1 /* $NetBSD: bcrypt.c,v 1.22 2021/10/16 10:53:33 nia Exp $ */ 2 /* $OpenBSD: bcrypt.c,v 1.16 2002/02/19 19:39:36 millert Exp $ */ 3 4 /* 5 * Copyright 1997 Niels Provos <provos (at) physnet.uni-hamburg.de> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by Niels Provos. 19 * 4. The name of the author may not be used to endorse or promote products 20 * derived from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 23 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 24 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 25 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 27 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 31 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 /* This password hashing algorithm was designed by David Mazieres 35 * <dm (at) lcs.mit.edu> and works as follows: 36 * 37 * 1. state := InitState () 38 * 2. state := ExpandKey (state, salt, password) 3. 39 * REPEAT rounds: 40 * state := ExpandKey (state, 0, salt) 41 * state := ExpandKey(state, 0, password) 42 * 4. ctext := "OrpheanBeholderScryDoubt" 43 * 5. REPEAT 64: 44 * ctext := Encrypt_ECB (state, ctext); 45 * 6. RETURN Concatenate (salt, ctext); 46 * 47 */ 48 #include <sys/cdefs.h> 49 __RCSID("$NetBSD: bcrypt.c,v 1.22 2021/10/16 10:53:33 nia Exp $"); 50 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <sys/types.h> 54 #include <string.h> 55 #include <pwd.h> 56 #include <errno.h> 57 #include <limits.h> 58 59 #include "crypt.h" 60 #include "blowfish.c" 61 62 /* This implementation is adaptable to current computing power. 63 * You can have up to 2^31 rounds which should be enough for some 64 * time to come. 65 */ 66 67 #define BCRYPT_VERSION '2' 68 #define BCRYPT_MAXSALT 16 /* Precomputation is just so nice */ 69 #define BCRYPT_MAXSALTLEN (7 + (BCRYPT_MAXSALT * 4 + 2) / 3 + 1) 70 #define BCRYPT_BLOCKS 6 /* Ciphertext blocks */ 71 #define BCRYPT_MINROUNDS 16 /* we have log2(rounds) in salt */ 72 73 static void encode_salt(char *, u_int8_t *, u_int16_t, u_int8_t); 74 static void encode_base64(u_int8_t *, u_int8_t *, u_int16_t); 75 static void decode_base64(u_int8_t *, u_int16_t, const u_int8_t *); 76 77 crypt_private char *__bcrypt(const char *, const char *); /* XXX */ 78 79 static char encrypted[_PASSWORD_LEN]; 80 81 static const u_int8_t Base64Code[] = 82 "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; 83 84 char *bcrypt_gensalt(u_int8_t); 85 86 static const u_int8_t index_64[128] = 87 { 88 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 89 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 90 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 91 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 92 255, 255, 255, 255, 255, 255, 0, 1, 54, 55, 93 56, 57, 58, 59, 60, 61, 62, 63, 255, 255, 94 255, 255, 255, 255, 255, 2, 3, 4, 5, 6, 95 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 96 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 97 255, 255, 255, 255, 255, 255, 28, 29, 30, 98 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 99 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 100 51, 52, 53, 255, 255, 255, 255, 255 101 }; 102 #define CHAR64(c) ( (c) > 127 ? 