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/bitops.h> 15 #include <linux/export.h> 16 #include <linux/module.h> 17 #include <linux/string.h> 18 #include <crypto/sha2.h> 19 #include <asm/unaligned.h> 20 21 static const u32 SHA256_K[] = { 22 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 23 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 24 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 25 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 26 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 27 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 28 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 29 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 30 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 31 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 32 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 33 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 34 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 35 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 36 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 37 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2, 38 }; 39 40 static inline u32 Ch(u32 x, u32 y, u32 z) 41 { 42 return z ^ (x & (y ^ z)); 43 } 44 45 static inline u32 Maj(u32 x, u32 y, u32 z) 46 { 47 return (x & y) | (z & (x | y)); 48 } 49 50 #define e0(x) (ror32(x, 2) ^ ror32(x, 13) ^ ror32(x, 22)) 51 #define e1(x) (ror32(x, 6) ^ ror32(x, 11) ^ ror32(x, 25)) 52 #define s0(x) (ror32(x, 7) ^ ror32(x, 18) ^ (x >> 3)) 53 #define s1(x) (ror32(x, 17) ^ ror32(x, 19) ^ (x >> 10)) 54 55 static inline void LOAD_OP(int I, u32 *W, const u8 *input) 56 { 57 W[I] = get_unaligned_be32((__u32 *)input + I); 58 } 59 60 static inline void BLEND_OP(int I, u32 *W) 61 { 62 W[I] = s1(W[I-2]) + W[I-7] + s0(W[I-15]) + W[I-16]; 63 } 64 65 #define SHA256_ROUND(i, a, b, c, d, e, f, g, h) do { \ 66 u32 t1, t2; \ 67 t1 = h + e1(e) + Ch(e, f, g) + SHA256_K[i] + W[i]; \ 68 t2 = e0(a) + Maj(a, b, c); \ 69 d += t1; \ 70 h = t1 + t2; \ 71 } while (0) 72 73 static void sha256_transform(u32 *state, const u8 *input, u32 *W) 74 { 75 u32 a, b, c, d, e, f, g, h; 76 int i; 77 78 /* load the input */ 79 for (i = 0; i < 16; i += 8) { 80 LOAD_OP(i + 0, W, input); 81 LOAD_OP(i + 1, W, input); 82 LOAD_OP(i + 2, W, input); 83 LOAD_OP(i + 3, W, input); 84 LOAD_OP(i + 4, W, input); 85 LOAD_OP(i + 5, W, input); 86 LOAD_OP(i + 6, W, input); 87 LOAD_OP(i + 7, W, input); 88 } 89 90 /* now blend */ 91 for (i = 16; i < 64; i += 8) { 92 BLEND_OP(i + 0, W); 93 BLEND_OP(i + 1, W); 94 BLEND_OP(i + 2, W); 95 BLEND_OP(i + 3, W); 96 BLEND_OP(i + 4, W); 97 BLEND_OP(i + 5, W); 98 BLEND_OP(i + 6, W); 99 BLEND_OP(i + 7, W); 100 } 101 102 /* load the state into our registers */ 103 a = state[0]; b = state[1]; c = state[2]; d = state[3]; 104 e = state[4]; f = state[5]; g = state[6]; h = state[7]; 105 106 /* now iterate */ 107 for (i = 0; i < 64; i += 8) { 108 SHA256_ROUND(i + 0, a, b, c, d, e, f, g, h); 109 SHA256_ROUND(i + 1, h, a, b, c, d, e, f, g); 110 SHA256_ROUND(i + 2, g, h, a, b, c, d, e, f); 111 SHA256_ROUND(i + 3, f, g, h, a, b, c, d, e); 112 SHA256_ROUND(i + 4, e, f, g, h, a, b, c, d); 113 SHA256_ROUND(i + 5, d, e, f, g, h, a, b, c); 114 SHA256_ROUND(i + 6, c, d, e, f, g, h, a, b); 115 SHA256_ROUND(i + 7, b, c, d, e, f, g, h, a); 116 } 117 118 state[0] += a; state[1] += b; state[2] += c; state[3] += d; 119 state[4] += e; state[5] += f; state[6] += g; state[7] += h; 120 } 121 122 void sha256_update(struct sha256_state *sctx, const u8 *data, unsigned int len) 123 { 124 unsigned int partial, done; 125 const u8 *src; 126 u32 W[64]; 127 128 partial = sctx->count & 0x3f; 129 sctx->count += len; 130 done = 0; 131 src = data; 132 133 if ((partial + len) > 63) { 134 if (partial) { 135 done = -partial; 136 memcpy(sctx->buf + partial, data, done + 64); 137 src = sctx->buf; 138 } 139 140 do { 141 sha256_transform(sctx->state, src, W); 142 done += 64; 143 src = data + done; 144 } while (done + 63 < len); 145 146 memzero_explicit(W, sizeof(W)); 147 148 partial = 0; 149 } 150 memcpy(sctx->buf + partial, src, len - done); 151 } 152 EXPORT_SYMBOL(sha256_update); 153 154 void sha224_update(struct sha256_state *sctx, const u8 *data, unsigned int len) 155 { 156 sha256_update(sctx, data, len); 157 } 158 EXPORT_SYMBOL(sha224_update); 159 160 static void __sha256_final(struct sha256_state *sctx, u8 *out, int digest_words) 161 { 162 __be32 *dst = (__be32 *)out; 163 __be64 bits; 164 unsigned int index, pad_len; 165 int i; 166 static const u8 padding[64] = { 0x80, }; 167 168 /* Save number of bits */ 169 bits = cpu_to_be64(sctx->count << 3); 170 171 /* Pad out to 56 mod 64. */ 172 index = sctx->count & 0x3f; 173 pad_len = (index < 56) ? (56 - index) : ((64+56) - index); 174 sha256_update(sctx, padding, pad_len); 175 176 /* Append length (before padding) */ 177 sha256_update(sctx, (const u8 *)&bits, sizeof(bits)); 178 179 /* Store state in digest */ 180 for (i = 0; i < digest_words; i++) 181 put_unaligned_be32(sctx->state[i], &dst[i]); 182 183 /* Zeroize sensitive information. */ 184 memzero_explicit(sctx, sizeof(*sctx)); 185 } 186 187 void sha256_final(struct sha256_state *sctx, u8 *out) 188 { 189 __sha256_final(sctx, out, 8); 190 } 191 EXPORT_SYMBOL(sha256_final); 192 193 void sha224_final(struct sha256_state *sctx, u8 *out) 194 { 195 __sha256_final(sctx, out, 7); 196 } 197 EXPORT_SYMBOL(sha224_final); 198 199 void sha256(const u8 *data, unsigned int len, u8 *out) 200 { 201 struct sha256_state sctx; 202 203 sha256_init(&sctx); 204 sha256_update(&sctx, data, len); 205 sha256_final(&sctx, out); 206 } 207 EXPORT_SYMBOL(sha256); 208 209 MODULE_LICENSE("GPL"); 210