1 /*
2 * GRUB -- GRand Unified Bootloader
3 * Copyright (C) 1999,2000,2001,2002,2003,2004 Free Software Foundation, Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
18 */
19 /*
20 * Copyright 2007 Sun Microsystems, Inc. All rights reserved.
21 * Use is subject to license terms.
22 */
23
24 #pragma ident "%Z%%M% %I% %E% SMI"
25
26 #include "fsys_zfs.h"
27
28 /*
29 * SHA-256 checksum, as specified in FIPS 180-2, available at:
30 * http://csrc.nist.gov/cryptval
31 *
32 * This is a very compact implementation of SHA-256.
33 * It is designed to be simple and portable, not to be fast.
34 */
35
36 /*
37 * The literal definitions according to FIPS180-2 would be:
38 *
39 * Ch(x, y, z) (((x) & (y)) ^ ((~(x)) & (z)))
40 * Maj(x, y, z) (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
41 *
42 * We use logical equivalents which require one less op.
43 */
44 #define Ch(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
45 #define Maj(x, y, z) (((x) & (y)) ^ ((z) & ((x) ^ (y))))
46 #define Rot32(x, s) (((x) >> s) | ((x) << (32 - s)))
47 #define SIGMA0(x) (Rot32(x, 2) ^ Rot32(x, 13) ^ Rot32(x, 22))
48 #define SIGMA1(x) (Rot32(x, 6) ^ Rot32(x, 11) ^ Rot32(x, 25))
49 #define sigma0(x) (Rot32(x, 7) ^ Rot32(x, 18) ^ ((x) >> 3))
50 #define sigma1(x) (Rot32(x, 17) ^ Rot32(x, 19) ^ ((x) >> 10))
51
52 static const uint32_t SHA256_K[64] = {
53 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
54 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
55 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
56 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
57 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
58 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
59 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
60 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
61 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
62 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
63 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
64 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
65 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
66 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
67 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
68 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
69 };
70
71 static void
72 SHA256Transform(uint32_t *H, const uint8_t *cp)
73 {
74 uint32_t a, b, c, d, e, f, g, h, t, T1, T2, W[64];
75
76 for (t = 0; t < 16; t++, cp += 4)
77 W[t] = (cp[0] << 24) | (cp[1] << 16) | (cp[2] << 8) | cp[3];
78
79 for (t = 16; t < 64; t++)
80 W[t] = sigma1(W[t - 2]) + W[t - 7] +
81 sigma0(W[t - 15]) + W[t - 16];
82
83 a = H[0]; b = H[1]; c = H[2]; d = H[3];
84 e = H[4]; f = H[5]; g = H[6]; h = H[7];
85
86 for (t = 0; t < 64; t++) {
87 T1 = h + SIGMA1(e) + Ch(e, f, g) + SHA256_K[t] + W[t];
88 T2 = SIGMA0(a) + Maj(a, b, c);
89 h = g; g = f; f = e; e = d + T1;
90 d = c; c = b; b = a; a = T1 + T2;
91 }
92
93 H[0] += a; H[1] += b; H[2] += c; H[3] += d;
94 H[4] += e; H[5] += f; H[6] += g; H[7] += h;
95 }
96
97 void
98 zio_checksum_SHA256(const void *buf, uint64_t size, zio_cksum_t *zcp)
99 {
100 uint32_t H[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
101 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 };
102 uint8_t pad[128];
103 int padsize = size & 63;
104 int i;
105
106 for (i = 0; i < size - padsize; i += 64)
107 SHA256Transform(H, (uint8_t *)buf + i);
108
109 for (i = 0; i < padsize; i++)
110 pad[i] = ((uint8_t *)buf)[i];
111
112 for (pad[padsize++] = 0x80; (padsize & 63) != 56; padsize++)
113 pad[padsize] = 0;
114
115 for (i = 0; i < 8; i++)
116 pad[padsize++] = (size << 3) >> (56 - 8 * i);
117
118 for (i = 0; i < padsize; i += 64)
119 SHA256Transform(H, pad + i);
120
121 ZIO_SET_CHECKSUM(zcp,
122 (uint64_t)H[0] << 32 | H[1],
123 (uint64_t)H[2] << 32 | H[3],
124 (uint64_t)H[4] << 32 | H[5],
125 (uint64_t)H[6] << 32 | H[7]);
126 }