1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * SHA-1 and HMAC-SHA1 library functions 4 */ 5 6 #include <crypto/hmac.h> 7 #include <crypto/sha1.h> 8 #include <linux/bitops.h> 9 #include <linux/export.h> 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/string.h> 13 #include <linux/unaligned.h> 14 #include <linux/wordpart.h> 15 16 static const struct sha1_block_state sha1_iv = { 17 .h = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 }, 18 }; 19 20 /* 21 * If you have 32 registers or more, the compiler can (and should) 22 * try to change the array[] accesses into registers. However, on 23 * machines with less than ~25 registers, that won't really work, 24 * and at least gcc will make an unholy mess of it. 25 * 26 * So to avoid that mess which just slows things down, we force 27 * the stores to memory to actually happen (we might be better off 28 * with a 'W(t)=(val);asm("":"+m" (W(t))' there instead, as 29 * suggested by Artur Skawina - that will also make gcc unable to 30 * try to do the silly "optimize away loads" part because it won't 31 * see what the value will be). 32 * 33 * Ben Herrenschmidt reports that on PPC, the C version comes close 34 * to the optimized asm with this (ie on PPC you don't want that 35 * 'volatile', since there are lots of registers). 36 * 37 * On ARM we get the best code generation by forcing a full memory barrier 38 * between each SHA_ROUND, otherwise gcc happily get wild with spilling and 39 * the stack frame size simply explode and performance goes down the drain. 40 */ 41 42 #ifdef CONFIG_X86 43 #define setW(x, val) (*(volatile __u32 *)&W(x) = (val)) 44 #elif defined(CONFIG_ARM) 45 #define setW(x, val) do { W(x) = (val); __asm__("":::"memory"); } while (0) 46 #else 47 #define setW(x, val) (W(x) = (val)) 48 #endif 49 50 /* This "rolls" over the 512-bit array */ 51 #define W(x) (array[(x)&15]) 52 53 /* 54 * Where do we get the source from? The first 16 iterations get it from 55 * the input data, the next mix it from the 512-bit array. 56 */ 57 #define SHA_SRC(t) get_unaligned_be32((__u32 *)data + t) 58 #define SHA_MIX(t) rol32(W(t+13) ^ W(t+8) ^ W(t+2) ^ W(t), 1) 59 60 #define SHA_ROUND(t, input, fn, constant, A, B, C, D, E) do { \ 61 __u32 TEMP = input(t); setW(t, TEMP); \ 62 E += TEMP + rol32(A,5) + (fn) + (constant); \ 63 B = ror32(B, 2); \ 64 TEMP = E; E = D; D = C; C = B; B = A; A = TEMP; } while (0) 65 66 #define T_0_15(t, A, B, C, D, E) SHA_ROUND(t, SHA_SRC, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E ) 67 #define T_16_19(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (((C^D)&B)^D) , 0x5a827999, A, B, C, D, E ) 68 #define T_20_39(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0x6ed9eba1, A, B, C, D, E ) 69 #define T_40_59(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, ((B&C)+(D&(B^C))) , 0x8f1bbcdc, A, B, C, D, E ) 70 #define T_60_79(t, A, B, C, D, E) SHA_ROUND(t, SHA_MIX, (B^C^D) , 0xca62c1d6, A, B, C, D, E ) 71 72 /** 73 * sha1_transform - single block SHA1 transform (deprecated) 74 * 75 * @digest: 160 bit digest to update 76 * @data: 512 bits of data to hash 77 * @array: 16 words of workspace (see note) 78 * 79 * This function executes SHA-1's internal compression function. It updates the 80 * 160-bit internal state (@digest) with a single 512-bit data block (@data). 81 * 82 * Don't use this function. SHA-1 is no longer considered secure. And even if 83 * you do have to use SHA-1, this isn't the correct way to hash something with 84 * SHA-1 as this doesn't handle padding and finalization. 