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aes128ctr: use an union to avoid breaking aliasing rules.

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This commit is contained in:
Frank Denis 2014-05-26 15:36:16 -07:00
parent c712feaae3
commit 9981651750
2 changed files with 27 additions and 24 deletions
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7
src/libsodium/crypto_stream/aes128ctr/portable/int128.h
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@ -11,9 +11,10 @@
# endif
#endif
typedef struct{
uint64_t a;
uint64_t b;
typedef union {
uint64_t u64[2];
uint32_t u32[4];
uint8_t u8[16];
} int128;
#define xor2 crypto_stream_aes128ctr_portable_xor2

44
src/libsodium/crypto_stream/aes128ctr/portable/int128_aes128ctr.c
View File

@ -6,35 +6,37 @@
void xor2(int128 *r, const int128 *x)
{
r->a ^= x->a;
r->b ^= x->b;
r->u64[0] ^= x->u64[0];
r->u64[1] ^= x->u64[1];
}
void and2(int128 *r, const int128 *x)
{
r->a &= x->a;
r->b &= x->b;
r->u64[0] &= x->u64[0];
r->u64[1] &= x->u64[1];
}
void or2(int128 *r, const int128 *x)
{
r->a |= x->a;
r->b |= x->b;
r->u64[0] |= x->u64[0];
r->u64[1] |= x->u64[1];
}
void copy2(int128 *r, const int128 *x)
{
r->a = x->a;
r->b = x->b;
r->u64[0] = x->u64[0];
r->u64[1] = x->u64[1];
}
void shufb(int128 *r, const unsigned char *l)
{
unsigned char ct[16];
unsigned char *cr;
int128 t;
uint8_t *ct;
uint8_t *cr;
memcpy(ct, r, 16);
cr = (unsigned char *)r;
copy2(&t, r);
cr = r->u8;
ct = t.u8;
cr[0] = ct[l[0]];
cr[1] = ct[l[1]];
cr[2] = ct[l[2]];
@ -55,13 +57,13 @@ void shufb(int128 *r, const unsigned char *l)
void shufd(int128 *r, const int128 *x, const unsigned int c)
{
unsigned char tp[16];
const unsigned char *xp = (const unsigned char *) x;
memcpy(tp + 0, xp + (c >> 0 & 3) * 4, 4);
memcpy(tp + 4, xp + (c >> 2 & 3) * 4, 4);
memcpy(tp + 8, xp + (c >> 4 & 3) * 4, 4);
memcpy(tp + 12, xp + (c >> 6 & 3) * 4, 4);
memcpy(r, tp, 16);
int128 t;
t.u32[0] = x->u32[c >> 0 & 3];
t.u32[1] = x->u32[c >> 2 & 3];
t.u32[2] = x->u32[c >> 4 & 3];
t.u32[3] = x->u32[c >> 6 & 3];
copy2(r, &t);
}
void rshift32_littleendian(int128 *r, const unsigned int n)
@ -108,8 +110,8 @@ void lshift64_littleendian(int128 *r, const unsigned int n)
void toggle(int128 *r)
{
r->a ^= 0xffffffffffffffffULL;
r->b ^= 0xffffffffffffffffULL;
r->u64[0] ^= 0xffffffffffffffffULL;
r->u64[1] ^= 0xffffffffffffffffULL;
}
void xor_rcon(int128 *r)