1 /* $NetBSD: md5crypt.c,v 1.4 2001/09/10 12:33:25 ad 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 1.4 2001/09/10 12:33:25 ad Exp $"); 19 #endif /* not lint */ 20 21 #include <unistd.h> 22 #include <stdio.h> 23 #include <string.h> 24 #include <md5.h> 25 #include <string.h> 26 27 #define MD5_MAGIC "$1$" 28 #define MD5_MAGIC_LEN 3 29 30 char *__md5crypt(const char *pw, const char *salt); /* XXX */ 31 32 static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */ 33 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; 34 35 static void to64(char *, u_int32_t, int); 36 37 static void 38 to64(char *s, u_int32_t v, int n) 39 { 40 41 while (--n >= 0) { 42 *s++ = itoa64[v & 0x3f]; 43 v >>= 6; 44 } 45 } 46 47 /* 48 * MD5 password encryption. 49 */ 50 char * 51 __md5crypt(const char *pw, const char *salt) 52 { 53 static char passwd[120], *p; 54 const char *sp, *ep; 55 unsigned char final[16]; 56 unsigned int i, sl, pwl; 57 MD5_CTX ctx, ctx1; 58 u_int32_t l; 59 int pl; 60 61 pwl = strlen(pw); 62 63 /* Refine the salt first */ 64 sp = salt; 65 66 /* If it starts with the magic string, then skip that */ 67 if (strncmp(sp, MD5_MAGIC, MD5_MAGIC_LEN) == 0) 68 sp += MD5_MAGIC_LEN; 69 70 /* It stops at the first '$', max 8 chars */ 71 for (ep = sp; *ep != '\0' && *ep != '$' && ep < (sp + 8); ep++) 72 continue; 73 74 /* get the length of the true salt */ 75 sl = ep - sp; 76 77 MD5Init(&ctx); 78 79 /* The password first, since that is what is most unknown */ 80 MD5Update(&ctx, (const unsigned char *)pw, pwl); 81 82 /* Then our magic string */ 83 MD5Update(&ctx, (const unsigned char *)MD5_MAGIC, MD5_MAGIC_LEN); 84 85 /* Then the raw salt */ 86 MD5Update(&ctx, (const unsigned char *)sp, sl); 87 88 /* Then just as many characters of the MD5(pw,salt,pw) */ 89 MD5Init(&ctx1); 90 MD5Update(&ctx1, (const unsigned char *)pw, pwl); 91 MD5Update(&ctx1, (const unsigned char *)sp, sl); 92 MD5Update(&ctx1, (const unsigned char *)pw, pwl); 93 MD5Final(final, &ctx1); 94 95 for (pl = pwl; pl > 0; pl -= 16) 96 MD5Update(&ctx, final, (unsigned int)(pl > 16 ? 16 : pl)); 97 98 /* Don't leave anything around in vm they could use. */ 99 memset(final, 0, sizeof(final)); 100 101 /* Then something really weird... */ 102 for (i = pwl; i != 0; i >>= 1) 103 if ((i & 1) != 0) 104 MD5Update(&ctx, final, 1); 105 else 106 MD5Update(&ctx, (const unsigned char *)pw, 1); 107 108 /* Now make the output string */ 109 memcpy(passwd, MD5_MAGIC, MD5_MAGIC_LEN); 110 strlcpy(passwd + MD5_MAGIC_LEN, sp, sl + 1); 111 strcat(passwd, "$"); 112 113 MD5Final(final, &ctx); 114 115 /* 116 * And now, just to make sure things don't run too fast. On a 60 MHz 117 * Pentium this takes 34 msec, so you would need 30 seconds to build 118 * a 1000 entry dictionary... 119 */ 120 for (i = 0; i < 1000; i++) { 121 MD5Init(&ctx1); 122 123 if ((i & 1) != 0) 124 MD5Update(&ctx1, (const unsigned char *)pw, pwl); 125 else 126 MD5Update(&ctx1, final, 16); 127 128 if ((i % 3) != 0) 129 MD5Update(&ctx1, (const unsigned char *)sp, sl); 130 131 if ((i % 7) != 0) 132 MD5Update(&ctx1, (const unsigned char *)pw, pwl); 133 134 if ((i & 1) != 0) 135 MD5Update(&ctx1, final, 16); 136 else 137 MD5Update(&ctx1, (const unsigned char *)pw, pwl); 138 139 MD5Final(final, &ctx1); 140 } 141 142 p = passwd + sl + MD5_MAGIC_LEN + 1; 143 144 l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; to64(p,l,4); p += 4; 145 l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; to64(p,l,4); p += 4; 146 l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; to64(p,l,4); p += 4; 147 l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; to64(p,l,4); p += 4; 148 l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; to64(p,l,4); p += 4; 149 l = final[11] ; to64(p,l,2); p += 2; 150 *p = '\0'; 151 152 /* Don't leave anything around in vm they could use. */ 153 memset(final, 0, sizeof(final)); 154 return (passwd); 155 } 156