freebsd-skq/eBones/krb/sendauth.c
Geoff Rehmet 60643d379b Initial import of eBones.
(Including all changes for FreeBSD - importing the original eBones distribution
would be too complex at this stage, since I don't have access to Piero's 
CVS.)
(If you want to include eBones in your system, don't forget to include
MAKE_EBONES in /etc/make.conf.)
(This stuff is now also suppable from braae.ru.ac.za.)

Bones originally from MIT SIPB.
Original port to FreeBSD 1.x  by Piero Serini.
Moved to FreeBSD 2.0 by Doug Rabson and Geoff Rehmet.
Nice bug fixes from Doug Rabson.
1994-09-30 14:50:09 +00:00

258 lines
7.8 KiB
C

/*
* Copyright 1987, 1988 by the Massachusetts Institute of Technology.
* For copying and distribution information, please see the file
* <Copyright.MIT>.
*
* from: sendauth.c,v 4.6 90/03/10 23:18:28 jon Exp $
* $Id: sendauth.c,v 1.2 1994/07/19 19:26:23 g89r4222 Exp $
*/
#ifndef lint
static char rcsid[] =
"$Id: sendauth.c,v 1.2 1994/07/19 19:26:23 g89r4222 Exp $";
#endif lint
#include <krb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <syslog.h>
#include <errno.h>
#include <stdio.h>
#include <strings.h>
#define KRB_SENDAUTH_VERS "AUTHV0.1" /* MUST be KRB_SENDAUTH_VLEN chars */
/*
* If the protocol changes, you will need to change the version string
* and make appropriate changes in krb_recvauth.c
*/
extern int errno;
extern char *krb_get_phost();
/*
* This file contains two routines: krb_sendauth() and krb_sendsrv().
*
* krb_sendauth() transmits a ticket over a file descriptor for a
* desired service, instance, and realm, doing mutual authentication
* with the server if desired.
*
* krb_sendsvc() sends a service name to a remote knetd server.
*/
/*
* 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
*/
/*
* XXX: Note that krb_rd_priv() is coded in such a way that
* "msg_data->app_data" will be pointing into "priv_buf", which
* will disappear when krb_sendauth() returns.
*/
int
krb_sendauth(options, fd, ticket, service, inst, realm, checksum,
msg_data, cred, schedule, laddr, faddr, version)
long 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, *inst, *realm; /* service name, instance, realm */
u_long checksum; /* checksum to include in request */
MSG_DAT *msg_data; /* mutual auth MSG_DAT (return) */
CREDENTIALS *cred; /* credentials (return) */
Key_schedule 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 rem, i, cc;
char srv_inst[INST_SZ];
char krb_realm[REALM_SZ];
char buf[BUFSIZ];
long tkt_len;
u_char priv_buf[1024];
u_long cksum;
rem=KSUCCESS;
/* get current realm if not passed in */
if (!realm) {
rem = krb_get_lrealm(krb_realm,1);
if (rem != KSUCCESS)
return(rem);
realm = krb_realm;
}
/* copy instance into local storage, canonicalizing if desired */
if (options & KOPT_DONT_CANON)
(void) strncpy(srv_inst, inst, INST_SZ);
else
(void) strncpy(srv_inst, krb_get_phost(inst), INST_SZ);
/* get the ticket if desired */
if (!(options & KOPT_DONT_MK_REQ)) {
rem = krb_mk_req(ticket, service, srv_inst, realm, checksum);
if (rem != KSUCCESS)
return(rem);
}
#ifdef ATHENA_COMPAT
/* this is only for compatibility with old servers */
if (options & KOPT_DO_OLDSTYLE) {
(void) sprintf(buf,"%d ",ticket->length);
(void) write(fd, buf, strlen(buf));
(void) write(fd, (char *) ticket->dat, ticket->length);
return(rem);
}
#endif ATHENA_COMPAT
/* if mutual auth, get credentials so we have service session
keys for decryption below */
if (options & KOPT_DO_MUTUAL)
if (cc = krb_get_cred(service, srv_inst, realm, cred))
return(cc);
/* zero the buffer */
(void) bzero(buf, BUFSIZ);
/* insert version strings */
(void) strncpy(buf, KRB_SENDAUTH_VERS, KRB_SENDAUTH_VLEN);
(void) strncpy(buf+KRB_SENDAUTH_VLEN, version, KRB_SENDAUTH_VLEN);
/* increment past vers strings */
i = 2*KRB_SENDAUTH_VLEN;
/* put ticket length into buffer */
tkt_len = htonl((unsigned long) ticket->length);
(void) bcopy((char *) &tkt_len, buf+i, sizeof(tkt_len));
i += sizeof(tkt_len);
/* put ticket into buffer */
(void) bcopy((char *) ticket->dat, buf+i, ticket->length);
i += ticket->length;
/* write the request to the server */
if ((cc = krb_net_write(fd, buf, i)) != i)
return(cc);
/* mutual authentication, if desired */
if (options & KOPT_DO_MUTUAL) {
/* get the length of the reply */
if (krb_net_read(fd, (char *) &tkt_len, sizeof(tkt_len)) !=
sizeof(tkt_len))
return(errno);
tkt_len = ntohl((unsigned long)tkt_len);
/* if the length is negative, the server failed to recognize us. */
if ((tkt_len < 0) || (tkt_len > sizeof(priv_buf)))
return(KFAILURE); /* XXX */
/* read the reply... */
if (krb_net_read(fd, (char *)priv_buf, (int) tkt_len) != (int) tkt_len)
return(errno);
/* ...and decrypt it */
#ifndef NOENCRYPTION
key_sched(cred->session,schedule);
#endif
if (cc = krb_rd_priv(priv_buf,(unsigned long) tkt_len, schedule,
cred->session, faddr, laddr, msg_data))
return(cc);
/* fetch the (modified) checksum */
(void) bcopy((char *)msg_data->app_data, (char *)&cksum,
sizeof(cksum));
cksum = ntohl(cksum);
/* if it doesn't match, fail */
if (cksum != checksum + 1)
return(KFAILURE); /* XXX */
}
return(KSUCCESS);
}
#ifdef ATHENA_COMPAT
/*
* krb_sendsvc
*/
int
krb_sendsvc(fd, service)
int fd;
char *service;
{
/* write the service name length and then the service name to
the fd */
long serv_length;
int cc;
serv_length = htonl((unsigned long)strlen(service));
if ((cc = krb_net_write(fd, (char *) &serv_length,
sizeof(serv_length)))
!= sizeof(serv_length))
return(cc);
if ((cc = krb_net_write(fd, service, strlen(service)))
!= strlen(service))
return(cc);
return(KSUCCESS);
}
#endif ATHENA_COMPAT