1 /* 2 * sha.c: routines to compute SHA-1/224/256/384/512 digests 3 * 4 * Ref: NIST FIPS PUB 180-4 Secure Hash Standard 5 * 6 * Copyright (C) 2003-2023 Mark Shelor, All Rights Reserved 7 * 8 * Version: 6.04 9 * Sat Feb 25 12:00:50 PM MST 2023 10 * 11 */ 12 13 #include <stdio.h> 14 #include <stdlib.h> 15 #include <stddef.h> 16 #include <string.h> 17 #include <ctype.h> 18 #include "sha.h" 19 #include "sha64bit.h" 20 21 #define W32 SHA32 /* useful abbreviations */ 22 #define C32 SHA32_CONST 23 #define SR32 SHA32_SHR 24 #define SL32 SHA32_SHL 25 #define LO32 SHA_LO32 26 #define UCHR unsigned char 27 #define UINT unsigned int 28 #define ULNG unsigned long 29 #define VP void * 30 31 #define ROTR(x, n) (SR32(x, n) | SL32(x, 32-(n))) 32 #define ROTL(x, n) (SL32(x, n) | SR32(x, 32-(n))) 33 34 #define Ch(x, y, z) ((z) ^ ((x) & ((y) ^ (z)))) 35 #define Pa(x, y, z) ((x) ^ (y) ^ (z)) 36 #define Ma(x, y, z) (((x) & (y)) | ((z) & ((x) | (y)))) 37 38 #define SIGMA0(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22)) 39 #define SIGMA1(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25)) 40 #define sigma0(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SR32(x, 3)) 41 #define sigma1(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SR32(x, 10)) 42 43 #define K1 C32(0x5a827999) /* SHA-1 constants */ 44 #define K2 C32(0x6ed9eba1) 45 #define K3 C32(0x8f1bbcdc) 46 #define K4 C32(0xca62c1d6) 47 48 static const W32 K256[64] = /* SHA-224/256 constants */ 49 { 50 C32(0x428a2f98), C32(0x71374491), C32(0xb5c0fbcf), C32(0xe9b5dba5), 51 C32(0x3956c25b), C32(0x59f111f1), C32(0x923f82a4), C32(0xab1c5ed5), 52 C32(0xd807aa98), C32(0x12835b01), C32(0x243185be), C32(0x550c7dc3), 53 C32(0x72be5d74), C32(0x80deb1fe), C32(0x9bdc06a7), C32(0xc19bf174), 54 C32(0xe49b69c1), C32(0xefbe4786), C32(0x0fc19dc6), C32(0x240ca1cc), 55 C32(0x2de92c6f), C32(0x4a7484aa), C32(0x5cb0a9dc), C32(0x76f988da), 56 C32(0x983e5152), C32(0xa831c66d), C32(0xb00327c8), C32(0xbf597fc7), 57 C32(0xc6e00bf3), C32(0xd5a79147), C32(0x06ca6351), C32(0x14292967), 58 C32(0x27b70a85), C32(0x2e1b2138), C32(0x4d2c6dfc), C32(0x53380d13), 59 C32(0x650a7354), C32(0x766a0abb), C32(0x81c2c92e), C32(0x92722c85), 60 C32(0xa2bfe8a1), C32(0xa81a664b), C32(0xc24b8b70), C32(0xc76c51a3), 61 C32(0xd192e819), C32(0xd6990624), C32(0xf40e3585), C32(0x106aa070), 62 C32(0x19a4c116), C32(0x1e376c08), C32(0x2748774c), C32(0x34b0bcb5), 63 C32(0x391c0cb3), C32(0x4ed8aa4a), C32(0x5b9cca4f), C32(0x682e6ff3), 64 C32(0x748f82ee), C32(0x78a5636f), C32(0x84c87814), C32(0x8cc70208), 