optimize make_kn (from HEAD, by Andy)

/* 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)