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mirror of https://github.com/Mbed-TLS/mbedtls.git synced 2025-08-01 10:06:53 +03:00

Fix data loss in unsigned int cast in PK

This patch introduces some additional checks in the PK module for 64-bit
systems only. The problem is that the API functions in the PK
abstraction accept a size_t value for the hashlen, while the RSA module
accepts an unsigned int for the hashlen. Instead of silently casting
size_t to unsigned int, this change checks whether the hashlen overflows
an unsigned int and returns an error.
This commit is contained in:
Andres AG
2017-01-19 11:24:33 +00:00
committed by Simon Butcher
parent b65c2be5f1
commit 72849877d0
2 changed files with 28 additions and 1 deletions

View File

@ -30,6 +30,7 @@
/* Even if RSA not activated, for the sake of RSA-alt */
#include "mbedtls/rsa.h"
#include "mbedtls/bignum.h"
#include <string.h>
@ -49,6 +50,8 @@
#define mbedtls_free free
#endif
#include <limits.h>
#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
/* Implementation that should never be optimized out by the compiler */
static void mbedtls_zeroize( void *v, size_t n ) {
@ -74,6 +77,11 @@ static int rsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
{
int ret;
#if defined(MBEDTLS_HAVE_INT64)
if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
#endif /* MBEDTLS_HAVE_INT64 */
if( sig_len < ((mbedtls_rsa_context *) ctx)->len )
return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
@ -93,6 +101,11 @@ static int rsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
unsigned char *sig, size_t *sig_len,
int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
{
#if defined(MBEDTLS_HAVE_INT64)
if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
#endif /* MBEDTLS_HAVE_INT64 */
*sig_len = ((mbedtls_rsa_context *) ctx)->len;
return( mbedtls_rsa_pkcs1_sign( (mbedtls_rsa_context *) ctx, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
@ -402,6 +415,11 @@ static int rsa_alt_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
{
mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
#if defined(MBEDTLS_HAVE_INT64)
if( UINT_MAX < hash_len )
return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
#endif /* MBEDTLS_HAVE_INT64 */
*sig_len = rsa_alt->key_len_func( rsa_alt->key );
return( rsa_alt->sign_func( rsa_alt->key, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,