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      1 #pragma ident	"%Z%%M%	%I%	%E% SMI"
      2 
      3 /*
      4   * Copyright2001 by the Massachusetts Institute of Technology.
      5  * Copyright 1993 by OpenVision Technologies, Inc.
      6  *
      7  * Permission to use, copy, modify, distribute, and sell this software
      8  * and its documentation for any purpose is hereby granted without fee,
      9  * provided that the above copyright notice appears in all copies and
     10  * that both that copyright notice and this permission notice appear in
     11  * supporting documentation, and that the name of OpenVision not be used
     12  * in advertising or publicity pertaining to distribution of the software
     13  * without specific, written prior permission. OpenVision makes no
     14  * representations about the suitability of this software for any
     15  * purpose.  It is provided "as is" without express or implied warranty.
     16  *
     17  * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
     18  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
     19  * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
     20  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
     21  * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
     22  * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
     23  * PERFORMANCE OF THIS SOFTWARE.
     24  */
     25 
     26 #include "gssapiP_krb5.h"
     27 #include "k5-int.h"
     28 
     29 /*
     30  * $Id: util_seqnum.c 15007 2002-11-15 16:12:20Z epeisach $
     31  */
     32 
     33 krb5_error_code
     34 kg_make_seq_num(context, key, direction, seqnum, cksum, buf)
     35      krb5_context context;
     36      krb5_keyblock *key;
     37      int direction;
     38      krb5_ui_4 seqnum;
     39      unsigned char *cksum;
     40      unsigned char *buf;
     41 {
     42    unsigned char plain[8];
     43 
     44    plain[4] = direction;
     45    plain[5] = direction;
     46    plain[6] = direction;
     47    plain[7] = direction;
     48    if (key->enctype == ENCTYPE_ARCFOUR_HMAC ) {
     49      /* Yes, Microsoft used big-endian sequence number.*/
     50      plain[0] = (seqnum>>24) & 0xff;
     51      plain[1] = (seqnum>>16) & 0xff;
     52      plain[2] = (seqnum>>8) & 0xff;
     53      plain[3] = seqnum & 0xff;
     54      return kg_arcfour_docrypt (context, key, 0,
     55 				cksum, 8,
     56 				&plain[0], 8,
     57 				buf);
     58 
     59    }
     60 
     61    plain[0] = (unsigned char) (seqnum&0xff);
     62    plain[1] = (unsigned char) ((seqnum>>8)&0xff);
     63    plain[2] = (unsigned char) ((seqnum>>16)&0xff);
     64    plain[3] = (unsigned char) ((seqnum>>24)&0xff);
     65 
     66    return(kg_encrypt(context, key, KG_USAGE_SEQ, cksum, plain, buf, 8));
     67 }
     68 
     69 krb5_error_code kg_get_seq_num(context, key, cksum, buf, direction, seqnum)
     70      krb5_context context;
     71      krb5_keyblock *key;
     72      unsigned char *cksum;
     73      unsigned char *buf;
     74      int *direction;
     75      krb5_ui_4 *seqnum;
     76 {
     77    krb5_error_code code;
     78    unsigned char plain[8];
     79 
     80    if (key->enctype == ENCTYPE_ARCFOUR_HMAC) {
     81      code = kg_arcfour_docrypt (context, key, 0,
     82 				cksum, 8,
     83 				buf, 8,
     84 				plain);
     85    } else {
     86      code = kg_decrypt(context, key, KG_USAGE_SEQ, cksum, buf, plain, 8);
     87    }
     88    if (code)
     89       return(code);
     90 
     91    if ((plain[4] != plain[5]) ||
     92        (plain[4] != plain[6]) ||
     93        (plain[4] != plain[7]))
     94       return((krb5_error_code) KG_BAD_SEQ);
     95 
     96    *direction = plain[4];
     97    if (key->enctype == ENCTYPE_ARCFOUR_HMAC) {
     98      *seqnum = (plain[3]|(plain[2]<<8) | (plain[1]<<16)| (plain[0]<<24));
     99    } else {
    100      *seqnum = ((plain[0]) |
    101 	      (plain[1]<<8) |
    102 	      (plain[2]<<16) |
    103 	      (plain[3]<<24));
    104    }
    105 
    106    return(0);
    107 }
    108