Commit 03cf7e78 authored by Andy Polyakov's avatar Andy Polyakov
Browse files

cmac.c: optimize make_kn and move zero_iv to const segment.

parent ce0727f9

crypto/cmac/cmac.c

+9 −10
Original line number Diff line number Diff line
@@ -77,19 +77,17 @@ struct CMAC_CTX_st 


/* Make temporary keys K1 and K2 */



static void make_kn(unsigned char *k1, unsigned char *l, int bl)

static void make_kn(unsigned char *k1, const unsigned char *l, int bl)

	{

	int i;

	unsigned char c = l[0], carry = c>>7, cnext;



	/* Shift block to left, including carry */

	for (i = 0; i < bl; i++)

		{

		k1[i] = l[i] << 1;

		if (i < bl - 1 && l[i + 1] & 0x80)

			k1[i] |= 1;

		}

	for (i = 0; i < bl-1; i++, c = cnext)

		k1[i] = (c << 1) | ((cnext=l[i+1]) >> 7);



	/* If MSB set fixup with R */

	if (l[0] & 0x80)

		k1[bl - 1] ^= bl == 16 ? 0x87 : 0x1b;

	k1[i] = (c << 1) ^ ((0-carry)&(bl==16?0x87:0x1b));

	}



CMAC_CTX *CMAC_CTX_new(void)
@@ -143,7 +141,8 @@ int CMAC_CTX_copy(CMAC_CTX *out, const CMAC_CTX *in) 
int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen, 

			const EVP_CIPHER *cipher, ENGINE *impl)

	{

	static unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH];

	__fips_constseg

	static const unsigned char zero_iv[EVP_MAX_BLOCK_LENGTH] = {0};

	/* All zeros means restart */

	if (!key && !cipher && !impl && keylen == 0)

		{