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 * ----------------------------------------------------------------------------
9 * $FreeBSD: src/lib/libcrypt/crypt-md5.c,v 1.5.2.1 2001/05/24 12:20:02 markm Exp $
13 #if defined(LIBC_SCCS) && !defined(lint)
14 static const char rcsid[] = \
15 "$FreeBSD: src/lib/libcrypt/crypt-md5.c,v 1.5.2.1 2001/05/24 12:20:02 markm Exp $";
16 #endif /* LIBC_SCCS and not lint */
34 static char *magic = "$1$"; /*
35 * This string is magic for
36 * this algorithm. Having
37 * it this way, we can get
40 static char passwd[120], *p;
41 static const char *sp,*ep;
42 unsigned char final[MD5_SIZE];
47 /* Refine the Salt first */
50 /* If it starts with the magic string, then skip that */
51 if(!strncmp(sp,magic,strlen(magic)))
54 /* It stops at the first '$', max 8 chars */
55 for(ep=sp;*ep && *ep != '$' && ep < (sp+8);ep++)
58 /* get the length of the true salt */
63 /* The password first, since that is what is most unknown */
64 MD5Update(&ctx,pw,strlen(pw));
66 /* Then our magic string */
67 MD5Update(&ctx,magic,strlen(magic));
69 /* Then the raw salt */
70 MD5Update(&ctx,sp,sl);
72 /* Then just as many characters of the MD5(pw,salt,pw) */
74 MD5Update(&ctx1,pw,strlen(pw));
75 MD5Update(&ctx1,sp,sl);
76 MD5Update(&ctx1,pw,strlen(pw));
77 MD5Final(final,&ctx1);
78 for(pl = strlen(pw); pl > 0; pl -= MD5_SIZE)
79 MD5Update(&ctx,final,pl>MD5_SIZE ? MD5_SIZE : pl);
81 /* Don't leave anything around in vm they could use. */
82 memset(final,0,sizeof final);
84 /* Then something really weird... */
85 for (i = strlen(pw); i ; i >>= 1)
87 MD5Update(&ctx, final, 1);
89 MD5Update(&ctx, pw, 1);
91 /* Now make the output string */
93 strncat(passwd,sp,sl);
99 * and now, just to make sure things don't run too fast
100 * On a 60 Mhz Pentium this takes 34 msec, so you would
101 * need 30 seconds to build a 1000 entry dictionary...
103 for(i=0;i<1000;i++) {
106 MD5Update(&ctx1,pw,strlen(pw));
108 MD5Update(&ctx1,final,MD5_SIZE);
111 MD5Update(&ctx1,sp,sl);
114 MD5Update(&ctx1,pw,strlen(pw));
117 MD5Update(&ctx1,final,MD5_SIZE);
119 MD5Update(&ctx1,pw,strlen(pw));
120 MD5Final(final,&ctx1);
123 p = passwd + strlen(passwd);
125 l = (final[ 0]<<16) | (final[ 6]<<8) | final[12];
126 _crypt_to64(p,l,4); p += 4;
127 l = (final[ 1]<<16) | (final[ 7]<<8) | final[13];
128 _crypt_to64(p,l,4); p += 4;
129 l = (final[ 2]<<16) | (final[ 8]<<8) | final[14];
130 _crypt_to64(p,l,4); p += 4;
131 l = (final[ 3]<<16) | (final[ 9]<<8) | final[15];
132 _crypt_to64(p,l,4); p += 4;
133 l = (final[ 4]<<16) | (final[10]<<8) | final[ 5];
134 _crypt_to64(p,l,4); p += 4;
136 _crypt_to64(p,l,2); p += 2;
139 /* Don't leave anything around in vm they could use. */
140 memset(final,0,sizeof final);