yuzu/mbedtls
1
0
Fork 0
mirror of https://github.com/yuzu-emu/mbedtls.git synced 2024-12-23 07:05:37 +00:00
Code Issues Packages Projects Releases Wiki Activity

Prevent building the HAVEGE module on platforms where it doesn't work

Browse source 
If int is not capable of storing as many values as unsigned, the code
may generate a trap value. If signed int and unsigned int aren't
32-bit types, the code may calculate meaningless values.
This commit is contained in:
Gilles Peskine 2019-06-17 15:12:51 +02:00
parent 31a4ba7264
commit 04659a023e
1 changed files with 11 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

11
library/havege.c
View file

@ -38,8 +38,19 @@
#include "mbedtls/timing.h"
#include "mbedtls/platform_util.h"
#include <limits.h>
#include <string.h>
/* If int isn't capable of storing 2^32 distinct values, the code of this
* module may cause a processor trap or a miscalculation. If int is more
* than 32 bits, the code may not calculate the intended values. */
#if INT_MIN + 1 != -0x7fffffff
#error "The HAVEGE module requires int to be exactly 32 bits, with INT_MIN = -2^31."
#endif
#if UINT_MAX != 0xffffffff
#error "The HAVEGE module requires unsigned to be exactly 32 bits."
#endif
/* ------------------------------------------------------------------------
* On average, one iteration accesses two 8-word blocks in the havege WALK
* table, and generates 16 words in the RES array.