lib/crypto/sha256.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * SHA-256, as specified in
   4  * http://csrc.nist.gov/groups/STM/cavp/documents/shs/sha256-384-512.pdf
   5  *
   6  * SHA-256 code by Jean-Luc Cooke <jlcooke@certainkey.com>.
   7  *
   8  * Copyright (c) Jean-Luc Cooke <jlcooke@certainkey.com>
   9  * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
  10  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  11  * Copyright (c) 2014 Red Hat Inc.
  12  */
  13
  14 #include <linux/unaligned.h>
  15 #include <crypto/sha256_base.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/string.h>
  19
  20 static const u32 SHA256_K[] = {
  21         0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
  22         0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
  23         0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
  24         0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
  25         0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
  26         0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
  27         0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
  28         0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
  29         0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
  30         0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
  31         0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
  32         0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
  33         0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
  34         0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
  35         0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
  36         0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
  37 };
  38
  39 static inline u32 Ch(u32 x, u32 y, u32 z)
  40 {
  41         return z ^ (x & (y ^ z));
  42 }
  43
  44 static inline u32 Maj(u32 x, u32 y, u32 z)
  45 {
  46         return (x & y) | (z & (x | y));
  47 }
  48
  49 #define e0(x)       (ror32(x, 2) ^ ror32(x, 13) ^ ror32(x, 22))
  50 #define e1(x)       (ror32(x, 6) ^ ror32(x, 11) ^ ror32(x, 25))
  51 #define s0(x)       (ror32(x, 7) ^ ror32(x, 18) ^ (x >> 3))
  52 #define s1(x)       (ror32(x, 17) ^ ror32(x, 19) ^ (x >> 10))
  53
  54 static inline void LOAD_OP(int I, u32 *W, const u8 *input)
  55 {
  56         W[I] = get_unaligned_be32((__u32 *)input + I);
  57 }
  58
  59 static inline void BLEND_OP(int I, u32 *W)
  60 {
  61         W[I] = s1(W[I-2]) + W[I-7] + s0(W[I-15]) + W[I-16];
  62 }
  63
  64 #define SHA256_ROUND(i, a, b, c, d, e, f, g, h) do {            \
  65         u32 t1, t2;                                             \
  66         t1 = h + e1(e) + Ch(e, f, g) + SHA256_K[i] + W[i];      \
  67         t2 = e0(a) + Maj(a, b, c);                              \
  68         d += t1;                                                \
  69         h = t1 + t2;                                            \
  70 } while (0)
  71
  72 static void sha256_transform(u32 *state, const u8 *input, u32 *W)
  73 {
  74         u32 a, b, c, d, e, f, g, h;
  75         int i;
  76
  77         /* load the input */
  78         for (i = 0; i < 16; i += 8) {
  79                 LOAD_OP(i + 0, W, input);
  80                 LOAD_OP(i + 1, W, input);
  81                 LOAD_OP(i + 2, W, input);
  82                 LOAD_OP(i + 3, W, input);
  83                 LOAD_OP(i + 4, W, input);
  84                 LOAD_OP(i + 5, W, input);
  85                 LOAD_OP(i + 6, W, input);
  86                 LOAD_OP(i + 7, W, input);
  87         }
  88
  89         /* now blend */
  90         for (i = 16; i < 64; i += 8) {
  91                 BLEND_OP(i + 0, W);
  92                 BLEND_OP(i + 1, W);
  93                 BLEND_OP(i + 2, W);
  94                 BLEND_OP(i + 3, W);
  95                 BLEND_OP(i + 4, W);
  96                 BLEND_OP(i + 5, W);
  97                 BLEND_OP(i + 6, W);
  98                 BLEND_OP(i + 7, W);
  99         }
 100
 101         /* load the state into our registers */
 102         a = state[0];  b = state[1];  c = state[2];  d = state[3];
 103         e = state[4];  f = state[5];  g = state[6];  h = state[7];
 104
 105         /* now iterate */
 106         for (i = 0; i < 64; i += 8) {
 107                 SHA256_ROUND(i + 0, a, b, c, d, e, f, g, h);
 108                 SHA256_ROUND(i + 1, h, a, b, c, d, e, f, g);
 109                 SHA256_ROUND(i + 2, g, h, a, b, c, d, e, f);
 110                 SHA256_ROUND(i + 3, f, g, h, a, b, c, d, e);
 111                 SHA256_ROUND(i + 4, e, f, g, h, a, b, c, d);
 112                 SHA256_ROUND(i + 5, d, e, f, g, h, a, b, c);
 113                 SHA256_ROUND(i + 6, c, d, e, f, g, h, a, b);
 114                 SHA256_ROUND(i + 7, b, c, d, e, f, g, h, a);
 115         }
 116
 117         state[0] += a; state[1] += b; state[2] += c; state[3] += d;
 118         state[4] += e; state[5] += f; state[6] += g; state[7] += h;
 119 }
 120
 121 static void sha256_transform_blocks(struct sha256_state *sctx,
 122                                     const u8 *input, int blocks)
 123 {
 124         u32 W[64];
 125
 126         do {
 127                 sha256_transform(sctx->state, input, W);
 128                 input += SHA256_BLOCK_SIZE;
 129         } while (--blocks);
 130
 131         memzero_explicit(W, sizeof(W));
 132 }
 133
 134 void sha256_update(struct sha256_state *sctx, const u8 *data, unsigned int len)
 135 {
 136         lib_sha256_base_do_update(sctx, data, len, sha256_transform_blocks);
 137 }
 138 EXPORT_SYMBOL(sha256_update);
 139
 140 static void __sha256_final(struct sha256_state *sctx, u8 *out, int digest_size)
 141 {
 142         lib_sha256_base_do_finalize(sctx, sha256_transform_blocks);
 143         lib_sha256_base_finish(sctx, out, digest_size);
 144 }
 145
 146 void sha256_final(struct sha256_state *sctx, u8 *out)
 147 {
 148         __sha256_final(sctx, out, 32);
 149 }
 150 EXPORT_SYMBOL(sha256_final);
 151
 152 void sha224_final(struct sha256_state *sctx, u8 *out)
 153 {
 154         __sha256_final(sctx, out, 28);
 155 }
 156 EXPORT_SYMBOL(sha224_final);
 157
 158 void sha256(const u8 *data, unsigned int len, u8 *out)
 159 {
 160         struct sha256_state sctx;
 161
 162         sha256_init(&sctx);
 163         sha256_update(&sctx, data, len);
 164         sha256_final(&sctx, out);
 165 }
 166 EXPORT_SYMBOL(sha256);
 167
 168 MODULE_DESCRIPTION("SHA-256 Algorithm");
 169 MODULE_LICENSE("GPL");