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 #include "crypt.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 (u_int8_t); 75 76 static void encode_salt (char *, u_int8_t *, u_int16_t, u_int8_t); 77 static void encode_base64 (u_int8_t *, u_int8_t *, u_int16_t); 78 static void decode_base64 (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 83 static const u_int8_t Base64Code[] = 84 "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; 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, u_int8_t *data) 106 { 107 u_int8_t *bp = buffer; 108 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++ = (c1 << 2) | ((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++ = ((c2 & 0x0f) << 4) | ((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 /* Generates a salt for this version of crypt. 152 Since versions may change. Keeping this here 153 seems sensible. 154 */ 155 156 char * 157 bcrypt_gensalt(u_int8_t log_rounds) 158 { 159 u_int8_t csalt[BCRYPT_MAXSALT]; 160 u_int16_t i; 161 u_int32_t seed = 0; 162 163 for (i = 0; i < BCRYPT_MAXSALT; i++) { 164 if (i % 4 == 0) 165 seed = arc4random(); 166 csalt[i] = seed & 0xff; 167 seed = seed >> 8; 168 } 169 170 if (log_rounds < 4) 171 log_rounds = 4; 172 173 encode_salt(gsalt, csalt, BCRYPT_MAXSALT, log_rounds); 174 return gsalt; 175 } 176 /* We handle $Vers$log2(NumRounds)$salt+passwd$ 177 i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */ 178 179 char * 180 crypt_blowfish(const char *key, const char *salt) 181 { 182 blf_ctx state; 183 u_int32_t rounds, i, k; 184 u_int16_t j; 185 u_int8_t key_len, salt_len, logr, minor; 186 u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt"; 187 u_int8_t csalt[BCRYPT_MAXSALT]; 188 u_int32_t cdata[BCRYPT_BLOCKS]; 189 static const char *magic = "$2a$04$"; 190 191 /* Defaults */ 192 minor = 'a'; 193 logr = 4; 194 rounds = 1 << logr; 195 196 /* If it starts with the magic string, then skip that */ 197 if(!strncmp(salt, magic, strlen(magic))) { 198 salt += strlen(magic); 199 } 200 else if (*salt == '$') { 201 202 /* Discard "$" identifier */ 203 salt++; 204 205 if (*salt > BCRYPT_VERSION) { 206 /* How do I handle errors ? Return NULL according to 207 crypt(3) */ 208 return NULL; 209 } 210 211 /* Check for minor versions */ 212 if (salt[1] != '$') { 213 switch (salt[1]) { 214 case 'a': 215 /* 'ab' should not yield the same as 'abab' */ 216 minor = salt[1]; 217 salt++; 218 break; 219 default: 220 return NULL; 221 } 222 } else 223 minor = 0; 224 225 /* Discard version + "$" identifier */ 226 salt += 2; 227 228 if (salt[2] != '$') 229 /* Out of sync with passwd entry */ 230 return NULL; 231 232 /* Computer power doesnt increase linear, 2^x should be fine */ 233 if ((rounds = (u_int32_t) 1 << (logr = atoi(salt))) < BCRYPT_MINROUNDS) 234 return NULL; 235 236 /* Discard num rounds + "$" identifier */ 237 salt += 3; 238 } 239 240 241 /* We dont want the base64 salt but the raw data */ 242 decode_base64(csalt, BCRYPT_MAXSALT, (u_int8_t *) salt); 243 salt_len = BCRYPT_MAXSALT; 244 key_len = strlen(key) + (minor >= 'a' ? 1 : 0); 245 246 /* Setting up S-Boxes and Subkeys */ 247 Blowfish_initstate(&state); 248 Blowfish_expandstate(&state, csalt, salt_len, 249 (u_int8_t *) key, key_len); 250 for (k = 0; k < rounds; k++) { 251 Blowfish_expand0state(&state, (u_int8_t *) key, key_len); 252 Blowfish_expand0state(&state, csalt, salt_len); 253 } 254 255 /* This can be precomputed later */ 256 j = 0; 257 for (i = 0; i < BCRYPT_BLOCKS; i++) 258 cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j); 259 260 /* Now do the encryption */ 261 for (k = 0; k < 64; k++) 262 blf_enc(&state, cdata, BCRYPT_BLOCKS / 2); 263 264 for (i = 0; i < BCRYPT_BLOCKS; i++) { 265 ciphertext[4 * i + 3] = cdata[i] & 0xff; 266 cdata[i] = cdata[i] >> 8; 267 ciphertext[4 * i + 2] = cdata[i] & 0xff; 268 cdata[i] = cdata[i] >> 8; 269 ciphertext[4 * i + 1] = cdata[i] & 0xff; 270 cdata[i] = cdata[i] >> 8; 271 ciphertext[4 * i + 0] = cdata[i] & 0xff; 272 } 273 274 275 i = 0; 276 encrypted[i++] = '$'; 277 encrypted[i++] = BCRYPT_VERSION; 278 if (minor) 279 encrypted[i++] = minor; 280 encrypted[i++] = '$'; 281 282 snprintf(encrypted + i, 4, "%2.2u$", logr); 283 284 encode_base64((u_int8_t *) encrypted + i + 3, csalt, BCRYPT_MAXSALT); 285 encode_base64((u_int8_t *) encrypted + strlen(encrypted), ciphertext, 286 4 * BCRYPT_BLOCKS - 1); 287 return encrypted; 288 } 289 290 static void 291 encode_base64(u_int8_t *buffer, u_int8_t *data, u_int16_t len) 292 { 293 u_int8_t *bp = buffer; 294 u_int8_t *p = data; 295 u_int8_t c1, c2; 296 while (p < data + len) { 297 c1 = *p++; 298 *bp++ = Base64Code[(c1 >> 2)]; 299 c1 = (c1 & 0x03) << 4; 300 if (p >= data + len) { 301 *bp++ = Base64Code[c1]; 302 break; 303 } 304 c2 = *p++; 305 c1 |= (c2 >> 4) & 0x0f; 306 *bp++ = Base64Code[c1]; 307 c1 = (c2 & 0x0f) << 2; 308 if (p >= data + len) { 309 *bp++ = Base64Code[c1]; 310 break; 311 } 312 c2 = *p++; 313 c1 |= (c2 >> 6) & 0x03; 314 *bp++ = Base64Code[c1]; 315 *bp++ = Base64Code[c2 & 0x3f]; 316 } 317 *bp = '\0'; 318 } 319 #if 0 320 void 321 main() 322 { 323 char blubber[73]; 324 char salt[100]; 325 char *p; 326 salt[0] = '$'; 327 salt[1] = BCRYPT_VERSION; 328 salt[2] = '$'; 329 330 snprintf(salt + 3, 4, "%2.2u$", 5); 331 332 printf("24 bytes of salt: "); 333 fgets(salt + 6, 94, stdin); 334 salt[99] = 0; 335 printf("72 bytes of password: "); 336 fpurge(stdin); 337 fgets(blubber, 73, stdin); 338 blubber[72] = 0; 339 340 p = crypt(blubber, salt); 341 printf("Passwd entry: %s\n\n", p); 342 343 p = bcrypt_gensalt(5); 344 printf("Generated salt: %s\n", p); 345 p = crypt(blubber, p); 346 printf("Passwd entry: %s\n", p); 347 } 348 #endif 349