1 /* $OpenBSD: bcrypt.c,v 1.29 2014/02/24 19:45:43 tedu Exp $ */
4 * Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 * must display the following acknowledgement:
17 * This product includes software developed by Niels Provos.
18 * 4. The name of the author may not be used to endorse or promote products
19 * derived from this software without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
36 /* This password hashing algorithm was designed by David Mazieres
37 * <dm@lcs.mit.edu> and works as follows:
39 * 1. state := InitState ()
40 * 2. state := ExpandKey (state, salt, password)
42 * state := ExpandKey (state, 0, password)
43 * state := ExpandKey (state, 0, salt)
44 * 4. ctext := "OrpheanBeholderScryDoubt"
46 * ctext := Encrypt_ECB (state, ctext);
47 * 6. RETURN Concatenate (salt, ctext);
52 * FreeBSD implementation by Paul Herman <pherman@frenchfries.net>
53 * and updated by Xin Li <delphij@FreeBSD.org>
58 #include <sys/types.h>
64 /* This implementation is adaptable to current computing power.
65 * You can have up to 2^31 rounds which should be enough for some
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_MINLOGROUNDS 4 /* we have log2(rounds) in salt */
75 static void encode_base64(u_int8_t *, u_int8_t *, u_int16_t);
76 static void decode_base64(u_int8_t *, u_int16_t, const u_int8_t *);
78 const static u_int8_t Base64Code[] =
79 "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
81 const static u_int8_t index_64[128] = {
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
96 #define CHAR64(c) ( (c) > 127 ? 255 : index_64[(c)])
99 decode_base64(u_int8_t *buffer, u_int16_t len, const u_int8_t *data)
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) {
106 c2 = CHAR64(*(p + 1));
109 if (c1 == 255 || c2 == 255)
112 *bp++ = (c1 << 2) | ((c2 & 0x30) >> 4);
113 if (bp >= buffer + len)
116 c3 = CHAR64(*(p + 2));
120 *bp++ = ((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2);
121 if (bp >= buffer + len)
124 c4 = CHAR64(*(p + 3));
127 *bp++ = ((c3 & 0x03) << 6) | c4;
133 /* We handle $Vers$log2(NumRounds)$salt+passwd$
134 i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */
137 crypt_blowfish(const char *key, const char *salt, char *buffer)
140 u_int32_t rounds, i, k;
143 u_int8_t salt_len, logr, minr;
144 u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt";
145 u_int8_t csalt[BCRYPT_MAXSALT];
146 u_int32_t cdata[BCRYPT_BLOCKS];
151 logr = BCRYPT_MINLOGROUNDS;
155 /* Discard "$" identifier */
158 if (*salt > BCRYPT_VERSION)
161 /* Check for minor versions */
162 if (salt[1] != '$') {
164 case 'a': /* 'ab' should not yield the same as 'abab' */
165 case 'b': /* cap input length at 72 bytes */
166 case 'y': /* same as 'b', for compatibility
167 * with openwall crypt_blowfish
178 /* Discard version + "$" identifier */
182 /* Out of sync with passwd entry */
185 memcpy(arounds, salt, sizeof(arounds));
186 if (arounds[sizeof(arounds) - 1] != '$')
188 arounds[sizeof(arounds) - 1] = 0;
189 logr = strtonum(arounds, BCRYPT_MINLOGROUNDS, 31, NULL);
192 /* Computer power doesn't increase linearly, 2^x should be fine */
195 /* Discard num rounds + "$" identifier */
199 if (strlen(salt) * 3 / 4 < BCRYPT_MAXSALT)
202 /* We dont want the base64 salt but the raw data */
203 decode_base64(csalt, BCRYPT_MAXSALT, (const u_int8_t *) salt);
204 salt_len = BCRYPT_MAXSALT;
206 key_len = (u_int8_t)(strlen(key) + (minr >= 'a' ? 1 : 0));
208 /* strlen() returns a size_t, but the function calls
209 * below result in implicit casts to a narrower integer
210 * type, so cap key_len at the actual maximum supported
211 * length here to avoid integer wraparound */
212 key_len = strlen(key);
215 key_len++; /* include the NUL */
218 /* Setting up S-Boxes and Subkeys */
219 Blowfish_initstate(&state);
220 Blowfish_expandstate(&state, csalt, salt_len,
221 (const u_int8_t *) key, key_len);
222 for (k = 0; k < rounds; k++) {
223 Blowfish_expand0state(&state, (const u_int8_t *) key, key_len);
224 Blowfish_expand0state(&state, csalt, salt_len);
227 /* This can be precomputed later */
229 for (i = 0; i < BCRYPT_BLOCKS; i++)
230 cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j);
232 /* Now do the encryption */
233 for (k = 0; k < 64; k++)
234 blf_enc(&state, cdata, BCRYPT_BLOCKS / 2);
236 for (i = 0; i < BCRYPT_BLOCKS; i++) {
237 ciphertext[4 * i + 3] = cdata[i] & 0xff;
238 cdata[i] = cdata[i] >> 8;
239 ciphertext[4 * i + 2] = cdata[i] & 0xff;
240 cdata[i] = cdata[i] >> 8;
241 ciphertext[4 * i + 1] = cdata[i] & 0xff;
242 cdata[i] = cdata[i] >> 8;
243 ciphertext[4 * i + 0] = cdata[i] & 0xff;
248 *buffer++ = BCRYPT_VERSION;
253 snprintf(buffer, 4, "%2.2u$", logr);
256 encode_base64((u_int8_t *)buffer, csalt, BCRYPT_MAXSALT);
257 buffer += strlen(buffer);
258 encode_base64((u_int8_t *)buffer, ciphertext, 4 * BCRYPT_BLOCKS - 1);
259 memset(&state, 0, sizeof(state));
260 memset(ciphertext, 0, sizeof(ciphertext));
261 memset(csalt, 0, sizeof(csalt));
262 memset(cdata, 0, sizeof(cdata));
267 encode_base64(u_int8_t *buffer, u_int8_t *data, u_int16_t len)
269 u_int8_t *bp = buffer;
272 while (p < data + len) {
274 *bp++ = Base64Code[(c1 >> 2)];
275 c1 = (c1 & 0x03) << 4;
276 if (p >= data + len) {
277 *bp++ = Base64Code[c1];
281 c1 |= (c2 >> 4) & 0x0f;
282 *bp++ = Base64Code[c1];
283 c1 = (c2 & 0x0f) << 2;
284 if (p >= data + len) {
285 *bp++ = Base64Code[c1];
289 c1 |= (c2 >> 6) & 0x03;
290 *bp++ = Base64Code[c1];
291 *bp++ = Base64Code[c2 & 0x3f];
303 salt[1] = BCRYPT_VERSION;
306 snprintf(salt + 3, 4, "%2.2u$", 5);
308 printf("24 bytes of salt: ");
309 fgets(salt + 6, sizeof(salt) - 6, stdin);
311 printf("72 bytes of password: ");
313 fgets(blubber, sizeof(blubber), stdin);
316 p = crypt(blubber, salt);
317 printf("Passwd entry: %s\n\n", p);
319 p = bcrypt_gensalt(5);
320 printf("Generated salt: %s\n", p);
321 p = crypt(blubber, p);
322 printf("Passwd entry: %s\n", p);