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/*
* SHA transform algorithm, originally taken from code written by
* Peter Gutmann, and placed in the public domain.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/cryptohash.h>
/* The SHA f()-functions. */
#define f1(x,y,z) (z ^ (x & (y ^ z))) /* x ? y : z */
#define f2(x,y,z) (x ^ y ^ z) /* XOR */
#define f3(x,y,z) ((x & y) + (z & (x ^ y))) /* majority */
/* The SHA Mysterious Constants */
#define K1 0x5A827999L /* Rounds 0-19: sqrt(2) * 2^30 */
#define K2 0x6ED9EBA1L /* Rounds 20-39: sqrt(3) * 2^30 */
#define K3 0x8F1BBCDCL /* Rounds 40-59: sqrt(5) * 2^30 */
#define K4 0xCA62C1D6L /* Rounds 60-79: sqrt(10) * 2^30 */
/**
* sha_transform - single block SHA1 transform
*
* @digest: 160 bit digest to update
* @data: 512 bits of data to hash
* @W: 80 words of workspace (see note)
*
* This function generates a SHA1 digest for a single 512-bit block.
* Be warned, it does not handle padding and message digest, do not
* confuse it with the full FIPS 180-1 digest algorithm for variable
* length messages.
*
* Note: If the hash is security sensitive, the caller should be sure
* to clear the workspace. This is left to the caller to avoid
* unnecessary clears between chained hashing operations.
*/
void sha_transform(__u32 *digest, const char *in, __u32 *W)
{
__u32 a, b, c, d, e, t, i;
for (i = 0; i < 16; i++)
W[i] = be32_to_cpu(((const __be32 *)in)[i]);
for (i = 0; i < 64; i++)
W[i+16] = rol32(W[i+13] ^ W[i+8] ^ W[i+2] ^ W[i], 1);
a = digest[0];
b = digest[1];
c = digest[2];
d = digest[3];
e = digest[4];
for (i = 0; i < 20; i++) {
t = f1(b, c, d) + K1 + rol32(a, 5) + e + W[i];
e = d; d = c; c = rol32(b, 30); b = a; a = t;
}
for (; i < 40; i ++) {
t = f2(b, c, d) + K2 + rol32(a, 5) + e + W[i];
e = d; d = c; c = rol32(b, 30); b = a; a = t;
}
for (; i < 60; i ++) {
t = f3(b, c, d) + K3 + rol32(a, 5) + e + W[i];
e = d; d = c; c = rol32(b, 30); b = a; a = t;
}
for (; i < 80; i ++) {
t = f2(b, c, d) + K4 + rol32(a, 5) + e + W[i];
e = d; d = c; c = rol32(b, 30); b = a; a = t;
}
digest[0] += a;
digest[1] += b;
digest[2] += c;
digest[3] += d;
digest[4] += e;
}
EXPORT_SYMBOL(sha_transform);
/**
* sha_init - initialize the vectors for a SHA1 digest
* @buf: vector to initialize
*/
void sha_init(__u32 *buf)
{
buf[0] = 0x67452301;
buf[1] = 0xefcdab89;
buf[2] = 0x98badcfe;
buf[3] = 0x10325476;
buf[4] = 0xc3d2e1f0;
}