255 : index_64[(c)]) 103 104 static void 105 decode_base64(u_int8_t *buffer, u_int16_t len, const u_int8_t *data) 106 { 107 u_int8_t *bp = buffer; 108 const u_int8_t *p = data; 109 u_int8_t c1, c2, c3, c4; 110 while (bp < buffer + len) { 111 c1 = CHAR64(*p); 112 c2 = CHAR64(*(p + 1)); 113 114 /* Invalid data */ 115 if (c1 == 255 || c2 == 255) 116 break; 117 118 *bp++ = ((u_int32_t)c1 << 2) | (((u_int32_t)c2 & 0x30) >> 4); 119 if (bp >= buffer + len) 120 break; 121 122 c3 = CHAR64(*(p + 2)); 123 if (c3 == 255) 124 break; 125 126 *bp++ = (((u_int32_t)c2 & 0x0f) << 4) | (((uint32_t)c3 & 0x3c) >> 2); 127 if (bp >= buffer + len) 128 break; 129 130 c4 = CHAR64(*(p + 3)); 131 if (c4 == 255) 132 break; 133 *bp++ = ((c3 & 0x03) << 6) | c4; 134 135 p += 4; 136 } 137 } 138 139 static void 140 encode_salt(char *salt, u_int8_t *csalt, u_int16_t clen, u_int8_t logr) 141 { 142 salt[0] = '$'; 143 salt[1] = BCRYPT_VERSION; 144 salt[2] = 'a'; 145 salt[3] = '$'; 146 147 snprintf(salt + 4, 4, "%2.2u$", logr); 148 149 encode_base64((u_int8_t *) salt + 7, csalt, clen); 150 } 151 152 crypt_private int 153 __gensalt_blowfish(char *salt, size_t saltlen, const char *option) 154 { 155 size_t i; 156 u_int32_t seed = 0; 157 u_int8_t csalt[BCRYPT_MAXSALT]; 158 unsigned long nrounds; 159 char *ep; 160 161 if (saltlen < BCRYPT_MAXSALTLEN) { 162 errno = ENOSPC; 163 return -1; 164 } 165 if (option == NULL) { 166 errno = EINVAL; 167 return -1; 168 } 169 nrounds = strtoul(option, &ep, 0); 170 if (option == ep || *ep) { 171 errno = EINVAL; 172 return -1; 173 } 174 if (errno == ERANGE && nrounds == ULONG_MAX) 175 return -1; 176 177 if (nrounds < 4) 178 nrounds = 4; 179 else if (nrounds > 31) 180 nrounds = 31; 181 182 for (i = 0; i < BCRYPT_MAXSALT; i++) { 183 if (i % 4 == 0) 184 seed = arc4random(); 185 csalt[i] = seed & 0xff; 186 seed = seed >> 8; 187 } 188 encode_salt(salt, csalt, BCRYPT_MAXSALT, (u_int8_t)nrounds); 189 return 0; 190 } 191 192 /* Generates a salt for this version of crypt. 193 Since versions may change. Keeping this here 194 seems sensible. 195 XXX: compat. 196 */ 197 char * 198 bcrypt_gensalt(u_int8_t log_rounds) 199 { 200 static char gsalt[BCRYPT_MAXSALTLEN]; 201 char num[10]; 202 203 (void)snprintf(num, sizeof(num), "%d", log_rounds); 204 if (__gensalt_blowfish(gsalt, sizeof(gsalt), num) == -1) 205 return NULL; 206 return gsalt; 207 } 208 209 /* We handle $Vers$log2(NumRounds)$salt+passwd$ 210 i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */ 211 212 crypt_private char * 213 __bcrypt(const char *key, const char *salt) 214 { 215 blf_ctx state; 216 u_int32_t rounds, i, k; 217 u_int16_t j; 218 u_int8_t key_len, salt_len, logr, minor; 219 u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt"; 220 u_int8_t csalt[BCRYPT_MAXSALT]; 221 u_int32_t cdata[BCRYPT_BLOCKS]; 222 int n; 223 size_t len; 224 225 /* Discard "$" identifier */ 226 salt++; 227 228 if (*salt > BCRYPT_VERSION) 229 return NULL; 230 231 /* Check for minor versions */ 232 if (salt[1] != '$') { 233 switch (salt[1]) { 234 case 'a': 235 /* 'ab' should not yield the same as 'abab' */ 236 minor = salt[1]; 237 salt++; 238 break; 239 default: 240 return NULL; 241 } 242 } else 243 minor = 0; 244 245 /* Discard version + "$" identifier */ 246 salt += 2; 247 248 if (salt[2] != '$') 249 /* Out of sync with passwd entry */ 250 return NULL; 251 252 /* Computer power doesn't increase linear, 2^x should be fine */ 253 n = atoi(salt); 