net/sunrpc/auth_gss/gss_krb5_seqnum.c

   1 /*
   2  *  linux/net/sunrpc/gss_krb5_seqnum.c
   3  *
   4  *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/util_seqnum.c
   5  *
   6  *  Copyright (c) 2000 The Regents of the University of Michigan.
   7  *  All rights reserved.
   8  *
   9  *  Andy Adamson   <andros@umich.edu>
  10  */
  11
  12 /*
  13  * Copyright 1993 by OpenVision Technologies, Inc.
  14  *
  15  * Permission to use, copy, modify, distribute, and sell this software
  16  * and its documentation for any purpose is hereby granted without fee,
  17  * provided that the above copyright notice appears in all copies and
  18  * that both that copyright notice and this permission notice appear in
  19  * supporting documentation, and that the name of OpenVision not be used
  20  * in advertising or publicity pertaining to distribution of the software
  21  * without specific, written prior permission. OpenVision makes no
  22  * representations about the suitability of this software for any
  23  * purpose.  It is provided "as is" without express or implied warranty.
  24  *
  25  * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  26  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  27  * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  28  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
  29  * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
  30  * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  31  * PERFORMANCE OF THIS SOFTWARE.
  32  */
  33
  34 #include <linux/types.h>
  35 #include <linux/slab.h>
  36 #include <linux/sunrpc/gss_krb5.h>
  37 #include <linux/crypto.h>
  38
  39 #ifdef RPC_DEBUG
  40 # define RPCDBG_FACILITY        RPCDBG_AUTH
  41 #endif
  42
  43 s32
  44 krb5_make_seq_num(struct crypto_tfm *key,
  45                 int direction,
  46                 s32 seqnum,
  47                 unsigned char *cksum, unsigned char *buf)
  48 {
  49         unsigned char plain[8];
  50
  51         plain[0] = (unsigned char) (seqnum & 0xff);
  52         plain[1] = (unsigned char) ((seqnum >> 8) & 0xff);
  53         plain[2] = (unsigned char) ((seqnum >> 16) & 0xff);
  54         plain[3] = (unsigned char) ((seqnum >> 24) & 0xff);
  55
  56         plain[4] = direction;
  57         plain[5] = direction;
  58         plain[6] = direction;
  59         plain[7] = direction;
  60
  61         return krb5_encrypt(key, cksum, plain, buf, 8);
  62 }
  63
  64 s32
  65 krb5_get_seq_num(struct crypto_tfm *key,
  66                unsigned char *cksum,
  67                unsigned char *buf,
  68                int *direction, s32 * seqnum)
  69 {
  70         s32 code;
  71         unsigned char plain[8];
  72
  73         dprintk("RPC:      krb5_get_seq_num:\n");
  74
  75         if ((code = krb5_decrypt(key, cksum, buf, plain, 8)))
  76                 return code;
  77
  78         if ((plain[4] != plain[5]) || (plain[4] != plain[6])
  79                                    || (plain[4] != plain[7]))
  80                 return (s32)KG_BAD_SEQ;
  81
  82         *direction = plain[4];
  83
  84         *seqnum = ((plain[0]) |
  85                    (plain[1] << 8) | (plain[2] << 16) | (plain[3] << 24));
  86
  87         return (0);
  88 }