65 C32(0x90befffa), C32(0xa4506ceb), C32(0xbef9a3f7), C32(0xc67178f2) 66 }; 67 68 static const W32 H01[8] = /* SHA-1 initial hash value */ 69 { 70 C32(0x67452301), C32(0xefcdab89), C32(0x98badcfe), C32(0x10325476), 71 C32(0xc3d2e1f0), C32(0x00000000), C32(0x00000000), C32(0x00000000) 72 }; 73 74 static const W32 H0224[8] = /* SHA-224 initial hash value */ 75 { 76 C32(0xc1059ed8), C32(0x367cd507), C32(0x3070dd17), C32(0xf70e5939), 77 C32(0xffc00b31), C32(0x68581511), C32(0x64f98fa7), C32(0xbefa4fa4) 78 }; 79 80 static const W32 H0256[8] = /* SHA-256 initial hash value */ 81 { 82 C32(0x6a09e667), C32(0xbb67ae85), C32(0x3c6ef372), C32(0xa54ff53a), 83 C32(0x510e527f), C32(0x9b05688c), C32(0x1f83d9ab), C32(0x5be0cd19) 84 }; 85 86 static void sha1(SHA *s, UCHR *block) /* SHA-1 transform */ 87 { 88 W32 a, b, c, d, e; 89 W32 W[16]; 90 W32 *wp = W; 91 W32 *H = s->H32; 92 93 SHA32_SCHED(W, block); 94 95 /* 96 * Use SHA-1 alternate method from FIPS PUB 180-4 (ref. 6.1.3) 97 * 98 * To improve performance, unroll the loop and consolidate assignments 99 * by changing the roles of variables "a" through "e" at each step. 100 * Note that the variable "T" is no longer needed. 101 */ 102 103 #define M1(a, b, c, d, e, f, k, w) \ 104 e += ROTL(a, 5) + f(b, c, d) + k + w; \ 105 b = ROTL(b, 30) 106 107 #define M11(f, k, w) M1(a, b, c, d, e, f, k, w); 108 #define M12(f, k, w) M1(e, a, b, c, d, f, k, w); 109 #define M13(f, k, w) M1(d, e, a, b, c, f, k, w); 110 #define M14(f, k, w) M1(c, d, e, a, b, f, k, w); 111 #define M15(f, k, w) M1(b, c, d, e, a, f, k, w); 112 113 #define W11(s) W[(s+ 0) & 0xf] 114 #define W12(s) W[(s+13) & 0xf] 115 #define W13(s) W[(s+ 8) & 0xf] 116 #define W14(s) W[(s+ 2) & 0xf] 117 118 #define A1(s) (W11(s) = ROTL(W11(s) ^ W12(s) ^ W13(s) ^ W14(s), 1)) 119 120 a = H[0]; b = H[1]; c = H[2]; d = H[3]; e = H[4]; 121 122 M11(Ch, K1, *wp++); M12(Ch, K1, *wp++); M13(Ch, K1, *wp++); 123 M14(Ch, K1, *wp++); M15(Ch, K1, *wp++); M11(Ch, K1, *wp++); 124 M12(Ch, K1, *wp++); M13(Ch, K1, *wp++); M14(Ch, K1, *wp++); 125 M15(Ch, K1, *wp++); M11(Ch, K1, *wp++); M12(Ch, K1, *wp++); 126 M13(Ch, K1, *wp++); M14(Ch, K1, *wp++); M15(Ch, K1, *wp++); 127 M11(Ch, K1, *wp ); M12(Ch, K1, A1( 0)); M13(Ch, K1, A1( 1)); 128 M14(Ch, K1, A1( 2)); M15(Ch, K1, A1( 3)); M11(Pa, K2, A1( 4)); 129 M12(Pa, K2, A1( 5)); M13(Pa, K2, A1( 6)); M14(Pa, K2, A1( 7)); 130 M15(Pa, K2, A1( 8)); M11(Pa, K2, A1( 9)); M12(Pa, K2, A1(10)); 131 M13(Pa, K2, A1(11)); M14(Pa, K2, A1(12)); M15(Pa, K2, A1(13)); 132 M11(Pa, K2, A1(14)); M12(Pa, K2, A1(15)); M13(Pa, K2, A1( 