From 808639b812995caa392fc8c75896ee0cd5aa91ce Mon Sep 17 00:00:00 2001 From: Gilles Peskine Date: Tue, 11 Sep 2018 16:54:57 +0200 Subject: [PATCH] HMAC_DRBG: report all errors from HMAC functions Make sure that any error from mbedtls_md_hmac_xxx is propagated. --- library/hmac_drbg.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/library/hmac_drbg.c b/library/hmac_drbg.c index e80d81ee6..73c606b99 100644 --- a/library/hmac_drbg.c +++ b/library/hmac_drbg.c @@ -135,7 +135,9 @@ 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 ) @@ -164,7 +166,8 @@ 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; @@ -212,7 +215,8 @@ 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; @@ -316,9 +320,13 @@ 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; @@ -428,6 +436,7 @@ 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 ) );