1 /* $NetBSD: md5crypt.c,v 1.8 2004/07/02 00:05:23 sjg Exp $ */ 2 3 /* 4 * ---------------------------------------------------------------------------- 5 * "THE BEER-WARE LICENSE" (Revision 42): 6 * <phk@login.dknet.dk> wrote this file. As long as you retain this notice you 7 * can do whatever you want with this stuff. If we meet some day, and you think 8 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp 9 * ---------------------------------------------------------------------------- 10 * 11 * from FreeBSD: crypt.c,v 1.5 1996/10/14 08:34:02 phk Exp 12 * via OpenBSD: md5crypt.c,v 1.9 1997/07/23 20:58:27 kstailey Exp 13 * 14 */ 15 16 #include <sys/cdefs.h> 17 #if !defined(lint) 18 __RCSID("$NetBSD: md5crypt.c,v 1.8 2004/07/02 00:05:23 sjg Exp $"); 19 #endif /* not lint */ 20 21 /* 22 * NOTE: We are also built for inclusion in libcrypto; when built for that 23 * environment, use the libcrypto versions of the MD5 routines, so save 24 * having to pull two versions into the same program. 25 */ 26 27 #include <unistd.h> 28 #include <stdio.h> 29 #include <string.h> 30 #ifdef libcrypto 31 #include <openssl/md5.h> 32 #else 33 #include <md5.h> 34 #endif 35 #include <string.h> 36 37 #include "crypt.h" 38 39 #define MD5_MAGIC "$1$" 40 #define MD5_MAGIC_LEN 3 41 42 #ifdef libcrypto 43 #define INIT(x) MD5_Init((x)) 44 #define UPDATE(x, b, l) MD5_Update((x), (b), (l)) 45 #define FINAL(v, x) MD5_Final((v), (x)) 46 #else 47 #define INIT(x) MD5Init((x)) 48 #define UPDATE(x, b, l) MD5Update((x), (b), (l)) 49 #define FINAL(v, x) MD5Final((v), (x)) 50 #endif 51 52 53 /* 54 * MD5 password encryption. 55 */ 56 char * 57 __md5crypt(const char *pw, const char *salt) 58 { 59 static char passwd[120], *p; 60 const char *sp, *ep; 61 unsigned char final[16]; 62 unsigned int i, sl, pwl; 63 MD5_CTX ctx, ctx1; 64 u_int32_t l; 65 int pl; 66 67 pwl = strlen(pw); 68 69 /* Refine the salt first */ 70 sp = salt; 71 72 /* If it starts with the magic string, then skip that */ 73 if (strncmp(sp, MD5_MAGIC, MD5_MAGIC_LEN) == 0) 74 sp += MD5_MAGIC_LEN; 75 76 /* It stops at the first '$', max 8 chars */ 77 for (ep = sp; *ep != '\0' && *ep != '$' && ep < (sp + 8); ep++) 78 continue; 79 80 /* get the length of the true salt */ 81 sl = ep - sp; 82 83 INIT(&ctx); 84 85 /* The password first, since that is what is most unknown */ 86 UPDATE(&ctx, (const unsigned char *)pw, pwl); 87 88 /* Then our magic string */ 89 UPDATE(&ctx, (const unsigned char *)MD5_MAGIC, MD5_MAGIC_LEN); 90 91 /* Then the raw salt */ 92 UPDATE(&ctx, (const unsigned char *)sp, sl); 93 94 /* Then just as many characters of the MD5(pw,salt,pw) */ 95 INIT(&ctx1); 96 UPDATE(&ctx1, (const unsigned char *)pw, pwl); 97 UPDATE(&ctx1, (const unsigned char *)sp, sl); 98 UPDATE(&ctx1, (const unsigned char *)pw, pwl); 99 FINAL(final, &ctx1); 100 101 for (pl = pwl; pl > 0; pl -= 16) 102 UPDATE(&ctx, final, (unsigned int)(pl > 16 ? 16 : pl)); 103 104 /* Don't leave anything around in vm they could use. */ 105 memset(final, 0, sizeof(final)); 106 107 /* Then something really weird... */ 108 for (i = pwl; i != 0; i >>= 1) 109 if ((i & 1) != 0) 110 UPDATE(&ctx, final, 1); 111 else 112 UPDATE(&ctx, (const unsigned char *)pw, 1); 113 114 /* Now make the output string */ 115 memcpy(passwd, MD5_MAGIC, MD5_MAGIC_LEN); 116 strlcpy(passwd + MD5_MAGIC_LEN, sp, sl + 1); 117 strlcat(passwd, "$", sizeof(passwd)); 118 119 FINAL(final, &ctx); 120 121 /* 122 * And now, just to make sure things don't run too fast. On a 60 MHz 123 * Pentium this takes 34 msec, so you would need 30 seconds to build 124 * a 1000 entry dictionary... 125 */ 126 for (i = 0; i < 1000; i++) { 127 INIT(&ctx1); 128 129 if ((i & 1) != 0) 130 UPDATE(&ctx1, (const unsigned char *)pw, pwl); 131 else 132 UPDATE(&ctx1, final, 16); 133 134 if ((i % 3) != 0) 135 UPDATE(&ctx1, (const unsigned char *)sp, sl); 136 137 if ((i % 7) != 0) 138 UPDATE(&ctx1, (const unsigned char *)pw, pwl); 139 140 if ((i & 1) != 0) 141 UPDATE(&ctx1, final, 16); 142 else 143 UPDATE(&ctx1, (const unsigned char *)pw, pwl); 144 145 FINAL(final, &ctx1); 146 } 147 148 p = passwd + sl + MD5_MAGIC_LEN + 1; 149 150 l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; __crypt_to64(p,l,4); p += 4; 151 l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; __crypt_to64(p,l,4); p += 4; 152 l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; __crypt_to64(p,l,4); p += 4; 153 l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; __crypt_to64(p,l,4); p += 4; 154 l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; __crypt_to64(p,l,4); p += 4; 155 l = final[11] ; __crypt_to64(p,l,2); p += 2; 156 *p = '\0'; 157 158 /* Don't leave anything around in vm they could use. */ 159 memset(final, 0, sizeof(final)); 160 return (passwd); 161 } 162