diff options
Diffstat (limited to 'lib/libcrypt/crypt-md5.c')
| -rw-r--r-- | lib/libcrypt/crypt-md5.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/lib/libcrypt/crypt-md5.c b/lib/libcrypt/crypt-md5.c new file mode 100644 index 000000000000..609fbbf67b77 --- /dev/null +++ b/lib/libcrypt/crypt-md5.c @@ -0,0 +1,147 @@ +/*- + * SPDX-License-Identifier: BSD-2-Clause + * + * 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/types.h> + +#include <err.h> +#include <md5.h> +#include <stdio.h> +#include <string.h> +#include <strings.h> +#include <unistd.h> + +#include "crypt.h" + +/* + * UNIX password + */ + +int +crypt_md5(const char *pw, const char *salt, char *buffer) +{ + MD5_CTX ctx,ctx1; + unsigned long l; + int sl, pl; + u_int i; + u_char final[MD5_SIZE]; + const char *ep; + static const char *magic = "$1$"; + + /* If the salt starts with the magic string, skip that. */ + if (!strncmp(salt, magic, strlen(magic))) + salt += strlen(magic); + + /* It stops at the first '$', max 8 chars */ + for (ep = salt; *ep && *ep != '$' && ep < salt + 8; ep++) + continue; + + /* get the length of the true salt */ + sl = ep - salt; + + 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 *)salt, (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 *)salt, (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. */ + explicit_bzero(final, 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 */ + buffer = stpcpy(buffer, magic); + buffer = stpncpy(buffer, salt, (u_int)sl); + *buffer++ = '$'; + + 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 *)salt, (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); + } + + l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; + _crypt_to64(buffer, l, 4); buffer += 4; + l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; + _crypt_to64(buffer, l, 4); buffer += 4; + l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; + _crypt_to64(buffer, l, 4); buffer += 4; + l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; + _crypt_to64(buffer, l, 4); buffer += 4; + l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; + _crypt_to64(buffer, l, 4); buffer += 4; + l = final[11]; + _crypt_to64(buffer, l, 2); buffer += 2; + *buffer = '\0'; + + /* Don't leave anything around in vm they could use. */ + explicit_bzero(final, sizeof(final)); + + return (0); +} |