1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 #pragma ident "%Z%%M% %I% %E% SMI" 27 28 #include <sys/zfs_context.h> 29 #include <sys/zio.h> 30 #include <sys/zio_checksum.h> 31 32 /* 33 * SHA-256 checksum, as specified in FIPS 180-3, available at: 34 * http://csrc.nist.gov/publications/PubsFIPS.html 35 * 36 * This is a very compact implementation of SHA-256. 37 * It is designed to be simple and portable, not to be fast. 38 */ 39 40 /* 41 * The literal definitions of Ch() and Maj() according to FIPS 180-3 are: 42 * 43 * Ch(x, y, z) (x & y) ^ (~x & z) 44 * Maj(x, y, z) (x & y) ^ (x & z) ^ (y & z) 45 * 46 * We use equivalent logical reductions here that require one less op. 47 */ 48 #define Ch(x, y, z) ((z) ^ ((x) & ((y) ^ (z)))) 49 #define Maj(x, y, z) (((x) & (y)) ^ ((z) & ((x) ^ (y)))) 50 #define Rot32(x, s) (((x) >> s) | ((x) << (32 - s))) 51 #define SIGMA0(x) (Rot32(x, 2) ^ Rot32(x, 13) ^ Rot32(x, 22)) 52 #define SIGMA1(x) (Rot32(x, 6) ^ Rot32(x, 11) ^ Rot32(x, 25)) 53 #define sigma0(x) (Rot32(x, 7) ^ Rot32(x, 18) ^ ((x) >> 3)) 54 #define sigma1(x) (Rot32(x, 17) ^ Rot32(x, 19) ^ ((x) >> 10)) 55 56 static const uint32_t SHA256_K[64] = { 57 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 58 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 59 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 60 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 61 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 62 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 63 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 64 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 65 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 66 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 67 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 68 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 69 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 70 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 71 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 72 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 73 }; 74 75 static void 76 SHA256Transform(uint32_t *H, const uint8_t *cp) 77 { 78 uint32_t a, b, c, d, e, f, g, h, t, T1, T2, W[64]; 79 80 for (t = 0; t < 16; t++, cp += 4) 81 W[t] = (cp[0] << 24) | (cp[1] << 16) | (cp[2] << 8) | cp[3]; 82 83 for (t = 16; t < 64; t++) 84 W[t] = sigma1(W[t - 2]) + W[t - 7] + 85 sigma0(W[t - 15]) + W[t - 16]; 86 87 a = H[0]; b = H[1]; c = H[2]; d = H[3]; 88 e = H[4]; f = H[5]; g = H[6]; h = H[7]; 89 90 for (t = 0; t < 64; t++) { 91 T1 = h + SIGMA1(e) + Ch(e, f, g) + SHA256_K[t] + W[t]; 92 T2 = SIGMA0(a) + Maj(a, b, c); 93 h = g; g = f; f = e; e = d + T1; 94 d = c; c = b; b = a; a = T1 + T2; 95 } 96 97 H[0] += a; H[1] += b; H[2] += c; H[3] += d; 98 H[4] += e; H[5] += f; H[6] += g; H[7] += h; 99 } 100 101 void 102 zio_checksum_SHA256(const void *buf, uint64_t size, zio_cksum_t *zcp) 103 { 104 uint32_t H[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 105 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 }; 106 uint8_t pad[128]; 107 int i, padsize; 108 109 for (i = 0; i < (size & ~63ULL); i += 64) 110 SHA256Transform(H, (uint8_t *)buf + i); 111 112 for (padsize = 0; i < size; i++) 113 pad[padsize++] = *((uint8_t *)buf + i); 114 115 for (pad[padsize++] = 0x80; (padsize & 63) != 56; padsize++) 116 pad[padsize] = 0; 117 118 for (i = 56; i >= 0; i -= 8) 119 pad[padsize++] = (size << 3) >> i; 120 121 for (i = 0; i < padsize; i += 64) 122 SHA256Transform(H, pad + i); 123 124 ZIO_SET_CHECKSUM(zcp, 125 (uint64_t)H[0] << 32 | H[1], 126 (uint64_t)H[2] << 32 | H[3], 127 (uint64_t)H[4] << 32 | H[5], 128 (uint64_t)H[6] << 32 | H[7]); 129 } 130