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/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* lib/krb5/krb/rd_priv.c */
/*
* Copyright 1990,1991,2007 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.
*/
#include "k5-int.h"
#include "int-proto.h"
#include "auth_con.h"
/*
Parses a KRB_PRIV message from inbuf, placing the confidential user
data in *outbuf.
key specifies the key to be used for decryption of the message.
outbuf points to allocated storage which the caller should
free when finished.
Returns system errors, integrity errors.
*/
static krb5_error_code
rd_priv_basic(krb5_context context, krb5_auth_context ac,
const krb5_data *inbuf, const krb5_key key,
krb5_replay_data *replaydata, krb5_data *outbuf)
{
krb5_error_code retval;
krb5_priv * privmsg;
krb5_data scratch;
krb5_priv_enc_part * privmsg_enc_part;
krb5_data *iv = NULL;
if (!krb5_is_krb_priv(inbuf))
return KRB5KRB_AP_ERR_MSG_TYPE;
/* decode private message */
if ((retval = decode_krb5_priv(inbuf, &privmsg)))
return retval;
if (ac->cstate.length > 0)
iv = &ac->cstate;
scratch.length = privmsg->enc_part.ciphertext.length;
if (!(scratch.data = malloc(scratch.length))) {
retval = ENOMEM;
goto cleanup_privmsg;
}
if ((retval = krb5_k_decrypt(context, key,
KRB5_KEYUSAGE_KRB_PRIV_ENCPART, iv,
&privmsg->enc_part, &scratch)))
goto cleanup_scratch;
/* now decode the decrypted stuff */
if ((retval = decode_krb5_enc_priv_part(&scratch, &privmsg_enc_part)))
goto cleanup_scratch;
retval = k5_privsafe_check_addrs(context, ac, privmsg_enc_part->s_address,
privmsg_enc_part->r_address);
if (retval)
goto cleanup_data;
replaydata->timestamp = privmsg_enc_part->timestamp;
replaydata->usec = privmsg_enc_part->usec;
replaydata->seq = privmsg_enc_part->seq_number;
/* everything is ok - return data to the user */
*outbuf = privmsg_enc_part->user_data;
retval = 0;
cleanup_data:;
if (retval == 0)
privmsg_enc_part->user_data.data = 0;
krb5_free_priv_enc_part(context, privmsg_enc_part);
cleanup_scratch:;
memset(scratch.data, 0, scratch.length);
free(scratch.data);
cleanup_privmsg:;
free(privmsg->enc_part.ciphertext.data);
free(privmsg);
return retval;
}
krb5_error_code KRB5_CALLCONV
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 retval;
krb5_key key;
krb5_replay_data replaydata;
/* Get key */
if ((key = auth_context->recv_subkey) == NULL)
key = auth_context->key;
if (((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_TIME) ||
(auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
(outdata == NULL))
/* Need a better error */
return KRB5_RC_REQUIRED;
if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_TIME) &&
(auth_context->remote_addr == NULL))
return KRB5_REMOTE_ADDR_REQUIRED;
if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_TIME) &&
(auth_context->rcache == NULL))
return KRB5_RC_REQUIRED;
memset(&replaydata, 0, sizeof(replaydata));
retval = rd_priv_basic(context, auth_context, inbuf, key, &replaydata,
outbuf);
if (retval)
return retval;
if (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_TIME) {
krb5_donot_replay replay;
if ((retval = krb5_check_clockskew(context, replaydata.timestamp)))
goto error;
if ((retval = krb5_gen_replay_name(context, auth_context->remote_addr,
"_priv", &replay.client)))
goto error;
replay.server = ""; /* XXX */
replay.msghash = NULL;
replay.cusec = replaydata.usec;
replay.ctime = replaydata.timestamp;
if ((retval = krb5_rc_store(context, auth_context->rcache, &replay))) {
free(replay.client);
goto error;
}
free(replay.client);
}
if (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
if (!k5_privsafe_check_seqnum(context, auth_context, replaydata.seq)) {
retval = KRB5KRB_AP_ERR_BADORDER;
goto error;
}
auth_context->remote_seq_number++;
}
if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_TIME) ||
(auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)) {
outdata->timestamp = replaydata.timestamp;
outdata->usec = replaydata.usec;
outdata->seq = replaydata.seq;
}
/* everything is ok - return data to the user */
return 0;
error:;
free(outbuf->data);
outbuf->length = 0;
outbuf->data = NULL;
return retval;
}
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