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 static char error[] = ":"; 76 77 static const u_int8_t Base64Code[] = 78 "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; 79 80 static const u_int8_t index_64[128] = 81 { 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, 255, 255, 255, 255, 86 255, 255, 255, 255, 255, 255, 0, 1, 54, 55, 87 56, 57, 58, 59, 60, 61, 62, 63, 255, 255, 88 255, 255, 255, 255, 255, 2, 3, 4, 5, 6, 89 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 90 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 91 255, 255, 255, 255, 255, 255, 28, 29, 30, 92 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 93 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 94 51, 52, 53, 255, 255, 255, 255, 255 95 }; 96 #define CHAR64(c) ( (c) > 127 ? 255 : index_64[(c)]) 97 98 static void 99 decode_base64(u_int8_t *buffer, u_int16_t len, const u_int8_t *data) 100 { 101 u_int8_t *bp = buffer; 102 const u_int8_t *p = data; 103 u_int8_t c1, c2, c3, c4; 104 while (bp < buffer + len) { 105 c1 = CHAR64(*p); 106 c2 = CHAR64(*(p + 1)); 107 108 /* Invalid data */ 109 if (c1 == 255 || c2 == 255) 110 break; 111 112 *bp++ = (u_int8_t)((c1 << 2) | ((c2 & 0x30) >> 4)); 113 if (bp >= buffer + len) 114 break; 115 116 c3 = CHAR64(*(p + 2)); 117 if (c3 == 255) 118 break; 119 120 *bp++ = ((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2); 121 if (bp >= buffer + len) 122 break; 123 124 c4 = CHAR64(*(p + 3)); 125 if (c4 == 255) 126 break; 127 *bp++ = ((c3 & 0x03) << 6) | c4; 128 129 p += 4; 130 } 131 } 132 133 /* We handle $Vers$log2(NumRounds)$salt+passwd$ 134 i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */ 135 136 char * 137 crypt_blowfish(const char *key, const char *salt) 138 { 139 blf_ctx state; 140 u_int32_t rounds, i, k; 141 u_int16_t j; 142 u_int8_t key_len, salt_len, logr, minr; 143 u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt"; 144 u_int8_t csalt[BCRYPT_MAXSALT]; 145 u_int32_t cdata[BCRYPT_BLOCKS]; 146 static const char *magic = "$2a$04$"; 147 148 /* Defaults */ 149 minr = 'a'; 150 logr = 4; 151 rounds = 1 << logr; 152 153 /* If it starts with the magic string, then skip that */ 154 if(!strncmp(salt, magic, strlen(magic))) { 155 salt += strlen(magic); 156 } 157 else if (*salt == '$') { 158 159 /* Discard "$" identifier */ 160 salt++; 161 162 if (*salt > BCRYPT_VERSION) { 163 /* How do I handle errors ? Return ':' */ 164 return error; 165 } 166 167 /* Check for minor versions */ 168 if (salt[1] != '$') { 169 switch (salt[1]) { 170 case 'a': 171 /* 'ab' should not yield the same as 'abab' */ 172 minr = (u_int8_t)salt[1]; 173 salt++; 174 break; 175 default: 176 return error; 177 } 178 } else 179 minr = 0; 180 181 /* Discard version + "$" identifier */ 182 salt += 2; 183 184 if (salt[2] != '$') 185 /* Out of sync with passwd entry */ 186 return error; 187 188 /* Computer power doesnt increase linear, 2^x should be fine */ 189 logr = (u_int8_t)atoi(salt); 190 rounds = 1 << logr; 191 if (rounds < BCRYPT_MINROUNDS) 192 return error; 193 194 /* Discard num rounds + "$" identifier */ 195 salt += 3; 196 } 197 198 199 /* We dont want the base64 salt but the raw data */ 200 decode_base64(csalt, BCRYPT_MAXSALT, (const u_int8_t *)salt); 201 salt_len = BCRYPT_MAXSALT; 202 key_len = (u_int8_t)(strlen(key) + (minr >= 'a' ? 