1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2003 Poul-Henning Kamp 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29#include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32#include <sys/types.h> 33 34#include <err.h> 35#include <md5.h> 36#include <stdio.h> 37#include <string.h> 38#include <unistd.h> 39 40#include "crypt.h" 41 42 /* 43 * UNIX password 44 */ 45 46 int 47 crypt_md5(const char *pw, const char *salt, char *buffer) 48{ 49 MD5_CTX ctx,ctx1; 50 unsigned long l; 51 int sl, pl; 52 u_int i; 53 u_char final[MD5_SIZE]; 54 const char *ep; 55 static const char *magic = "1ドル$"; 56 57 /* If the salt starts with the magic string, skip that. */ 58 if (!strncmp(salt, magic, strlen(magic))) 59 salt += strlen(magic); 60 61 /* It stops at the first '$', max 8 chars */ 62 for (ep = salt; *ep && *ep != '$' && ep < salt + 8; ep++) 63 continue; 64 65 /* get the length of the true salt */ 66 sl = ep - salt; 67 68 MD5Init(&ctx); 69 70 /* The password first, since that is what is most unknown */ 71 MD5Update(&ctx, (const u_char *)pw, strlen(pw)); 72 73 /* Then our magic string */ 74 MD5Update(&ctx, (const u_char *)magic, strlen(magic)); 75 76 /* Then the raw salt */ 77 MD5Update(&ctx, (const u_char *)salt, (u_int)sl); 78 79 /* Then just as many characters of the MD5(pw,salt,pw) */ 80 MD5Init(&ctx1); 81 MD5Update(&ctx1, (const u_char *)pw, strlen(pw)); 82 MD5Update(&ctx1, (const u_char *)salt, (u_int)sl); 83 MD5Update(&ctx1, (const u_char *)pw, strlen(pw)); 84 MD5Final(final, &ctx1); 85 for(pl = (int)strlen(pw); pl > 0; pl -= MD5_SIZE) 86 MD5Update(&ctx, (const u_char *)final, 87 (u_int)(pl > MD5_SIZE ? MD5_SIZE : pl)); 88 89 /* Don't leave anything around in vm they could use. */ 90 memset(final, 0, sizeof(final)); 91 92 /* Then something really weird... */ 93 for (i = strlen(pw); i; i >>= 1) 94 if(i & 1) 95 MD5Update(&ctx, (const u_char *)final, 1); 96 else 97 MD5Update(&ctx, (const u_char *)pw, 1); 98 99 /* Now make the output string */ 100 buffer = stpcpy(buffer, magic); 101 buffer = stpncpy(buffer, salt, (u_int)sl); 102 *buffer++ = '$'; 103 104 MD5Final(final, &ctx); 105 106 /* 107 * and now, just to make sure things don't run too fast 108 * On a 60 Mhz Pentium this takes 34 msec, so you would 109 * need 30 seconds to build a 1000 entry dictionary... 110 */ 111 for(i = 0; i < 1000; i++) { 112 MD5Init(&ctx1); 113 if(i & 1) 114 MD5Update(&ctx1, (const u_char *)pw, strlen(pw)); 115 else 116 MD5Update(&ctx1, (const u_char *)final, MD5_SIZE); 117 118 if(i % 3) 119 MD5Update(&ctx1, (const u_char *)salt, (u_int)sl); 120 121 if(i % 7) 122 MD5Update(&ctx1, (const u_char *)pw, strlen(pw)); 123 124 if(i & 1) 125 MD5Update(&ctx1, (const u_char *)final, MD5_SIZE); 126 else 127 MD5Update(&ctx1, (const u_char *)pw, strlen(pw)); 128 MD5Final(final, &ctx1); 129 } 130 131 l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; 132 _crypt_to64(buffer, l, 4); buffer += 4; 133 l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; 134 _crypt_to64(buffer, l, 4); buffer += 4; 135 l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; 136 _crypt_to64(buffer, l, 4); buffer += 4; 137 l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; 138 _crypt_to64(buffer, l, 4); buffer += 4; 139 l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; 140 _crypt_to64(buffer, l, 4); buffer += 4; 141 l = final[11]; 142 _crypt_to64(buffer, l, 2); buffer += 2; 143 *buffer = '0円'; 144 145 /* Don't leave anything around in vm they could use. */ 146 memset(final, 0, sizeof(final)); 147 148 return (0); 149} 150