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 */ 11 12 #include <unistd.h> 13 #include <stdio.h> 14 #include <string.h> 15 #include <err.h> 16 17 #include "crypt.h" 18 19 #define MD5Init _libcrypt_MD5Init 20 #define MD5Final _libcrypt_MD5Final 21 #define MD5Pad _libcrypt_MD5Pad 22 #define MD5Transform _libcrypt_MD5Transform 23 #define MD5Update _libcrypt_MD5Update 24 #define WITH_OPENSSL 25 #include "private_md5.h" 26 27 /* magic sizes, moved out from crypt.h */ 28 #define MD5_SIZE 16 29 30 /* 31 * UNIX password 32 */ 33 34 char * 35 crypt_md5(const char *pw, const char *salt) 36 { 37 static const char *magic = "$1$"; /* 38 * This string is magic for 39 * this algorithm. Having 40 * it this way, we can get 41 * get better later on 42 */ 43 static char passwd[120], *p; 44 static const char *sp,*ep; 45 unsigned char final[MD5_SIZE]; 46 int sl,pl,i; 47 MD5_CTX ctx,ctx1; 48 unsigned long l; 49 50 /* Refine the Salt first */ 51 sp = salt; 52 53 /* If it starts with the magic string, then skip that */ 54 if(!strncmp(sp,magic,strlen(magic))) 55 sp += strlen(magic); 56 57 /* It stops at the first '$', max 8 chars */ 58 for(ep=sp;*ep && *ep != '$' && ep < (sp+8);ep++) 59 continue; 60 61 /* get the length of the true salt */ 62 sl = ep - sp; 63 64 MD5Init(&ctx); 65 66 /* The password first, since that is what is most unknown */ 67 MD5Update(&ctx,pw,strlen(pw)); 68 69 /* Then our magic string */ 70 MD5Update(&ctx,magic,strlen(magic)); 71 72 /* Then the raw salt */ 73 MD5Update(&ctx,sp,sl); 74 75 /* Then just as many characters of the MD5(pw,salt,pw) */ 76 MD5Init(&ctx1); 77 MD5Update(&ctx1,pw,strlen(pw)); 78 MD5Update(&ctx1,sp,sl); 79 MD5Update(&ctx1,pw,strlen(pw)); 80 MD5Final(final,&ctx1); 81 for(pl = strlen(pw); pl > 0; pl -= MD5_SIZE) 82 MD5Update(&ctx,final,pl>MD5_SIZE ? MD5_SIZE : pl); 83 84 /* Don't leave anything around in vm they could use. */ 85 memset(final,0,sizeof final); 86 87 /* Then something really weird... */ 88 for (i = strlen(pw); i ; i >>= 1) 89 if(i&1) 90 MD5Update(&ctx, final, 1); 91 else 92 MD5Update(&ctx, pw, 1); 93 94 /* Now make the output string */ 95 strcpy(passwd,magic); 96 strncat(passwd,sp,sl); 97 strcat(passwd,"$"); 98 99 MD5Final(final,&ctx); 100 101 /* 102 * and now, just to make sure things don't run too fast 103 * On a 60 Mhz Pentium this takes 34 msec, so you would 104 * need 30 seconds to build a 1000 entry dictionary... 105 */ 106 for(i=0;i<1000;i++) { 107 MD5Init(&ctx1); 108 if(i & 1) 109 MD5Update(&ctx1,pw,strlen(pw)); 110 else 111 MD5Update(&ctx1,final,MD5_SIZE); 112 113 if(i % 3) 114 MD5Update(&ctx1,sp,sl); 115 116 if(i % 7) 117 MD5Update(&ctx1,pw,strlen(pw)); 118 119 if(i & 1) 120 MD5Update(&ctx1,final,MD5_SIZE); 121 else 122 MD5Update(&ctx1,pw,strlen(pw)); 123 MD5Final(final,&ctx1); 124 } 125 126 p = passwd + strlen(passwd); 127 128 l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; 129 _crypt_to64(p,l,4); p += 4; 130 l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; 131 _crypt_to64(p,l,4); p += 4; 132 l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; 133 _crypt_to64(p,l,4); p += 4; 134 l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; 135 _crypt_to64(p,l,4); p += 4; 136 l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; 137 _crypt_to64(p,l,4); p += 4; 138 l = final[11] ; 139 _crypt_to64(p,l,2); p += 2; 140 *p = '\0'; 141 142 /* Don't leave anything around in vm they could use. */ 143 memset(final,0,sizeof final); 144 145 return passwd; 146 } 147 148