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/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*
* kdc/dispatch.c
*
* Copyright 1990, 2009 by the Massachusetts Institute of Technology.
*
* 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.
*
*
* Dispatch an incoming packet.
*/
#include "k5-int.h"
#include <syslog.h>
#include "kdc_util.h"
#include "extern.h"
#include "adm_proto.h"
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
static krb5_int32 last_usec = 0, last_os_random = 0;
krb5_error_code
dispatch(krb5_data *pkt, const krb5_fulladdr *from, krb5_data **response)
{
krb5_error_code retval;
krb5_kdc_req *as_req;
krb5_int32 now, now_usec;
/* decode incoming packet, and dispatch */
#ifndef NOCACHE
/* try the replay lookaside buffer */
if (kdc_check_lookaside(pkt, response)) {
/* a hit! */
const char *name = 0;
char buf[46];
name = inet_ntop (ADDRTYPE2FAMILY (from->address->addrtype),
from->address->contents, buf, sizeof (buf));
if (name == 0)
name = "[unknown address type]";
krb5_klog_syslog(LOG_INFO,
"DISPATCH: repeated (retransmitted?) request from %s, resending previous response",
name);
return 0;
}
#endif
retval = krb5_crypto_us_timeofday(&now, &now_usec);
if (retval == 0) {
krb5_int32 usec_difference = now_usec-last_usec;
krb5_data data;
if(last_os_random == 0)
last_os_random = now;
/* Grab random data from OS every hour*/
if(now-last_os_random >= 60*60) {
krb5_c_random_os_entropy(kdc_context, 0, NULL);
last_os_random = now;
}
data.length = sizeof(krb5_int32);
data.data = (void *) &usec_difference;
krb5_c_random_add_entropy(kdc_context,
KRB5_C_RANDSOURCE_TIMING, &data);
last_usec = now_usec;
}
/* try TGS_REQ first; they are more common! */
if (krb5_is_tgs_req(pkt)) {
retval = process_tgs_req(pkt, from, response);
} else if (krb5_is_as_req(pkt)) {
if (!(retval = decode_krb5_as_req(pkt, &as_req))) {
/*
* setup_server_realm() sets up the global realm-specific data
* pointer.
* process_as_req frees the request if it is called
*/
if (!(retval = setup_server_realm(as_req->server))) {
retval = process_as_req(as_req, pkt, from, response);
}
else krb5_free_kdc_req(kdc_context, as_req);
}
}
else
retval = KRB5KRB_AP_ERR_MSG_TYPE;
#ifndef NOCACHE
/* put the response into the lookaside buffer */
if (!retval && *response != NULL)
kdc_insert_lookaside(pkt, *response);
#endif
return retval;
}
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