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.
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
34 /* This password hashing algorithm was designed by David Mazieres
35 * <dm@lcs.mit.edu> and works as follows:
37 * 1. state := InitState ()
38 * 2. state := ExpandKey (state, salt, password) 3.
40 * state := ExpandKey (state, 0, salt)
41 * state := ExpandKey(state, 0, password)
42 * 4. ctext := "OrpheanBeholderScryDoubt"
44 * ctext := Encrypt_ECB (state, ctext);
45 * 6. RETURN Concatenate (salt, ctext);
50 * FreeBSD implementation by Paul Herman <pherman@frenchfries.net>
55 #include <sys/types.h>
61 /* This implementation is adaptable to current computing power.
62 * You can have up to 2^31 rounds which should be enough for some
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 */
71 char *bcrypt_gensalt(u_int8_t);
73 static void encode_salt(char *, u_int8_t *, u_int16_t, u_int8_t);
74 static void encode_base64(u_int8_t *, u_int8_t *, u_int16_t);
75 static void decode_base64(u_int8_t *, u_int16_t, const u_int8_t *);
77 static char encrypted[_PASSWORD_LEN];
78 static char gsalt[BCRYPT_MAXSALT * 4 / 3 + 1];
79 static char error[] = ":";
81 static const u_int8_t Base64Code[] =
82 "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
84 static const u_int8_t index_64[128] =
86 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
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, 0, 1, 54, 55,
91 56, 57, 58, 59, 60, 61, 62, 63, 255, 255,
92 255, 255, 255, 255, 255, 2, 3, 4, 5, 6,
93 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
94 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27,
95 255, 255, 255, 255, 255, 255, 28, 29, 30,
96 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
97 41, 42, 43, 44, 45, 46, 47, 48, 49, 50,
98 51, 52, 53, 255, 255, 255, 255, 255
100 #define CHAR64(c) ( (c) > 127 ? 255 : index_64[(c)])
103 decode_base64(u_int8_t *buffer, u_int16_t len, const u_int8_t *data)
105 u_int8_t *bp = buffer;
106 const u_int8_t *p = data;
107 u_int8_t c1, c2, c3, c4;
108 while (bp < buffer + len) {
110 c2 = CHAR64(*(p + 1));
113 if (c1 == 255 || c2 == 255)
116 *bp++ = (u_int8_t)((c1 << 2) | ((c2 & 0x30) >> 4));
117 if (bp >= buffer + len)
120 c3 = CHAR64(*(p + 2));
124 *bp++ = ((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2);
125 if (bp >= buffer + len)
128 c4 = CHAR64(*(p + 3));
131 *bp++ = ((c3 & 0x03) << 6) | c4;
138 encode_salt(char *salt, u_int8_t *csalt, u_int16_t clen, u_int8_t logr)
141 salt[1] = BCRYPT_VERSION;
145 snprintf(salt + 4, 4, "%2.2u$", logr);
147 encode_base64((u_int8_t *) salt + 7, csalt, clen);
149 /* Generates a salt for this version of crypt.