85 * 86 * Note: If the hash is security sensitive, the caller should be sure 87 * to clear the workspace. This is left to the caller to avoid 88 * unnecessary clears between chained hashing operations. 89 */ 90 void sha1_transform(__u32 *digest, const char *data, __u32 *array) 91 { 92 __u32 A, B, C, D, E; 93 unsigned int i = 0; 94 95 A = digest[0]; 96 B = digest[1]; 97 C = digest[2]; 98 D = digest[3]; 99 E = digest[4]; 100 101 /* Round 1 - iterations 0-16 take their input from 'data' */ 102 for (; i < 16; ++i) 103 T_0_15(i, A, B, C, D, E); 104 105 /* Round 1 - tail. Input from 512-bit mixing array */ 106 for (; i < 20; ++i) 107 T_16_19(i, A, B, C, D, E); 108 109 /* Round 2 */ 110 for (; i < 40; ++i) 111 T_20_39(i, A, B, C, D, E); 112 113 /* Round 3 */ 114 for (; i < 60; ++i) 115 T_40_59(i, A, B, C, D, E); 116 117 /* Round 4 */ 118 for (; i < 80; ++i) 119 T_60_79(i, A, B, C, D, E); 120 121 digest[0] += A; 122 digest[1] += B; 123 digest[2] += C; 124 digest[3] += D; 125 digest[4] += E; 126 } 127 EXPORT_SYMBOL(sha1_transform); 128 129 /** 130 * sha1_init_raw - initialize the vectors for a SHA1 digest 131 * @buf: vector to initialize 132 */ 133 void sha1_init_raw(__u32 *buf) 134 { 135 buf[0] = 0x67452301; 136 buf[1] = 0xefcdab89; 137 buf[2] = 0x98badcfe; 138 buf[3] = 0x10325476; 139 buf[4] = 0xc3d2e1f0; 140 } 141 EXPORT_SYMBOL(sha1_init_raw); 142 143 static void __maybe_unused sha1_blocks_generic(struct sha1_block_state *state, 144 const u8 *data, size_t nblocks) 145 { 146 u32 workspace[SHA1_WORKSPACE_WORDS]; 147 148 do { 149 sha1_transform(state->h, data, workspace); 150 data += SHA1_BLOCK_SIZE; 151 } while (--nblocks); 152 153 memzero_explicit(workspace, sizeof(workspace)); 154 } 155 156 #ifdef CONFIG_CRYPTO_LIB_SHA1_ARCH 157 #include "sha1.h" /* $(SRCARCH)/sha1.h */ 158 #else 159 #define sha1_blocks sha1_blocks_generic 160 #endif 161 162 void sha1_init(struct sha1_ctx *ctx) 163 { 164 ctx->state = sha1_iv; 165 ctx->bytecount = 0; 166 } 167 EXPORT_SYMBOL_GPL(sha1_init); 168 169 void sha1_update(struct sha1_ctx *ctx, const u8 *data, size_t len) 170 { 171 size_t partial = ctx->bytecount % SHA1_BLOCK_SIZE; 172 173 ctx->bytecount += len; 174 175 if (partial + len >= SHA1_BLOCK_SIZE) { 176 size_t nblocks; 177 178 if (partial) { 179 size_t l = SHA1_BLOCK_SIZE - partial; 180 181 memcpy(&ctx->buf[partial], data, l); 182 data += l; 183 len -= l; 184 185 sha1_blocks(&ctx->state, ctx->buf, 1); 186 } 187 188 nblocks = len / SHA1_BLOCK_SIZE; 189 len %= SHA1_BLOCK_SIZE; 190 191 if (nblocks) { 192 sha1_blocks(&ctx->state, data, nblocks); 193 data += nblocks * SHA1_BLOCK_SIZE; 194 } 195 partial = 0; 196 } 197 if (len) 198 memcpy(&ctx->buf[partial], data, len); 199 } 200 EXPORT_SYMBOL_GPL(sha1_update); 201 202 static void __sha1_final(struct sha1_ctx *ctx, u8 out[SHA1_DIGEST_SIZE]) 203 { 204 u64 bitcount = ctx->bytecount << 3; 205 size_t partial = ctx->bytecount % SHA1_BLOCK_SIZE; 206 207 ctx->buf[partial++] = 0x80; 208 if (partial > SHA1_BLOCK_SIZE - 8) { 209 memset(&ctx->buf[partial], 0, SHA1_BLOCK_SIZE - partial); 210 sha1_blocks(&ctx->state, ctx->buf, 1); 211 partial = 0; 212 } 213 memset(&ctx->buf[partial], 0, SHA1_BLOCK_SIZE - 8 - partial); 214 *(__be64 *)&ctx->buf[SHA1_BLOCK_SIZE - 8] = cpu_to_be64(bitcount); 215 sha1_blocks(&ctx->state, ctx->buf, 1); 216 217 for (size_t i = 0; i < SHA1_DIGEST_SIZE; i += 4) 218 put_unaligned_be32(ctx->state.h[i / 4], out + i); 219 } 220 221 void sha1_final(struct sha1_ctx *ctx, u8 out[SHA1_DIGEST_SIZE]) 222 { 223 __sha1_final(ctx, out); 224 memzero_explicit(ctx, sizeof(*ctx)); 225 } 226 EXPORT_SYMBOL_GPL(sha1_final); 227 228 void sha1(const u8 *data, size_t len, u8 out[SHA1_DIGEST_SIZE]) 229 { 230 struct sha1_ctx ctx; 231 232 sha1_init(&ctx); 233 