0)); 133 M14(Pa, K2, A1( 1)); M15(Pa, K2, A1( 2)); M11(Pa, K2, A1( 3)); 134 M12(Pa, K2, A1( 4)); M13(Pa, K2, A1( 5)); M14(Pa, K2, A1( 6)); 135 M15(Pa, K2, A1( 7)); M11(Ma, K3, A1( 8)); M12(Ma, K3, A1( 9)); 136 M13(Ma, K3, A1(10)); M14(Ma, K3, A1(11)); M15(Ma, K3, A1(12)); 137 M11(Ma, K3, A1(13)); M12(Ma, K3, A1(14)); M13(Ma, K3, A1(15)); 138 M14(Ma, K3, A1( 0)); M15(Ma, K3, A1( 1)); M11(Ma, K3, A1( 2)); 139 M12(Ma, K3, A1( 3)); M13(Ma, K3, A1( 4)); M14(Ma, K3, A1( 5)); 140 M15(Ma, K3, A1( 6)); M11(Ma, K3, A1( 7)); M12(Ma, K3, A1( 8)); 141 M13(Ma, K3, A1( 9)); M14(Ma, K3, A1(10)); M15(Ma, K3, A1(11)); 142 M11(Pa, K4, A1(12)); M12(Pa, K4, A1(13)); M13(Pa, K4, A1(14)); 143 M14(Pa, K4, A1(15)); M15(Pa, K4, A1( 0)); M11(Pa, K4, A1( 1)); 144 M12(Pa, K4, A1( 2)); M13(Pa, K4, A1( 3)); M14(Pa, K4, A1( 4)); 145 M15(Pa, K4, A1( 5)); M11(Pa, K4, A1( 6)); M12(Pa, K4, A1( 7)); 146 M13(Pa, K4, A1( 8)); M14(Pa, K4, A1( 9)); M15(Pa, K4, A1(10)); 147 M11(Pa, K4, A1(11)); M12(Pa, K4, A1(12)); M13(Pa, K4, A1(13)); 148 M14(Pa, K4, A1(14)); M15(Pa, K4, A1(15)); 149 150 H[0] += a; H[1] += b; H[2] += c; H[3] += d; H[4] += e; 151 } 152 153 static void sha256(SHA *s, UCHR *block) /* SHA-224/256 transform */ 154 { 155 W32 a, b, c, d, e, f, g, h, T1; 156 W32 W[16]; 157 const W32 *kp = K256; 158 W32 *wp = W; 159 W32 *H = s->H32; 160 161 SHA32_SCHED(W, block); 162 163 /* 164 * Use same technique as in sha1() 165 * 166 * To improve performance, unroll the loop and consolidate assignments 167 * by changing the roles of variables "a" through "h" at each step. 168 * Note that the variable "T2" is no longer needed. 169 */ 170 171 #define M2(a, b, c, d, e, f, g, h, w) \ 172 T1 = h + SIGMA1(e) + Ch(e, f, g) + (*kp++) + w; \ 173 h = T1 + SIGMA0(a) + Ma(a, b, c); d += T1; 174 175 #define W21(s) W[(s+ 0) & 0xf] 176 #define W22(s) W[(s+14) & 0xf] 177 #define W23(s) W[(s+ 9) & 0xf] 178 #define W24(s) W[(s+ 1) & 0xf] 179 180 #define A2(s) (W21(s) += sigma1(W22(s)) + W23(s) + sigma0(W24(s))) 181 182 #define M21(w) M2(a, b, c, d, e, f, g, h, w) 183 #define M22(w) M2(h, a, b, c, d, e, f, g, w) 184 #define M23(w) M2(g, h, a, b, c, d, e, f, w) 185 #define M24(w) M2(f, g, h, a, b, c, d, e, w) 186 #define M25(w) M2(e, f, g, h, a, b, c, d, w) 187 #define M26(w) M2(d, e, f, g, h, a, b, c, w) 188 #define M27(w) M2(c, d, e, f, g, h, a, b, w) 189 #define M28(w) M2(b, c, d, e, f, g, h, a, w) 190 191 a = H[0]; b = H[1]; c = H[2]; d = H[3]; 192 e = H[4]; f = H[5]; g = H[6]; h = H[7]; 193 194 M21( *wp++); M22( *wp++); M23( *wp++); M24( *wp++); 