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/*
* lib/krb4/cr_ciph.c
*
* Copyright 1986, 1987, 1988, 2000 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 "krb.h"
#include "prot.h"
#include "des.h"
#include <string.h>
/*
* This routine is used by the authentication server to create
* a packet for its client, containing a ticket for the requested
* service (given in "tkt"), and some information about the ticket,
#ifndef NOENCRYPTION
* all encrypted in the given key ("key").
#endif
*
* Returns KSUCCESS no matter what.
*
* The length of the cipher is stored in c->length; the format of
* c->dat is as follows:
*
* variable
* type or constant data
* ---- ----------- ----
*
*
* 8 bytes session session key for client, service
*
* string service service name
*
* string instance service instance
*
* string realm KDC realm
*
* unsigned char life ticket lifetime
*
* unsigned char kvno service key version number
*
* unsigned char tkt->length length of following ticket
*
* data tkt->dat ticket for service
*
* 4 bytes kdc_time KDC's timestamp
*
* <=7 bytes null null pad to 8 byte multiple
*
*/
int
create_ciph(c, session, service, instance, realm, life, kvno, tkt,
kdc_time, key)
KTEXT c; /* Text block to hold ciphertext */
C_Block session; /* Session key to send to user */
char *service; /* Service name on ticket */
char *instance; /* Instance name on ticket */
char *realm; /* Realm of this KDC */
unsigned long life; /* Lifetime of the ticket */
int kvno; /* Key version number for service */
KTEXT tkt; /* The ticket for the service */
unsigned long kdc_time; /* KDC time */
C_Block key; /* Key to encrypt ciphertext with */
{
unsigned char *ptr;
size_t servicelen, instancelen, realmlen;
Key_schedule key_s;
ptr = c->dat;
/* Validate lengths. */
servicelen = strlen(service) + 1;
instancelen = strlen(instance) + 1;
realmlen = strlen(realm) + 1;
if (sizeof(c->dat) / 8 < ((8 + servicelen + instancelen + realmlen
+ 1 + 1 + 1 + tkt->length
+ 4 + 7) / 8)
|| tkt->length > 255 || tkt->length < 0) {
c->length = 0;
return KFAILURE;
}
memcpy(ptr, session, 8);
ptr += 8;
memcpy(ptr, service, servicelen);
ptr += servicelen;
memcpy(ptr, instance, instancelen);
ptr += instancelen;
memcpy(ptr, realm, realmlen);
ptr += realmlen;
*ptr++ = life;
*ptr++ = kvno;
*ptr++ = tkt->length;
memcpy(ptr, tkt->dat, (size_t)tkt->length);
ptr += tkt->length;
KRB4_PUT32BE(ptr, kdc_time);
/* guarantee null padded encrypted data to multiple of 8 bytes */
memset(ptr, 0, 7);
c->length = (((ptr - c->dat) + 7) / 8) * 8;
#ifndef NOENCRYPTION
key_sched(key, key_s);
pcbc_encrypt((C_Block *)c->dat, (C_Block *)c->dat,
(long)c->length, key_s, (C_Block*)key, ENCRYPT);
memset(key_s, 0, sizeof(key_s));
#endif /* NOENCRYPTION */
return KSUCCESS;
}
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