1 /* $NetBSD: md5crypt.c,v 1.9 2007/01/17 23:24:22 hubertf 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 1.9 2007/01/17 23:24:22 hubertf 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 36 #include "crypt.h" 37 38 #define MD5_MAGIC "$1$" 39 #define MD5_MAGIC_LEN 3 40 41 #ifdef libcrypto 42 #define INIT(x) MD5_Init((x)) 43 #define UPDATE(x, b, l) MD5_Update((x), (b), (l)) 44 #define FINAL(v, x) MD5_Final((v), (x)) 45 #else 46 #define INIT(x) MD5Init((x)) 47 #define UPDATE(x, b, l) MD5Update((x), (b), (l)) 48 #define FINAL(v, x) MD5Final((v), (x)) 49 #endif 50 51 52 /* 53 * MD5 password encryption. 54 */ 55 char * 56 __md5crypt(const char *pw, const char *salt) 57 { 58 static char passwd[120], *p; 59 const char *sp, *ep; 60 unsigned char final[16]; 61 unsigned int i, sl, pwl; 62 MD5_CTX ctx, ctx1; 63 u_int32_t l; 64 int pl; 65 66 pwl = strlen(pw); 67 68 /* Refine the salt first */ 69 sp = salt; 70 71 /* If it starts with the magic string, then skip that */ 72 if (strncmp(sp, MD5_MAGIC, MD5_MAGIC_LEN) == 0) 73 sp += MD5_MAGIC_LEN; 74 75 /* It stops at the first '$', max 8 chars */ 76 for (ep = sp; *ep != '\0' && *ep != '$' && ep < (sp + 8); ep++) 77 continue; 78 79 /* get the length of the true salt */ 80 sl = ep - sp; 81 82 INIT(&ctx); 83 84 /* The password first, since that is what is most unknown */ 85 UPDATE(&ctx, (const unsigned char *)pw, pwl); 86 87 /* Then our magic string */ 88 UPDATE(&ctx, (const unsigned char *)MD5_MAGIC, MD5_MAGIC_LEN); 89 90 /* Then the raw salt */ 91 UPDATE(&ctx, (const unsigned char *)sp, sl); 92 93 /* Then just as many characters of the MD5(pw,salt,pw) */ 94 INIT(&ctx1); 95 UPDATE(&ctx1, (const unsigned char *)pw, pwl); 96 UPDATE(&ctx1, (const unsigned char *)sp, sl); 97 UPDATE(&ctx1, (const unsigned char *)pw, pwl); 98 FINAL(final, &ctx1); 99 100 for (pl = pwl; pl > 0; pl -= 16) 101 UPDATE(&ctx, final, (unsigned int)(pl > 16 ? 16 : pl)); 102 103 /* Don't leave anything around in vm they could use. */ 104 memset(final, 0, sizeof(final)); 105 106 /* Then something really weird... */ 107 for (i = pwl; i != 0; i >>= 1) 108 if ((i & 1) != 0) 109 UPDATE(&ctx, final, 1); 110 else 111 UPDATE(&ctx, (const unsigned char *)pw, 1); 112 113 /* Now make the output string */ 114 memcpy(passwd, MD5_MAGIC, MD5_MAGIC_LEN); 115 strlcpy(passwd + MD5_MAGIC_LEN, sp, sl + 1); 116 strlcat(passwd, "$", sizeof(passwd)); 117 118 FINAL(final, &ctx); 119 120 /* 121 * And now, just to make sure things don't run too fast. On a 60 MHz 122 * Pentium this takes 34 msec, so you would need 30 seconds to build 123 * a 1000 entry dictionary... 124 */ 125 for (i = 0; i < 1000; i++) { 126 INIT(&ctx1); 127 128 if ((i & 1) != 0) 129 UPDATE(&ctx1, (const unsigned char *)pw, pwl); 130 else 131 UPDATE(&ctx1, final, 16); 132 133 if ((i % 3) != 0) 134 UPDATE(&ctx1, (const unsigned char *)sp, sl); 135 136 if ((i % 7) != 0) 137 UPDATE(&ctx1, (const unsigned char *)pw, pwl); 138 139 if ((i & 1) != 0) 140 UPDATE(&ctx1, final, 16); 141 else 142 UPDATE(&ctx1, (const unsigned char *)pw, pwl); 143 144 FINAL(final, &ctx1); 145 } 146 147 p = passwd + sl + MD5_MAGIC_LEN + 1; 148 149 l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; __crypt_to64(p,l,4); p += 4; 150 l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; __crypt_to64(p,l,4); p += 4; 151 l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; __crypt_to64(p,l,4); p += 4; 152 l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; __crypt_to64(p,l,4); p += 4; 153 l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; __crypt_to64(p,l,4); p += 4; 154 l = final[11] ; __crypt_to64(p,l,2); p += 2; 155 *p = '\0'; 156 157 /* Don't leave anything around in vm they could use. */ 158 memset(final, 0, sizeof(final)); 159 return (passwd); 160 } 161