external/cddl/osnet/dist/uts/common/fs/zfs/sha256.c

   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 }