sha1_update(&ctx, data, len); 234 sha1_final(&ctx, out); 235 } 236 EXPORT_SYMBOL_GPL(sha1); 237 238 static void __hmac_sha1_preparekey(struct sha1_block_state *istate, 239 struct sha1_block_state *ostate, 240 const u8 *raw_key, size_t raw_key_len) 241 { 242 union { 243 u8 b[SHA1_BLOCK_SIZE]; 244 unsigned long w[SHA1_BLOCK_SIZE / sizeof(unsigned long)]; 245 } derived_key = { 0 }; 246 247 if (unlikely(raw_key_len > SHA1_BLOCK_SIZE)) 248 sha1(raw_key, raw_key_len, derived_key.b); 249 else 250 memcpy(derived_key.b, raw_key, raw_key_len); 251 252 for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++) 253 derived_key.w[i] ^= REPEAT_BYTE(HMAC_IPAD_VALUE); 254 *istate = sha1_iv; 255 sha1_blocks(istate, derived_key.b, 1); 256 257 for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++) 258 derived_key.w[i] ^= REPEAT_BYTE(HMAC_OPAD_VALUE ^ 259 HMAC_IPAD_VALUE); 260 *ostate = sha1_iv; 261 sha1_blocks(ostate, derived_key.b, 1); 262 263 memzero_explicit(&derived_key, sizeof(derived_key)); 264 } 265 266 void hmac_sha1_preparekey(struct hmac_sha1_key *key, 267 const u8 *raw_key, size_t raw_key_len) 268 { 269 __hmac_sha1_preparekey(&key->istate, &key->ostate, 270 raw_key, raw_key_len); 271 } 272 EXPORT_SYMBOL_GPL(hmac_sha1_preparekey); 273 274 void hmac_sha1_init(struct hmac_sha1_ctx *ctx, const struct hmac_sha1_key *key) 275 { 276 ctx->sha_ctx.state = key->istate; 277 ctx->sha_ctx.bytecount = SHA1_BLOCK_SIZE; 278 ctx->ostate = key->ostate; 279 } 280 EXPORT_SYMBOL_GPL(hmac_sha1_init); 281 282 void hmac_sha1_init_usingrawkey(struct hmac_sha1_ctx *ctx, 283 const u8 *raw_key, size_t raw_key_len) 284 { 285 __hmac_sha1_preparekey(&ctx->sha_ctx.state, &ctx->ostate, 286 raw_key, raw_key_len); 287 ctx->sha_ctx.bytecount = SHA1_BLOCK_SIZE; 288 } 289 EXPORT_SYMBOL_GPL(hmac_sha1_init_usingrawkey); 290 291 void hmac_sha1_final(struct hmac_sha1_ctx *ctx, u8 out[SHA1_DIGEST_SIZE]) 292 { 293 /* Generate the padded input for the outer hash in ctx->sha_ctx.buf. */ 294 __sha1_final(&ctx->sha_ctx, ctx->sha_ctx.buf); 295 memset(&ctx->sha_ctx.buf[SHA1_DIGEST_SIZE], 0, 296 SHA1_BLOCK_SIZE - SHA1_DIGEST_SIZE); 297 ctx->sha_ctx.buf[SHA1_DIGEST_SIZE] = 0x80; 298 *(__be32 *)&ctx->sha_ctx.buf[SHA1_BLOCK_SIZE - 4] = 299 cpu_to_be32(8 * (SHA1_BLOCK_SIZE + SHA1_DIGEST_SIZE)); 300 301 /* Compute the outer hash, which gives the HMAC value. */ 302 sha1_blocks(&ctx->ostate, ctx->sha_ctx.buf, 1); 303 for (size_t i = 0; i < SHA1_DIGEST_SIZE; i += 4) 304 put_unaligned_be32(ctx->ostate.h[i / 4], out + i); 305 306 memzero_explicit(ctx, sizeof(*ctx)); 307 } 308 EXPORT_SYMBOL_GPL(hmac_sha1_final); 309 310 void hmac_sha1(const struct hmac_sha1_key *key, 311 const u8 *data, size_t data_len, u8 out[SHA1_DIGEST_SIZE]) 312 { 313 struct hmac_sha1_ctx ctx; 314 315 hmac_sha1_init(&ctx, key); 316 hmac_sha1_update(&ctx, data, data_len); 317 hmac_sha1_final(&ctx, out); 318 } 319 EXPORT_SYMBOL_GPL(hmac_sha1); 320 321 void hmac_sha1_usingrawkey(const u8 *raw_key, size_t raw_key_len, 322 const u8 *data, size_t data_len, 323 u8 out[SHA1_DIGEST_SIZE]) 324 { 325 struct hmac_sha1_ctx ctx; 326 327 hmac_sha1_init_usingrawkey(&ctx, raw_key, raw_key_len); 328 hmac_sha1_update(&ctx, data, data_len); 329 hmac_sha1_final(&ctx, out); 330 } 331 EXPORT_SYMBOL_GPL(hmac_sha1_usingrawkey); 332 333 #ifdef sha1_mod_init_arch 334 static int __init sha1_mod_init(void) 335 { 336 sha1_mod_init_arch(); 337 return 0; 338 } 339 subsys_initcall(sha1_mod_init); 340 341 static void __exit sha1_mod_exit(void) 342 { 343 } 344 module_exit(sha1_mod_exit); 345 #endif 346 347 MODULE_DESCRIPTION("SHA-1 and HMAC-SHA1 library functions"); 348 MODULE_LICENSE("GPL"); 349