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 #include <stdio.h> 54 #include <stdlib.h> 55 #include <sys/types.h> 56 #include <string.h> 57 #include <pwd.h> 58 #include "blowfish.h" 59 #include "crypt.h" 60 61 /* This implementation is adaptable to current computing power. 62 * You can have up to 2^31 rounds which should be enough for some 63 * time to come. 64 */ 65 66 #define BCRYPT_VERSION '2' 67 #define BCRYPT_MAXSALT 16 /* Precomputation is just so nice */ 68 #define BCRYPT_BLOCKS 6 /* Ciphertext blocks */ 69 #define BCRYPT_MINROUNDS 16 /* we have log2(rounds) in salt */ 70 71 static void encode_base64(u_int8_t *, u_int8_t *, u_int16_t); 72 static void decode_base64(u_int8_t *, u_int16_t, const u_int8_t *); 73 74 static char encrypted[_PASSWORD_LEN]; 75 76 static const u_int8_t Base64Code[] = 77 "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; 78 79 static const u_int8_t index_64[128] = 80 { 81 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 82 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 83 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 84 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 85 255, 255, 255, 255, 255, 255, 0, 1, 54, 55, 86 56, 57, 58, 59, 60, 61, 62, 63, 255, 255, 87 255, 255, 255, 255, 255, 2, 3, 4, 5, 6, 88 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 89 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 90 255, 255, 255, 255, 255, 255, 28, 29, 30, 91 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 92 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 93 51, 52, 53, 255, 255, 255, 255, 255 94 }; 95 #define CHAR64(c) ( (c) > 127 ? 255 : index_64[(c)]) 96 97 static void 98 decode_base64(u_int8_t *buffer, u_int16_t len, const u_int8_t *data) 99 { 100 u_int8_t *bp = buffer; 101 const u_int8_t *p = data; 102 u_int8_t c1, c2, c3, c4; 103 while (bp < buffer + len) { 104 c1 = CHAR64(*p); 105 c2 = CHAR64(*(p + 1)); 106 107 /* Invalid data */ 108 if (c1 == 255 || c2 == 255) 109 break; 110 111 *bp++ = (u_int8_t)((c1 << 2) | ((c2 & 0x30) >> 4)); 112 if (bp >= buffer + len) 113 break; 114 115 c3 = CHAR64(*(p + 2)); 116 if (c3 == 255) 117 break; 118 119 *bp++ = ((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2); 120 if (bp >= buffer + len) 121 break; 122 123 c4 = CHAR64(*(p + 3)); 124 if (c4 == 255) 125 break; 126 *bp++ = ((c3 & 0x03) << 6) | c4; 127 128 p += 4; 129 } 130 } 131 132 /* We handle $Vers$log2(NumRounds)$salt+passwd$ 133 i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */ 134 135 char * 136 crypt_blowfish(const char *key, const char *salt) 137 { 138 blf_ctx state; 139 u_int32_t rounds, i, k; 140 u_int16_t j; 141 u_int8_t key_len, salt_len, logr, minr; 142 u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt"; 143 u_int8_t csalt[BCRYPT_MAXSALT]; 144 u_int32_t cdata[BCRYPT_BLOCKS]; 145 static const char *magic = "$2a$04$"; 146 147 /* Defaults */ 148 minr = 'a'; 149 logr = 4; 150 rounds = 1 << logr; 151 152 /* If it starts with the magic string, then skip that */ 153 if(!strncmp(salt, magic, strlen(magic))) { 154 salt += strlen(magic); 155 } 156 else if (*salt == '$') { 157 158 /* Discard "$" identifier */ 159 salt++; 160 161 if (*salt > BCRYPT_VERSION) { 162 /* How do I handle errors ? Return NULL */ 163 return NULL; 164 } 165 166 /* Check for minor versions */ 167 if (salt[1] != '$') { 168 switch (salt[1]) { 169 case 'a': 170 /* 