crypto/external/bsd/heimdal/dist/lib/krb5/rd_priv.c

   1 /*      $NetBSD: rd_priv.c,v 1.1.1.1 2011/04/13 18:15:37 elric Exp $    */
   2
   3 /*
   4  * Copyright (c) 1997-2007 Kungliga Tekniska Högskolan
   5  * (Royal Institute of Technology, Stockholm, Sweden).
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  *
  15  * 2. Redistributions in binary form must reproduce the above copyright
  16  *    notice, this list of conditions and the following disclaimer in the
  17  *    documentation and/or other materials provided with the distribution.
  18  *
  19  * 3. Neither the name of the Institute nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include "krb5_locl.h"
  37
  38 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
  39 krb5_rd_priv(krb5_context context,
  40              krb5_auth_context auth_context,
  41              const krb5_data *inbuf,
  42              krb5_data *outbuf,
  43              krb5_replay_data *outdata)
  44 {
  45     krb5_error_code ret;
  46     KRB_PRIV priv;
  47     EncKrbPrivPart part;
  48     size_t len;
  49     krb5_data plain;
  50     krb5_keyblock *key;
  51     krb5_crypto crypto;
  52
  53     krb5_data_zero(outbuf);
  54
  55     if ((auth_context->flags &
  56          (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)))
  57     {
  58         if (outdata == NULL) {
  59             krb5_clear_error_message (context);
  60             return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
  61         }
  62         /* if these fields are not present in the priv-part, silently
  63            return zero */
  64         memset(outdata, 0, sizeof(*outdata));
  65     }
  66
  67     memset(&priv, 0, sizeof(priv));
  68     ret = decode_KRB_PRIV (inbuf->data, inbuf->length, &priv, &len);
  69     if (ret) {
  70         krb5_clear_error_message (context);
  71         goto failure;
  72     }
  73     if (priv.pvno != 5) {
  74         krb5_clear_error_message (context);
  75         ret = KRB5KRB_AP_ERR_BADVERSION;
  76         goto failure;
  77     }
  78     if (priv.msg_type != krb_priv) {
  79         krb5_clear_error_message (context);
  80         ret = KRB5KRB_AP_ERR_MSG_TYPE;
  81         goto failure;
  82     }
  83
  84     if (auth_context->remote_subkey)
  85         key = auth_context->remote_subkey;
  86     else if (auth_context->local_subkey)
  87         key = auth_context->local_subkey;
  88     else
  89         key = auth_context->keyblock;
  90
  91     ret = krb5_crypto_init(context, key, 0, &crypto);
  92     if (ret)
  93         goto failure;
  94     ret = krb5_decrypt_EncryptedData(context,
  95                                      crypto,
  96                                      KRB5_KU_KRB_PRIV,
  97                                      &priv.enc_part,
  98                                      &plain);
  99     krb5_crypto_destroy(context, crypto);
 100     if (ret)
 101         goto failure;
 102
 103     ret = decode_EncKrbPrivPart (plain.data, plain.length, &part, &len);
 104     krb5_data_free (&plain);
 105     if (ret) {
 106         krb5_clear_error_message (context);
 107         goto failure;
 108     }
 109
 110     /* check sender address */
 111
 112     if (part.s_address
 113         && auth_context->remote_address
 114         && !krb5_address_compare (context,
 115                                   auth_context->remote_address,
 116                                   part.s_address)) {
 117         krb5_clear_error_message (context);
 118         ret = KRB5KRB_AP_ERR_BADADDR;
 119         goto failure_part;
 120     }
 121
 122     /* check receiver address */
 123
 124     if (part.r_address
 125         && auth_context->local_address
 126         && !krb5_address_compare (context,
 127                                   auth_context->local_address,
 128                                   part.r_address)) {
 129         krb5_clear_error_message (context);
 130         ret = KRB5KRB_AP_ERR_BADADDR;
 131         goto failure_part;
 132     }
 133
 134     /* check timestamp */
 135     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
 136         krb5_timestamp sec;
 137
 138         krb5_timeofday (context, &sec);
 139         if (part.timestamp == NULL ||
 140             part.usec      == NULL ||
 141             abs(*part.timestamp - sec) > context->max_skew) {
 142             krb5_clear_error_message (context);
 143             ret = KRB5KRB_AP_ERR_SKEW;
 144             goto failure_part;
 145         }
 146     }
 147
 148     /* XXX - check replay cache */
 149
 150     /* check sequence number. since MIT krb5 cannot generate a sequence
 151        number of zero but instead generates no sequence number, we accept that
 152     */
 153
 154     if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
 155         if ((part.seq_number == NULL
 156              && auth_context->remote_seqnumber != 0)
 157             || (part.seq_number != NULL
 158                 && *part.seq_number != auth_context->remote_seqnumber)) {
 159             krb5_clear_error_message (context);
 160             ret = KRB5KRB_AP_ERR_BADORDER;
 161             goto failure_part;
 162         }
 163         auth_context->remote_seqnumber++;
 164     }
 165
 166     ret = krb5_data_copy (outbuf, part.user_data.data, part.user_data.length);
 167     if (ret)
 168         goto failure_part;
 169
 170     if ((auth_context->flags &
 171          (KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) {
 172         if(part.timestamp)
 173             outdata->timestamp = *part.timestamp;
 174         if(part.usec)
 175             outdata->usec = *part.usec;
 176         if(part.seq_number)
 177             outdata->seq = *part.seq_number;
 178     }
 179
 180   failure_part:
 181     free_EncKrbPrivPart (&part);
 182
 183   failure:
 184     free_KRB_PRIV (&priv);
 185     return ret;
 186 }