From 808639b812995caa392fc8c75896ee0cd5aa91ce Mon Sep 17 00:00:00 2001
From: Gilles Peskine <Gilles.Peskine@arm.com>
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 ) );