diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/libstrongswan/utils.c | 41 |
1 files changed, 32 insertions, 9 deletions
diff --git a/src/libstrongswan/utils.c b/src/libstrongswan/utils.c index 4a0eff45f..73edb2280 100644 --- a/src/libstrongswan/utils.c +++ b/src/libstrongswan/utils.c @@ -58,20 +58,43 @@ void *clalloc(void * pointer, size_t size) /** * Described in header. */ -void memxor(u_int8_t dest[], u_int8_t src[], size_t n) +void memxor(u_int8_t dst[], u_int8_t src[], size_t n) { - int i = 0, m; + int m, i; - m = n - sizeof(long); - while (i < m) + /* byte wise XOR until dst aligned */ + for (i = 0; (int)&dst[i] % sizeof(long); i++) { - *(long*)(dest + i) ^= *(long*)(src + i); - i += sizeof(long); + dst[i] ^= src[i]; } - while (i < n) + /* try to use words if src shares an aligment with dst */ + switch (((int)&src[i] % sizeof(long))) { - dest[i] ^= src[i]; - i++; + case 0: + for (m = n - sizeof(long); i <= m; i += sizeof(long)) + { + *(long*)&dst[i] ^= *(long*)&src[i]; + } + break; + case sizeof(int): + for (m = n - sizeof(int); i <= m; i += sizeof(int)) + { + *(int*)&dst[i] ^= *(int*)&src[i]; + } + break; + case sizeof(short): + for (m = n - sizeof(short); i <= m; i += sizeof(short)) + { + *(short*)&dst[i] ^= *(short*)&src[i]; + } + break; + default: + break; + } + /* byte wise XOR of the rest */ + for (; i < n; i++) + { + dst[i] ^= src[i]; } } |