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 * ----------------------------------------------------------------------------
10 * $FreeBSD: src/lib/libcrypt/crypt-md5.c,v 1.5 1999/12/17 20:21:45 peter Exp $
22 char *crypt_md5(const char *pw, const char *salt)
24 static char *magic = "$1$"; /*
25 * This string is magic for
26 * this algorithm. Having
27 * it this way, we can get
30 static char passwd[120], *p;
31 static const char *sp,*ep;
32 unsigned char final[MD5_SIZE];
37 /* Refine the Salt first */
40 /* If it starts with the magic string, then skip that */
41 if(!strncmp(sp,magic,strlen(magic)))
44 /* It stops at the first '$', max 8 chars */
45 for(ep=sp;*ep && *ep != '$' && ep < (sp+8);ep++)
48 /* get the length of the true salt */
53 /* The password first, since that is what is most unknown */
54 MD5Update(&ctx,pw,strlen(pw));
56 /* Then our magic string */
57 MD5Update(&ctx,magic,strlen(magic));
59 /* Then the raw salt */
60 MD5Update(&ctx,sp,sl);
62 /* Then just as many characters of the MD5(pw,salt,pw) */
64 MD5Update(&ctx1,pw,strlen(pw));
65 MD5Update(&ctx1,sp,sl);
66 MD5Update(&ctx1,pw,strlen(pw));
67 MD5Final(final,&ctx1);
68 for(pl = strlen(pw); pl > 0; pl -= MD5_SIZE)
69 MD5Update(&ctx,final,pl>MD5_SIZE ? MD5_SIZE : pl);
71 /* Don't leave anything around in vm they could use. */
72 memset(final,0,sizeof final);
74 /* Then something really weird... */
75 for (i = strlen(pw); i ; i >>= 1)
77 MD5Update(&ctx, final, 1);
79 MD5Update(&ctx, pw, 1);
81 /* Now make the output string */
83 strncat(passwd,sp,sl);
89 * and now, just to make sure things don't run too fast
90 * On a 60 Mhz Pentium this takes 34 msec, so you would
91 * need 30 seconds to build a 1000 entry dictionary...
96 MD5Update(&ctx1,pw,strlen(pw));
98 MD5Update(&ctx1,final,MD5_SIZE);
101 MD5Update(&ctx1,sp,sl);
104 MD5Update(&ctx1,pw,strlen(pw));
107 MD5Update(&ctx1,final,MD5_SIZE);
109 MD5Update(&ctx1,pw,strlen(pw));
110 MD5Final(final,&ctx1);
113 p = passwd + strlen(passwd);
115 l = (final[ 0]<<16) | (final[ 6]<<8) | final[12];
116 _crypt_to64(p,l,4); p += 4;
117 l = (final[ 1]<<16) | (final[ 7]<<8) | final[13];
118 _crypt_to64(p,l,4); p += 4;
119 l = (final[ 2]<<16) | (final[ 8]<<8) | final[14];
120 _crypt_to64(p,l,4); p += 4;
121 l = (final[ 3]<<16) | (final[ 9]<<8) | final[15];
122 _crypt_to64(p,l,4); p += 4;
123 l = (final[ 4]<<16) | (final[10]<<8) | final[ 5];
124 _crypt_to64(p,l,4); p += 4;
126 _crypt_to64(p,l,2); p += 2;
129 /* Don't leave anything around in vm they could use. */
130 memset(final,0,sizeof final);