fs/zfs_sha256.c

   1 /*
   2  *  GRUB  --  GRand Unified Bootloader
   3  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
   4  *  Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
   5  *  Copyright (C) 2009  Free Software Foundation, Inc.
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License as published by
   9  *  the Free Software Foundation; either version 3 of the License, or
  10  *  (at your option) any later version.
  11  *
  12  *  This program is distributed in the hope that it will be useful,
  13  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *  GNU General Public License for more details.
  16  *
  17  *  You should have received a copy of the GNU General Public License
  18  *  along with this program; if not, write to the Free Software
  19  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #include <grub/err.h>
  23 #include <grub/file.h>
  24 #include <grub/mm.h>
  25 #include <grub/misc.h>
  26 #include <grub/disk.h>
  27 #include <grub/dl.h>
  28 #include <grub/types.h>
  29 #include <grub/zfs/zfs.h>
  30 #include <grub/zfs/zio.h>
  31 #include <grub/zfs/dnode.h>
  32 #include <grub/zfs/uberblock_impl.h>
  33 #include <grub/zfs/vdev_impl.h>
  34 #include <grub/zfs/zio_checksum.h>
  35 #include <grub/zfs/zap_impl.h>
  36 #include <grub/zfs/zap_leaf.h>
  37 #include <grub/zfs/zfs_znode.h>
  38 #include <grub/zfs/dmu.h>
  39 #include <grub/zfs/dmu_objset.h>
  40 #include <grub/zfs/dsl_dir.h>
  41 #include <grub/zfs/dsl_dataset.h>
  42
  43 /*
  44  * SHA-256 checksum, as specified in FIPS 180-2, available at:
  45  * http://csrc.nist.gov/cryptval
  46  *
  47  * This is a very compact implementation of SHA-256.
  48  * It is designed to be simple and portable, not to be fast.
  49  */
  50
  51 /*
  52  * The literal definitions according to FIPS180-2 would be:
  53  *
  54  *      Ch(x, y, z)     (((x) & (y)) ^ ((~(x)) & (z)))
  55  *      Maj(x, y, z)    (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
  56  *
  57  * We use logical equivalents which require one less op.
  58  */
  59 #define Ch(x, y, z)     ((z) ^ ((x) & ((y) ^ (z))))
  60 #define Maj(x, y, z)    (((x) & (y)) ^ ((z) & ((x) ^ (y))))
  61 #define Rot32(x, s)     (((x) >> s) | ((x) << (32 - s)))
  62 #define SIGMA0(x)       (Rot32(x, 2) ^ Rot32(x, 13) ^ Rot32(x, 22))
  63 #define SIGMA1(x)       (Rot32(x, 6) ^ Rot32(x, 11) ^ Rot32(x, 25))
  64 #define sigma0(x)       (Rot32(x, 7) ^ Rot32(x, 18) ^ ((x) >> 3))
  65 #define sigma1(x)       (Rot32(x, 17) ^ Rot32(x, 19) ^ ((x) >> 10))
  66
  67 static const grub_uint32_t SHA256_K[64] = {
  68         0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
  69         0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
  70         0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
  71         0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
  72         0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
  73         0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
  74         0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
  75         0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
  76         0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
  77         0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
  78         0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
  79         0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
  80         0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
  81         0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
  82         0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
  83         0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
  84 };
  85
  86 static void
  87 SHA256Transform(grub_uint32_t *H, const grub_uint8_t *cp)
  88 {
  89         grub_uint32_t a, b, c, d, e, f, g, h, t, T1, T2, W[64];
  90
  91         for (t = 0; t < 16; t++, cp += 4)
  92                 W[t] = (cp[0] << 24) | (cp[1] << 16) | (cp[2] << 8) | cp[3];
  93
  94         for (t = 16; t < 64; t++)
  95                 W[t] = sigma1(W[t - 2]) + W[t - 7] +
  96                     sigma0(W[t - 15]) + W[t - 16];
  97
  98         a = H[0]; b = H[1]; c = H[2]; d = H[3];
  99         e = H[4]; f = H[5]; g = H[6]; h = H[7];
 100
 101         for (t = 0; t < 64; t++) {
 102                 T1 = h + SIGMA1(e) + Ch(e, f, g) + SHA256_K[t] + W[t];
 103                 T2 = SIGMA0(a) + Maj(a, b, c);
 104                 h = g; g = f; f = e; e = d + T1;
 105                 d = c; c = b; b = a; a = T1 + T2;
 106         }
 107
 108         H[0] += a; H[1] += b; H[2] += c; H[3] += d;
 109         H[4] += e; H[5] += f; H[6] += g; H[7] += h;
 110 }
 111
 112 void
 113 zio_checksum_SHA256(const void *buf, grub_uint64_t size,
 114                     grub_zfs_endian_t endian, zio_cksum_t *zcp)
 115 {
 116   grub_uint32_t H[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
 117                          0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 };
 118   grub_uint8_t pad[128];
 119   unsigned padsize = size & 63;
 120   unsigned i;
 121
 122   for (i = 0; i < size - padsize; i += 64)
 123     SHA256Transform(H, (grub_uint8_t *)buf + i);
 124
 125   for (i = 0; i < padsize; i++)
 126     pad[i] = ((grub_uint8_t *)buf)[i];
 127
 128   for (pad[padsize++] = 0x80; (padsize & 63) != 56; padsize++)
 129     pad[padsize] = 0;
 130
 131   for (i = 0; i < 8; i++)
 132     pad[padsize++] = (size << 3) >> (56 - 8 * i);
 133
 134   for (i = 0; i < padsize; i += 64)
 135     SHA256Transform(H, pad + i);
 136
 137   zcp->zc_word[0] = grub_cpu_to_zfs64 ((grub_uint64_t)H[0] << 32 | H[1],
 138                                        endian);
 139   zcp->zc_word[1] = grub_cpu_to_zfs64 ((grub_uint64_t)H[2] << 32 | H[3],
 140                                        endian);
 141   zcp->zc_word[2] = grub_cpu_to_zfs64 ((grub_uint64_t)H[4] << 32 | H[5],
 142                                        endian);
 143   zcp->zc_word[3] = grub_cpu_to_zfs64 ((grub_uint64_t)H[6] << 32 | H[7],
 144                                        endian);
 145 }