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/slab.h>
  63 #include <linux/jiffies.h>
  64 #include <linux/sunrpc/gss_krb5.h>
  65 #include <linux/random.h>
  66 #include <asm/scatterlist.h>
  67 #include <linux/crypto.h>
  68
  69 #ifdef RPC_DEBUG
  70 # define RPCDBG_FACILITY        RPCDBG_AUTH
  71 #endif
  72
  73 spinlock_t krb5_seq_lock = SPIN_LOCK_UNLOCKED;
  74
  75 u32
  76 gss_get_mic_kerberos(struct gss_ctx *gss_ctx, struct xdr_buf *text,
  77                 struct xdr_netobj *token)
  78 {
  79         struct krb5_ctx         *ctx = gss_ctx->internal_ctx_id;
  80         s32                     checksum_type;
  81         char                    cksumdata[16];
  82         struct xdr_netobj       md5cksum = {.len = 0, .data = cksumdata};
  83         unsigned char           *ptr, *krb5_hdr, *msg_start;
  84         s32                     now;
  85         u32                     seq_send;
  86
  87         dprintk("RPC:     gss_krb5_seal\n");
  88
  89         now = get_seconds();
  90
  91         switch (ctx->signalg) {
  92                 case SGN_ALG_DES_MAC_MD5:
  93                         checksum_type = CKSUMTYPE_RSA_MD5;
  94                         break;
  95                 default:
  96                         dprintk("RPC:      gss_krb5_seal: ctx->signalg %d not"
  97                                 " supported\n", ctx->signalg);
  98                         goto out_err;
  99         }
 100         if (ctx->sealalg != SEAL_ALG_NONE && ctx->sealalg != SEAL_ALG_DES) {
 101                 dprintk("RPC:      gss_krb5_seal: ctx->sealalg %d not supported\n",
 102                         ctx->sealalg);
 103                 goto out_err;
 104         }
 105
 106         token->len = g_token_size(&ctx->mech_used, 22);
 107
 108         ptr = token->data;
 109         g_make_token_header(&ctx->mech_used, 22, &ptr);
 110
 111         *ptr++ = (unsigned char) ((KG_TOK_MIC_MSG>>8)&0xff);
 112         *ptr++ = (unsigned char) (KG_TOK_MIC_MSG&0xff);
 113
 114         /* ptr now at byte 2 of header described in rfc 1964, section 1.2.1: */
 115         krb5_hdr = ptr - 2;
 116         msg_start = krb5_hdr + 24;
 117
 118         *(u16 *)(krb5_hdr + 2) = htons(ctx->signalg);
 119         memset(krb5_hdr + 4, 0xff, 4);
 120
 121         if (make_checksum(checksum_type, krb5_hdr, 8, text, 0, &md5cksum))
 122                         goto out_err;
 123
 124         switch (ctx->signalg) {
 125         case SGN_ALG_DES_MAC_MD5:
 126                 if (krb5_encrypt(ctx->seq, NULL, md5cksum.data,
 127                                   md5cksum.data, md5cksum.len))
 128                         goto out_err;
 129                 memcpy(krb5_hdr + 16,
 130                        md5cksum.data + md5cksum.len - KRB5_CKSUM_LENGTH,
 131                        KRB5_CKSUM_LENGTH);
 132
 133                 dprintk("RPC:      make_seal_token: cksum data: \n");
 134                 print_hexl((u32 *) (krb5_hdr + 16), KRB5_CKSUM_LENGTH, 0);
 135                 break;
 136         default:
 137                 BUG();
 138         }
 139
 140         spin_lock(&krb5_seq_lock);
 141         seq_send = ctx->seq_send++;
 142         spin_unlock(&krb5_seq_lock);
 143
 144         if ((krb5_make_seq_num(ctx->seq, ctx->initiate ? 0 : 0xff,
 145                                seq_send, krb5_hdr + 16, krb5_hdr + 8)))
 146                 goto out_err;
 147
 148         return ((ctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE);
 149 out_err:
 150         return GSS_S_FAILURE;
 151 }