254 if (n > 31 || n < 0) 255 return NULL; 256 logr = (u_int8_t)n; 257 if ((rounds = (u_int32_t) 1 << logr) < BCRYPT_MINROUNDS) 258 return NULL; 259 260 /* Discard num rounds + "$" identifier */ 261 salt += 3; 262 263 if (strlen(salt) * 3 / 4 < BCRYPT_MAXSALT) 264 return NULL; 265 266 /* We dont want the base64 salt but the raw data */ 267 decode_base64(csalt, BCRYPT_MAXSALT, (const u_int8_t *)salt); 268 salt_len = BCRYPT_MAXSALT; 269 len = strlen(key); 270 if (len > 72) 271 key_len = 72; 272 else 273 key_len = (uint8_t)len; 274 key_len += minor >= 'a' ? 1 : 0; 275 276 /* Setting up S-Boxes and Subkeys */ 277 Blowfish_initstate(&state); 278 Blowfish_expandstate(&state, csalt, salt_len, 279 (const u_int8_t *) key, key_len); 280 for (k = 0; k < rounds; k++) { 281 Blowfish_expand0state(&state, (const u_int8_t *) key, key_len); 282 Blowfish_expand0state(&state, csalt, salt_len); 283 } 284 285 /* This can be precomputed later */ 286 j = 0; 287 for (i = 0; i < BCRYPT_BLOCKS; i++) 288 cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j); 289 290 /* Now do the encryption */ 291 for (k = 0; k < 64; k++) 292 blf_enc(&state, cdata, BCRYPT_BLOCKS / 2); 293 294 for (i = 0; i < BCRYPT_BLOCKS; i++) { 295 ciphertext[4 * i + 3] = cdata[i] & 0xff; 296 cdata[i] = cdata[i] >> 8; 297 ciphertext[4 * i + 2] = cdata[i] & 0xff; 298 cdata[i] = cdata[i] >> 8; 299 ciphertext[4 * i + 1] = cdata[i] & 0xff; 300 cdata[i] = cdata[i] >> 8; 301 ciphertext[4 * i + 0] = cdata[i] & 0xff; 302 } 303 304 305 i = 0; 306 encrypted[i++] = '$'; 307 encrypted[i++] = BCRYPT_VERSION; 308 if (minor) 309 encrypted[i++] = minor; 310 encrypted[i++] = '$'; 311 312 snprintf(encrypted + i, 4, "%2.2u$", logr); 313 314 encode_base64((u_int8_t *) encrypted + i + 3, csalt, BCRYPT_MAXSALT); 315 encode_base64((u_int8_t *) encrypted + strlen(encrypted), ciphertext, 316 4 * BCRYPT_BLOCKS - 1); 317 explicit_memset(&state, 0, sizeof(state)); 318 return encrypted; 319 } 320 321 static void 322 encode_base64(u_int8_t *buffer, u_int8_t *data, u_int16_t len) 323 { 324 u_int8_t *bp = buffer; 325 u_int8_t *p = data; 326 u_int8_t c1, c2; 327 while (p < data + len) { 328 c1 = *p++; 329 *bp++ = Base64Code[((u_int32_t)c1 >> 2)]; 330 c1 = (c1 & 0x03) << 4; 331 if (p >= data + len) { 332 *bp++ = Base64Code[c1]; 333 break; 334 } 335 c2 = *p++; 336 c1 |= ((u_int32_t)c2 >> 4) & 0x0f; 337 *bp++ = Base64Code[c1]; 338 c1 = (c2 & 0x0f) << 2; 339 if (p >= data + len) { 340 *bp++ = Base64Code[c1]; 341 break; 342 } 343 c2 = *p++; 344 c1 |= ((u_int32_t)c2 >> 6) & 0x03; 345 *bp++ = Base64Code[c1]; 346 *bp++ = Base64Code[c2 & 0x3f]; 347 } 348 *bp = '\0'; 349 } 350 #if 0 351 void 352 main() 353 { 354 char blubber[73]; 355 char salt[100]; 356 char *p; 357 salt[0] = '$'; 358 salt[1] = BCRYPT_VERSION; 359 salt[2] = '$'; 360 361 snprintf(salt + 3, 4, "%2.2u$", 5); 362 363 printf("24 bytes of salt: "); 364 fgets(salt + 6, 94, stdin); 365 salt[99] = 0; 366 printf("72 bytes of password: "); 367 fpurge(stdin); 368 fgets(blubber, 73, stdin); 369 blubber[72] = 0; 370 371 p = crypt(blubber, salt); 372 printf("Passwd entry: %s\n\n", p); 373 374 p = bcrypt_gensalt(5); 375 printf("Generated salt: %s\n", p); 376 p = crypt(blubber, p); 377 printf("Passwd entry: %s\n", p); 378 } 379 #endif 380
Indexes created Sat Sep 20 22:09:52 GMT 2025