usr/src/lib/gss_mechs/mech_krb5/crypto/dk/stringtokey.c

   1 /*
   2  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
   3  * Use is subject to license terms.
   4  */
   5
   6
   7 /*
   8  * Copyright (C) 1998 by the FundsXpress, INC.
   9  *
  10  * All rights reserved.
  11  *
  12  * Export of this software from the United States of America may require
  13  * a specific license from the United States Government.  It is the
  14  * responsibility of any person or organization contemplating export to
  15  * 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 FundsXpress. not be used in advertising or publicity pertaining
  23  * to distribution of the software without specific, written prior
  24  * permission.  FundsXpress 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  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  29  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  30  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  31  */
  32
  33 #include "dk.h"
  34
  35 static const unsigned char kerberos[] = "kerberos";
  36 #define kerberos_len (sizeof(kerberos)-1)
  37
  38 krb5_error_code
  39 krb5int_dk_string_to_key(
  40                          krb5_context context,
  41                          const struct krb5_enc_provider *enc,
  42                          const krb5_data *string, const krb5_data *salt,
  43                          const krb5_data *parms, krb5_keyblock *key)
  44 {
  45     krb5_error_code ret;
  46     size_t keybytes, keylength, concatlen;
  47     unsigned char *concat, *foldstring, *foldkeydata;
  48     krb5_data indata;
  49     krb5_keyblock foldkey;
  50
  51     /* key->length is checked by krb5_derive_key */
  52
  53     keybytes = enc->keybytes;
  54     keylength = enc->keylength;
  55
  56     concatlen = string->length+(salt?salt->length:0);
  57
  58     if ((concat = (unsigned char *) malloc(concatlen)) == NULL)
  59         return(ENOMEM);
  60     if ((foldstring = (unsigned char *) malloc(keybytes)) == NULL) {
  61         free(concat);
  62         return(ENOMEM);
  63     }
  64     if ((foldkeydata = (unsigned char *) malloc(keylength)) == NULL) {
  65         free(foldstring);
  66         free(concat);
  67         return(ENOMEM);
  68     }
  69
  70     /* construct input string ( = string + salt), fold it, make_key it */
  71
  72     memcpy(concat, string->data, string->length);
  73     if (salt)
  74         memcpy(concat+string->length, salt->data, salt->length);
  75
  76     krb5_nfold(concatlen*8, concat, keybytes*8, foldstring);
  77
  78     indata.length = keybytes;
  79     indata.data = (char *) foldstring;
  80
  81     /* Solaris Kerberos */
  82     memset(&foldkey, 0, sizeof (krb5_keyblock));
  83     foldkey.enctype = key->enctype;
  84     foldkey.length = keylength;
  85     foldkey.contents = foldkeydata;
  86
  87     /* Solaris Kerberos */
  88     (*(enc->make_key))(context, &indata, &foldkey);
  89
  90     /* now derive the key from this one */
  91
  92     indata.length = kerberos_len;
  93     indata.data = (char *) kerberos;
  94     /* Solaris Kerberos */
  95     if ((ret = krb5_derive_key(context, enc, &foldkey, key, &indata)))
  96         (void) memset(key->contents, 0, key->length);
  97
  98     /* ret is set correctly by the prior call */
  99
 100     memset(concat, 0, concatlen);
 101     memset(foldstring, 0, keybytes);
 102     memset(foldkeydata, 0, keylength);
 103
 104     free(foldkeydata);
 105     free(foldstring);
 106     free(concat);
 107
 108     return(ret);
 109 }