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reduce typecasts and byte swapping

This commit is contained in:
drochner 2011-06-08 10:14:16 +00:00
parent 7ee80c6f6e
commit 2706a22ac6
1 changed files with 35 additions and 31 deletions
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66
sys/opencrypto/gmac.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: gmac.c,v 1.1 2011/05/26 21:50:03 drochner Exp $ */
/* $NetBSD: gmac.c,v 1.2 2011/06/08 10:14:16 drochner Exp $ */
/* OpenBSD: gmac.c,v 1.3 2011/01/11 15:44:23 deraadt Exp */
/*
@ -37,23 +37,19 @@ void
ghash_gfmul(const uint32_t *X, const uint32_t *Y, uint32_t *product)
{
uint32_t v[4];
uint32_t z[4] = { 0, 0, 0, 0};
const uint8_t *x = (const uint8_t *)X;
uint32_t mul;
int i;
v[0] = be32toh(Y[0]);
v[1] = be32toh(Y[1]);
v[2] = be32toh(Y[2]);
v[3] = be32toh(Y[3]);
memcpy(v, Y, GMAC_BLOCK_LEN);
memset(product, 0, GMAC_BLOCK_LEN);
for (i = 0; i < GMAC_BLOCK_LEN * 8; i++) {
/* update Z */
if (x[i >> 3] & (1 << (~i & 7))) {
z[0] ^= v[0];
z[1] ^= v[1];
z[2] ^= v[2];
z[3] ^= v[3];
if (X[i >> 5] & (1 << (~i & 31))) {
product[0] ^= v[0];
product[1] ^= v[1];
product[2] ^= v[2];
product[3] ^= v[3];
} /* else: we preserve old values */
/* update V */
@ -63,28 +59,26 @@ ghash_gfmul(const uint32_t *X, const uint32_t *Y, uint32_t *product)
v[1] = (v[0] << 31) | (v[1] >> 1);
v[0] = (v[0] >> 1) ^ (0xe1000000 * mul);
}
product[0] = htobe32(z[0]);
product[1] = htobe32(z[1]);
product[2] = htobe32(z[2]);
product[3] = htobe32(z[3]);
}
void
ghash_update(GHASH_CTX *ctx, const uint8_t *X, size_t len)
{
uint8_t *s = (uint8_t *)ctx->S;
uint8_t *y = (uint8_t *)ctx->Z;
uint32_t x;
uint32_t *s = ctx->S;
uint32_t *y = ctx->Z;
int i, j;
for (i = 0; i < len / GMAC_BLOCK_LEN; i++) {
for (j = 0; j < GMAC_BLOCK_LEN; j++)
s[j] = y[j] ^ X[j];
for (j = 0; j < GMAC_BLOCK_LEN/4; j++) {
x = (X[0] << 24) | (X[1] << 16) | (X[2] << 8) | X[3];
s[j] = y[j] ^ x;
X += 4;
}
ghash_gfmul(ctx->S, ctx->H, ctx->S);
ghash_gfmul(ctx->H, ctx->S, ctx->S);
y = s;
X += GMAC_BLOCK_LEN;
}
memcpy(ctx->Z, ctx->S, GMAC_BLOCK_LEN);
@ -102,6 +96,8 @@ AES_GMAC_Init(AES_GMAC_CTX *ctx)
void
AES_GMAC_Setkey(AES_GMAC_CTX *ctx, const uint8_t *key, uint16_t klen)
{
int i;
ctx->rounds = rijndaelKeySetupEnc(ctx->K, (const u_char *)key,
(klen - AESCTR_NONCESIZE) * 8);
/* copy out salt to the counter block */
@ -109,6 +105,8 @@ AES_GMAC_Setkey(AES_GMAC_CTX *ctx, const uint8_t *key, uint16_t klen)
/* prepare a hash subkey */
rijndaelEncrypt(ctx->K, ctx->rounds, (void *)ctx->ghash.H,
(void *)ctx->ghash.H);
for (i = 0; i < 4; i++)
ctx->ghash.H[i] = be32toh(ctx->ghash.H[i]);
}
void
@ -121,18 +119,16 @@ AES_GMAC_Reinit(AES_GMAC_CTX *ctx, const uint8_t *iv, uint16_t ivlen)
int
AES_GMAC_Update(AES_GMAC_CTX *ctx, const uint8_t *data, uint16_t len)
{
uint32_t blk[4] = { 0, 0, 0, 0 };
uint8_t blk[16] = { 0 };
int plen;
if (len > 0) {
plen = len % GMAC_BLOCK_LEN;
if (len >= GMAC_BLOCK_LEN)
ghash_update(&ctx->ghash, (const uint8_t *)data,
len - plen);
ghash_update(&ctx->ghash, data, len - plen);
if (plen) {
memcpy(blk, data + (len - plen), plen);
ghash_update(&ctx->ghash, (uint8_t *)blk,
GMAC_BLOCK_LEN);
ghash_update(&ctx->ghash, blk, GMAC_BLOCK_LEN);
}
}
return (0);
@ -141,13 +137,21 @@ AES_GMAC_Update(AES_GMAC_CTX *ctx, const uint8_t *data, uint16_t len)
void
AES_GMAC_Final(uint8_t digest[GMAC_DIGEST_LEN], AES_GMAC_CTX *ctx)
{
uint8_t keystream[GMAC_BLOCK_LEN];
uint8_t keystream[GMAC_BLOCK_LEN], *k, *d;
int i;
/* do one round of GCTR */
ctx->J[GMAC_BLOCK_LEN - 1] = 1;
rijndaelEncrypt(ctx->K, ctx->rounds, ctx->J, keystream);
for (i = 0; i < GMAC_DIGEST_LEN; i++)
digest[i] = ((uint8_t *)ctx->ghash.S)[i] ^ keystream[i];
k = keystream;
d = digest;
for (i = 0; i < GMAC_DIGEST_LEN/4; i++) {
d[0] = (uint8_t)(ctx->ghash.S[i] >> 24) ^ k[0];
d[1] = (uint8_t)(ctx->ghash.S[i] >> 16) ^ k[1];
d[2] = (uint8_t)(ctx->ghash.S[i] >> 8) ^ k[2];
d[3] = (uint8_t)ctx->ghash.S[i] ^ k[3];
d += 4;
k += 4;
}
memset(keystream, 0, sizeof(keystream));
}