freebsd-skq/eBones/krb/krb_get_in_tkt.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

298 lines
8.8 KiB
C

/*
* Copyright 1986, 1987, 1988 by the Massachusetts Institute
* of Technology.
* For copying and distribution information, please see the file
* <Copyright.MIT>.
*
* from: der: krb_get_in_tkt.c,v 4.19 89/07/18 16:31:31 jtkohl Exp $
* $Id: krb_get_in_tkt.c,v 1.2 1994/07/19 19:25:47 g89r4222 Exp $
*/
#ifndef lint
static char *rcsid =
"$Id: krb_get_in_tkt.c,v 1.2 1994/07/19 19:25:47 g89r4222 Exp $";
#endif /* lint */
#include <krb.h>
#include <des.h>
#include <prot.h>
#include <stdio.h>
#include <strings.h>
#include <errno.h>
/* use the bsd time.h struct defs for PC too! */
#include <sys/time.h>
#include <sys/types.h>
int swap_bytes;
/*
* decrypt_tkt(): Given user, instance, realm, passwd, key_proc
* and the cipher text sent from the KDC, decrypt the cipher text
* using the key returned by key_proc.
*/
static int decrypt_tkt(user, instance, realm, arg, key_proc, cipp)
char *user;
char *instance;
char *realm;
char *arg;
int (*key_proc)();
KTEXT *cipp;
{
KTEXT cip = *cipp;
C_Block key; /* Key for decrypting cipher */
Key_schedule key_s;
#ifndef NOENCRYPTION
/* Attempt to decrypt it */
#endif
/* generate a key */
{
register int rc;
rc = (*key_proc)(user,instance,realm,arg,key);
if (rc)
return(rc);
}
#ifndef NOENCRYPTION
key_sched(key,key_s);
pcbc_encrypt((C_Block *)cip->dat,(C_Block *)cip->dat,
(long) cip->length,key_s,key,DES_DECRYPT);
#endif /* !NOENCRYPTION */
/* Get rid of all traces of key */
bzero((char *)key,sizeof(key));
bzero((char *)key_s,sizeof(key_s));
return(0);
}
/*
* krb_get_in_tkt() gets a ticket for a given principal to use a given
* service and stores the returned ticket and session key for future
* use.
*
* The "user", "instance", and "realm" arguments give the identity of
* the client who will use the ticket. The "service" and "sinstance"
* arguments give the identity of the server that the client wishes
* to use. (The realm of the server is the same as the Kerberos server
* to whom the request is sent.) The "life" argument indicates the
* desired lifetime of the ticket; the "key_proc" argument is a pointer
* to the routine used for getting the client's private key to decrypt
* the reply from Kerberos. The "decrypt_proc" argument is a pointer
* to the routine used to decrypt the reply from Kerberos; and "arg"
* is an argument to be passed on to the "key_proc" routine.
*
* If all goes well, krb_get_in_tkt() returns INTK_OK, otherwise it
* returns an error code: If an AUTH_MSG_ERR_REPLY packet is returned
* by Kerberos, then the error code it contains is returned. Other
* error codes returned by this routine include INTK_PROT to indicate
* wrong protocol version, INTK_BADPW to indicate bad password (if
* decrypted ticket didn't make sense), INTK_ERR if the ticket was for
* the wrong server or the ticket store couldn't be initialized.
*
* The format of the message sent to Kerberos is as follows:
*
* Size Variable Field
* ---- -------- -----
*
* 1 byte KRB_PROT_VERSION protocol version number
* 1 byte AUTH_MSG_KDC_REQUEST | message type
* HOST_BYTE_ORDER local byte order in lsb
* string user client's name
* string instance client's instance
* string realm client's realm
* 4 bytes tlocal.tv_sec timestamp in seconds
* 1 byte life desired lifetime
* string service service's name
* string sinstance service's instance
*/
krb_get_in_tkt(user, instance, realm, service, sinstance, life,
key_proc, decrypt_proc, arg)
char *user;
char *instance;
char *realm;
char *service;
char *sinstance;
int life;
int (*key_proc)();
int (*decrypt_proc)();
char *arg;
{
KTEXT_ST pkt_st;
KTEXT pkt = &pkt_st; /* Packet to KDC */
KTEXT_ST rpkt_st;
KTEXT rpkt = &rpkt_st; /* Returned packet */
KTEXT_ST cip_st;
KTEXT cip = &cip_st; /* Returned Ciphertext */
KTEXT_ST tkt_st;
KTEXT tkt = &tkt_st; /* Current ticket */
C_Block ses; /* Session key for tkt */
int kvno; /* Kvno for session key */
unsigned char *v = pkt->dat; /* Prot vers no */
unsigned char *t = (pkt->dat+1); /* Prot msg type */
char s_name[SNAME_SZ];
char s_instance[INST_SZ];
char rlm[REALM_SZ];
