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Damien Millerdd1c7ba1999-11-19 15:53:20 +11001/*
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
10/*
11 * Ported from FreeBSD to Linux, only minimal changes. --marekm
12 */
13
14/*
15 * Adapted from shadow-19990607 by Tudor Bosman, tudorb@jm.nu
16 */
17
18#include "config.h"
19
Damien Millerbeb4ba51999-12-28 15:09:35 +110020#if defined(HAVE_MD5_PASSWORDS) && !defined(HAVE_MD5_CRYPT)
Damien Millerdd1c7ba1999-11-19 15:53:20 +110021
22#include <unistd.h>
23#include <string.h>
Damien Millerdd1c7ba1999-11-19 15:53:20 +110024#include <openssl/md5.h>
Damien Millerdd1c7ba1999-11-19 15:53:20 +110025
26static unsigned char itoa64[] = /* 0 ... 63 => ascii - 64 */
27 "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
28
29static char *magic = "$1$"; /*
30 * This string is magic for
31 * this algorithm. Having
32 * it this way, we can get
33 * get better later on
34 */
35
36static void
37to64(char *s, unsigned long v, int n)
38{
39 while (--n >= 0) {
40 *s++ = itoa64[v&0x3f];
41 v >>= 6;
42 }
43}
44
45int
46is_md5_salt(const char *salt)
47{
48 return (!strncmp(salt, magic, strlen(magic)));
49}
50
51/*
52 * UNIX password
53 *
54 * Use MD5 for what it is best at...
55 */
56
57char *
58md5_crypt(const char *pw, const char *salt)
59{
60 static char passwd[120], *p;
61 static const char *sp,*ep;
62 unsigned char final[16];
63 int sl,pl,i,j;
64 MD5_CTX ctx,ctx1;
65 unsigned long l;
66
67 /* Refine the Salt first */
68 sp = salt;
69
70 /* If it starts with the magic string, then skip that */
71 if(!strncmp(sp,magic,strlen(magic)))
72 sp += strlen(magic);
73
74 /* It stops at the first '$', max 8 chars */
75 for(ep=sp;*ep && *ep != '$' && ep < (sp+8);ep++)
76 continue;
77
78 /* get the length of the true salt */
79 sl = ep - sp;
80
81 MD5_Init(&ctx);
82
83 /* The password first, since that is what is most unknown */
84 MD5_Update(&ctx,pw,strlen(pw));
85
86 /* Then our magic string */
87 MD5_Update(&ctx,magic,strlen(magic));
88
89 /* Then the raw salt */
90 MD5_Update(&ctx,sp,sl);
91
92 /* Then just as many characters of the MD5(pw,salt,pw) */
93 MD5_Init(&ctx1);
94 MD5_Update(&ctx1,pw,strlen(pw));
95 MD5_Update(&ctx1,sp,sl);
96 MD5_Update(&ctx1,pw,strlen(pw));
97 MD5_Final(final,&ctx1);
98 for(pl = strlen(pw); pl > 0; pl -= 16)
99 MD5_Update(&ctx,final,pl>16 ? 16 : pl);
100
101 /* Don't leave anything around in vm they could use. */
102 memset(final,0,sizeof final);
103
104 /* Then something really weird... */
105 for (j=0,i = strlen(pw); i ; i >>= 1)
106 if(i&1)
107 MD5_Update(&ctx, final+j, 1);
108 else
109 MD5_Update(&ctx, pw+j, 1);
110
111 /* Now make the output string */
112 strcpy(passwd,magic);
113 strncat(passwd,sp,sl);
114 strcat(passwd,"$");
115
116 MD5_Final(final,&ctx);
117
118 /*
119 * and now, just to make sure things don't run too fast
120 * On a 60 Mhz Pentium this takes 34 msec, so you would
121 * need 30 seconds to build a 1000 entry dictionary...
122 */
123 for(i=0;i<1000;i++) {
124 MD5_Init(&ctx1);
125 if(i & 1)
126 MD5_Update(&ctx1,pw,strlen(pw));
127 else
128 MD5_Update(&ctx1,final,16);
129
130 if(i % 3)
131 MD5_Update(&ctx1,sp,sl);
132
133 if(i % 7)
134 MD5_Update(&ctx1,pw,strlen(pw));
135
136 if(i & 1)
137 MD5_Update(&ctx1,final,16);
138 else
139 MD5_Update(&ctx1,pw,strlen(pw));
140 MD5_Final(final,&ctx1);
141 }
142
143 p = passwd + strlen(passwd);
144
145 l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; to64(p,l,4); p += 4;
146 l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; to64(p,l,4); p += 4;
147 l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; to64(p,l,4); p += 4;
148 l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; to64(p,l,4); p += 4;
149 l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; to64(p,l,4); p += 4;
150 l = final[11] ; to64(p,l,2); p += 2;
151 *p = '\0';
152
153 /* Don't leave anything around in vm they could use. */
154 memset(final,0,sizeof final);
155
156 return passwd;
157}
158
Damien Millerbeb4ba51999-12-28 15:09:35 +1100159#endif /* defined(HAVE_MD5_PASSWORDS) && !defined(HAVE_MD5_CRYPT) */