usr/src/lib/gss_mechs/mech_krb5/crypto/des/string2key.c

   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 }