/* * Copyright 2003 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ /* $OpenBSD: bcrypt.c,v 1.16 2002/02/19 19:39:36 millert Exp $ */ /* * Copyright 1997 Niels Provos * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by Niels Provos. * 4. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * This password hashing algorithm was designed by David Mazieres * and works as follows: * * 1. state := InitState () * 2. state := ExpandKey (state, salt, password) 3. * REPEAT rounds: * state := ExpandKey (state, 0, salt) * state := ExpandKey(state, 0, password) * 4. ctext := "OrpheanBeholderScryDoubt" * 5. REPEAT 64: * ctext := Encrypt_ECB (state, ctext); * 6. RETURN Concatenate (salt, ctext); * */ #if 0 #include #endif #include #include #include #include #include #include extern uint32_t arc4random(); /* * This implementation is adaptable to current computing power. * You can have up to 2^31 rounds which should be enough for some * time to come. */ #define BCRYPT_VERSION '2' #define BCRYPT_MAXSALT 16 /* Precomputation is just so nice */ #define BCRYPT_BLOCKS 6 /* Ciphertext blocks */ #define BCRYPT_MINLOGROUNDS 4 /* we have log2(rounds) in salt */ #define BCRYPT_MAXLOGROUNDS 31 char *bcrypt_gensalt(uint8_t); static void encode_salt(char *, uint8_t *, uint16_t, uint8_t); static void encode_base64(uint8_t *, uint8_t *, uint16_t); static void decode_base64(uint8_t *, uint16_t, uint8_t *); static char encrypted[128]; /* _PASSWORD_LEN in on OpenBSD */ static char gsalt[BCRYPT_MAXSALT * 4 / 3 + 1]; static char error[] = ":"; static uint8_t Base64Code[] = "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; static uint8_t index_64[128] = { 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 0, 1, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 255, 255, 255, 255, 255, 255, 255, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 255, 255, 255, 255, 255, 255, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 255, 255, 255, 255, 255 }; #define CHAR64(c) ((c) > 127 ? 255 : index_64[(c)]) static void decode_base64(uint8_t *buffer, uint16_t len, uint8_t *data) { uint8_t *bp = buffer; uint8_t *p = data; uint8_t c1, c2, c3, c4; while (bp < buffer + len) { c1 = CHAR64(*p); c2 = CHAR64(*(p + 1)); /* Invalid data */ if (c1 == 255 || c2 == 255) break; *bp++ = (c1 << 2) | ((c2 & 0x30) >> 4); if (bp >= buffer + len) break; c3 = CHAR64(*(p + 2)); if (c3 == 255) break; *bp++ = ((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2); if (bp >= buffer + len) break; c4 = CHAR64(*(p + 3)); if (c4 == 255) break; *bp++ = ((c3 & 0x03) << 6) | c4; p += 4; } } static void encode_salt(char *salt, uint8_t *csalt, uint16_t clen, uint8_t logr) { salt[0] = '$'; salt[1] = BCRYPT_VERSION; salt[2] = 'a'; salt[3] = '$'; (void) snprintf(salt + 4, 4, "%2.2u$", logr); encode_base64((uint8_t *)salt + 7, csalt, clen); } /* * Generates a salt for this version of crypt. * Since versions may change. Keeping this here * seems sensible. */ char * bcrypt_gensalt(uint8_t log_rounds) { uint8_t csalt[BCRYPT_MAXSALT]; uint16_t i; uint32_t seed = 0; for (i = 0; i < BCRYPT_MAXSALT; i++) { if (i % 4 == 0) seed = arc4random(); csalt[i] = seed & 0xff; seed = seed >> 8; } if (log_rounds < BCRYPT_MINLOGROUNDS) log_rounds = BCRYPT_MINLOGROUNDS; else if (log_rounds > BCRYPT_MAXLOGROUNDS) log_rounds = BCRYPT_MAXLOGROUNDS; encode_salt(gsalt, csalt, BCRYPT_MAXSALT, log_rounds); return (gsalt); } /* * We handle $Vers$log2(NumRounds)$salt+passwd$ * i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */ char * bcrypt(key, salt) const char *key; const char *salt; { blf_ctx state; uint32_t rounds, i, k; uint16_t j; size_t key_len; uint8_t salt_len, logr, minor; uint8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt"; uint8_t