195 M25( *wp++); M26( *wp++); M27( *wp++); M28( *wp++); 196 M21( *wp++); M22( *wp++); M23( *wp++); M24( *wp++); 197 M25( *wp++); M26( *wp++); M27( *wp++); M28( *wp ); 198 M21(A2( 0)); M22(A2( 1)); M23(A2( 2)); M24(A2( 3)); 199 M25(A2( 4)); M26(A2( 5)); M27(A2( 6)); M28(A2( 7)); 200 M21(A2( 8)); M22(A2( 9)); M23(A2(10)); M24(A2(11)); 201 M25(A2(12)); M26(A2(13)); M27(A2(14)); M28(A2(15)); 202 M21(A2( 0)); M22(A2( 1)); M23(A2( 2)); M24(A2( 3)); 203 M25(A2( 4)); M26(A2( 5)); M27(A2( 6)); M28(A2( 7)); 204 M21(A2( 8)); M22(A2( 9)); M23(A2(10)); M24(A2(11)); 205 M25(A2(12)); M26(A2(13)); M27(A2(14)); M28(A2(15)); 206 M21(A2( 0)); M22(A2( 1)); M23(A2( 2)); M24(A2( 3)); 207 M25(A2( 4)); M26(A2( 5)); M27(A2( 6)); M28(A2( 7)); 208 M21(A2( 8)); M22(A2( 9)); M23(A2(10)); M24(A2(11)); 209 M25(A2(12)); M26(A2(13)); M27(A2(14)); M28(A2(15)); 210 211 H[0] += a; H[1] += b; H[2] += c; H[3] += d; 212 H[4] += e; H[5] += f; H[6] += g; H[7] += h; 213 } 214 215 #include "sha64bit.c" 216 217 #define BITSET(s, pos) s[(pos) >> 3] & (UCHR) (0x01 << (7 - (pos) % 8)) 218 #define SETBIT(s, pos) s[(pos) >> 3] |= (UCHR) (0x01 << (7 - (pos) % 8)) 219 #define CLRBIT(s, pos) s[(pos) >> 3] &= (UCHR) ~(0x01 << (7 - (pos) % 8)) 220 #define NBYTES(nbits) (((nbits) + 7) >> 3) 221 #define HEXLEN(nbytes) ((nbytes) << 1) 222 #define B64LEN(nbytes) (((nbytes) % 3 == 0) ? ((nbytes) / 3) * 4 \ 223 : ((nbytes) / 3) * 4 + ((nbytes) % 3) + 1) 224 225 /* w32mem: writes 32-bit word to memory in big-endian order */ 226 static UCHR *w32mem(UCHR *mem, W32 w32) 227 { 228 int i; 229 230 for (i = 0; i < 4; i++) 231 *mem++ = (UCHR) (SR32(w32, 24-i*8) & 0xff); 232 return(mem); 233 } 234 235 /* memw32: returns 32-bit word from memory written in big-endian order */ 236 static W32 memw32(UCHR *mem) 237 { 238 int i; 239 W32 w = 0; 240 241 for (i = 0; i < 4; i++) 242 w = (w << 8) + *mem++; 243 return(w); 244 } 245 246 /* digcpy: writes current state to digest buffer */ 247 static UCHR *digcpy(SHA *s) 248 { 249 int i; 250 UCHR *d = s->digest; 251 W32 *p32 = s->H32; 252 W64 *p64 = s->H64; 253 254 if (s->alg <= SHA256) 255 for (i = 0; i < 8; i++, d += 4) 256 w32mem(d, *p32++); 257 else 258 for (i = 0; i < 8; i++, d += 8) { 259 w32mem(d, (W32) ((*p64 >> 16) >> 16)); 260 w32mem(d+4, (W32) (*p64++ & SHA32_MAX)); 261 } 262 return(s->digest); 263 } 264 265 /* statecpy: writes buffer to current state (opposite of digcpy) */ 266 static UCHR *statecpy(SHA *s, UCHR *buf) 267 { 268 int i; 269 W32 *p32 = s->H32; 270 W64 *p64 = s->H64; 271 272 if (s->alg <= SHA256) 273 for (i = 0; i < 8; i++, buf += 4) 274 *p32++ = memw32(buf); 275 else 276 for (i = 0; i < 8; i++, buf += 8) 277 *p64++ = (((W64)memw32(buf) << 16) << 16) + 278 memw32(buf+4); 279 return(buf); 280 } 281 282 #define SHA_INIT(s, algo, transform, state, state_t) \ 283 do { \ 284 Zero(s, 1, SHA); \ 285 s->alg = algo; s->sha = sha ## transform; \ 286 Copy(H0 ## algo, s->state, 8, state_t); \ 287 s->blocksize = SHA ## algo ## _BLOCK_BITS; \ 288 s->digestlen = SHA ## algo ## _DIGEST_BITS >> 3; \ 289 } while (0) 290 291 /* sharewind: resets digest object */ 292 static void sharewind(SHA *s) 293 { 294 if (s->alg == SHA1) SHA_INIT(s, 1, 1, H32, SHA32); 295 else if (s->alg == SHA224) SHA_INIT(s, 224, 256, H32, SHA32); 296 else if (s->alg == SHA256) SHA_INIT(s, 256, 256, H32, SHA32); 297 else if (s->alg == SHA384) SHA_INIT(s, 384, 512, H64, SHA64); 298 else if (s->alg == SHA512) SHA_INIT(s, 512, 512, H64, SHA64); 299 else if (s->alg == SHA512224) SHA_INIT(s, 512224, 512, H64, SHA64); 300 else if (s->alg == SHA512256) SHA_INIT(s, 512256, 512, H64, SHA64); 301 } 302 303 /* shainit: initializes digest object */ 304 static int shainit(SHA *s, int alg) 305 { 306 if (alg >= SHA384 && !sha_384_512) 307 return 0; 308 if (alg != SHA1 && alg != SHA224 && alg != SHA256 && 309 alg != SHA384 && alg != SHA512 && 310 alg != SHA512224 && alg != SHA512256) 311 return 0; 312 s->alg = alg; 313 sharewind(s); 314 return 1; 315 } 316 317 /* shadirect: updates state directly (w/o going through s->block) */ 318 static ULNG shadirect(UCHR *bitstr, ULNG bitcnt, SHA *s) 319 { 320 ULNG savecnt = bitcnt; 321 322 while (bitcnt >= s->blocksize) { 323 s->sha(s, bitstr); 324 bitstr += (s->blocksize >> 3); 325 bitcnt -= s->blocksize; 326 } 327 if (bitcnt > 0) { 328 Copy(bitstr, s->block, NBYTES(bitcnt), char); 329 s->blockcnt = bitcnt; 330 } 331 return(savecnt); 332 } 333 334 /* shabytes: updates state for byte-aligned data in s->block */ 335 static ULNG shabytes(UCHR *bitstr, ULNG bitcnt, SHA *s) 336 { 337 UINT offset; 338 UINT nbits; 339 ULNG savecnt = bitcnt; 340 341 offset = s->blockcnt >> 3; 342 if (s->blockcnt + bitcnt >= s->blocksize) { 343 nbits = s->blocksize - s->blockcnt; 344 Copy(bitstr, s->block+offset, nbits>>3, char); 345 bitcnt -= nbits; 346 bitstr += (nbits >> 3); 347 s->sha(s, s->block), s->blockcnt = 0; 348 shadirect(bitstr, bitcnt, s); 349 } 350 else { 351 Copy(bitstr, s->block+offset, NBYTES(bitcnt), char); 352 s->blockcnt += bitcnt; 353 } 354 return(savecnt); 355 } 356 357 /* shabits: updates state for