1 /*
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 * ----------------------------------------------------------------------------
8 *
9 * $FreeBSD: src/lib/libcrypt/crypt-md5.c,v 1.5.2.1 2001/05/24 12:20:02 markm Exp $
10 */
11
12 #include <unistd.h>
13 #include <stdio.h>
14 #include <string.h>
15 #include <err.h>
16
17 #include "crypt.h"
18
19 #define MD5Init _libcrypt_MD5Init
20 #define MD5Final _libcrypt_MD5Final
21 #define MD5Pad _libcrypt_MD5Pad
22 #define MD5Transform _libcrypt_MD5Transform
23 #define MD5Update _libcrypt_MD5Update
24 #define WITH_OPENSSL
25 #include "private_md5.h"
26
27 /* magic sizes, moved out from crypt.h */
28 #define MD5_SIZE 16
29
30 /*
31 * UNIX password
32 */
33
34 char *
crypt_md5(const char * pw,const char * salt)35 crypt_md5(const char *pw, const char *salt)
36 {
37 static const char *magic = "$1$"; /*
38 * This string is magic for
39 * this algorithm. Having
40 * it this way, we can get
41 * get better later on
42 */
43 static char passwd[120], *p;
44 static const char *sp,*ep;
45 unsigned char final[MD5_SIZE];
46 int sl,pl,i;
47 MD5_CTX ctx,ctx1;
48 unsigned long l;
49
50 /* Refine the Salt first */
51 sp = salt;
52
53 /* If it starts with the magic string, then skip that */
54 if(!strncmp(sp,magic,strlen(magic)))
55 sp += strlen(magic);
56
57 /* It stops at the first '$', max 8 chars */
58 for(ep=sp;*ep && *ep != '$' && ep < (sp+8);ep++)
59 continue;
60
61 /* get the length of the true salt */
62 sl = ep - sp;
63
64 MD5Init(&ctx);
65
66 /* The password first, since that is what is most unknown */
67 MD5Update(&ctx,pw,strlen(pw));
68
69 /* Then our magic string */
70 MD5Update(&ctx,magic,strlen(magic));
71
72 /* Then the raw salt */
73 MD5Update(&ctx,sp,sl);
74
75 /* Then just as many characters of the MD5(pw,salt,pw) */
76 MD5Init(&ctx1);
77 MD5Update(&ctx1,pw,strlen(pw));
78 MD5Update(&ctx1,sp,sl);
79 MD5Update(&ctx1,pw,strlen(pw));
80 MD5Final(final,&ctx1);
81 for(pl = strlen(pw); pl > 0; pl -= MD5_SIZE)
82 MD5Update(&ctx,final,pl>MD5_SIZE ? MD5_SIZE : pl);
83
84 /* Don't leave anything around in vm they could use. */
85 memset(final,0,sizeof final);
86
87 /* Then something really weird... */
88 for (i = strlen(pw); i ; i >>= 1)
89 if(i&1)
90 MD5Update(&ctx, final, 1);
91 else
92 MD5Update(&ctx, pw, 1);
93
94 /* Now make the output string */
95 strcpy(passwd,magic);
96 strncat(passwd,sp,sl);
97 strcat(passwd,"$");
98
99 MD5Final(final,&ctx);
100
101 /*
102 * and now, just to make sure things don't run too fast
103 * On a 60 Mhz Pentium this takes 34 msec, so you would
104 * need 30 seconds to build a 1000 entry dictionary...
105 */
106 for(i=0;i<1000;i++) {
107 MD5Init(&ctx1);
108 if(i & 1)
109 MD5Update(&ctx1,pw,strlen(pw));
110 else
111 MD5Update(&ctx1,final,MD5_SIZE);
112
113 if(i % 3)
114 MD5Update(&ctx1,sp,sl);
115
116 if(i % 7)
117 MD5Update(&ctx1,pw,strlen(pw));
118
119 if(i & 1)
120 MD5Update(&ctx1,final,MD5_SIZE);
121 else
122 MD5Update(&ctx1,pw,strlen(pw));
123 MD5Final(final,&ctx1);
124 }
125
126 p = passwd + strlen(passwd);
127
128 l = (final[ 0]<<16) | (final[ 6]<<8) | final[12];
129 _crypt_to64(p,l,4); p += 4;
130 l = (final[ 1]<<16) | (final[ 7]<<8) | final[13];
131 _crypt_to64(p,l,4); p += 4;
132 l = (final[ 2]<<16) | (final[ 8]<<8) | final[14];
133 _crypt_to64(p,l,4); p += 4;
134 l = (final[ 3]<<16) | (final[ 9]<<8) | final[15];
135 _crypt_to64(p,l,4); p += 4;
136 l = (final[ 4]<<16) | (final[10]<<8) | final[ 5];
137 _crypt_to64(p,l,4); p += 4;
138 l = final[11] ;
139 _crypt_to64(p,l,2); p += 2;
140 *p = '\0';
141
142 /* Don't leave anything around in vm they could use. */
143 memset(final,0,sizeof final);
144
145 return passwd;
146 }
147
148