/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2003 Poul-Henning Kamp
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <md5.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <crypt.h>
#define MD5_SIZE 16
/*
* UNIX password
*/
char *
crypt_md5_r(const char *pw, const char *salt, struct crypt_data *data)
{
MD5_CTX ctx,ctx1;
unsigned long l;
int sl, pl;
u_int i;
u_char final[MD5_SIZE];
const char *sp, *ep;
char *passwd = &data->buffer[0], *p;
static const char magic[] = "$1$";
/* Refine the Salt first */
sp = salt;
/* If it starts with the magic string, then skip that */
if(!strncmp(sp, magic, strlen(magic)))
sp += strlen(magic);
/* It stops at the first '$', max 8 chars */
for(ep = sp; *ep && *ep != '$' && ep < (sp + 8); ep++)
continue;
/* get the length of the true salt */
sl = ep - sp;
MD5Init(&ctx);
/* The password first, since that is what is most unknown */
MD5Update(&ctx, (const u_char *)pw, strlen(pw));
/* Then our magic string */
MD5Update(&ctx, (const u_char *)magic, strlen(magic));
/* Then the raw salt */
MD5Update(&ctx, (const u_char *)sp, (u_int)sl);
/* Then just as many characters of the MD5(pw,salt,pw) */
MD5Init(&ctx1);
MD5Update(&ctx1, (const u_char *)pw, strlen(pw));
MD5Update(&ctx1, (const u_char *)sp, (u_int)sl);
MD5Update(&ctx1, (const u_char *)pw, strlen(pw));
MD5Final(final, &ctx1);
for(pl = (int)strlen(pw); pl > 0; pl -= MD5_SIZE)
MD5Update(&ctx, (const u_char *)final,
(u_int)(pl > MD5_SIZE ? MD5_SIZE : pl));
/* Don't leave anything around in vm they could use. */
memset(final, 0, sizeof(final));
/* Then something really weird... */
for (i = strlen(pw); i; i >>= 1)
if(i & 1)
MD5Update(&ctx, (const u_char *)final, 1);
else
MD5Update(&ctx, (const u_char *)pw, 1);
/* Now make the output string */
strcpy(passwd, magic);
strncat(passwd, sp, (u_int)sl);
strcat(passwd, "$");
MD5Final(final, &ctx);
/*
* and now, just to make sure things don't run too fast
* On a 60 Mhz Pentium this takes 34 msec, so you would
* need 30 seconds to build a 1000 entry dictionary...
*/
for(i = 0; i < 1000; i++) {
MD5Init(&ctx1);
if(i & 1)
MD5Update(&ctx1, (const u_char *)pw, strlen(pw));
else
MD5Update(&ctx1, (const u_char *)final, MD5_SIZE);
if(i % 3)
MD5Update(&ctx1, (const u_char *)sp, (u_int)sl);
if(i % 7)
MD5Update(&ctx1, (const u_char *)pw, strlen(pw));
if(i & 1)
MD5Update(&ctx1, (const u_char *)final, MD5_SIZE);
else
MD5Update(&ctx1, (const u_char *)pw, strlen(pw));
MD5Final(final, &ctx1);
}
p = passwd + strlen(passwd);
l = (final[ 0]<<16) | (final[ 6]<<8) | final[12];
_crypt_to64(p, l, 4); p += 4;
l = (final[ 1]<<16) | (final[ 7]<<8) | final[13];
_crypt_to64(p, l, 4); p += 4;
l = (final[ 2]<<16) | (final[ 8]<<8) | final[14];
_crypt_to64(p, l, 4); p += 4;
l = (final[ 3]<<16) | (final[ 9]<<8) | final[15];
_crypt_to64(p, l, 4); p += 4;
l = (final[ 4]<<16) | (final[10]<<8) | final[ 5];
_crypt_to64(p, l, 4); p += 4;
l = final[11];
_crypt_to64(p, l, 2); p += 2;
*p = '\0';
/* Don't leave anything around in vm they could use. */
memset(final, 0, sizeof(final));
return (passwd);
}
struct crypt_format crypt_md5_format =
CRYPT_FORMAT_INITIALIZER(crypt_md5_r, "$1$");
