xref: /illumos-gate/usr/src/lib/gss_mechs/mech_krb5/crypto/des/string2key.c (revision 694c35faa87b858ecdadfe4fc592615f4eefbb07)
1 /*
2  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * lib/crypto/des/string2key.c
8  *
9  * Copyright 1990,1991 by the Massachusetts Institute of Technology.
10  * All Rights Reserved.
11  *
12  * Export of this software from the United States of America may
13  *   require a specific license from the United States Government.
14  *   It is the responsibility of any person or organization contemplating
15  *   export to obtain such a license before exporting.
16  *
17  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
18  * distribute this software and its documentation for any purpose and
19  * without fee is hereby granted, provided that the above copyright
20  * notice appear in all copies and that both that copyright notice and
21  * this permission notice appear in supporting documentation, and that
22  * the name of M.I.T. not be used in advertising or publicity pertaining
23  * to distribution of the software without specific, written prior
24  * permission.  M.I.T. makes no representations about the suitability of
25  * this software for any purpose.  It is provided "as is" without express
26  * or implied warranty.
27  */
28 
29 #include <k5-int.h>
30 #include <des_int.h>
31 
32 /*
33 	converts the string pointed to by "data" into an encryption key
34 	of type "enctype".  *keyblock is filled in with the key info;
35 	in particular, keyblock->contents is to be set to allocated storage.
36 	It is the responsibility of the caller to release this storage
37 	when the generated key no longer needed.
38 
39 	The routine may use "salt" to seed or alter the conversion
40 	algorithm.
41 
42 	If the particular function called does not know how to make a
43 	key of type "enctype", an error may be returned.
44 
45 	returns: errors
46  */
47 
48 krb5_error_code
49 mit_des_string_to_key_int (krb5_context context,
50 	krb5_keyblock *keyblock,
51 	const krb5_data *data,
52 	const krb5_data *salt)
53 {
54     krb5_error_code retval = KRB5_PROG_ETYPE_NOSUPP;
55     register char *str, *copystr;
56     register krb5_octet *key;
57     register unsigned temp;
58     register long i;
59     register int j;
60     register long length;
61     unsigned char *k_p;
62     int forward;
63     register char *p_char;
64     char k_char[64];
65 
66 #ifndef min
67 #define min(A, B) ((A) < (B) ? (A): (B))
68 #endif
69 
70     keyblock->magic = KV5M_KEYBLOCK;
71     keyblock->length = sizeof(mit_des_cblock);
72     key = keyblock->contents;
73 
74     if (salt
75 	&& (salt->length == SALT_TYPE_AFS_LENGTH
76 	    /* XXX  Yuck!  Aren't we done with this yet?  */
77 	    || salt->length == (unsigned) -1)) {
78 	krb5_data afssalt;
79 	char *at;
80 
81 	afssalt.data = salt->data;
82 	at = strchr(afssalt.data, '@');
83 	if (at) {
84 	    *at = 0;
85 	    afssalt.length = at - afssalt.data;
86 	} else
87 	    afssalt.length = strlen(afssalt.data);
88 	return mit_afs_string_to_key(context, keyblock, data, &afssalt);
89     }
90 
91     length = data->length + (salt ? salt->length : 0);
92 
93     copystr = malloc((size_t) length);
94     if (!copystr) {
95 	return ENOMEM;
96     }
97 
98     (void) memcpy(copystr, (char *) data->data, data->length);
99     if (salt)
100 	(void) memcpy(copystr + data->length, (char *)salt->data, salt->length);
101 
102     /* convert to des key */
103     forward = 1;
104     p_char = k_char;
105 
106     /* init key array for bits */
107     (void) memset(k_char,0,sizeof(k_char));
108 
109 #if 0
110     if (mit_des_debug)
111 	fprintf(stdout,
112 		"\n\ninput str length = %d  string = %*s\nstring = 0x ",
113 		length,length,str);
114 #endif
115 
116     str = copystr;
117 
118     /* get next 8 bytes, strip parity, xor */
119     for (i = 1; i <= length; i++) {
120 	/* get next input key byte */
121 	temp = (unsigned int) *str++;
122 #if 0
123 	if (mit_des_debug)
124 	    fprintf(stdout,"%02x ",temp & 0xff);
125 #endif
126 	/* loop through bits within byte, ignore parity */
127 	for (j = 0; j <= 6; j++) {
128 	    if (forward)
129 		*p_char++ ^= (int) temp & 01;
130 	    else
131 		*--p_char ^= (int) temp & 01;
132 	    temp = temp >> 1;
133 	}
134 
135 	/* check and flip direction */
136 	if ((i%8) == 0)
137 	    forward = !forward;
138     }
139 
140     /* now stuff into the key mit_des_cblock, and force odd parity */
141     p_char = k_char;
142     k_p = (unsigned char *) key;
143 
144     for (i = 0; i <= 7; i++) {
145 	temp = 0;
146 	for (j = 0; j <= 6; j++)
147 	    temp |= *p_char++ << (1+j);
148 	*k_p++ = (unsigned char) temp;
149     }
150 
151     /* fix key parity */
152     mit_des_fixup_key_parity(key);
153     if (mit_des_is_weak_key(key))
154 	((krb5_octet *)key)[7] ^= 0xf0;
155 
156     retval = mit_des_cbc_cksum(context, (unsigned char*)copystr, key,
157 	length, keyblock, key);
158 
159     /* clean & free the input string */
160     (void) memset(copystr, 0, (size_t) length);
161     krb5_xfree(copystr);
162 
163     /* now fix up key parity again */
164     mit_des_fixup_key_parity(key);
165     if (mit_des_is_weak_key(key))
166 	((krb5_octet *)key)[7] ^= 0xf0;
167 
168     /*
169      * Because this routine actually modifies the original keyblock
170      * in place we cannot use the PKCS#11 key object handle created earlier.
171      * Destroy the existing object handle associated with the key,
172      * a correct handle will get created when the key is actually
173      * used for the first time.
174      */
175      if (keyblock->hKey != CK_INVALID_HANDLE) {
176 	(void)C_DestroyObject(krb_ctx_hSession(context), keyblock->hKey);
177 	keyblock->hKey = CK_INVALID_HANDLE;
178      }
179 
180     return retval;
181 }
182