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/* $KTH: mk_req.c,v 1.17 1997/05/30 17:42:38 bg Exp $ */
/*
* Copyright (c) 1995, 1996, 1997 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the Kungliga Tekniska
* Högskolan and its contributors.
*
* 4. 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 "krb_locl.h"
static int lifetime = 255; /* But no longer than TGT says. */
static void
build_request(KTEXT req, char *name, char *inst, char *realm,
u_int32_t checksum)
{
struct timeval tv;
unsigned char *p = req->dat;
p += krb_put_nir(name, inst, realm, p);
p += krb_put_int(checksum, p, 4);
/* Fill in the times on the request id */
gettimeofday(&tv, NULL);
*p++ = tv.tv_usec / 5000; /* 5ms */
p += krb_put_int(tv.tv_sec, p, 4);
/* Fill to a multiple of 8 bytes for DES */
req->length = ((p - req->dat + 7)/8) * 8;
}
/*
* krb_mk_req takes a text structure in which an authenticator is to
* be built, the name of a service, an instance, a realm,
* and a checksum. It then retrieves a ticket for
* the desired service and creates an authenticator in the text
* structure passed as the first argument. krb_mk_req returns
* KSUCCESS on success and a Kerberos error code on failure.
*
* The peer procedure on the other end is krb_rd_req. When making
* any changes to this routine it is important to make corresponding
* changes to krb_rd_req.
*
* The authenticator consists of the following:
*
* authent->dat
*
* unsigned char KRB_PROT_VERSION protocol version no.
* unsigned char AUTH_MSG_APPL_REQUEST message type
* (least significant
* bit of above) HOST_BYTE_ORDER local byte ordering
* unsigned char kvno from ticket server's key version
* string realm server's realm
* unsigned char tl ticket length
* unsigned char idl request id length
* text ticket->dat ticket for server
* text req_id->dat request id
*
* The ticket information is retrieved from the ticket cache or
* fetched from Kerberos. The request id (called the "authenticator"
* in the papers on Kerberos) contains the following:
*
* req_id->dat
*
* string cr.pname {name, instance, and
* string cr.pinst realm of principal
* string myrealm making this request}
* 4 bytes checksum checksum argument given
* unsigned char tv_local.tf_usec time (milliseconds)
* 4 bytes tv_local.tv_sec time (seconds)
*
* req_id->length = 3 strings + 3 terminating nulls + 5 bytes for time,
* all rounded up to multiple of 8.
*/
int
krb_mk_req(KTEXT authent, char *service, char *instance, char *realm,
int32_t checksum)
{
KTEXT_ST req_st;
KTEXT req_id = &req_st;
CREDENTIALS cr; /* Credentials used by retr */
KTEXT ticket = &(cr.ticket_st); /* Pointer to tkt_st */
int retval; /* Returned by krb_get_cred */
char myrealm[REALM_SZ];
unsigned char *p = authent->dat;
p += krb_put_int(KRB_PROT_VERSION, p, 1);
p += krb_put_int(AUTH_MSG_APPL_REQUEST, p, 1);
/* Get the ticket and move it into the authenticator */
if (krb_ap_req_debug)
krb_warning("Realm: %s\n", realm);
retval = krb_get_cred(service,instance,realm,&cr);
if (retval == RET_NOTKT) {
retval = get_ad_tkt(service, instance, realm, lifetime);
if (retval == KSUCCESS)
retval = krb_get_cred(service, instance, realm, &cr);
}
if (retval != KSUCCESS)
return retval;
/*
* With multi realm ticket files either find a matching TGT or
* else use the first TGT for inter-realm authentication.
*
* In myrealm hold the realm of the principal "owning" the
* corresponding ticket-granting-ticket.
*/
retval = krb_get_cred(KRB_TICKET_GRANTING_TICKET, realm, realm, 0);
if (retval == KSUCCESS)
strncpy(myrealm, realm, REALM_SZ);
else
retval = krb_get_tf_realm(TKT_FILE, myrealm);
if (retval != KSUCCESS)
return retval;
if (krb_ap_req_debug)
krb_warning("serv=%s.%s@%s princ=%s.%s@%s\n", service, instance, realm,
cr.pname, cr.pinst, myrealm);
p += krb_put_int(cr.kvno, p, 1);
p += krb_put_string(realm, p);
p += krb_put_int(ticket->length, p, 1);
build_request(req_id, cr.pname, cr.pinst, myrealm, checksum);
encrypt_ktext(req_id, &cr.session, DES_ENCRYPT);
p += krb_put_int(req_id->length, p, 1);
memcpy(p, ticket->dat, ticket->length);
p += ticket->length;
memcpy(p, req_id->dat, req_id->length);
p += req_id->length;
authent->length = p - authent->dat;
memset(&cr, 0, sizeof(cr));
memset(&req_st, 0, sizeof(req_st));
if (krb_ap_req_debug)
krb_warning("Authent->length = %d\n", authent->length);
return KSUCCESS;
}
/*
* krb_set_lifetime sets the default lifetime for additional tickets
* obtained via krb_mk_req().
*
* It returns the previous value of the default lifetime.
*/
int
krb_set_lifetime(int newval)
{
int olife = lifetime;
lifetime = newval;
return(olife);
}
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