bit-aligned data in s->block */ 358 static ULNG shabits(UCHR *bitstr, ULNG bitcnt, SHA *s) 359 { 360 ULNG i; 361 362 for (i = 0UL; i < bitcnt; i++) { 363 if (BITSET(bitstr, i)) 364 SETBIT(s->block, s->blockcnt); 365 else 366 CLRBIT(s->block, s->blockcnt); 367 if (++s->blockcnt == s->blocksize) 368 s->sha(s, s->block), s->blockcnt = 0; 369 } 370 return(bitcnt); 371 } 372 373 /* shawrite: triggers a state update using data in bitstr/bitcnt */ 374 static ULNG shawrite(UCHR *bitstr, ULNG bitcnt, SHA *s) 375 { 376 if (!bitcnt) 377 return(0); 378 if (SHA_LO32(s->lenll += bitcnt) < bitcnt) 379 if (SHA_LO32(++s->lenlh) == 0) 380 if (SHA_LO32(++s->lenhl) == 0) 381 s->lenhh++; 382 if (s->blockcnt == 0) 383 return(shadirect(bitstr, bitcnt, s)); 384 else if (s->blockcnt % 8 == 0) 385 return(shabytes(bitstr, bitcnt, s)); 386 else 387 return(shabits(bitstr, bitcnt, s)); 388 } 389 390 /* shafinish: pads remaining block(s) and computes final digest state */ 391 static void shafinish(SHA *s) 392 { 393 UINT lenpos, lhpos, llpos; 394 395 lenpos = s->blocksize == SHA1_BLOCK_BITS ? 448 : 896; 396 lhpos = s->blocksize == SHA1_BLOCK_BITS ? 56 : 120; 397 llpos = s->blocksize == SHA1_BLOCK_BITS ? 60 : 124; 398 SETBIT(s->block, s->blockcnt), s->blockcnt++; 399 while (s->blockcnt > lenpos) 400 if (s->blockcnt < s->blocksize) 401 CLRBIT(s->block, s->blockcnt), s->blockcnt++; 402 else 403 s->sha(s, s->block), s->blockcnt = 0; 404 while (s->blockcnt < lenpos) 405 CLRBIT(s->block, s->blockcnt), s->blockcnt++; 406 if (s->blocksize > SHA1_BLOCK_BITS) { 407 w32mem(s->block + 112, s->lenhh); 408 w32mem(s->block + 116, s->lenhl); 409 } 410 w32mem(s->block + lhpos, s->lenlh); 411 w32mem(s->block + llpos, s->lenll); 412 s->sha(s, s->block); 413 } 414 415 #define shadigest(state) digcpy(state) 416 417 /* xmap: translation map for hexadecimal encoding */ 418 static const char xmap[] = 419 "0123456789abcdef"; 420 421 /* shahex: returns pointer to current digest (hexadecimal) */ 422 static char *shahex(SHA *s) 423 { 424 UINT i; 425 char *h; 426 UCHR *d; 427 428 d = digcpy(s); 429 s->hex[0] = '\0'; 430 if (HEXLEN((size_t) s->digestlen) >= sizeof(s->hex)) 431 return(s->hex); 432 for (i = 0, h = s->hex; i < s->digestlen; i++) { 433 *h++ = xmap[(*d >> 4) & 0x0f]; 434 *h++ = xmap[(*d++ ) & 0x0f]; 435 } 436 *h = '\0'; 437 return(s->hex); 438 } 439 440 /* bmap: translation map for Base 64 encoding */ 441 static const char bmap[] = 442 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; 443 444 /* encbase64: encodes input (0 to 3 bytes) into