commit ecf6bebb9c36b02c0a4217abcd2b82358170ed08
author Gilles Peskine <Gilles.Peskine@arm.com> Fri Dec 10 21:35:10 2021 +0100
committer Gilles Peskine <Gilles.Peskine@arm.com> Sat Dec 11 15:00:57 2021 +0100
tree 8af66f1895afaf6e1ae3f2b21ece8f78ada57208
parent d5ba50e239fdb117172ba8162db607c5ad189577

Catch failures of md_hmac operations

Declare mbedtls_md functions as MBEDTLS_CHECK_RETURN_TYPICAL, meaning that
their return values should be checked.

Do check the return values in our code. We were already doing that
everywhere for hash calculations, but not for HMAC calculations.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>

include/mbedtls/md.h

diff --git a/include/mbedtls/md.h b/include/mbedtls/md.h
index fa2b152..2b668f5 100644
--- a/include/mbedtls/md.h
+++ b/include/mbedtls/md.h
@@ -29,6 +29,7 @@
 #include <stddef.h>
 
 #include "mbedtls/build_info.h"
+#include "mbedtls/platform_util.h"
 
 /** The selected feature is not available. */
 #define MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE                -0x5080
@@ -181,6 +182,7 @@
  *                  failure.
  * \return          #MBEDTLS_ERR_MD_ALLOC_FAILED on memory-allocation failure.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_setup( mbedtls_md_context_t *ctx, const mbedtls_md_info_t *md_info, int hmac );
 
 /**
@@ -202,6 +204,7 @@
  * \return          \c 0 on success.
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification failure.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_clone( mbedtls_md_context_t *dst,
                       const mbedtls_md_context_t *src );
 
@@ -251,6 +254,7 @@
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_starts( mbedtls_md_context_t *ctx );
 
 /**
@@ -269,6 +273,7 @@
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_update( mbedtls_md_context_t *ctx, const unsigned char *input, size_t ilen );
 
 /**
@@ -289,6 +294,7 @@
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_finish( mbedtls_md_context_t *ctx, unsigned char *output );
 
 /**
@@ -309,6 +315,7 @@
  * \return         #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                 failure.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md( const mbedtls_md_info_t *md_info, const unsigned char *input, size_t ilen,
         unsigned char *output );
 
@@ -330,6 +337,7 @@
  *                 the file pointed by \p path.
  * \return         #MBEDTLS_ERR_MD_BAD_INPUT_DATA if \p md_info was NULL.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_file( const mbedtls_md_info_t *md_info, const char *path,
                      unsigned char *output );
 #endif /* MBEDTLS_FS_IO */
@@ -352,6 +360,7 @@
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_hmac_starts( mbedtls_md_context_t *ctx, const unsigned char *key,
                     size_t keylen );
 
@@ -374,6 +383,7 @@
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_hmac_update( mbedtls_md_context_t *ctx, const unsigned char *input,
                     size_t ilen );
 
@@ -395,6 +405,7 @@
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_hmac_finish( mbedtls_md_context_t *ctx, unsigned char *output);
 
 /**
@@ -412,6 +423,7 @@
  * \return          #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                  failure.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_hmac_reset( mbedtls_md_context_t *ctx );
 
 /**
@@ -436,11 +448,13 @@
  * \return         #MBEDTLS_ERR_MD_BAD_INPUT_DATA on parameter-verification
  *                 failure.
  */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_hmac( const mbedtls_md_info_t *md_info, const unsigned char *key, size_t keylen,
                 const unsigned char *input, size_t ilen,
                 unsigned char *output );
 
 /* Internal use */
+MBEDTLS_CHECK_RETURN_TYPICAL
 int mbedtls_md_process( mbedtls_md_context_t *ctx, const unsigned char *data );
 
 #ifdef __cplusplus