mirrors/VeraCrypt
1
0
Fork 0
mirror of https://github.com/veracrypt/VeraCrypt.git synced 2026-10-21 13:52:36 +00:00
Code Issues Packages Projects Releases Wiki Activity

Crypto: no unaligned 64-bit accesses on 32-bit ARM (#1908)

Browse Source 
CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS was defined whenever
__ARM_FEATURE_UNALIGNED is set, which includes 32-bit ARMv6/ARMv7. There
the hardware handles unaligned single-word loads and stores, but not
LDRD/STRD/LDM, which the compiler uses for 64-bit words. Camellia
(camellia_load64/camellia_store64) and Whirlpool (HashMultipleBlocks on
unaligned input) then access 64-bit words through unaligned pointers.

camellia_set_key() raised SIGBUS in the XTS self-test on an ARMv7
(cortex-a15) build whose test key happened to be only 2-byte aligned.

Define the macro for AArch64 only among the ARM targets; on 32-bit ARM
the memcpy and aligned-copy paths are used instead.

Signed-off-by: Ville Takio <ville+git@takio.fi>
This commit is contained in:
Ville Takio
2026-10-09 06:28:13 +09:00
committed by GitHub
parent ed6613a001
commit cb1d9a4c3b
1 changed files with 4 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/Crypto/config.h
+4 -1
View File
@@ -263,7 +263,10 @@
#endif
#if !defined(CRYPTOPP_NO_UNALIGNED_DATA_ACCESS) && !defined(CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS)
#if (CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || defined(__powerpc__) || (__ARM_FEATURE_UNALIGNED >= 1))
// Users of this macro (Camellia, Whirlpool) load and store 64-bit words through
// unaligned pointers. 32-bit ARM supports unaligned single-word accesses only:
// the LDRD/STRD/LDM instructions used for 64-bit words still fault (SIGBUS).
#if (CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_X32 || defined(__powerpc__) || (defined(__aarch64__) && __ARM_FEATURE_UNALIGNED >= 1))
#define CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS
#endif
#endif