1 /* 2 * ---------------------------------------------------------------------------- 3 * "THE BEER-WARE LICENSE" (Revision 42): 4 * <phk@login.dknet.dk> wrote this file. As long as you retain this notice you 5 * can do whatever you want with this stuff. If we meet some day, and you think 6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 7 * ---------------------------------------------------------------------------- 8 * 9 * $FreeBSD: src/lib/libcrypt/crypt-md5.c,v 1.5.2.1 2001/05/24 12:20:02 markm Exp $ 10 * $DragonFly: src/lib/libcrypt/crypt-md5.c,v 1.2 2003/06/17 04:26:49 dillon Exp $ 11 * 12 * $FreeBSD: src/lib/libcrypt/crypt-md5.c,v 1.5.2.1 2001/05/24 12:20:02 markm Exp $ 13 */ 14 15 #include <unistd.h> 16 #include <stdio.h> 17 #include <string.h> 18 #include <md5.h> 19 #include <err.h> 20 #include "crypt.h" 21 22 /* 23 * UNIX password 24 */ 25 26 char * 27 crypt_md5(pw, salt) 28 const char *pw; 29 const char *salt; 30 { 31 static char *magic = "$1$"; /* 32 * This string is magic for 33 * this algorithm. Having 34 * it this way, we can get 35 * get better later on 36 */ 37 static char passwd[120], *p; 38 static const char *sp,*ep; 39 unsigned char final[MD5_SIZE]; 40 int sl,pl,i; 41 MD5_CTX ctx,ctx1; 42 unsigned long l; 43 44 /* Refine the Salt first */ 45 sp = salt; 46 47 /* If it starts with the magic string, then skip that */ 48 if(!strncmp(sp,magic,strlen(magic))) 49 sp += strlen(magic); 50 51 /* It stops at the first '$', max 8 chars */ 52 for(ep=sp;*ep && *ep != '$' && ep < (sp+8);ep++) 53 continue; 54 55 /* get the length of the true salt */ 56 sl = ep - sp; 57 58 MD5Init(&ctx); 59 60 /* The password first, since that is what is most unknown */ 61 MD5Update(&ctx,pw,strlen(pw)); 62 63 /* Then our magic string */ 64 MD5Update(&ctx,magic,strlen(magic)); 65 66 /* Then the raw salt */ 67 MD5Update(&ctx,sp,sl); 68 69 /* Then just as many characters of the MD5(pw,salt,pw) */ 70 MD5Init(&ctx1); 71 MD5Update(&ctx1,pw,strlen(pw)); 72 MD5Update(&ctx1,sp,sl); 73 MD5Update(&ctx1,pw,strlen(pw)); 74 MD5Final(final,&ctx1); 75 for(pl = strlen(pw); pl > 0; pl -= MD5_SIZE) 76 MD5Update(&ctx,final,pl>MD5_SIZE ? MD5_SIZE : pl); 77 78 /* Don't leave anything around in vm they could use. */ 79 memset(final,0,sizeof final); 80 81 /* Then something really weird... */ 82 for (i = strlen(pw); i ; i >>= 1) 83 if(i&1) 84 MD5Update(&ctx, final, 1); 85 else 86 MD5Update(&ctx, pw, 1); 87 88 /* Now make the output string */ 89 strcpy(passwd,magic); 90 strncat(passwd,sp,sl); 91 strcat(passwd,"$"); 92 93 MD5Final(final,&ctx); 94 95 /* 96 * and now, just to make sure things don't run too fast 97 * On a 60 Mhz Pentium this takes 34 msec, so you would 98 * need 30 seconds to build a 1000 entry dictionary... 99 */ 100 for(i=0;i<1000;i++) { 101 MD5Init(&ctx1); 102 if(i & 1) 103 MD5Update(&ctx1,pw,strlen(pw)); 104 else 105 MD5Update(&ctx1,final,MD5_SIZE); 106 107 if(i % 3) 108 MD5Update(&ctx1,sp,sl); 109 110 if(i % 7) 111 MD5Update(&ctx1,pw,strlen(pw)); 112 113 if(i & 1) 114 MD5Update(&ctx1,final,MD5_SIZE); 115 else 116 MD5Update(&ctx1,pw,strlen(pw)); 117 MD5Final(final,&ctx1); 118 } 119 120 p = passwd + strlen(passwd); 121 122 l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; 123 _crypt_to64(p,l,4); p += 4; 124 l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; 125 _crypt_to64(p,l,4); p += 4; 126 l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; 127 _crypt_to64(p,l,4); p += 4; 128 l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; 129 _crypt_to64(p,l,4); p += 4; 130 l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; 131 _crypt_to64(p,l,4); p += 4; 132 l = final[11] ; 133 _crypt_to64(p,l,2); p += 2; 134 *p = '\0'; 135 136 /* Don't leave anything around in vm they could use. */ 137 memset(final,0,sizeof final); 138 139 return passwd; 140 } 141 142