Add setbuf platform function

Add a platform function mbedtls_setbuf(), defaulting to setbuf().

The intent is to allow disabling stdio buffering when reading or writing
files with sensitive data, because this exposes the sensitive data to a
subsequent memory disclosure vulnerability.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
This commit is contained in:
Gilles Peskine 2022-06-30 17:01:40 +02:00
parent a745c7d439
commit 6497b5a1d1
5 changed files with 101 additions and 0 deletions

View file

@ -225,6 +225,7 @@
* Uncomment a macro to enable alternate implementation of specific base
* platform function
*/
//#define MBEDTLS_PLATFORM_SETBUF_ALT
//#define MBEDTLS_PLATFORM_EXIT_ALT
//#define MBEDTLS_PLATFORM_TIME_ALT
//#define MBEDTLS_PLATFORM_FPRINTF_ALT
@ -3288,6 +3289,7 @@
//#define MBEDTLS_PLATFORM_STD_MEM_HDR <stdlib.h> /**< Header to include if MBEDTLS_PLATFORM_NO_STD_FUNCTIONS is defined. Don't define if no header is needed. */
//#define MBEDTLS_PLATFORM_STD_CALLOC calloc /**< Default allocator to use, can be undefined */
//#define MBEDTLS_PLATFORM_STD_FREE free /**< Default free to use, can be undefined */
//#define MBEDTLS_PLATFORM_STD_SETBUF setbuf /**< Default setbuf to use, can be undefined */
//#define MBEDTLS_PLATFORM_STD_EXIT exit /**< Default exit to use, can be undefined */
//#define MBEDTLS_PLATFORM_STD_TIME time /**< Default time to use, can be undefined. MBEDTLS_HAVE_TIME must be enabled */
//#define MBEDTLS_PLATFORM_STD_FPRINTF fprintf /**< Default fprintf to use, can be undefined */
@ -3305,6 +3307,7 @@
//#define MBEDTLS_PLATFORM_CALLOC_MACRO calloc /**< Default allocator macro to use, can be undefined */
//#define MBEDTLS_PLATFORM_FREE_MACRO free /**< Default free macro to use, can be undefined */
//#define MBEDTLS_PLATFORM_EXIT_MACRO exit /**< Default exit macro to use, can be undefined */
//#define MBEDTLS_PLATFORM_SETBUF_MACRO setbuf /**< Default setbuf macro to use, can be undefined */
//#define MBEDTLS_PLATFORM_TIME_MACRO time /**< Default time macro to use, can be undefined. MBEDTLS_HAVE_TIME must be enabled */
//#define MBEDTLS_PLATFORM_TIME_TYPE_MACRO time_t /**< Default time macro to use, can be undefined. MBEDTLS_HAVE_TIME must be enabled */
//#define MBEDTLS_PLATFORM_FPRINTF_MACRO fprintf /**< Default fprintf macro to use, can be undefined */