150 Since versions may change. Keeping this here
155 bcrypt_gensalt(u_int8_t log_rounds)
157 u_int8_t csalt[BCRYPT_MAXSALT];
161 for (i = 0; i < BCRYPT_MAXSALT; i++) {
164 csalt[i] = seed & 0xff;
171 encode_salt(gsalt, csalt, BCRYPT_MAXSALT, log_rounds);
174 /* We handle $Vers$log2(NumRounds)$salt+passwd$
175 i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */
178 crypt_blowfish(const char *key, const char *salt)
181 u_int32_t rounds, i, k;
183 u_int8_t key_len, salt_len, logr, minr;
184 u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt";
185 u_int8_t csalt[BCRYPT_MAXSALT];
186 u_int32_t cdata[BCRYPT_BLOCKS];
187 static const char *magic = "$2a$04$";
194 /* If it starts with the magic string, then skip that */
195 if(!strncmp(salt, magic, strlen(magic))) {
196 salt += strlen(magic);
198 else if (*salt == '$') {
200 /* Discard "$" identifier */
203 if (*salt > BCRYPT_VERSION) {
204 /* How do I handle errors ? Return ':' */
208 /* Check for minor versions */
209 if (salt[1] != '$') {
212 /* 'ab' should not yield the same as 'abab' */
213 minr = (u_int8_t)salt[1];
222 /* Discard version + "$" identifier */
226 /* Out of sync with passwd entry */
229 /* Computer power doesnt increase linear, 2^x should be fine */
230 logr = (u_int8_t)atoi(salt);
232 if (rounds < BCRYPT_MINROUNDS)
235 /* Discard num rounds + "$" identifier */
240 /* We dont want the base64 salt but the raw data */
241 decode_base64(csalt, BCRYPT_MAXSALT, salt);
242 salt_len = BCRYPT_MAXSALT;
243 key_len = (u_int8_t)(strlen(key) + (minr >= 'a' ? 1 : 0));
245 /* Setting up S-Boxes and Subkeys */
246 Blowfish_initstate(&state);
247 Blowfish_expandstate(&state, csalt, salt_len,
248 (const u_int8_t *) key, key_len);
249 for (k = 0; k < rounds; k++) {
250 Blowfish_expand0state(&state, (const u_int8_t *) key, key_len);
251 Blowfish_expand0state(&state, csalt, salt_len);
254 /* This can be precomputed later */
256 for (i = 0; i < BCRYPT_BLOCKS; i++)
257 cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j);
259 /* Now do the encryption */
260 for (k = 0; k < 64; k++)
261 blf_enc(&state, cdata, BCRYPT_BLOCKS / 2);
263 for (i = 0; i < BCRYPT_BLOCKS; i++) {
264 ciphertext[4 * i + 3] = cdata[i] & 0xff;
265 cdata[i] = cdata[i] >> 8;
266 ciphertext[4 * i + 2] = cdata[i] & 0xff;
267 cdata[i] = cdata[i] >> 8;
268 ciphertext[4 * i + 1] = cdata[i] & 0xff;
269 cdata[i] = cdata[i] >> 8;
270 ciphertext[4 * i + 0] = cdata[i] & 0xff;
275 encrypted[i++] = '$';
276 encrypted[i++] = BCRYPT_VERSION;
278 encrypted[i++] = (int8_t)minr;
279 encrypted[i++] = '$';
281 snprintf(encrypted + i, 4, "%2.2u$", logr);
283 encode_base64((u_int8_t *) encrypted + i + 3, csalt, BCRYPT_MAXSALT);
284 encode_base64((u_int8_t *) encrypted + strlen(encrypted), ciphertext,
285 4 * BCRYPT_BLOCKS - 1);
290 encode_base64(u_int8_t *buffer, u_int8_t *data, u_int16_t len)
292 u_int8_t *bp = buffer;
295 while (p < data + len) {
297 *bp++ = Base64Code[(c1 >> 2)];
298 c1 = (c1 & 0x03) << 4;
299 if (p >= data + len) {
300 *bp++ = Base64Code[c1];
304 c1 |= (c2 >> 4) & 0x0f;
305 *bp++ = Base64Code[c1];
306 c1 = (c2 & 0x0f) << 2;
307 if (p >= data + len) {
308 *bp++ = Base64Code[c1];
312 c1 |= (c2 >> 6) & 0x03;
313 *bp++ = Base64Code[c1];
314 *bp++ = Base64Code[c2 & 0x3f];
327 salt[1] = BCRYPT_VERSION;
330 snprintf(salt + 3, 4, "%2.2u$", 5);
332 printf("24 bytes of salt: ");
333 fgets(salt + 6, 94, stdin);
335 printf("72 bytes of password: ");
337 fgets(blubber, 73, stdin);
340 p = crypt(blubber, salt);
341 printf("Passwd entry: %s\n\n", p);
343 p = bcrypt_gensalt(5);
344 printf("Generated salt: %s\n", p);
345 p = crypt(blubber, p);
346 printf("Passwd entry: %s\n", p);