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-rw-r--r--crypto/modes/ctr128.c41
1 files changed, 17 insertions, 24 deletions
diff --git a/crypto/modes/ctr128.c b/crypto/modes/ctr128.c
index f3bbcbf72376..bcafd6b6bfb1 100644
--- a/crypto/modes/ctr128.c
+++ b/crypto/modes/ctr128.c
@@ -67,23 +67,20 @@
/* increment counter (128-bit int) by 1 */
static void ctr128_inc(unsigned char *counter)
{
- u32 n = 16;
- u8 c;
+ u32 n = 16, c = 1;
do {
--n;
- c = counter[n];
- ++c;
- counter[n] = c;
- if (c)
- return;
+ c += counter[n];
+ counter[n] = (u8)c;
+ c >>= 8;
} while (n);
}
#if !defined(OPENSSL_SMALL_FOOTPRINT)
static void ctr128_inc_aligned(unsigned char *counter)
{
- size_t *data, c, n;
+ size_t *data, c, d, n;
const union {
long one;
char little;
@@ -91,20 +88,19 @@ static void ctr128_inc_aligned(unsigned char *counter)
1
};
- if (is_endian.little) {
+ if (is_endian.little || ((size_t)counter % sizeof(size_t)) != 0) {
ctr128_inc(counter);
return;
}
data = (size_t *)counter;
+ c = 1;
n = 16 / sizeof(size_t);
do {
--n;
- c = data[n];
- ++c;
- data[n] = c;
- if (c)
- return;
+ d = data[n] += c;
+ /* did addition carry? */
+ c = ((d - c) ^ d) >> (sizeof(size_t) * 8 - 1);
} while (n);
}
#endif
@@ -144,14 +140,14 @@ void CRYPTO_ctr128_encrypt(const unsigned char *in, unsigned char *out,
}
# if defined(STRICT_ALIGNMENT)
- if (((size_t)in | (size_t)out | (size_t)ivec) % sizeof(size_t) !=
- 0)
+ if (((size_t)in | (size_t)out | (size_t)ecount_buf)
+ % sizeof(size_t) != 0)
break;
# endif
while (len >= 16) {
(*block) (ivec, ecount_buf, key);
ctr128_inc_aligned(ivec);
- for (; n < 16; n += sizeof(size_t))
+ for (n = 0; n < 16; n += sizeof(size_t))
*(size_t *)(out + n) =
*(size_t *)(in + n) ^ *(size_t *)(ecount_buf + n);
len -= 16;
@@ -189,16 +185,13 @@ void CRYPTO_ctr128_encrypt(const unsigned char *in, unsigned char *out,
/* increment upper 96 bits of 128-bit counter by 1 */
static void ctr96_inc(unsigned char *counter)
{
- u32 n = 12;
- u8 c;
+ u32 n = 12, c = 1;
do {
--n;
- c = counter[n];
- ++c;
- counter[n] = c;
- if (c)
- return;
+ c += counter[n];
+ counter[n] = (u8)c;
+ c >>= 8;
} while (n);
}