325 lines
9.2 KiB
C
325 lines
9.2 KiB
C
/* $OpenBSD: bcrypt.c,v 1.57 2016/08/26 08:25:02 guenther Exp $ */
|
|
|
|
/*
|
|
* Copyright (c) 2014 Ted Unangst <tedu@openbsd.org>
|
|
* 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 <ctype.h>
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
#include <stdint.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <time.h>
|
|
|
|
#include "blf.h"
|
|
#include "blowfish.h"
|
|
#include "mpw-util.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_WORDS 6 /* Ciphertext words */
|
|
#define BCRYPT_MINLOGROUNDS 4 /* we have log2(rounds) in salt */
|
|
|
|
#define BCRYPT_SALTSPACE (7 + (BCRYPT_MAXSALT * 4 + 2) / 3 + 1)
|
|
#define BCRYPT_HASHSPACE 61
|
|
|
|
static int encode_base64(char *, const uint8_t *, size_t);
|
|
static int decode_base64(uint8_t *, size_t, const char *);
|
|
|
|
/*
|
|
* Generates a salt for this version of crypt.
|
|
*/
|
|
static int
|
|
bcrypt_initsalt(int log_rounds, uint8_t *salt, size_t saltbuflen) {
|
|
|
|
uint8_t csalt[BCRYPT_MAXSALT];
|
|
|
|
if (saltbuflen < BCRYPT_SALTSPACE) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
arc4random_buf( csalt, sizeof( csalt ) );
|
|
|
|
if (log_rounds < 4)
|
|
log_rounds = 4;
|
|
else if (log_rounds > 31)
|
|
log_rounds = 31;
|
|
|
|
snprintf( (char *)salt, saltbuflen, "$2b$%2.2u$", log_rounds );
|
|
encode_base64( (char *)salt + 7, csalt, sizeof( csalt ) );
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* the core bcrypt function
|
|
*/
|
|
static int
|
|
bcrypt_hashpass(const char *key, const uint8_t *salt, char *encrypted,
|
|
size_t encryptedlen) {
|
|
|
|
blf_ctx state;
|
|
uint32_t rounds, i, k;
|
|
uint16_t j;
|
|
size_t key_len;
|
|
uint8_t salt_len, logr, minor;
|
|
uint8_t ciphertext[4 * BCRYPT_WORDS] = "OrpheanBeholderScryDoubt";
|
|
uint8_t csalt[BCRYPT_MAXSALT];
|
|
uint32_t cdata[BCRYPT_WORDS];
|
|
|
|
if (encryptedlen < BCRYPT_HASHSPACE)
|
|
goto inval;
|
|
|
|
/* Check and discard "$" identifier */
|
|
if (salt[0] != '$')
|
|
goto inval;
|
|
salt += 1;
|
|
|
|
if (salt[0] != BCRYPT_VERSION)
|
|
goto inval;
|
|
|
|
/* Check for minor versions */
|
|
switch ((minor = salt[1])) {
|
|
case 'a':
|
|
key_len = (uint8_t)(strlen( key ) + 1);
|
|
break;
|
|
case 'b':
|
|
/* strlen() returns a size_t, but the function calls
|
|
* below result in implicit casts to a narrower integer
|
|
* type, so cap key_len at the actual maximum supported
|
|
* length here to avoid integer wraparound */
|
|
key_len = strlen( key );
|
|
if (key_len > 72)
|
|
key_len = 72;
|
|
key_len++; /* include the NUL */
|
|
break;
|
|
default:
|
|
goto inval;
|
|
}
|
|
if (salt[2] != '$')
|
|
goto inval;
|
|
/* Discard version + "$" identifier */
|
|
salt += 3;
|
|
|
|
/* Check and parse num rounds */
|
|
if (!isdigit( (unsigned char)salt[0] ) ||
|
|
!isdigit( (unsigned char)salt[1] ) || salt[2] != '$')
|
|
goto inval;
|
|
logr = (uint8_t)((salt[1] - '0') + ((salt[0] - '0') * 10));
|
|
if (logr < BCRYPT_MINLOGROUNDS || logr > 31)
|
|
goto inval;
|
|
/* Computer power doesn't increase linearly, 2^x should be fine */
|
|
rounds = 1U << logr;
|
|
|
|
/* Discard num rounds + "$" identifier */
|
|
salt += 3;
|
|
|
|
if (strlen( (char *)salt ) * 3 / 4 < BCRYPT_MAXSALT)
|
|
goto inval;
|
|
|
|
/* We dont want the base64 salt but the raw data */
|
|
if (decode_base64( csalt, BCRYPT_MAXSALT, (char *)salt ))
|
|
goto inval;
|
|
salt_len = BCRYPT_MAXSALT;
|
|
|
|
/* Setting up S-Boxes and Subkeys */
|
|
Blowfish_initstate( &state );
|
|
Blowfish_expandstate( &state, csalt, salt_len,
|
|
(uint8_t *)key, (uint16_t)key_len );