'ab' should not yield the same as 'abab' */ 171 minr = (u_int8_t)salt[1]; 172 salt++; 173 break; 174 default: 175 return NULL; 176 } 177 } else 178 minr = 0; 179 180 /* Discard version + "$" identifier */ 181 salt += 2; 182 183 if (salt[2] != '$') 184 /* Out of sync with passwd entry */ 185 return NULL; 186 187 /* Computer power doesnt increase linear, 2^x should be fine */ 188 logr = (u_int8_t)atoi(salt); 189 rounds = 1 << logr; 190 if (rounds < BCRYPT_MINROUNDS) 191 return NULL; 192 193 /* Discard num rounds + "$" identifier */ 194 salt += 3; 195 } 196 197 198 /* We dont want the base64 salt but the raw data */ 199 decode_base64(csalt, BCRYPT_MAXSALT, (const u_int8_t *)salt); 200 salt_len = BCRYPT_MAXSALT; 201 key_len = (u_int8_t)(strlen(key) + (minr >= 'a' ? 1 : 0)); 202 203 /* Setting up S-Boxes and Subkeys */ 204 Blowfish_initstate(&state); 205 Blowfish_expandstate(&state, csalt, salt_len, 206 (const u_int8_t *) key, key_len); 207 for (k = 0; k < rounds; k++) { 208 Blowfish_expand0state(&state, (const u_int8_t *) key, key_len); 209 Blowfish_expand0state(&state, csalt, salt_len); 210 } 211 212 /* This can be precomputed later */ 213 j = 0; 214 for (i = 0; i < BCRYPT_BLOCKS; i++) 215 cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j); 216 217 /* Now do the encryption */ 218 for (k = 0; k < 64; k++) 219 blf_enc(&state, cdata, BCRYPT_BLOCKS / 2); 220 221 for (i = 0; i < BCRYPT_BLOCKS; i++) { 222 ciphertext[4 * i + 3] = cdata[i] & 0xff; 223 cdata[i] = cdata[i] >> 8; 224 ciphertext[4 * i + 2] = cdata[i] & 0xff; 225 cdata[i] = cdata[i] >> 8; 226 ciphertext[4 * i + 1] = cdata[i] & 0xff; 227 cdata[i] = cdata[i] >> 8; 228 ciphertext[4 * i + 0] = cdata[i] & 0xff; 229 } 230 231 232 i = 0; 233 encrypted[i++] = '$'; 234 encrypted[i++] = BCRYPT_VERSION; 235 if (minr) 236 encrypted[i++] = (int8_t)minr; 237 encrypted[i++] = '$'; 238 239 snprintf(encrypted + i, 4, "%2.2u$", logr); 240 241 encode_base64((u_int8_t *) encrypted + i + 3, csalt, BCRYPT_MAXSALT); 242 encode_base64((u_int8_t *) encrypted + strlen(encrypted), ciphertext, 243 4 * BCRYPT_BLOCKS - 1); 244 return encrypted; 245 } 246 247 static void 248 encode_base64(u_int8_t *buffer, u_int8_t *data, u_int16_t len) 249 { 250 u_int8_t *bp = buffer; 251 u_int8_t *p = data; 252 u_int8_t c1, c2; 253 while (p < data + len) { 254 c1 = *p++; 255 *bp++ = Base64Code[(c1 >> 2)]; 256 c1 = (c1 & 0x03) << 4; 257 if (p >= data + len) { 258 *bp++ = Base64Code[c1]; 259 break; 260 } 261 c2 = *p++; 262 c1 |= (c2 >> 4) & 0x0f; 263 *bp++ = Base64Code[c1]; 264 c1 = (c2 & 0x0f) << 2; 265 if (p >= data + len) { 266 *bp++ = Base64Code[c1]; 267 break; 268 } 269 c2 = *p++; 270 c1 |= (c2 >> 6) & 0x03; 271 *bp++ = Base64Code[c1]; 272 *bp++ = Base64Code[c2 & 0x3f]; 273 } 274 *bp = '\0'; 275 } 276 277 #if 0 278 void 279 main() 280 { 281 char blubber[73]; 282 char salt[100]; 283 char *p; 284 salt[0] = '$'; 285 salt[1] = BCRYPT_VERSION; 286 salt[2] = '$'; 287 288 snprintf(salt + 3, 4, "%2.2u$", 5); 289 290 printf("24 bytes of salt: "); 291 fgets(salt + 6, 94, stdin); 292 salt[99] = 0; 293 printf("72 bytes of password: "); 294 fpurge(stdin); 295 fgets(blubber, 73, stdin); 296 blubber[72] = 0; 297 298 p = crypt(blubber, salt); 299 printf("Passwd entry: %s\n\n", p); 300 301 p = bcrypt_gensalt(5); 302 printf("Generated salt: %s\n", p); 303 p = crypt(blubber, p); 304 printf("Passwd entry: %s\n", p); 305 } 306 #endif 307