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/*
* Copyright (c) 1997-2007 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <krb5_locl.h>
RCSID("$Id: rd_priv.c 21751 2007-07-31 20:42:20Z lha $");
krb5_error_code KRB5_LIB_FUNCTION
krb5_rd_priv(krb5_context context,
krb5_auth_context auth_context,
const krb5_data *inbuf,
krb5_data *outbuf,
krb5_replay_data *outdata)
{
krb5_error_code ret;
KRB_PRIV priv;
EncKrbPrivPart part;
size_t len;
krb5_data plain;
krb5_keyblock *key;
krb5_crypto crypto;
if (outbuf)
krb5_data_zero(outbuf);
if ((auth_context->flags &
(KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
outdata == NULL) {
krb5_clear_error_string (context);
return KRB5_RC_REQUIRED; /* XXX better error, MIT returns this */
}
memset(&priv, 0, sizeof(priv));
ret = decode_KRB_PRIV (inbuf->data, inbuf->length, &priv, &len);
if (ret) {
krb5_clear_error_string (context);
goto failure;
}
if (priv.pvno != 5) {
krb5_clear_error_string (context);
ret = KRB5KRB_AP_ERR_BADVERSION;
goto failure;
}
if (priv.msg_type != krb_priv) {
krb5_clear_error_string (context);
ret = KRB5KRB_AP_ERR_MSG_TYPE;
goto failure;
}
if (auth_context->remote_subkey)
key = auth_context->remote_subkey;
else if (auth_context->local_subkey)
key = auth_context->local_subkey;
else
key = auth_context->keyblock;
ret = krb5_crypto_init(context, key, 0, &crypto);
if (ret)
goto failure;
ret = krb5_decrypt_EncryptedData(context,
crypto,
KRB5_KU_KRB_PRIV,
&priv.enc_part,
&plain);
krb5_crypto_destroy(context, crypto);
if (ret)
goto failure;
ret = decode_EncKrbPrivPart (plain.data, plain.length, &part, &len);
krb5_data_free (&plain);
if (ret) {
krb5_clear_error_string (context);
goto failure;
}
/* check sender address */
if (part.s_address
&& auth_context->remote_address
&& !krb5_address_compare (context,
auth_context->remote_address,
part.s_address)) {
krb5_clear_error_string (context);
ret = KRB5KRB_AP_ERR_BADADDR;
goto failure_part;
}
/* check receiver address */
if (part.r_address
&& auth_context->local_address
&& !krb5_address_compare (context,
auth_context->local_address,
part.r_address)) {
krb5_clear_error_string (context);
ret = KRB5KRB_AP_ERR_BADADDR;
goto failure_part;
}
/* check timestamp */
if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
krb5_timestamp sec;
krb5_timeofday (context, &sec);
if (part.timestamp == NULL ||
part.usec == NULL ||
abs(*part.timestamp - sec) > context->max_skew) {
krb5_clear_error_string (context);
ret = KRB5KRB_AP_ERR_SKEW;
goto failure_part;
}
}
/* XXX - check replay cache */
/* check sequence number. since MIT krb5 cannot generate a sequence
number of zero but instead generates no sequence number, we accept that
*/
if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
if ((part.seq_number == NULL
&& auth_context->remote_seqnumber != 0)
|| (part.seq_number != NULL
&& *part.seq_number != auth_context->remote_seqnumber)) {
krb5_clear_error_string (context);
ret = KRB5KRB_AP_ERR_BADORDER;
goto failure_part;
}
auth_context->remote_seqnumber++;
}
ret = krb5_data_copy (outbuf, part.user_data.data, part.user_data.length);
if (ret)
goto failure_part;
if ((auth_context->flags &
(KRB5_AUTH_CONTEXT_RET_TIME | KRB5_AUTH_CONTEXT_RET_SEQUENCE))) {
/* if these fields are not present in the priv-part, silently
return zero */
memset(outdata, 0, sizeof(*outdata));
if(part.timestamp)
outdata->timestamp = *part.timestamp;
if(part.usec)
outdata->usec = *part.usec;
if(part.seq_number)
outdata->seq = *part.seq_number;
}
failure_part:
free_EncKrbPrivPart (&part);
failure:
free_KRB_PRIV (&priv);
return ret;
}
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