cleanup;
/*
* Since the output of the RNGs is always the same for the same key and
* message, this limits the efficiency of blinding and leaks information
* through side channels. After mbedtls_ecdsa_sign_det() is removed NULL
* won't be a valid value for f_rng_blind anymore. Therefore it should
* be checked by the caller and this branch and check can be removed.
*/
ret = ecdsa_sign_internal( grp, r, s, d, buf, blen,
mbedtls_hmac_drbg_random, &rng_ctx,
mbedtls_hmac_drbg_random, &rng_ctx_blind );
}
cleanup:
mbedtls_hmac_drbg_free( &rng_ctx );
mbedtls_hmac_drbg_free( &rng_ctx_blind );
mbedtls_mpi_free( &h );
return( ret );
}
/*
* Deterministic signature wrappers
*/
int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r,
mbedtls_mpi *s, const mbedtls_mpi *d,
const unsigned char *buf, size_t blen,
mbedtls_md_type_t md_alg )
{
return( ecdsa_sign_det_internal( grp, r, s, d, buf, blen, md_alg,
NULL, NULL ) );
}
int mbedtls_ecdsa_sign_det_ext( mbedtls_ecp_group *grp, mbedtls_mpi *r,
mbedtls_mpi *s, const mbedtls_mpi *d,
const unsigned char *buf, size_t blen,
mbedtls_md_type_t md_alg,
int (*f_rng_blind)(void *, unsigned char *,
size_t),
void *p_rng_blind )
{
return( ecdsa_sign_det_internal( grp, r, s, d, buf, blen, md_alg,
f_rng_blind, p_rng_blind ) );
}
#endif /* MBEDTLS_ECDSA_DETERMINISTIC */
#if !defined(MBEDTLS_ECDSA_VERIFY_ALT)
@ -328,17 +413,15 @@ int mbedtls_ecdsa_write_signature( mbedtls_ecdsa_context *ctx, mbedtls_md_type_t
mbedtls_mpi_init( &s );
#if defined(MBEDTLS_ECDSA_DETERMINISTIC)
(void) f_rng;
(void) p_rng;
MBEDTLS_MPI_CHK( mbedtls_ecdsa_sign_det( &ctx->grp, &r, &s, &ctx->d,
hash, hlen, md_alg ) );
MBEDTLS_MPI_CHK( ecdsa_sign_det_internal( &ctx->grp, &r, &s, &ctx->d,
hash, hlen, md_alg,
f_rng, p_rng ) );
#else
(void) md_alg;
MBEDTLS_MPI_CHK( mbedtls_ecdsa_sign( &ctx->grp, &r, &s, &ctx->d,
hash, hlen, f_rng, p_rng ) );
#endif
#endif /* MBEDTLS_ECDSA_DETERMINISTIC */
MBEDTLS_MPI_CHK( ecdsa_signature_to_asn1( &r, &s, sig, slen ) );