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/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* lib/krb5/krb/rd_rep.c */
/*
* Copyright 1990,1991 by the Massachusetts Institute of Technology.
* All Rights Reserved.
*
* Export of this software from the United States of America may
* require a specific license from the United States Government.
* It is the responsibility of any person or organization contemplating
* export to obtain such a license before exporting.
*
* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
* distribute this software and its documentation for any purpose and
* without fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright notice and
* this permission notice appear in supporting documentation, and that
* the name of M.I.T. not be used in advertising or publicity pertaining
* to distribution of the software without specific, written prior
* permission. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is" without express
* or implied warranty.
*/
/*
* Copyright (c) 2006-2008, Novell, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * 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.
* * The copyright holder's name is not used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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 "k5-int.h"
#include "auth_con.h"
/*
* Parses a KRB_AP_REP message, returning its contents.
*
* repl is filled in with with a pointer to allocated memory containing
* the fields from the encrypted response.
*
* the key in kblock is used to decrypt the message.
*
* returns system errors, encryption errors, replay errors
*/
krb5_error_code KRB5_CALLCONV
krb5_rd_rep(krb5_context context, krb5_auth_context auth_context,
const krb5_data *inbuf, krb5_ap_rep_enc_part **repl)
{
krb5_error_code retval;
krb5_ap_rep *reply = NULL;
krb5_ap_rep_enc_part *enc = NULL;
krb5_data scratch;
*repl = NULL;
if (!krb5_is_ap_rep(inbuf))
return KRB5KRB_AP_ERR_MSG_TYPE;
/* Decode inbuf. */
retval = decode_krb5_ap_rep(inbuf, &reply);
if (retval)
return retval;
/* Put together an eblock for this encryption. */
scratch.length = reply->enc_part.ciphertext.length;
scratch.data = malloc(scratch.length);
if (scratch.data == NULL) {
retval = ENOMEM;
goto clean_scratch;
}
retval = krb5_k_decrypt(context, auth_context->key,
KRB5_KEYUSAGE_AP_REP_ENCPART, 0,
&reply->enc_part, &scratch);
if (retval)
goto clean_scratch;
/* Now decode the decrypted stuff. */
retval = decode_krb5_ap_rep_enc_part(&scratch, &enc);
if (retval)
goto clean_scratch;
/* Check reply fields. */
if ((enc->ctime != auth_context->authentp->ctime)
|| (enc->cusec != auth_context->authentp->cusec)) {
retval = KRB5_MUTUAL_FAILED;
goto clean_scratch;
}
/* Set auth subkey. */
if (enc->subkey) {
retval = krb5_auth_con_setrecvsubkey(context, auth_context,
enc->subkey);
if (retval)
goto clean_scratch;
retval = krb5_auth_con_setsendsubkey(context, auth_context,
enc->subkey);
if (retval) {
(void) krb5_auth_con_setrecvsubkey(context, auth_context, NULL);
goto clean_scratch;
}
/* Not used for anything yet. */
auth_context->negotiated_etype = enc->subkey->enctype;
}
/* Get remote sequence number. */
auth_context->remote_seq_number = enc->seq_number;
TRACE_RD_REP(context, enc->ctime, enc->cusec, enc->subkey,
enc->seq_number);
*repl = enc;
enc = NULL;
clean_scratch:
if (scratch.data)
memset(scratch.data, 0, scratch.length);
free(scratch.data);
krb5_free_ap_rep(context, reply);
krb5_free_ap_rep_enc_part(context, enc);
return retval;
}
krb5_error_code KRB5_CALLCONV
krb5_rd_rep_dce(krb5_context context, krb5_auth_context auth_context,
const krb5_data *inbuf, krb5_ui_4 *nonce)
{
krb5_error_code retval;
krb5_ap_rep * reply;
krb5_data scratch;
krb5_ap_rep_enc_part *repl = NULL;
if (!krb5_is_ap_rep(inbuf))
return KRB5KRB_AP_ERR_MSG_TYPE;
/* decode it */
if ((retval = decode_krb5_ap_rep(inbuf, &reply)))
return retval;
/* put together an eblock for this encryption */
scratch.length = reply->enc_part.ciphertext.length;
if (!(scratch.data = malloc(scratch.length))) {
krb5_free_ap_rep(context, reply);
return(ENOMEM);
}
if ((retval = krb5_k_decrypt(context, auth_context->key,
KRB5_KEYUSAGE_AP_REP_ENCPART, 0,
&reply->enc_part, &scratch)))
goto clean_scratch;
/* now decode the decrypted stuff */
retval = decode_krb5_ap_rep_enc_part(&scratch, &repl);
if (retval)
goto clean_scratch;
*nonce = repl->seq_number;
if (*nonce != auth_context->local_seq_number) {
retval = KRB5_MUTUAL_FAILED;
goto clean_scratch;
}
/* Must be NULL to prevent echoing for client AP-REP */
if (repl->subkey != NULL) {
retval = KRB5_MUTUAL_FAILED;
goto clean_scratch;
}
TRACE_RD_REP_DCE(context, repl->ctime, repl->cusec, repl->seq_number);
clean_scratch:
memset(scratch.data, 0, scratch.length);
if (repl != NULL)
krb5_free_ap_rep_enc_part(context, repl);
krb5_free_ap_rep(context, reply);
free(scratch.data);
return retval;
}
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