csalt[BCRYPT_MAXSALT]; uint32_t cdata[BCRYPT_BLOCKS]; char arounds[3]; /* Discard "$" identifier */ salt++; if (*salt > BCRYPT_VERSION) { /* How do I handle errors ? Return ':' */ return (error); } /* Check for minor versions */ if (salt[1] != '$') { switch (salt[1]) { case 'a': /* 'ab' should not yield the same as 'abab' */ case 'b': /* cap input length at 72 bytes */ minor = salt[1]; salt++; break; default: return (error); } } else minor = 0; /* Discard version + "$" identifier */ salt += 2; if (salt[2] != '$') /* Out of sync with passwd entry */ return (error); (void) memcpy(arounds, salt, sizeof (arounds)); if (arounds[sizeof (arounds) - 1] != '$') return (error); if ((logr = atoi(arounds)) < BCRYPT_MINLOGROUNDS || logr > BCRYPT_MAXLOGROUNDS) return (error); /* Computer power doesn't increase linear, 2^x should be fine */ rounds = 1U << logr; /* Discard num rounds + "$" identifier */ salt += 3; if (strlen(salt) * 3 / 4 < BCRYPT_MAXSALT) return (error); /* We dont want the base64 salt but the raw data */ decode_base64(csalt, BCRYPT_MAXSALT, (uint8_t *)salt); salt_len = BCRYPT_MAXSALT; if (minor <= 'a') key_len = (uint8_t)(strlen(key) + (minor >= 'a' ? 1 : 0)); else { /* * strlen() returns a size_t, but the function calls * below result in implicit casts to a narrower integer * type, so cap key_len at the actual maximum supported * length here to avoid integer wraparound */ key_len = strlen(key); if (key_len > 72) key_len = 72; key_len++; /* include the NUL */ } /* Setting up S-Boxes and Subkeys */ Blowfish_initstate(&state); Blowfish_expandstate(&state, csalt, salt_len, (uint8_t *)key, key_len); for (k = 0; k < rounds; k++) { Blowfish_expand0state(&state, (uint8_t *)key, key_len); Blowfish_expand0state(&state, csalt, salt_len); } /* This can be precomputed later */ j = 0; for (i = 0; i < BCRYPT_BLOCKS; i++) cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j); /* Now do the encryption */ for (k = 0; k < 64; k++) blf_enc(&state, cdata, BCRYPT_BLOCKS / 2); for (i = 0; i < BCRYPT_BLOCKS; i++) { ciphertext[4 * i + 3] = cdata[i] & 0xff; cdata[i] = cdata[i] >> 8; ciphertext[4 * i + 2] = cdata[i] & 0xff; cdata[i] = cdata[i] >> 8; ciphertext[4 * i + 1] = cdata[i] & 0xff; cdata[i] = cdata[i] >> 8; ciphertext[4 * i + 0] = cdata[i] & 0xff; } i = 0; encrypted[i++] = '$'; encrypted[i++] = BCRYPT_VERSION; if (minor) encrypted[i++] = minor; encrypted[i++] = '$'; (void) snprintf(encrypted + i, 4, "%2.2u$", logr); encode_base64((uint8_t *)encrypted + i + 3, csalt, BCRYPT_MAXSALT); encode_base64((uint8_t *)encrypted + strlen(encrypted), ciphertext, 4 * BCRYPT_BLOCKS - 1); return (encrypted); } static void encode_base64(uint8_t *buffer, uint8_t *data, uint16_t len) { uint8_t *bp = buffer; uint8_t *p = data; uint8_t c1, c2; while (p < data + len) { c1 = *p++; *bp++ = Base64Code[(c1 >> 2)]; c1 = (c1 & 0x03) << 4; if (p >= data + len) { *bp++ = Base64Code[c1]; break; } c2 = *p++; c1 |= (c2 >> 4) & 0x0f; *bp++ = Base64Code[c1]; c1 = (c2 & 0x0f) << 2; if (p >= data + len) { *bp++ = Base64Code[c1]; break; } c2 = *p++; c1 |= (c2 >> 6) & 0x03; *bp++ = Base64Code[c1]; *bp++ = Base64Code[c2 & 0x3f]; } *bp = '\0'; } #if 0 void main() { char blubber[73]; char salt[100]; char *p; salt[0] = '$'; salt[1] = BCRYPT_VERSION; salt[2] = '$'; snprintf(salt + 3, 4, "%2.2u$", 5); printf("24 bytes of salt: "); fgets(salt + 6, 94, stdin); salt[99] = 0; printf("72 bytes of password: "); fpurge(stdin); fgets(blubber, 73, stdin); blubber[72] = 0; p = crypt(blubber, salt); printf("Passwd entry: %s\n\n", p); p = bcrypt_gensalt(5); printf("Generated salt: %s\n", p); p = crypt(blubber, p); printf("Passwd entry: %s\n", p); } #endif