| /* $OpenBSD: bcrypt.c,v 1.24 2008/04/02 19:54:05 millert Exp $ */ |
| |
| /* |
| * Copyright 1997 Niels Provos <provos@physnet.uni-hamburg.de> |
| * 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 |
| * <dm@lcs.mit.edu> 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); |
| * |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/types.h> |
| #include <string.h> |
| #include <pwd.h> |
| |
| #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 *, u_int8_t *, u_int16_t, u_int8_t); |
| |
| 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 *); |
| |
| static char encrypted[_PASSWORD_LEN]; |
| 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, u_int16_t clen, u_int8_t logr) |
| { |
| salt[0] = '$'; |
| salt[1] = BCRYPT_VERSION; |
| salt[2] = 'a'; |
| salt[3] = '$'; |
| |
| snprintf(salt + 4, 4, "%2.2u$", logr); |
| |
| encode_base64((u_int8_t *) salt + 7, csalt, clen); |
| } |
| |
| /* We handle $Vers$log2(NumRounds)$salt+passwd$ |
| i.e. $2$04$iwouldntknowwhattosayetKdJ6iFtacBqJdKe6aW7ou */ |
| |
| char * |
| bcrypt(const char *key, const char *salt) |
| { |
| blf_ctx state; |
| u_int32_t rounds, i, k; |
| u_int16_t j; |
| u_int8_t key_len, salt_len, logr, minor; |
| u_int8_t ciphertext[4 * BCRYPT_BLOCKS] = "OrpheanBeholderScryDoubt"; |
| u_int8_t csalt[BCRYPT_MAXSALT]; |
| u_int32_t cdata[BCRYPT_BLOCKS]; |
| int n; |
| |
| /* Discard "$" identifier */ |
| salt++; |
| |
| if (*salt > BCRYPT_VERSION) { |
| /* How do I handle errors ? Return ':' */ |
| return error; |
| } |
| |
| /* Check for minor versions */ |
| if (salt[1] != '$') { |
| switch (salt[1]) { |
| case 'a': |
| /* 'ab' should not yield the same as 'abab' */ |
| 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; |
| |
| /* Computer power doesn't increase linear, 2^x should be fine */ |
| n = atoi(salt); |
| if (n > 31 || n < 0) |
| return error; |
| logr = (u_int8_t)n; |
| if ((rounds = (u_int32_t) 1 << logr) < BCRYPT_MINROUNDS) |
| return error; |
| |
| /* Discard num rounds + "$" identifier */ |
| salt += 3; |
| |
| if (strlen(salt) * 3 / 4 < BCRYPT_MAXSALT) |
| return error; |
| |
| /* We dont want the base64 salt but the raw data */ |
| decode_base64(csalt, BCRYPT_MAXSALT, (u_int8_t *) salt); |
| salt_len = BCRYPT_MAXSALT; |
| key_len = strlen(key) + (minor >= 'a' ? 1 : 0); |
| |
| /* Setting up S-Boxes and Subkeys */ |
| Blowfish_initstate(&state); |
| Blowfish_expandstate(&state, csalt, salt_len, |
| (u_int8_t *) key, key_len); |
| for (k = 0; k < rounds; k++) { |
| Blowfish_expand0state(&state, (u_int8_t *) key, key_len); |
| Blowfish_expand0state(&state, csalt, salt_len); |
| } |
| |
| /* This can be precomputed later */ |
| j = 0; |
| for (i = 0; i < BCRYPT_BLOCKS; i++) |
| cdata[i] = Blowfish_stream2word(ciphertext, 4 * BCRYPT_BLOCKS, &j); |
| |
| /* Now do the encryption */ |
| for (k = 0; k < 64; k++) |
| blf_enc(&state, cdata, BCRYPT_BLOCKS / 2); |
| |
| for (i = 0; i < BCRYPT_BLOCKS; i++) { |
| ciphertext[4 * i + 3] = cdata[i] & 0xff; |
| cdata[i] = cdata[i] >> 8; |
| ciphertext[4 * i + 2] = cdata[i] & 0xff; |
| cdata[i] = cdata[i] >> 8; |
| ciphertext[4 * i + 1] = cdata[i] & 0xff; |
| cdata[i] = cdata[i] >> 8; |
| ciphertext[4 * i + 0] = cdata[i] & 0xff; |
| } |
| |
| |
| i = 0; |
| encrypted[i++] = '$'; |
| encrypted[i++] = BCRYPT_VERSION; |
| if (minor) |
| encrypted[i++] = minor; |
| encrypted[i++] = '$'; |
| |
| snprintf(encrypted + i, 4, "%2.2u$", logr); |
| |
| 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)); |
| return encrypted; |
| } |
| |
| 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'; |
| } |