fs/zfs/zfs_sha256.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 1999,2000,2001,2002,2003,2004  Free Software Foundation, Inc.
   5  */
   6 /*
   7  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
   8  * Use is subject to license terms.
   9  */
  10
  11 #include <common.h>
  12 #include <malloc.h>
  13 #include <linux/stat.h>
  14 #include <linux/time.h>
  15 #include <linux/ctype.h>
  16 #include <asm/byteorder.h>
  17 #include "zfs_common.h"
  18
  19 #include <zfs/zfs.h>
  20 #include <zfs/zio.h>
  21 #include <zfs/dnode.h>
  22 #include <zfs/uberblock_impl.h>
  23 #include <zfs/vdev_impl.h>
  24 #include <zfs/zio_checksum.h>
  25 #include <zfs/zap_impl.h>
  26 #include <zfs/zap_leaf.h>
  27 #include <zfs/zfs_znode.h>
  28 #include <zfs/dmu.h>
  29 #include <zfs/dmu_objset.h>
  30 #include <zfs/dsl_dir.h>
  31 #include <zfs/dsl_dataset.h>
  32
  33 /*
  34  * SHA-256 checksum, as specified in FIPS 180-2, available at:
  35  * http://csrc.nist.gov/cryptval
  36  *
  37  * This is a very compact implementation of SHA-256.
  38  * It is designed to be simple and portable, not to be fast.
  39  */
  40
  41 /*
  42  * The literal definitions according to FIPS180-2 would be:
  43  *
  44  *      Ch(x, y, z)             (((x) & (y)) ^ ((~(x)) & (z)))
  45  *      Maj(x, y, z)    (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
  46  *
  47  * We use logical equivalents which require one less op.
  48  */
  49 #define Ch(x, y, z)     ((z) ^ ((x) & ((y) ^ (z))))
  50 #define Maj(x, y, z)    (((x) & (y)) ^ ((z) & ((x) ^ (y))))
  51 #define Rot32(x, s)     (((x) >> s) | ((x) << (32 - s)))
  52 #define SIGMA0(x)       (Rot32(x, 2) ^ Rot32(x, 13) ^ Rot32(x, 22))
  53 #define SIGMA1(x)       (Rot32(x, 6) ^ Rot32(x, 11) ^ Rot32(x, 25))
  54 #define sigma0(x)       (Rot32(x, 7) ^ Rot32(x, 18) ^ ((x) >> 3))
  55 #define sigma1(x)       (Rot32(x, 17) ^ Rot32(x, 19) ^ ((x) >> 10))
  56
  57 static const uint32_t SHA256_K[64] = {
  58         0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
  59         0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
  60         0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
  61         0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
  62         0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
  63         0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
  64         0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
  65         0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
  66         0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
  67         0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
  68         0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
  69         0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
  70         0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
  71         0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
  72         0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
  73         0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
  74 };
  75
  76 static void
  77 SHA256Transform(uint32_t *H, const uint8_t *cp)
  78 {
  79         uint32_t a, b, c, d, e, f, g, h, t, T1, T2, W[64];
  80
  81         for (t = 0; t < 16; t++, cp += 4)
  82                 W[t] = (cp[0] << 24) | (cp[1] << 16) | (cp[2] << 8) | cp[3];
  83
  84         for (t = 16; t < 64; t++)
  85                 W[t] = sigma1(W[t - 2]) + W[t - 7] +
  86                         sigma0(W[t - 15]) + W[t - 16];
  87
  88         a = H[0]; b = H[1]; c = H[2]; d = H[3];
  89         e = H[4]; f = H[5]; g = H[6]; h = H[7];
  90
  91         for (t = 0; t < 64; t++) {
  92                 T1 = h + SIGMA1(e) + Ch(e, f, g) + SHA256_K[t] + W[t];
  93                 T2 = SIGMA0(a) + Maj(a, b, c);
  94                 h = g; g = f; f = e; e = d + T1;
  95                 d = c; c = b; b = a; a = T1 + T2;
  96         }
  97
  98         H[0] += a; H[1] += b; H[2] += c; H[3] += d;
  99         H[4] += e; H[5] += f; H[6] += g; H[7] += h;
 100 }
 101
 102 void
 103 zio_checksum_SHA256(const void *buf, uint64_t size,
 104                                         zfs_endian_t endian, zio_cksum_t *zcp)
 105 {
 106         uint32_t H[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
 107                                           0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 };
 108         uint8_t pad[128];
 109         unsigned padsize = size & 63;
 110         unsigned i;
 111
 112         for (i = 0; i < size - padsize; i += 64)
 113                 SHA256Transform(H, (uint8_t *)buf + i);
 114
 115         for (i = 0; i < padsize; i++)
 116                 pad[i] = ((uint8_t *)buf)[i];
 117
 118         for (pad[padsize++] = 0x80; (padsize & 63) != 56; padsize++)
 119                 pad[padsize] = 0;
 120
 121         for (i = 0; i < 8; i++)
 122                 pad[padsize++] = (size << 3) >> (56 - 8 * i);
 123
 124         for (i = 0; i < padsize; i += 64)
 125                 SHA256Transform(H, pad + i);
 126
 127         zcp->zc_word[0] = cpu_to_zfs64((uint64_t)H[0] << 32 | H[1],
 128                                                                                 endian);
 129         zcp->zc_word[1] = cpu_to_zfs64((uint64_t)H[2] << 32 | H[3],
 130                                                                                 endian);
 131         zcp->zc_word[2] = cpu_to_zfs64((uint64_t)H[4] << 32 | H[5],
 132                                                                                 endian);
 133         zcp->zc_word[3] = cpu_to_zfs64((uint64_t)H[6] << 32 | H[7],
 134                                                                                 endian);
 135 }