int lifetime;
int msg_byte_order;
int kerror;
unsigned long exp_date;
char *ptr;
struct timeval t_local;
unsigned long rep_err_code;
unsigned long kdc_time; /* KDC time */
/* BUILD REQUEST PACKET */
/* Set up the fixed part of the packet */
*v = (unsigned char) KRB_PROT_VERSION;
*t = (unsigned char) AUTH_MSG_KDC_REQUEST;
*t |= HOST_BYTE_ORDER;
/* Now for the variable info */
(void) strcpy((char *)(pkt->dat+2),user); /* aname */
pkt->length = 3 + strlen(user);
(void) strcpy((char *)(pkt->dat+pkt->length),
instance); /* instance */
pkt->length += 1 + strlen(instance);
(void) strcpy((char *)(pkt->dat+pkt->length),realm); /* realm */
pkt->length += 1 + strlen(realm);
(void) gettimeofday(&t_local,(struct timezone *) 0);
/* timestamp */
bcopy((char *)&(t_local.tv_sec),(char *)(pkt->dat+pkt->length), 4);
pkt->length += 4;
*(pkt->dat+(pkt->length)++) = (char) life;
(void) strcpy((char *)(pkt->dat+pkt->length),service);
pkt->length += 1 + strlen(service);
(void) strcpy((char *)(pkt->dat+pkt->length),sinstance);
pkt->length += 1 + strlen(sinstance);
rpkt->length = 0;
/* SEND THE REQUEST AND RECEIVE THE RETURN PACKET */
if (kerror = send_to_kdc(pkt, rpkt, realm)) return(kerror);
/* check packet version of the returned packet */
if (pkt_version(rpkt) != KRB_PROT_VERSION)
return(INTK_PROT);
/* Check byte order */
msg_byte_order = pkt_msg_type(rpkt) & 1;
swap_bytes = 0;
if (msg_byte_order != HOST_BYTE_ORDER) {
swap_bytes++;
}
switch (pkt_msg_type(rpkt) & ~1) {
case AUTH_MSG_KDC_REPLY:
break;
case AUTH_MSG_ERR_REPLY:
bcopy(pkt_err_code(rpkt),(char *) &rep_err_code,4);
if (swap_bytes) swap_u_long(rep_err_code);
return((int)rep_err_code);
default:
return(INTK_PROT);
}
/* EXTRACT INFORMATION FROM RETURN PACKET */
/* get the principal's expiration date */
bcopy(pkt_x_date(rpkt),(char *) &exp_date,sizeof(exp_date));
if (swap_bytes) swap_u_long(exp_date);
/* Extract the ciphertext */
cip->length = pkt_clen(rpkt); /* let clen do the swap */
if ((cip->length < 0) || (cip->length > sizeof(cip->dat)))
return(INTK_ERR); /* no appropriate error code
currently defined for INTK_ */
/* copy information from return packet into "cip" */
bcopy((char *) pkt_cipher(rpkt),(char *)(cip->dat),cip->length);
/* Attempt to decrypt the reply. */
if (decrypt_proc == NULL)
decrypt_proc = decrypt_tkt;
(*decrypt_proc)(user, instance, realm, arg, key_proc, &cip);
ptr = (char *) cip->dat;
/* extract session key */
bcopy(ptr,(char *)ses,8);
ptr += 8;
if ((strlen(ptr) + (ptr - (char *) cip->dat)) > cip->length)
return(INTK_BADPW);
/* extract server's name */
(void) strcpy(s_name,ptr);
ptr += strlen(s_name) + 1;
if ((strlen(ptr) + (ptr - (char *) cip->dat)) > cip->length)
return(INTK_BADPW);
/* extract server's instance */
(void) strcpy(s_instance,ptr);
ptr += strlen(s_instance) + 1;
if ((strlen(ptr) + (ptr - (char *) cip->dat)) > cip->length)
return(INTK_BADPW);
/* extract server's realm */
(void) strcpy(rlm,ptr);
ptr += strlen(rlm) + 1;
/* extract ticket lifetime, server key version, ticket length */
/* be sure to avoid sign extension on lifetime! */
lifetime = (unsigned char) ptr[0];
kvno = (unsigned char) ptr[1];
tkt->length = (unsigned char) ptr[2];
ptr += 3;
if ((tkt->length < 0) ||
((tkt->length + (ptr - (char *) cip->dat)) > cip->length))
return(INTK_BADPW);
/* extract ticket itself */
bcopy(ptr,(char *)(tkt->dat),tkt->length);
ptr += tkt->length;
if (strcmp(s_name, service) || strcmp(s_instance, sinstance) ||
strcmp(rlm, realm)) /* not what we asked for */
return(INTK_ERR); /* we need a better code here XXX */
/* check KDC time stamp */
bcopy(ptr,(char *)&kdc_time,4); /* Time (coarse) */
if (swap_bytes) swap_u_long(kdc_time);
ptr += 4;
(void) gettimeofday(&t_local,(struct timezone *) 0);
if (abs((int)(t_local.tv_sec - kdc_time)) > CLOCK_SKEW) {
return(RD_AP_TIME); /* XXX should probably be better
code */
}
/* initialize ticket cache */
if (in_tkt(user,instance) != KSUCCESS)
return(INTK_ERR);
/* stash ticket, session key, etc. for future use */
if (kerror = save_credentials(s_name, s_instance, rlm, ses,
lifetime, kvno, tkt, t_local.tv_sec))
return(kerror);
return(INTK_OK);
}