HMAC_DRBG: report all errors from HMAC functions

Make sure that any error from mbedtls_md_hmac_xxx is propagated.
This commit is contained in:
Gilles Peskine 2018-09-11 16:54:57 +02:00
parent e0e9c573ad
commit b7f71c8bc1

View file

@ -137,7 +137,9 @@ int mbedtls_hmac_drbg_seed_buf( mbedtls_hmac_drbg_context *ctx,
* Use the V memory location, which is currently all 0, to initialize the
* MD context with an all-zero key. Then set V to its initial value.
*/
mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, mbedtls_md_get_size( md_info ) );
if( ( ret = mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V,
mbedtls_md_get_size( md_info ) ) ) != 0 )
return( ret );
memset( ctx->V, 0x01, mbedtls_md_get_size( md_info ) );
if( ( ret = mbedtls_hmac_drbg_update_ret( ctx, data, data_len ) ) != 0 )
@ -166,7 +168,8 @@ int mbedtls_hmac_drbg_reseed( mbedtls_hmac_drbg_context *ctx,
memset( seed, 0, MBEDTLS_HMAC_DRBG_MAX_SEED_INPUT );
/* IV. Gather entropy_len bytes of entropy for the seed */
if( ctx->f_entropy( ctx->p_entropy, seed, ctx->entropy_len ) != 0 )
if( ( ret = ctx->f_entropy( ctx->p_entropy,
seed, ctx->entropy_len ) ) != 0 )
return( MBEDTLS_ERR_HMAC_DRBG_ENTROPY_SOURCE_FAILED );
seedlen = ctx->entropy_len;
@ -214,7 +217,8 @@ int mbedtls_hmac_drbg_seed( mbedtls_hmac_drbg_context *ctx,
* Use the V memory location, which is currently all 0, to initialize the
* MD context with an all-zero key. Then set V to its initial value.
*/
mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, md_size );
if( ( ret = mbedtls_md_hmac_starts( &ctx->md_ctx, ctx->V, md_size ) ) != 0 )
return( ret );
memset( ctx->V, 0x01, md_size );
ctx->f_entropy = f_entropy;
@ -318,9 +322,13 @@ int mbedtls_hmac_drbg_random_with_add( void *p_rng,
{
size_t use_len = left > md_len ? md_len : left;
mbedtls_md_hmac_reset( &ctx->md_ctx );
mbedtls_md_hmac_update( &ctx->md_ctx, ctx->V, md_len );
mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V );
if( ( ret = mbedtls_md_hmac_reset( &ctx->md_ctx ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md_hmac_update( &ctx->md_ctx,
ctx->V, md_len ) ) != 0 )
goto exit;
if( ( ret = mbedtls_md_hmac_finish( &ctx->md_ctx, ctx->V ) ) != 0 )
goto exit;
memcpy( out, ctx->V, use_len );
out += use_len;
@ -430,6 +438,7 @@ int mbedtls_hmac_drbg_update_seed_file( mbedtls_hmac_drbg_context *ctx, const ch
ret = MBEDTLS_ERR_HMAC_DRBG_FILE_IO_ERROR;
else
ret = mbedtls_hmac_drbg_update_ret( ctx, buf, n );
fclose( f );
mbedtls_platform_zeroize( buf, sizeof( buf ) );