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 * $FreeBSD: src/secure/lib/libcrypt/crypt-blowfish.c,v 1.1.2.1 2001/05/24 12:20:03 markm Exp $ 31 */ 32 33 /* This password hashing algorithm was designed by David Mazieres 34 * <dm@lcs.mit.edu> and works as follows: 35 * 36 * 1. state := InitState () 37 * 2. state := ExpandKey (state, salt, password) 3. 38 * REPEAT rounds: 39 * state := ExpandKey (state, 0, salt) 40 * state := ExpandKey(state, 0, password) 41 * 4. ctext := "OrpheanBeholderScryDoubt" 42 * 5. REPEAT 64: 43 * ctext := Encrypt_ECB (state, ctext); 44 * 6. RETURN Concatenate (salt, ctext); 45 * 46 */ 47 48 /* 49 * FreeBSD implementation by Paul Herman <pherman@frenchfries.net> 50 */ 51 52 #if 0 53 #include <stdio.h> 54 #endif 55 56 #include <stdio.h> 57 #include <stdlib.h> 58 #include <sys/types.h> 59 #include <string.h> 60 #include <pwd.h> 61 #include "blowfish.h" 62 63 /* This implementation is adaptable to current computing power. 64 * You can have up to 2^31 rounds which should be enough for some 65 * time to come. 66 */ 67 68 #define BCRYPT_VERSION '2' 69 #define BCRYPT_MAXSALT 16 /* Precomputation is just so nice */ 70 #define BCRYPT_BLOCKS 6 /* Ciphertext blocks */ 71 #define BCRYPT_MINROUNDS 16 /* we have log2(rounds) in salt */ 72 73 char *bcrypt_gensalt (u_int8_t); 74 75 static void encode_salt (char *, u_int8_t *, u_int16_t, u_int8_t); 76 static void encode_base64 (u_int8_t *, u_int8_t *, u_int16_t); 77 static void decode_base64 (u_int8_t *, u_int16_t, u_int8_t *); 78 79 static char encrypted[_PASSWORD_LEN]; 80 static char gsalt[BCRYPT_MAXSALT * 4 / 3 + 1]; 81 82 static const u_int8_t Base64Code[] = 83 "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; 84 85 static const u_int8_t index_64[128] = 86 { 87 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 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, 0, 1, 54, 55, 92 56, 57, 58, 59, 60, 61, 62, 63, 255, 255, 93 255, 255, 255, 255, 255, 2, 3, 4, 5, 6, 94 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 95 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 96 255, 255, 255, 255, 255, 255, 28, 29, 30, 97 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 98 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 99 51, 52, 53, 255, 255, 255, 255, 255 100 }; 101 #define CHAR64(c) ( (c) > 127 ? 255 : index_64[(c)]) 102 103 #ifdef __STDC__ 104 static void 105 decode_base64(u_int8_t *buffer, u_int16_t len, u_int8_t *data) 106 #else 107 static void 108 decode_base64(buffer, len, data) 109 u_int8_t *buffer; 110 u_int16_t len; 111 u_int8_t *data; 112 #endif 113 { 114 u_int8_t *bp = buffer; 115 u_int8_t *p = data; 116 u_int8_t c1, c2, c3, c4; 117 while (bp < buffer + len) { 118 c1 = CHAR64(*p); 119 c2 = CHAR64(*(p + 1)); 120 121 /* Invalid data */ 122 if (c1 == 255 || c2 == 255) 123 break; 124 125 *bp++ = (c1 << 2) | ((c2 & 0x30) >> 4); 126 if (bp >= buffer + len) 127 break; 128 129 c3 = CHAR64(*(p + 2)); 130 if (c3 == 255) 131 break; 132 133 *bp++ = ((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2); 134 if (bp >= buffer + len) 135 break; 136 137 c4 = CHAR64(*(p + 3)); 138 if (c4 == 255) 139 break; 140 *bp++ = ((c3 & 0x03) << 6) | c4; 141 142 p += 4; 143 } 144 } 145 146 #ifdef __STDC__ 147 static void 148 encode_salt(char *salt, u_int8_t *csalt, u_int16_t clen, u_int8_t logr) 149 #else 150 static void 151 encode_salt(salt, csalt, clen, logr) 152 char *salt; 153 u_int8_t *csalt; 154 u_int16_t clen; 155 u_int8_t logr; 156 #endif 157 { 158 salt[0] = '$'; 159 salt[1] = BCRYPT_VERSION; 160 salt[2] = 'a'; 161 salt[3] = '$'; 162 163 snprintf(salt + 4, 4, "%2.2u$", logr); 164 165 encode_base64((u_int8_t *) salt + 7, csalt, clen); 166 } 167 /* Generates a salt for this version of crypt. 168 Since versions may change. Keeping this here 169 seems sensible. 170 */ 171 172 #ifdef __STDC__ 173 char * 174 bcrypt_gensalt(u_int8_t log_rounds) 175 #else 176 char * 177 bcrypt_gensalt(log_rounds) 178 u_int8_t log_rounds; 179 #endif 180 { 181 u_int8_t csalt[BCRYPT_MAXSALT]; 182 u_int16_t i; 183 u_int32_t seed = 0; 184 185 for (i = 0; i < BCRYPT_MAXSALT; i++) { 186 if (i % 4 == 0) 187 seed = arc4random(); 188 csalt[i] = seed & 0xff; 189 seed = seed >> 8; 190 } 191 192 if (log_rounds < 4) 193 log_rounds = 4; 194 195 encode_salt(gsalt, csalt, BCRYPT_MAXSALT, log_rounds); 196 return gsalt; 197 } 198 /* We handle $Vers$log2(NumRounds)$salt+passwd$ 199 i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */ 200 201 char * 202 crypt_blowfish(key, salt) 203 const char *key; 204 const char *salt; 205 { 206 blf_ctx state; 207 u_int32_t rounds, i, k; 208 u_int16_t j; 209 u_int8_t key_len, salt_len, logr, minor; 210 u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt"; 211 u_int8_t csalt[BCRYPT_MAXSALT]; 212 u_int32_t cdata[BCRYPT_BLOCKS]; 213 static char *magic = "$2a$04$"; 214 215 /* Defaults */ 216 minor = 'a'; 217 logr = 4; 218 rounds = 1 << logr; 219 220 /* If it starts with the magic string, then skip that */ 221 if(!strncmp(salt, magic, strlen(magic))) { 222 salt += strlen(magic); 223 } 224 else if (*salt == '$') { 225 226 /* Discard "$" identifier */ 227 salt++; 228 229 if (*salt > BCRYPT_VERSION) { 230 /* How do I handle errors ? Return NULL according to 231 crypt(3) */ 232 return NULL; 233 } 234 235 /* Check for minor versions */ 236 if (salt[1] != '$') { 237 switch (salt[1]) { 238 case 'a': 239 /* 'ab' should not yield the same as 'abab' */ 240 minor = salt[1]; 241 salt++; 242 break; 243 default: 244 return NULL; 245 } 246 } else 247 minor = 0; 248 249 /* Discard version + "$" identifier */ 250 salt += 2; 251 252 if (salt[2] != '$') 253 /* Out of sync with passwd entry */ 254 return NULL; 255 256 /* Computer power doesnt increase linear, 2^x should be fine */ 257 if ((rounds = (u_int32_t) 1 << (logr = atoi(salt))) < BCRYPT_MINROUNDS) 258 return NULL; 259 260 /* Discard num rounds + "$" identifier */ 261 salt += 3; 262 } 263 264 265 /* We dont want the base64 salt but the raw data */ 266 decode_base64(csalt, BCRYPT_MAXSALT, (u_int8_t *) salt); 267 salt_len = BCRYPT_MAXSALT; 268 key_len = strlen(key) + (minor >= 'a' ? 