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/* $OpenBSD: sendauth.c,v 1.7 1998/02/25 15:51:40 art Exp $ */
/* $KTH: sendauth.c,v 1.15 1997/04/18 14:11:36 joda Exp $ */
/*
* This source code is no longer held under any constraint of USA
* `cryptographic laws' since it was exported legally. The cryptographic
* functions were removed from the code and a "Bones" distribution was
* made. A Commodity Jurisdiction Request #012-94 was filed with the
* USA State Department, who handed it to the Commerce department. The
* code was determined to fall under General License GTDA under ECCN 5D96G,
* and hence exportable. The cryptographic interfaces were re-added by Eric
* Young, and then KTH proceeded to maintain the code in the free world.
*
*/
/*
* Copyright (C) 1989 by the Massachusetts Institute of Technology
*
* Export of this software from the United States of America is assumed
* to 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. 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_locl.h"
/*
* krb_sendauth() transmits a ticket over a file descriptor for a
* desired service, instance, and realm, doing mutual authentication
* with the server if desired.
*/
/*
* The first argument to krb_sendauth() contains a bitfield of
* options (the options are defined in "krb.h"):
*
* KOPT_DONT_CANON Don't canonicalize instance as a hostname.
* (If this option is not chosen, krb_get_phost()
* is called to canonicalize it.)
*
* KOPT_DONT_MK_REQ Don't request server ticket from Kerberos.
* A ticket must be supplied in the "ticket"
* argument.
* (If this option is not chosen, and there
* is no ticket for the given server in the
* ticket cache, one will be fetched using
* krb_mk_req() and returned in "ticket".)
*
* KOPT_DO_MUTUAL Do mutual authentication, requiring that the
* receiving server return the checksum+1 encrypted
* in the session key. The mutual authentication
* is done using krb_mk_priv() on the other side
* (see "recvauth.c") and krb_rd_priv() on this
* side.
*
* The "fd" argument is a file descriptor to write to the remote
* server on. The "ticket" argument is used to store the new ticket
* from the krb_mk_req() call. If the KOPT_DONT_MK_REQ options is
* chosen, the ticket must be supplied in the "ticket" argument.
* The "service", "inst", and "realm" arguments identify the ticket.
* If "realm" is null, the local realm is used.
*
* The following arguments are only needed if the KOPT_DO_MUTUAL option
* is chosen:
*
* The "checksum" argument is a number that the server will add 1 to
* to authenticate itself back to the client; the "msg_data" argument
* holds the returned mutual-authentication message from the server
* (i.e., the checksum+1); the "cred" structure is used to hold the
* session key of the server, extracted from the ticket file, for use
* in decrypting the mutual authentication message from the server;
* and "schedule" holds the key schedule for that decryption. The
* the local and server addresses are given in "laddr" and "faddr".
*
* The application protocol version number (of up to KRB_SENDAUTH_VLEN
* characters) is passed in "version".
*
* If all goes well, KSUCCESS is returned, otherwise some error code.
*
* The format of the message sent to the server is:
*
* Size Variable Field
* ---- -------- -----
*
* KRB_SENDAUTH_VLEN KRB_SENDAUTH_VER sendauth protocol
* bytes version number
*
* KRB_SENDAUTH_VLEN version application protocol
* bytes version number
*
* 4 bytes ticket->length length of ticket
*
* ticket->length ticket->dat ticket itself
*/
int
krb_sendauth(int32_t options, /* bit-pattern of options */
int fd, /* file descriptor to write onto */
KTEXT ticket, /* where to put ticket (return); or
* supplied in case of KOPT_DONT_MK_REQ */
char *service, /* service name, instance, realm */
char *instance,
char *realm,
u_int32_t checksum, /* checksum to include in request */
MSG_DAT *msg_data, /* mutual auth MSG_DAT (return) */
CREDENTIALS *cred, /* credentials (return) */
struct des_ks_struct *schedule, /* key schedule (return) */
struct sockaddr_in *laddr, /* local address */
struct sockaddr_in *faddr, /* address of foreign host on fd */
char *version) /* version string */
{
int ret;
KTEXT_ST buf;
char realrealm[REALM_SZ];
if (realm == NULL) {
ret = krb_get_lrealm (realrealm, 1);
if (ret != KSUCCESS)
return ret;
realm = realrealm;
}
ret = krb_mk_auth (options, ticket, service, instance, realm, checksum,
version, &buf);
if (ret != KSUCCESS)
return ret;
ret = krb_net_write(fd, buf.dat, buf.length);
if(ret < 0)
return -1;
if (options & KOPT_DO_MUTUAL) {
char tmp[4];
u_int32_t len;
char inst[INST_SZ];
char *i;
ret = krb_net_read (fd, tmp, 4);
if (ret < 0)
return -1;
krb_get_int (tmp, &len, 4, 0);
if (len == 0xFFFFFFFF || len > sizeof(buf.dat))
return KFAILURE;
buf.length = len;
ret = krb_net_read (fd, buf.dat, len);
if (ret < 0)
return -1;
if (options & KOPT_DONT_CANON)
i = instance;
else
i = krb_get_phost(instance);
strncpy (inst, i, sizeof(inst));
inst[sizeof(inst) - 1] = '\0';
ret = krb_get_cred (service, inst, realm, cred);
if (ret != KSUCCESS)
return ret;
des_key_sched(&cred->session, schedule);
ret = krb_check_auth (&buf, checksum, msg_data, &cred->session,
schedule, laddr, faddr);
if (ret != KSUCCESS)
return ret;
}
return KSUCCESS;
}
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