Root/lib/sha1.c

1/*
2 * SHA transform algorithm, originally taken from code written by
3 * Peter Gutmann, and placed in the public domain.
4 */
5
6#include <linux/kernel.h>
7#include <linux/module.h>
8#include <linux/cryptohash.h>
9
10/* The SHA f()-functions. */
11
12#define f1(x,y,z) (z ^ (x & (y ^ z))) /* x ? y : z */
13#define f2(x,y,z) (x ^ y ^ z) /* XOR */
14#define f3(x,y,z) ((x & y) + (z & (x ^ y))) /* majority */
15
16/* The SHA Mysterious Constants */
17
18#define K1 0x5A827999L /* Rounds 0-19: sqrt(2) * 2^30 */
19#define K2 0x6ED9EBA1L /* Rounds 20-39: sqrt(3) * 2^30 */
20#define K3 0x8F1BBCDCL /* Rounds 40-59: sqrt(5) * 2^30 */
21#define K4 0xCA62C1D6L /* Rounds 60-79: sqrt(10) * 2^30 */
22
23/**
24 * sha_transform - single block SHA1 transform
25 *
26 * @digest: 160 bit digest to update
27 * @data: 512 bits of data to hash
28 * @W: 80 words of workspace (see note)
29 *
30 * This function generates a SHA1 digest for a single 512-bit block.
31 * Be warned, it does not handle padding and message digest, do not
32 * confuse it with the full FIPS 180-1 digest algorithm for variable
33 * length messages.
34 *
35 * Note: If the hash is security sensitive, the caller should be sure
36 * to clear the workspace. This is left to the caller to avoid
37 * unnecessary clears between chained hashing operations.
38 */
39void sha_transform(__u32 *digest, const char *in, __u32 *W)
40{
41    __u32 a, b, c, d, e, t, i;
42
43    for (i = 0; i < 16; i++)
44        W[i] = be32_to_cpu(((const __be32 *)in)[i]);
45
46    for (i = 0; i < 64; i++)
47        W[i+16] = rol32(W[i+13] ^ W[i+8] ^ W[i+2] ^ W[i], 1);
48
49    a = digest[0];
50    b = digest[1];
51    c = digest[2];
52    d = digest[3];
53    e = digest[4];
54
55    for (i = 0; i < 20; i++) {
56        t = f1(b, c, d) + K1 + rol32(a, 5) + e + W[i];
57        e = d; d = c; c = rol32(b, 30); b = a; a = t;
58    }
59
60    for (; i < 40; i ++) {
61        t = f2(b, c, d) + K2 + rol32(a, 5) + e + W[i];
62        e = d; d = c; c = rol32(b, 30); b = a; a = t;
63    }
64
65    for (; i < 60; i ++) {
66        t = f3(b, c, d) + K3 + rol32(a, 5) + e + W[i];
67        e = d; d = c; c = rol32(b, 30); b = a; a = t;
68    }
69
70    for (; i < 80; i ++) {
71        t = f2(b, c, d) + K4 + rol32(a, 5) + e + W[i];
72        e = d; d = c; c = rol32(b, 30); b = a; a = t;
73    }
74
75    digest[0] += a;
76    digest[1] += b;
77    digest[2] += c;
78    digest[3] += d;
79    digest[4] += e;
80}
81EXPORT_SYMBOL(sha_transform);
82
83/**
84 * sha_init - initialize the vectors for a SHA1 digest
85 * @buf: vector to initialize
86 */
87void sha_init(__u32 *buf)
88{
89    buf[0] = 0x67452301;
90    buf[1] = 0xefcdab89;
91    buf[2] = 0x98badcfe;
92    buf[3] = 0x10325476;
93    buf[4] = 0xc3d2e1f0;
94}
95
96

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