1 : 0); 269 270 /* Setting up S-Boxes and Subkeys */ 271 Blowfish_initstate(&state); 272 Blowfish_expandstate(&state, csalt, salt_len, 273 (u_int8_t *) key, key_len); 274 for (k = 0; k < rounds; k++) { 275 Blowfish_expand0state(&state, (u_int8_t *) key, key_len); 276 Blowfish_expand0state(&state, csalt, salt_len); 277 } 278 279 /* This can be precomputed later */ 280 j = 0; 281 for (i = 0; i < BCRYPT_BLOCKS; i++) 282 cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j); 283 284 /* Now do the encryption */ 285 for (k = 0; k < 64; k++) 286 blf_enc(&state, cdata, BCRYPT_BLOCKS / 2); 287 288 for (i = 0; i < BCRYPT_BLOCKS; i++) { 289 ciphertext[4 * i + 3] = cdata[i] & 0xff; 290 cdata[i] = cdata[i] >> 8; 291 ciphertext[4 * i + 2] = cdata[i] & 0xff; 292 cdata[i] = cdata[i] >> 8; 293 ciphertext[4 * i + 1] = cdata[i] & 0xff; 294 cdata[i] = cdata[i] >> 8; 295 ciphertext[4 * i + 0] = cdata[i] & 0xff; 296 } 297 298 299 i = 0; 300 encrypted[i++] = '$'; 301 encrypted[i++] = BCRYPT_VERSION; 302 if (minor) 303 encrypted[i++] = minor; 304 encrypted[i++] = '$'; 305 306 snprintf(encrypted + i, 4, "%2.2u$", logr); 307 308 encode_base64((u_int8_t *) encrypted + i + 3, csalt, BCRYPT_MAXSALT); 309 encode_base64((u_int8_t *) encrypted + strlen(encrypted), ciphertext, 310 4 * BCRYPT_BLOCKS - 1); 311 return encrypted; 312 } 313 314 #ifdef __STDC__ 315 static void 316 encode_base64(u_int8_t *buffer, u_int8_t *data, u_int16_t len) 317 #else 318 static void 319 encode_base64(buffer, data, len) 320 u_int8_t *buffer; 321 u_int8_t *data; 322 u_int16_t len; 323 #endif 324 { 325 u_int8_t *bp = buffer; 326 u_int8_t *p = data; 327 u_int8_t c1, c2; 328 while (p < data + len) { 329 c1 = *p++; 330 *bp++ = Base64Code[(c1 >> 2)]; 331 c1 = (c1 & 0x03) << 4; 332 if (p >= data + len) { 333 *bp++ = Base64Code[c1]; 334 break; 335 } 336 c2 = *p++; 337 c1 |= (c2 >> 4) & 0x0f; 338 *bp++ = Base64Code[c1]; 339 c1 = (c2 & 0x0f) << 2; 340 if (p >= data + len) { 341 *bp++ = Base64Code[c1]; 342 break; 343 } 344 c2 = *p++; 345 c1 |= (c2 >> 6) & 0x03; 346 *bp++ = Base64Code[c1]; 347 *bp++ = Base64Code[c2 & 0x3f]; 348 } 349 *bp = '\0'; 350 } 351 #if 0 352 void 353 main() 354 { 355 char blubber[73]; 356 char salt[100]; 357 char *p; 358 salt[0] = '$'; 359 salt[1] = BCRYPT_VERSION; 360 salt[2] = '$'; 361 362 snprintf(salt + 3, 4, "%2.2u$", 5); 363 364 printf("24 bytes of salt: "); 365 fgets(salt + 6, 94, stdin); 366 salt[99] = 0; 367 printf("72 bytes of password: "); 368 fpurge(stdin); 369 fgets(blubber, 73, stdin); 370 blubber[72] = 0; 371 372 p = crypt(blubber, salt); 373 printf("Passwd entry: %s\n\n", p); 374 375 p = bcrypt_gensalt(5); 376 printf("Generated salt: %s\n", p); 377 p = crypt(blubber, p); 378 printf("Passwd entry: %s\n", p); 379 } 380 #endif 381