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 } 127