Base 64 */ 445 static void encbase64(UCHR *in, UINT n, char *out) 446 { 447 UCHR byte[3] = {0, 0, 0}; 448 449 out[0] = '\0'; 450 if (n < 1 || n > 3) 451 return; 452 Copy(in, byte, n, UCHR); 453 out[0] = bmap[byte[0] >> 2]; 454 out[1] = bmap[((byte[0] & 0x03) << 4) | (byte[1] >> 4)]; 455 out[2] = bmap[((byte[1] & 0x0f) << 2) | (byte[2] >> 6)]; 456 out[3] = bmap[byte[2] & 0x3f]; 457 out[n+1] = '\0'; 458 } 459 460 /* shabase64: returns pointer to current digest (Base 64) */ 461 static char *shabase64(SHA *s) 462 { 463 UINT n; 464 UCHR *q; 465 char out[5]; 466 467 q = digcpy(s); 468 s->base64[0] = '\0'; 469 if (B64LEN((size_t) s->digestlen) >= sizeof(s->base64)) 470 return(s->base64); 471 for (n = s->digestlen; n > 3; n -= 3, q += 3) { 472 encbase64(q, 3, out); 473 strcat(s->base64, out); 474 } 475 encbase64(q, n, out); 476 strcat(s->base64, out); 477 return(s->base64); 478 } 479 480 /* hmacinit: initializes HMAC-SHA digest object */ 481 static HMAC *hmacinit(HMAC *h, int alg, UCHR *key, UINT keylen) 482 { 483 UINT i; 484 SHA ksha; 485 486 Zero(h, 1, HMAC); 487 if (!shainit(&h->isha, alg)) 488 return(NULL); 489 if (!shainit(&h->osha, alg)) 490 return(NULL); 491 if (keylen <= h->osha.blocksize / 8) 492 Copy(key, h->key, keylen, char); 493 else { 494 if (!shainit(&ksha, alg)) 495 return(NULL); 496 shawrite(key, keylen * 8, &ksha); 497 shafinish(&ksha); 498 Copy(digcpy(&ksha), h->key, ksha.digestlen, char); 499 } 500 h->digestlen = h->osha.digestlen; 501 for (i = 0; i < h->osha.blocksize / 8; i++) 502 h->key[i] ^= 0x5c; 503 shawrite(h->key, h->osha.blocksize, &h->osha); 504 for (i = 0; i < h->isha.blocksize / 8; i++) 505 h->key[i] ^= (0x5c ^ 0x36); 506 shawrite(h->key, h->isha.blocksize, &h->isha); 507 Zero(h->key, sizeof(h->key), char); 508 return(h); 509 } 510 511 /* hmacwrite: triggers a state update using data in bitstr/bitcnt */ 512 static ULNG hmacwrite(UCHR *bitstr, ULNG bitcnt, HMAC *h) 513 { 514 return(shawrite(bitstr, bitcnt, &h->isha)); 515 } 516 517 /* hmacfinish: computes final digest state */ 518 static void hmacfinish(HMAC *h) 519 { 520 shafinish(&h->isha); 521 shawrite(digcpy(&h->isha), h->isha.digestlen * 8, &h->osha); 522 shafinish(&h->osha); 523 } 524 525 #define hmacdigest(h) digcpy(&(h)->osha) 526 527 /* hmachex: returns pointer to digest (hexadecimal) */ 528 static char *hmachex(HMAC *h) 529 { 530 return(shahex(&h->osha)); 531 } 532 533 /* hmacbase64: returns pointer to digest (Base 64) */ 534 static char *hmacbase64(HMAC *h) 535 { 536 return(shabase64(&h->osha)); 537 } 538