1 | /* |
2 | * SHA transform algorithm, originally taken from code written by |
3 | * Peter Gutmann, and placed in the public domain. |
4 | */ |
5 | |
6 | static uint32_t |
7 | rol32(uint32_t word, int shift) |
8 | { |
9 | return (word << shift) | (word >> (32 - shift)); |
10 | } |
11 | |
12 | /* The SHA f()-functions. */ |
13 | |
14 | #define f1(x,y,z) (z ^ (x & (y ^ z))) /* x ? y : z */ |
15 | #define f2(x,y,z) (x ^ y ^ z) /* XOR */ |
16 | #define f3(x,y,z) ((x & y) + (z & (x ^ y))) /* majority */ |
17 | |
18 | /* The SHA Mysterious Constants */ |
19 | |
20 | #define K1 0x5A827999L /* Rounds 0-19: sqrt(2) * 2^30 */ |
21 | #define K2 0x6ED9EBA1L /* Rounds 20-39: sqrt(3) * 2^30 */ |
22 | #define K3 0x8F1BBCDCL /* Rounds 40-59: sqrt(5) * 2^30 */ |
23 | #define K4 0xCA62C1D6L /* Rounds 60-79: sqrt(10) * 2^30 */ |
24 | |
25 | /** |
26 | * sha_transform - single block SHA1 transform |
27 | * |
28 | * @digest: 160 bit digest to update |
29 | * @data: 512 bits of data to hash |
30 | * @W: 80 words of workspace (see note) |
31 | * |
32 | * This function generates a SHA1 digest for a single 512-bit block. |
33 | * Be warned, it does not handle padding and message digest, do not |
34 | * confuse it with the full FIPS 180-1 digest algorithm for variable |
35 | * length messages. |
36 | * |
37 | * Note: If the hash is security sensitive, the caller should be sure |
38 | * to clear the workspace. This is left to the caller to avoid |
39 | * unnecessary clears between chained hashing operations. |
40 | */ |
41 | static void sha_transform(uint32_t *digest, const unsigned char *in, uint32_t *W) |
42 | { |
43 | uint32_t a, b, c, d, e, t, i; |
44 | |
45 | for (i = 0; i < 16; i++) { |
46 | int ofs = 4 * i; |
47 | |
48 | /* word load/store may be unaligned here, so use bytes instead */ |
49 | W[i] = |
50 | (in[ofs+0] << 24) | |
51 | (in[ofs+1] << 16) | |
52 | (in[ofs+2] << 8) | |
53 | in[ofs+3]; |
54 | } |
55 | |
56 | for (i = 0; i < 64; i++) |
57 | W[i+16] = rol32(W[i+13] ^ W[i+8] ^ W[i+2] ^ W[i], 1); |
58 | |
59 | a = digest[0]; |
60 | b = digest[1]; |
61 | c = digest[2]; |
62 | d = digest[3]; |
63 | e = digest[4]; |
64 | |
65 | for (i = 0; i < 20; i++) { |
66 | t = f1(b, c, d) + K1 + rol32(a, 5) + e + W[i]; |
67 | e = d; d = c; c = rol32(b, 30); b = a; a = t; |
68 | } |
69 | |
70 | for (; i < 40; i ++) { |
71 | t = f2(b, c, d) + K2 + rol32(a, 5) + e + W[i]; |
72 | e = d; d = c; c = rol32(b, 30); b = a; a = t; |
73 | } |
74 | |
75 | for (; i < 60; i ++) { |
76 | t = f3(b, c, d) + K3 + rol32(a, 5) + e + W[i]; |
77 | e = d; d = c; c = rol32(b, 30); b = a; a = t; |
78 | } |
79 | |
80 | for (; i < 80; i ++) { |
81 | t = f2(b, c, d) + K4 + rol32(a, 5) + e + W[i]; |
82 | e = d; d = c; c = rol32(b, 30); b = a; a = t; |
83 | } |
84 | |
85 | digest[0] += a; |
86 | digest[1] += b; |
87 | digest[2] += c; |
88 | digest[3] += d; |
89 | digest[4] += e; |
90 | } |
91 | |
92 | /** |
93 | * sha_init - initialize the vectors for a SHA1 digest |
94 | * @buf: vector to initialize |
95 | */ |
96 | static void sha_init(uint32_t *buf) |
97 | { |
98 | buf[0] = 0x67452301; |
99 | buf[1] = 0xefcdab89; |
100 | buf[2] = 0x98badcfe; |
101 | buf[3] = 0x10325476; |
102 | buf[4] = 0xc3d2e1f0; |
103 | } |
104 | |
105 | |