1 : 0)); 203 204 /* Setting up S-Boxes and Subkeys */ 205 Blowfish_initstate(&state); 206 Blowfish_expandstate(&state, csalt, salt_len, 207 (const u_int8_t *) key, key_len); 208 for (k = 0; k < rounds; k++) { 209 Blowfish_expand0state(&state, (const u_int8_t *) key, key_len); 210 Blowfish_expand0state(&state, csalt, salt_len); 211 } 212 213 /* This can be precomputed later */ 214 j = 0; 215 for (i = 0; i < BCRYPT_BLOCKS; i++) 216 cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j); 217 218 /* Now do the encryption */ 219 for (k = 0; k < 64; k++) 220 blf_enc(&state, cdata, BCRYPT_BLOCKS / 2); 221 222 for (i = 0; i < BCRYPT_BLOCKS; i++) { 223 ciphertext[4 * i + 3] = cdata[i] & 0xff; 224 cdata[i] = cdata[i] >> 8; 225 ciphertext[4 * i + 2] = cdata[i] & 0xff; 226 cdata[i] = cdata[i] >> 8; 227 ciphertext[4 * i + 1] = cdata[i] & 0xff; 228 cdata[i] = cdata[i] >> 8; 229 ciphertext[4 * i + 0] = cdata[i] & 0xff; 230 } 231 232 233 i = 0; 234 encrypted[i++] = '$'; 235 encrypted[i++] = BCRYPT_VERSION; 236 if (minr) 237 encrypted[i++] = (int8_t)minr; 238 encrypted[i++] = '$'; 239 240 snprintf(encrypted + i, 4, "%2.2u$", logr); 241 242 encode_base64((u_int8_t *) encrypted + i + 3, csalt, BCRYPT_MAXSALT); 243 encode_base64((u_int8_t *) encrypted + strlen(encrypted), ciphertext, 244 4 * BCRYPT_BLOCKS - 1); 245 return encrypted; 246 } 247 248 static void 249 encode_base64(u_int8_t *buffer, u_int8_t *data, u_int16_t len) 250 { 251 u_int8_t *bp = buffer; 252 u_int8_t *p = data; 253 u_int8_t c1, c2; 254 while (p < data + len) { 255 c1 = *p++; 256 *bp++ = Base64Code[(c1 >> 2)]; 257 c1 = (c1 & 0x03) << 4; 258 if (p >= data + len) { 259 *bp++ = Base64Code[c1]; 260 break; 261 } 262 c2 = *p++; 263 c1 |= (c2 >> 4) & 0x0f; 264 *bp++ = Base64Code[c1]; 265 c1 = (c2 & 0x0f) << 2; 266 if (p >= data + len) { 267 *bp++ = Base64Code[c1]; 268 break; 269 } 270 c2 = *p++; 271 c1 |= (c2 >> 6) & 0x03; 272 *bp++ = Base64Code[c1]; 273 *bp++ = Base64Code[c2 & 0x3f]; 274 } 275 *bp = '\0'; 276 } 277 278 #if 0 279 void 280 main() 281 { 282 char blubber[73]; 283 char salt[100]; 284 char *p; 285 salt[0] = '$'; 286 salt[1] = BCRYPT_VERSION; 287 salt[2] = '$'; 288 289 snprintf(salt + 3, 4, "%2.2u$", 5); 290 291 printf("24 bytes of salt: "); 292 fgets(salt + 6, 94, stdin); 293 salt[99] = 0; 294 printf("72 bytes of password: "); 295 fpurge(stdin); 296 fgets(blubber, 73, stdin); 297 blubber[72] = 0; 298 299 p = crypt(blubber, salt); 300 printf("Passwd entry: %s\n\n", p); 301 302 p = bcrypt_gensalt(5); 303 printf("Generated salt: %s\n", p); 304 p = crypt(blubber, p); 305 printf("Passwd entry: %s\n", p); 306 } 307 #endif 308