/* $OpenBSD: bcrypt.c,v 1.31 2014/03/22 23:02:03 tedu Exp $ */ /* * Copyright (c) 1997 Niels Provos <provos@umich.edu> * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* This password hashing algorithm was designed by David Mazieres * <dm@lcs.mit.edu> and works as follows: * * 1. state := InitState () * 2. state := ExpandKey (state, salt, password) * 3. REPEAT rounds: * state := ExpandKey (state, 0, password) * state := ExpandKey (state, 0, salt) * 4. ctext := "OrpheanBeholderScryDoubt" * 5. REPEAT 64: * ctext := Encrypt_ECB (state, ctext); * 6. RETURN Concatenate (salt, ctext); * */ #include <stdio.h> #include <stdlib.h> #include <sys/types.h> #include <string.h> #include "node_blf.h" #ifdef _WIN32 #define snprintf _snprintf #endif //#if !defined(__APPLE__) && !defined(__MACH__) //#include "bsd/stdlib.h" //#endif /* 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. */ static void encode_base64(u_int8_t *, u_int8_t *, u_int16_t); static void decode_base64(u_int8_t *, u_int16_t, u_int8_t *); const static char* error = ":"; const static u_int8_t Base64Code[] = "./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"; const static u_int8_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(u_int8_t *buffer, u_int16_t len, u_int8_t *data) { u_int8_t *bp = buffer; u_int8_t *p = data; u_int8_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; } } void encode_salt(char *salt, u_int8_t *csalt, char minor, u_int16_t clen, u_int8_t logr) { salt[0] = '$'; salt[1] = BCRYPT_VERSION; salt[2] = minor; salt[3] = '$'; // Max rounds are 31 snprintf(salt + 4, 4, "%2.2u$", logr & 0x001F); encode_base64((u_int8_t *) salt + 7, csalt, clen); } /* Generates a salt for this version of crypt. Since versions may change. Keeping this here seems sensible. from: http://mail-index.netbsd.org/tech-crypto/2002/05/24/msg000204.html */ void bcrypt_gensalt(char minor, u_int8_t log_rounds, u_int8_t *seed, char *gsalt) { if (log_rounds < 4) log_rounds = 4; else if (log_rounds > 31) log_rounds = 31; encode_salt(gsalt, seed, minor, BCRYPT_MAXSALT, log_rounds); } /* We handle $Vers$log2(NumRounds)$salt+passwd$ i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */ void bcrypt(const char *key, size_t key_len, const char *salt, char *encrypted) { blf_ctx state; u_int32_t rounds, i, k; u_int16_t j; u_int8_t salt_len, logr, minor; u_int8_t ciphertext[4 * BCRYPT_BLOCKS+1] = "OrpheanBeholderScryDoubt"; u_int8_t csalt[BCRYPT_MAXSALT]; u_int32_t cdata[BCRYPT_BLOCKS]; int n; /* Discard "$" identifier */ salt++; if (*salt > BCRYPT_VERSION) { /* How do I handle errors ? Return ':' */ strcpy(encrypted, error); return; } /* Check for minor versions */ if (salt[1] != '$') { 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: strcpy(encrypted, error); return; } } else minor = 0; /* Discard version + "$" identifier */ salt += 2; if (salt[2] != '$') { /* Out of sync with passwd entry */ strcpy(encrypted, error); return; } /* Computer power doesn't increase linear, 2^x should be fine */ n = atoi(salt); if (n > 31 || n < 0) { strcpy(encrypted, error); return; } logr = (u_int8_t)n; if ((rounds = (u_int32_t) 1 << logr) < BCRYPT_MINROUNDS) { strcpy(encrypted, error); return; } /* Discard num rounds + "$" identifier */ salt += 3; if (strlen(salt) * 3 / 4 < BCRYPT_MAXSALT) { strcpy(encrypted, error); return; } /* We dont want the base64 salt but the raw data */ decode_base64(csalt, BCRYPT_MAXSALT, (u_int8_t *) salt); salt_len = BCRYPT_MAXSALT; if (minor <= 'a') key_len = (u_int8_t)(key_len + (minor >= 'a' ? 1 : 0)); else { /* cap key_len at the actual maximum supported * length here to avoid integer wraparound */ if (key_len > 72) key_len = 72; key_len++; /* include the NUL */ } /* Setting up S-Boxes and Subkeys */ Blowfish_initstate(&state); Blowfish_expandstate(&state, csalt, salt_len, (u_int8_t *) key, key_len); for (k = 0; k < rounds; k++) { Blowfish_expand0state(&state, (u_int8_t *) key, key_len); Blowfish_expand0state(&state, csalt, salt_len); } /* This can be precomputed later */ j = 0; for (i = 0; i < BCRYPT_BLOCKS; i++) cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j); /* Now do the encryption */ for (k = 0; k < 64; k++) blf_enc(&state, cdata, BCRYPT_BLOCKS / 2); for (i = 0; i < BCRYPT_BLOCKS; i++) { ciphertext[4 * i + 3] = cdata[i] & 0xff; cdata[i] = cdata[i] >> 8; ciphertext[4 * i + 2] = cdata[i] & 0xff; cdata[i] = cdata[i] >> 8; ciphertext[4 * i + 1] = cdata[i] & 0xff; cdata[i] = cdata[i] >> 8; ciphertext[4 * i + 0] = cdata[i] & 0xff; } i = 0; encrypted[i++] = '$'; encrypted[i++] = BCRYPT_VERSION; if (minor) encrypted[i++] = minor; encrypted[i++] = '$'; snprintf(encrypted + i, 4, "%2.2u$", logr & 0x001F); encode_base64((u_int8_t *) encrypted + i + 3, csalt, BCRYPT_MAXSALT); encode_base64((u_int8_t *) encrypted + strlen(encrypted), 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)); } u_int32_t bcrypt_get_rounds(const char * hash) { /* skip past the leading "$" */ if (!hash || *(hash++) != '$') return 0; /* skip past version */ if (0 == (*hash++)) return 0; if (*hash && *hash != '$') hash++; if (*hash++ != '$') return 0; return atoi(hash); } static void encode_base64(u_int8_t *buffer, u_int8_t *data, u_int16_t len) { u_int8_t *bp = buffer; u_int8_t *p = data; u_int8_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'; }