| 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 | |
