1 /* 2 * Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by Niels Provos. 16 * 4. The name of the author may not be used to endorse or promote products 17 * derived from this software without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 /* This password hashing algorithm was designed by David Mazieres 35 * <dm@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 49 /* 50 * FreeBSD implementation by Paul Herman <pherman@frenchfries.net> 51 */ 52 53 #if 0 54 #include <stdio.h> 55 #endif 56 57 #include <stdio.h> 58 #include <stdlib.h> 59 #include <sys/types.h> 60 #include <string.h> 61 #include <pwd.h> 62 #include "blowfish.h" 63 64 /* This implementation is adaptable to current computing power. 65 * You can have up to 2^31 rounds which should be enough for some 66 * time to come. 67 */ 68 69 #define BCRYPT_VERSION '2' 70 #define BCRYPT_MAXSALT 16 /* Precomputation is just so nice */ 71 #define BCRYPT_BLOCKS 6 /* Ciphertext blocks */ 72 #define BCRYPT_MINROUNDS 16 /* we have log2(rounds) in salt */ 73 74 char *bcrypt_gensalt __P((u_int8_t)); 75 76 static void encode_salt __P((char *, u_int8_t *, u_int16_t, u_int8_t)); 77 static void encode_base64 __P((u_int8_t *, u_int8_t *, u_int16_t)); 78 static void decode_base64 __P((u_int8_t *, u_int16_t, u_int8_t *)); 79 80 static char encrypted[_PASSWORD_LEN]; 81 static char gsalt[BCRYPT_MAXSALT * 4 / 3 + 1]; 82 static char error[] = ":"; 83 84 const static u_int8_t Base64Code[] = 85 "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; 86 87 const static u_int8_t index_64[128] = 88 { 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, 255, 255, 255, 255, 93 255, 255, 255, 255, 255, 255, 0, 1, 54, 55, 94 56, 57, 58, 59, 60, 61, 62, 63, 255, 255, 95 255, 255, 255, 255, 255, 2, 3, 4, 5, 6, 96 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 97 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 98 255, 255, 255, 255, 255, 255, 28, 29, 30, 99 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 100 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 101 51, 52, 53, 255, 255, 255, 255, 255 102 }; 103 #define CHAR64(c) ( (c) > 127 ? 255 : index_64[(c)]) 104 105 #ifdef __STDC__ 106 static void 107 decode_base64(u_int8_t *buffer, u_int16_t len, u_int8_t *data) 108 #else 109 static void 110 decode_base64(buffer, len, data) 111 u_int8_t *buffer; 112 u_int16_t len; 113 u_int8_t *data; 114 #endif 115 { 116 u_int8_t *bp = buffer; 117 u_int8_t *p = data; 118 u_int8_t c1, c2, c3, c4; 119 while (bp < buffer + len) { 120 c1 = CHAR64(*p); 121 c2 = CHAR64(*(p + 1)); 122 123 /* Invalid data */ 124 if (c1 == 255 || c2 == 255) 125 break; 126 127 *bp++ = (c1 << 2) | ((c2 & 0x30) >> 4); 128 if (bp >= buffer + len) 129 break; 130 131 c3 = CHAR64(*(p + 2)); 132 if (c3 == 255) 133 break; 134 135 *bp++ = ((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2); 136 if (bp >= buffer + len) 137 break; 138 139 c4 = CHAR64(*(p + 3)); 140 if (c4 == 255) 141 break; 142 *bp++ = ((c3 & 0x03) << 6) | c4; 143 144 p += 4; 145 } 146 } 147 148 #ifdef __STDC__ 149 static void 150 encode_salt(char *salt, u_int8_t *csalt, u_int16_t clen, u_int8_t logr) 151 #else 152 static void 153 encode_salt(salt, csalt, clen, logr) 154 char *salt; 155 u_int8_t *csalt; 156 u_int16_t clen; 157 u_int8_t logr; 158 #endif 159 { 160 salt[0] = '$'; 161 salt[1] = BCRYPT_VERSION; 162 salt[2] = 'a'; 163 salt[3] = '$'; 164 165 snprintf(salt + 4, 4, "%2.2u$", logr); 166 167 encode_base64((u_int8_t *) salt + 7, csalt, clen); 168 } 169 /* Generates a salt for this version of crypt. 170 Since versions may change. Keeping this here 171 seems sensible. 172 */ 173 174 #ifdef __STDC__ 175 char * 176 bcrypt_gensalt(u_int8_t log_rounds) 177 #else 178 char * 179 bcrypt_gensalt(log_rounds) 180 u_int8_t log_rounds; 181 #endif 182 { 183 u_int8_t csalt[BCRYPT_MAXSALT]; 184 u_int16_t i; 185 u_int32_t seed = 0; 186 187 for (i = 0; i < BCRYPT_MAXSALT; i++) { 188 if (i % 4 == 0) 189 seed = arc4random(); 190 csalt[i] = seed & 0xff; 191 seed = seed >> 8; 192 } 193 194 if (log_rounds < 4) 195 log_rounds = 4; 196 197 encode_salt(gsalt, csalt, BCRYPT_MAXSALT, log_rounds); 198 return gsalt; 199 } 200 /* We handle $Vers$log2(NumRounds)$salt+passwd$ 201 i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */ 202 203 char * 204 crypt_blowfish(key, salt) 205 const char *key; 206 const char *salt; 207 { 208 blf_ctx state; 209 u_int32_t rounds, i, k; 210 u_int16_t j; 211 u_int8_t key_len, salt_len, logr, minor; 212 u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt"; 213 u_int8_t csalt[BCRYPT_MAXSALT]; 214 u_int32_t cdata[BCRYPT_BLOCKS]; 215 static char *magic = "$2a$04$"; 216 217 /* Defaults */ 218 minor = 'a'; 219 logr = 4; 220 rounds = 1 << logr; 221 222 /* If it starts with the magic string, then skip that */ 223 if(!strncmp(salt, magic, strlen(magic))) { 224 salt += strlen(magic); 225 } 226 else if (*salt == '$') { 227 228 /* Discard "$" identifier */ 229 salt++; 230 231 if (*salt > BCRYPT_VERSION) { 232 /* How do I handle errors ? Return ':' */ 233 return error; 234 } 235 236 /* Check for minor versions */ 237 if (salt[1] != '$') { 238 switch (salt[1]) { 239 case 'a': 240 /* 'ab' should not yield the same as 'abab' */ 241 minor = salt[1]; 242 salt++; 243 break; 244 default: 245 return error; 246 } 247 } else 248 minor = 0; 249 250 /* Discard version + "$" identifier */ 251 salt += 2; 252 253 if (salt[2] != '$') 254 /* Out of sync with passwd entry */ 255 return error; 256 257 /* Computer power doesnt increase linear, 2^x should be fine */ 258 if ((rounds = (u_int32_t) 1 << (logr = atoi(salt))) < BCRYPT_MINROUNDS) 259 return error; 260 261 /* Discard num rounds + "$" identifier */ 262 salt += 3; 263 } 264 265 266 /* We dont want the base64 salt but the raw data */ 267 decode_base64(csalt, BCRYPT_MAXSALT, (u_int8_t *) salt); 268 salt_len = BCRYPT_MAXSALT; 269 key_len = strlen(key) + (minor >= 'a' ? 1 : 0); 270 271 /* Setting up S-Boxes and Subkeys */ 272 Blowfish_initstate(&state); 273 Blowfish_expandstate(&state, csalt, salt_len, 274 (u_int8_t *) key, key_len); 275 for (k = 0; k < rounds; k++) { 276 Blowfish_expand0state(&state, (u_int8_t *) key, key_len); 277 Blowfish_expand0state(&state, csalt, salt_len); 278 } 279 280 /* This can be precomputed later */ 281 j = 0; 282 for (i = 0; i < BCRYPT_BLOCKS; i++) 283 cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j); 284 285 /* Now do the encryption */ 286 for (k = 0; k < 64; k++) 287 blf_enc(&state, cdata, BCRYPT_BLOCKS / 2); 288 289 for (i = 0; i < BCRYPT_BLOCKS; i++) { 290 ciphertext[4 * i + 3] = cdata[i] & 0xff; 291 cdata[i] = cdata[i] >> 8; 292 ciphertext[4 * i + 2] = cdata[i] & 0xff; 293 cdata[i] = cdata[i] >> 8; 294 ciphertext[4 * i + 1] = cdata[i] & 0xff; 295 cdata[i] = cdata[i] >> 8; 296 ciphertext[4 * i + 0] = cdata[i] & 0xff; 297 } 298 299 300 i = 0; 301 encrypted[i++] = '$'; 302 encrypted[i++] = BCRYPT_VERSION; 303 if (minor) 304 encrypted[i++] = minor; 305 encrypted[i++] = '$'; 306 307 snprintf(encrypted + i, 4, "%2.2u$", logr); 308 309 encode_base64((u_int8_t *) encrypted + i + 3, csalt, BCRYPT_MAXSALT); 310 encode_base64((u_int8_t *) encrypted + strlen(encrypted), ciphertext, 311 4 * BCRYPT_BLOCKS - 1); 312 return encrypted; 313 } 314 315 #ifdef __STDC__ 316 static void 317 encode_base64(u_int8_t *buffer, u_int8_t *data, u_int16_t len) 318 #else 319 static void 320 encode_base64(buffer, data, len) 321 u_int8_t *buffer; 322 u_int8_t *data; 323 u_int16_t len; 324 #endif 325 { 326 u_int8_t *bp = buffer; 327 u_int8_t *p = data; 328 u_int8_t c1, c2; 329 while (p < data + len) { 330 c1 = *p++; 331 *bp++ = Base64Code[(c1 >> 2)]; 332 c1 = (c1 & 0x03) << 4; 333 if (p >= data + len) { 334 *bp++ = Base64Code[c1]; 335 break; 336 } 337 c2 = *p++; 338 c1 |= (c2 >> 4) & 0x0f; 339 *bp++ = Base64Code[c1]; 340 c1 = (c2 & 0x0f) << 2; 341 if (p >= data + len) { 342 *bp++ = Base64Code[c1]; 343 break; 344 } 345 c2 = *p++; 346 c1 |= (c2 >> 6) & 0x03; 347 *bp++ = Base64Code[c1]; 348 *bp++ = Base64Code[c2 & 0x3f]; 349 } 350 *bp = '\0'; 351 } 352 #if 0 353 void 354 main() 355 { 356 char blubber[73]; 357 char salt[100]; 358 char *p; 359 salt[0] = '$'; 360 salt[1] = BCRYPT_VERSION; 361 salt[2] = '$'; 362 363 snprintf(salt + 3, 4, "%2.2u$", 5); 364 365 printf("24 bytes of salt: "); 366 fgets(salt + 6, 94, stdin); 367 salt[99] = 0; 368 printf("72 bytes of password: "); 369 fpurge(stdin); 370 fgets(blubber, 73, stdin); 371 blubber[72] = 0; 372 373 p = crypt(blubber, salt); 374 printf("Passwd entry: %s\n\n", p); 375 376 p = bcrypt_gensalt(5); 377 printf("Generated salt: %s\n", p); 378 p = crypt(blubber, p); 379 printf("Passwd entry: %s\n", p); 380 } 381 #endif 382