/* $OpenBSD: bcrypt.c,v 1.24 2008/04/02 19:54:05 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); */ /* This also includes code from the following version: * $OpenBSD: bcrypt.c,v 1.46 2014/11/24 * * with the following copyright information: * Copyright (c) 2014 Ted Unangst * Copyright (c) 1997 Niels Provos */ #include #include #include #include #include #include "erl_blf.h" /* 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_MINROUNDS 16 /* we have log2(rounds) in salt */ char *bcrypt(const char *, const char *); void encode_salt(char *, uint8_t *, uint16_t, uint8_t); static void encode_base64(uint8_t *, uint8_t *, size_t); static void decode_base64(uint8_t *, size_t, uint8_t *); static char encrypted[_PASSWORD_LEN]; static char error[] = ":"; const static uint8_t Base64Code[] = "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; const 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)]) /* * read buflen (after decoding) bytes of data from b64data */ static void decode_base64(uint8_t *buffer, size_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; } } /* * Turn len bytes of data into base64 encoded data. * This works without = padding. */ static void encode_base64(uint8_t *buffer, uint8_t *data, size_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'; } /* * Generates a salt for bcrypt. */ void encode_salt(char *salt, uint8_t *csalt, uint16_t clen, uint8_t logr) { if (logr < 4) logr = 4; else if (logr > 31) logr = 31; salt[0] = '$'; salt[1] = BCRYPT_VERSION; salt[2] = 'b'; salt[3] = '$'; snprintf(salt + 4, 4, "%2.2u$", logr); encode_base64((uint8_t *) salt + 7, csalt, clen); } /* * the core bcrypt function */ char * bcrypt(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]; int n; /* Discard "$" identifier */ salt++; if (*salt > BCRYPT_VERSION) { /* How do I handle errors ? Return ':' */ return error; } /* Check for minor versions */ switch ((minor = salt[1])) { case 'a': key_len = (uint8_t)(strlen(key) + 1); break; case 'b': /* strlen() returns a size_t, but the function calls * below result in implicit casts to a narrower integer * type, so cap key_len at the actual maximum supported * length here to avoid integer wraparound */ key_len = strlen(key); if (key_len > 72) key_len = 72; key_len++; /* include the NUL */ break; default: return error; } if (salt[2] != '$') return error; /* Discard version + "$" identifier */ salt += 3; /* Computer power doesn't increase linear, 2^x should be fine */ n = atoi(salt); if (n > 31 || n < 0) return error; logr = (uint8_t)n; if ((rounds = (uint32_t) 1 << logr) < BCRYPT_MINROUNDS) return error; /* Discard num rounds + "$" 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; /* 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; } snprintf(encrypted, 8, "$2%c$%2.2u$", minor, logr); encode_base64((uint8_t *) encrypted + 7, csalt, BCRYPT_MAXSALT); encode_base64((uint8_t *) encrypted + 7 + 22, ciphertext, 4 * BCRYPT_BLOCKS - 1); memset(&state, 0, sizeof(state)); memset(ciphertext, 0, sizeof(ciphertext)); memset(csalt, 0, sizeof(csalt)); memset(cdata, 0, sizeof(cdata)); return encrypted; }