net/sunrpc/auth_gss/gss_krb5_seal.c

   1 /*
   2  *  linux/net/sunrpc/gss_krb5_seal.c
   3  *
   4  *  Adapted from MIT Kerberos 5-1.2.1 lib/gssapi/krb5/k5seal.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  *  J. Bruce Fields     <bfields@umich.edu>
  11  */
  12
  13 /*
  14  * Copyright 1993 by OpenVision Technologies, Inc.
  15  *
  16  * Permission to use, copy, modify, distribute, and sell this software
  17  * and its documentation for any purpose is hereby granted without fee,
  18  * provided that the above copyright notice appears in all copies and
  19  * that both that copyright notice and this permission notice appear in
  20  * supporting documentation, and that the name of OpenVision not be used
  21  * in advertising or publicity pertaining to distribution of the software
  22  * without specific, written prior permission. OpenVision makes no
  23  * representations about the suitability of this software for any
  24  * purpose.  It is provided "as is" without express or implied warranty.
  25  *
  26  * OPENVISION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  27  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  28  * EVENT SHALL OPENVISION BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  29  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
  30  * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
  31  * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  32  * PERFORMANCE OF THIS SOFTWARE.
  33  */
  34
  35 /*
  36  * Copyright (C) 1998 by the FundsXpress, INC.
  37  *
  38  * All rights reserved.
  39  *
  40  * Export of this software from the United States of America may require
  41  * a specific license from the United States Government.  It is the
  42  * responsibility of any person or organization contemplating export to
  43  * obtain such a license before exporting.
  44  *
  45  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
  46  * distribute this software and its documentation for any purpose and
  47  * without fee is hereby granted, provided that the above copyright
  48  * notice appear in all copies and that both that copyright notice and
  49  * this permission notice appear in supporting documentation, and that
  50  * the name of FundsXpress. not be used in advertising or publicity pertaining
  51  * to distribution of the software without specific, written prior
  52  * permission.  FundsXpress makes no representations about the suitability of
  53  * this software for any purpose.  It is provided "as is" without express
  54  * or implied warranty.
  55  *
  56  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  57  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  58  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  59  */
  60
  61 #include <linux/types.h>
  62 #include <linux/jiffies.h>
  63 #include <linux/sunrpc/gss_krb5.h>
  64 #include <linux/random.h>
  65 #include <linux/crypto.h>
  66
  67 #ifdef RPC_DEBUG
  68 # define RPCDBG_FACILITY        RPCDBG_AUTH
  69 #endif
  70
  71 DEFINE_SPINLOCK(krb5_seq_lock);
  72
  73 u32
  74 gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text,
  75                 struct xdr_netobj *token)
  76 {
  77         struct krb5_ctx         *ctx = gss_ctx->internal_ctx_id;
  78         char                    cksumdata[16];
  79         struct xdr_netobj       md5cksum = {.len = 0, .data = cksumdata};
  80         unsigned char           *ptr, *msg_start;
  81         s32                     now;
  82         u32                     seq_send;
  83
  84         dprintk("RPC:       gss_krb5_seal\n");
  85         BUG_ON(ctx == NULL);
  86
  87         now = get_seconds();
  88
  89         token->len = g_token_size(&ctx->mech_used, GSS_KRB5_TOK_HDR_LEN + 8);
  90
  91         ptr = token->data;
  92         g_make_token_header(&ctx->mech_used, GSS_KRB5_TOK_HDR_LEN + 8, &ptr);
  93
  94         /* ptr now at header described in rfc 1964, section 1.2.1: */
  95         ptr[0] = (unsigned char) ((KG_TOK_MIC_MSG >> 8) & 0xff);
  96         ptr[1] = (unsigned char) (KG_TOK_MIC_MSG & 0xff);
  97
  98         msg_start = ptr + GSS_KRB5_TOK_HDR_LEN + 8;
  99
 100         *(__be16 *)(ptr + 2) = htons(SGN_ALG_DES_MAC_MD5);
 101         memset(ptr + 4, 0xff, 4);
 102
 103         if (make_checksum("md5", ptr, 8, text, 0, &md5cksum))
 104                 return GSS_S_FAILURE;
 105
 106         if (krb5_encrypt(ctx->seq, NULL, md5cksum.data,
 107                           md5cksum.data, md5cksum.len))
 108                 return GSS_S_FAILURE;
 109
 110         memcpy(ptr + GSS_KRB5_TOK_HDR_LEN, md5cksum.data + md5cksum.len - 8, 8);
 111
 112         spin_lock(&krb5_seq_lock);
 113         seq_send = ctx->seq_send++;
 114         spin_unlock(&krb5_seq_lock);
 115
 116         if (krb5_make_seq_num(ctx->seq, ctx->initiate ? 0 : 0xff,
 117                               seq_send, ptr + GSS_KRB5_TOK_HDR_LEN,
 118                               ptr + 8))
 119                 return GSS_S_FAILURE;
 120
 121         return (ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE;
 122 }