|
|
for (k = 0; k < rounds; k++) {
|
|
Blowfish_expand0state( &state, (uint8_t *)key, (uint16_t)key_len );
|
|
Blowfish_expand0state( &state, csalt, salt_len );
|
|
}
|
|
|
|
/* This can be precomputed later */
|
|
j = 0;
|
|
for (i = 0; i < BCRYPT_WORDS; i++)
|
|
cdata[i] = Blowfish_stream2word( ciphertext, 4 * BCRYPT_WORDS, &j );
|
|
|
|
/* Now do the encryption */
|
|
for (k = 0; k < 64; k++)
|
|
blf_enc( &state, cdata, BCRYPT_WORDS / 2 );
|
|
|
|
for (i = 0; i < BCRYPT_WORDS; i++) {
|
|
ciphertext[4 * i + 3] = (uint8_t)(cdata[i] & 0xff);
|
|
cdata[i] = cdata[i] >> 8;
|
|
ciphertext[4 * i + 2] = (uint8_t)(cdata[i] & 0xff);
|
|
cdata[i] = cdata[i] >> 8;
|
|
ciphertext[4 * i + 1] = (uint8_t)(cdata[i] & 0xff);
|
|
cdata[i] = cdata[i] >> 8;
|
|
ciphertext[4 * i + 0] = (uint8_t)(cdata[i] & 0xff);
|
|
}
|
|
|
|
snprintf( encrypted, 8, "$2%c$%2.2u$", minor, logr );
|
|
encode_base64( encrypted + 7, csalt, BCRYPT_MAXSALT );
|
|
encode_base64( encrypted + 7 + 22, ciphertext, 4 * BCRYPT_WORDS - 1 );
|
|
mpw_zero( &state, sizeof state );
|
|
mpw_zero( ciphertext, sizeof ciphertext );
|
|
mpw_zero( csalt, sizeof csalt );
|
|
mpw_zero( cdata, sizeof cdata );
|
|
return 0;
|
|
|
|
inval:
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* internal utilities
|
|
*/
|
|
static const uint8_t Base64Code[] =
|
|
"./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
|
|
|
|
static const 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 ? (uint8_t)255 : index_64[(c)])
|
|
|
|
/*
|
|
* read buflen (after decoding) bytes of data from b64data
|
|
*/
|
|
static int
|
|
decode_base64(uint8_t *buffer, size_t len, const char *b64data) {
|
|
|
|
uint8_t *bp = buffer;
|
|
const uint8_t *p = (uint8_t *)b64data;
|
|
uint8_t c1, c2, c3, c4;
|
|
|
|
while (bp < buffer + len) {
|
|
c1 = CHAR64( *p );
|
|
/* Invalid data */
|
|
if (c1 == 255)
|
|
return -1;
|
|
|
|
c2 = CHAR64( *(p + 1) );
|
|
if (c2 == 255)
|
|
return -1;
|
|
|
|
*bp++ = (uint8_t)((c1 << 2) | ((c2 & 0x30) >> 4));
|
|
if (bp >= buffer + len)
|
|
break;
|
|
|
|
c3 = CHAR64( *(p + 2) );
|
|
if (c3 == 255)
|
|
return -1;
|
|
|
|
*bp++ = (uint8_t)(((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2));
|
|
if (bp >= buffer + len)
|
|
break;
|
|
|
|
c4 = CHAR64( *(p + 3) );
|
|
if (c4 == 255)
|
|
return -1;
|
|
*bp++ = (uint8_t)(((c3 & 0x03) << 6) | c4);
|
|
|
|
p += 4;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Turn len bytes of data into base64 encoded data.
|
|
* This works without = padding.
|
|
*/
|
|
static int
|
|
encode_base64(char *b64buffer, const uint8_t *data, size_t len) {
|
|
|
|
uint8_t *bp = (uint8_t *)b64buffer;
|
|
const uint8_t *p = data;
|
|
uint8_t c1, c2;
|
|
|
|
while (p < data + len) {
|
|
c1 = *p++;
|
|
*bp++ = Base64Code[(c1 >> 2)];
|
|
c1 = (uint8_t)((c1 & 0x03) << 4);
|
|
if (p >= data + len) {
|
|
*bp++ = Base64Code[c1];
|
|
break;
|
|
}
|
|
c2 = *p++;
|
|
c1 |= (c2 >> 4) & 0x0f;
|
|
*bp++ = Base64Code[c1];
|
|
c1 = (uint8_t)((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';
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* classic interface
|
|
*/
|
|
static uint8_t *
|
|
bcrypt_gensalt(uint8_t log_rounds) {
|
|
|
|
static uint8_t gsalt[BCRYPT_SALTSPACE];
|
|
|
|
bcrypt_initsalt( log_rounds, gsalt, sizeof( gsalt ) );
|
|
|
|
return gsalt;
|
|
}
|
|
|
|
static char *
|
|
bcrypt(const char *pass, const uint8_t *salt) {
|
|
|
|
static char gencrypted[BCRYPT_HASHSPACE];
|
|
|
|
if (bcrypt_hashpass( pass, salt, gencrypted, sizeof( gencrypted ) ) != 0)
|
|
return NULL;
|
|
|
|
return gencrypted;
|
|
}
|