2 * $Id: md5_crypt.c,v 1.1.1.1 2000/06/20 22:12:03 agmorgan Exp $
3 * $FreeBSD: src/contrib/libpam/modules/pam_unix/md5_crypt.c,v 1.1.1.1.2.2 2001/06/11 15:28:30 markm Exp $
5 * ----------------------------------------------------------------------------
6 * "THE BEER-WARE LICENSE" (Revision 42):
7 * <phk@login.dknet.dk> wrote this file. As long as you retain this notice you
8 * can do whatever you want with this stuff. If we meet some day, and you think
9 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
10 * ----------------------------------------------------------------------------
12 * Origin: Id: crypt.c,v 1.3 1995/05/30 05:42:22 rgrimes Exp
19 static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */
20 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
22 static void to64(char *s, unsigned long v, int n)
25 *s++ = itoa64[v & 0x3f];
33 * Use MD5 for what it is best at...
36 char *MD5Name(crypt_md5)(const char *pw, const char *salt)
38 const char *magic = "$1$";
39 /* This string is magic for this algorithm. Having
40 * it this way, we can get get better later on */
41 static char passwd[120], *p;
42 static const char *sp, *ep;
43 unsigned char final[16];
48 /* Refine the Salt first */
51 /* If it starts with the magic string, then skip that */
52 if (!strncmp(sp, magic, strlen(magic)))
55 /* It stops at the first '$', max 8 chars */
56 for (ep = sp; *ep && *ep != '$' && ep < (sp + 8); ep++)
59 /* get the length of the true salt */
62 MD5Name(MD5Init)(&ctx);
64 /* The password first, since that is what is most unknown */
65 MD5Name(MD5Update)(&ctx,(unsigned const char *)pw,strlen(pw));
67 /* Then our magic string */
68 MD5Name(MD5Update)(&ctx,(unsigned const char *)magic,strlen(magic));
70 /* Then the raw salt */
71 MD5Name(MD5Update)(&ctx,(unsigned const char *)sp,sl);
73 /* Then just as many characters of the MD5(pw,salt,pw) */
74 MD5Name(MD5Init)(&ctx1);
75 MD5Name(MD5Update)(&ctx1,(unsigned const char *)pw,strlen(pw));
76 MD5Name(MD5Update)(&ctx1,(unsigned const char *)sp,sl);
77 MD5Name(MD5Update)(&ctx1,(unsigned const char *)pw,strlen(pw));
78 MD5Name(MD5Final)(final,&ctx1);
79 for (pl = strlen(pw); pl > 0; pl -= 16)
80 MD5Name(MD5Update)(&ctx,(unsigned const char *)final,pl>16 ? 16 : pl);
82 /* Don't leave anything around in vm they could use. */
83 memset(final, 0, sizeof final);
85 /* Then something really weird... */
86 for (j = 0, i = strlen(pw); i; i >>= 1)
88 MD5Name(MD5Update)(&ctx, (unsigned const char *)final+j, 1);
90 MD5Name(MD5Update)(&ctx, (unsigned const char *)pw+j, 1);
92 /* Now make the output string */
93 strcpy(passwd, magic);
94 strncat(passwd, sp, sl);
97 MD5Name(MD5Final)(final,&ctx);
100 * and now, just to make sure things don't run too fast
101 * On a 60 Mhz Pentium this takes 34 msec, so you would
102 * need 30 seconds to build a 1000 entry dictionary...
104 for (i = 0; i < 1000; i++) {
105 MD5Name(MD5Init)(&ctx1);
107 MD5Name(MD5Update)(&ctx1,(unsigned const char *)pw,strlen(pw));
109 MD5Name(MD5Update)(&ctx1,(unsigned const char *)final,16);
112 MD5Name(MD5Update)(&ctx1,(unsigned const char *)sp,sl);
115 MD5Name(MD5Update)(&ctx1,(unsigned const char *)pw,strlen(pw));
118 MD5Name(MD5Update)(&ctx1,(unsigned const char *)final,16);
120 MD5Name(MD5Update)(&ctx1,(unsigned const char *)pw,strlen(pw));
121 MD5Name(MD5Final)(final,&ctx1);
124 p = passwd + strlen(passwd);
126 l = (final[0] << 16) | (final[6] << 8) | final[12];
129 l = (final[1] << 16) | (final[7] << 8) | final[13];
132 l = (final[2] << 16) | (final[8] << 8) | final[14];
135 l = (final[3] << 16) | (final[9] << 8) | final[15];
138 l = (final[4] << 16) | (final[10] << 8) | final[5];
146 /* Don't leave anything around in vm they could use. */
147 memset(final, 0, sizeof final);