2 * Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
30 * $FreeBSD: src/secure/lib/libcrypt/crypt-blowfish.c,v 1.1.2.1 2001/05/24 12:20:03 markm Exp $
33 /* This password hashing algorithm was designed by David Mazieres
34 * <dm@lcs.mit.edu> and works as follows:
36 * 1. state := InitState ()
37 * 2. state := ExpandKey (state, salt, password) 3.
39 * state := ExpandKey (state, 0, salt)
40 * state := ExpandKey(state, 0, password)
41 * 4. ctext := "OrpheanBeholderScryDoubt"
43 * ctext := Encrypt_ECB (state, ctext);
44 * 6. RETURN Concatenate (salt, ctext);
49 * FreeBSD implementation by Paul Herman <pherman@frenchfries.net>
58 #include <sys/types.h>
63 /* This implementation is adaptable to current computing power.
64 * You can have up to 2^31 rounds which should be enough for some
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 */
73 char *bcrypt_gensalt __P((u_int8_t));
75 static void encode_salt __P((char *, u_int8_t *, u_int16_t, u_int8_t));
76 static void encode_base64 __P((u_int8_t *, u_int8_t *, u_int16_t));
77 static void decode_base64 __P((u_int8_t *, u_int16_t, u_int8_t *));
79 static char encrypted[_PASSWORD_LEN];
80 static char gsalt[BCRYPT_MAXSALT * 4 / 3 + 1];
81 static char error[] = ":";
83 const static u_int8_t Base64Code[] =
84 "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
86 const static u_int8_t index_64[128] =
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
102 #define CHAR64(c) ( (c) > 127 ? 255 : index_64[(c)])
106 decode_base64(u_int8_t *buffer, u_int16_t len, u_int8_t *data)
109 decode_base64(buffer, len, data)
115 u_int8_t *bp = buffer;
117 u_int8_t c1, c2, c3, c4;
118 while (bp < buffer + len) {
120 c2 = CHAR64(*(p + 1));
123 if (c1 == 255 || c2 == 255)
126 *bp++ = (c1 << 2) | ((c2 & 0x30) >> 4);
127 if (bp >= buffer + len)
130 c3 = CHAR64(*(p + 2));
134 *bp++ = ((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2);
135 if (bp >= buffer + len)
138 c4 = CHAR64(*(p + 3));
141 *bp++ = ((c3 & 0x03) << 6) | c4;
149 encode_salt(char *salt, u_int8_t *csalt, u_int16_t clen, u_int8_t logr)
152 encode_salt(salt, csalt, clen, logr)
160 salt[1] = BCRYPT_VERSION;
164 snprintf(salt + 4, 4, "%2.2u$", logr);
166 encode_base64((u_int8_t *) salt + 7, csalt, clen);
168 /* Generates a salt for this version of crypt.
169 Since versions may change. Keeping this here
175 bcrypt_gensalt(u_int8_t log_rounds)
178 bcrypt_gensalt(log_rounds)
182 u_int8_t csalt[BCRYPT_MAXSALT];
186 for (i = 0; i < BCRYPT_MAXSALT; i++) {
189 csalt[i] = seed & 0xff;
196 encode_salt(gsalt, csalt, BCRYPT_MAXSALT, log_rounds);
199 /* We handle $Vers$log2(NumRounds)$salt+passwd$
200 i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */
203 crypt_blowfish(key, salt)
208 u_int32_t rounds, i, k;
210 u_int8_t key_len, salt_len, logr, minor;
211 u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt";
212 u_int8_t csalt[BCRYPT_MAXSALT];
213 u_int32_t cdata[BCRYPT_BLOCKS];
214 static char *magic = "$2a$04$";
221 /* If it starts with the magic string, then skip that */
222 if(!strncmp(salt, magic, strlen(magic))) {
223 salt += strlen(magic);
225 else if (*salt == '$') {
227 /* Discard "$" identifier */
230 if (*salt > BCRYPT_VERSION) {
231 /* How do I handle errors ? Return ':' */
235 /* Check for minor versions */
236 if (salt[1] != '$') {
239 /* 'ab' should not yield the same as 'abab' */
249 /* Discard version + "$" identifier */
253 /* Out of sync with passwd entry */
256 /* Computer power doesnt increase linear, 2^x should be fine */
257 if ((rounds = (u_int32_t) 1 << (logr = atoi(salt))) < BCRYPT_MINROUNDS)
260 /* Discard num rounds + "$" identifier */
265 /* We dont want the base64 salt but the raw data */
266 decode_base64(csalt, BCRYPT_MAXSALT, (u_int8_t *) salt);
267 salt_len = BCRYPT_MAXSALT;
268 key_len = strlen(key) + (minor >= 'a' ? 1 : 0);
270 /* Setting up S-Boxes and Subkeys */
271 Blowfish_initstate(&state);
272 Blowfish_expandstate(&state, csalt, salt_len,
273 (u_int8_t *) key, key_len);
274 for (k = 0; k < rounds; k++) {
275 Blowfish_expand0state(&state, (u_int8_t *) key, key_len);
276 Blowfish_expand0state(&state, csalt, salt_len);
279 /* This can be precomputed later */
281 for (i = 0; i < BCRYPT_BLOCKS; i++)
282 cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j);
284 /* Now do the encryption */
285 for (k = 0; k < 64; k++)
286 blf_enc(&state, cdata, BCRYPT_BLOCKS / 2);
288 for (i = 0; i < BCRYPT_BLOCKS; i++) {
289 ciphertext[4 * i + 3] = cdata[i] & 0xff;
290 cdata[i] = cdata[i] >> 8;
291 ciphertext[4 * i + 2] = cdata[i] & 0xff;
292 cdata[i] = cdata[i] >> 8;
293 ciphertext[4 * i + 1] = cdata[i] & 0xff;
294 cdata[i] = cdata[i] >> 8;
295 ciphertext[4 * i + 0] = cdata[i] & 0xff;
300 encrypted[i++] = '$';
301 encrypted[i++] = BCRYPT_VERSION;
303 encrypted[i++] = minor;
304 encrypted[i++] = '$';
306 snprintf(encrypted + i, 4, "%2.2u$", logr);
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);
316 encode_base64(u_int8_t *buffer, u_int8_t *data, u_int16_t len)
319 encode_base64(buffer, data, len)
325 u_int8_t *bp = buffer;
328 while (p < data + len) {
330 *bp++ = Base64Code[(c1 >> 2)];
331 c1 = (c1 & 0x03) << 4;
332 if (p >= data + len) {
333 *bp++ = Base64Code[c1];
337 c1 |= (c2 >> 4) & 0x0f;
338 *bp++ = Base64Code[c1];
339 c1 = (c2 & 0x0f) << 2;
340 if (p >= data + len) {
341 *bp++ = Base64Code[c1];
345 c1 |= (c2 >> 6) & 0x03;
346 *bp++ = Base64Code[c1];
347 *bp++ = Base64Code[c2 & 0x3f];
359 salt[1] = BCRYPT_VERSION;
362 snprintf(salt + 3, 4, "%2.2u$", 5);
364 printf("24 bytes of salt: ");
365 fgets(salt + 6, 94, stdin);
367 printf("72 bytes of password: ");
369 fgets(blubber, 73, stdin);
372 p = crypt(blubber, salt);
373 printf("Passwd entry: %s\n\n", p);
375 p = bcrypt_gensalt(5);
376 printf("Generated salt: %s\n", p);
377 p = crypt(blubber, p);
378 printf("Passwd entry: %s\n", p);