a83b802bad
These are the start of a lot of work to clean up the FreeBSD eBones code. these changes include, but are not limited to: - Create prototypes for all the library routines - Make all the libraries compile clean with -Wall set - Fix numerous small bugs shown up in the above process - Prepare the code for libdes's removal to secure/ - add register, registerd and make_keypair to the make Lots more will follow in days to come. OK'ed by: rgrimes
279 lines
8.8 KiB
C
279 lines
8.8 KiB
C
/*
|
|
* Copyright 1987, 1988 by the Massachusetts Institute of Technology.
|
|
* For copying and distribution information, please see the file
|
|
* <Copyright.MIT>.
|
|
*
|
|
* from: recvauth.c,v 4.4 90/03/10 19:03:08 jon Exp $";
|
|
* $Id: recvauth.c,v 1.3 1995/07/18 16:39:38 mark Exp $
|
|
*/
|
|
|
|
#if 0
|
|
#ifndef lint
|
|
static char rcsid[] =
|
|
"$Id: recvauth.c,v 1.3 1995/07/18 16:39:38 mark Exp $";
|
|
#endif lint
|
|
#endif
|
|
|
|
#include <sys/types.h>
|
|
#include <netinet/in.h>
|
|
#include <syslog.h>
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <strings.h>
|
|
#include <krb.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_sendauth.c
|
|
* be sure to support old versions of krb_sendauth!
|
|
*/
|
|
|
|
/*
|
|
* krb_recvauth() reads (and optionally responds to) a message sent
|
|
* using krb_sendauth(). The "options" argument is a bit-field of
|
|
* selected options (see "sendauth.c" for options description).
|
|
* The only option relevant to krb_recvauth() is KOPT_DO_MUTUAL
|
|
* (mutual authentication requested). The "fd" argument supplies
|
|
* a file descriptor to read from (and write to, if mutual authenti-
|
|
* cation is requested).
|
|
*
|
|
* Part of the received message will be a Kerberos ticket sent by the
|
|
* client; this is read into the "ticket" argument. The "service" and
|
|
* "instance" arguments supply the server's Kerberos name. If the
|
|
* "instance" argument is the string "*", it is treated as a wild card
|
|
* and filled in during the krb_rd_req() call (see read_service_key()).
|
|
*
|
|
* The "faddr" and "laddr" give the sending (client) and receiving
|
|
* (local server) network addresses. ("laddr" may be left NULL unless
|
|
* mutual authentication is requested, in which case it must be set.)
|
|
*
|
|
* The authentication information extracted from the message is returned
|
|
* in "kdata". The "filename" argument indicates the file where the
|
|
* server's key can be found. (It is passed on to krb_rd_req().) If
|
|
* left null, the default "/etc/srvtab" will be used.
|
|
*
|
|
* If mutual authentication is requested, the session key schedule must
|
|
* be computed in order to reply; this schedule is returned in the
|
|
* "schedule" argument. A string containing the application version
|
|
* number from the received message is returned in "version", which
|
|
* should be large enough to hold a KRB_SENDAUTH_VLEN-character string.
|
|
*
|
|
* See krb_sendauth() for the format of the received client message.
|
|
*
|
|
* This routine supports another client format, for backward
|
|
* compatibility, consisting of:
|
|
*
|
|
* Size Variable Field
|
|
* ---- -------- -----
|
|
*
|
|
* string tmp_buf, tkt_len length of ticket, in
|
|
* ascii
|
|
*
|
|
* char ' ' (space char) separator
|
|
*
|
|
* tkt_len ticket->dat the ticket
|
|
*
|
|
* This old-style version does not support mutual authentication.
|
|
*
|
|
* krb_recvauth() first reads the protocol version string from the
|
|
* given file descriptor. If it doesn't match the current protocol
|
|
* version (KRB_SENDAUTH_VERS), the old-style format is assumed. In
|
|
* that case, the string of characters up to the first space is read
|
|
* and interpreted as the ticket length, then the ticket is read.
|
|
*
|
|
* If the first string did match KRB_SENDAUTH_VERS, krb_recvauth()
|
|
* next reads the application protocol version string. Then the
|
|
* ticket length and ticket itself are read.
|
|
*
|
|
* The ticket is decrypted and checked by the call to krb_rd_req().
|
|
* If no mutual authentication is required, the result of the
|
|
* krb_rd_req() call is retured by this routine. If mutual authenti-
|
|
* cation is required, a message in the following format is returned
|
|
* on "fd":
|
|
*
|
|
* Size Variable Field
|
|
* ---- -------- -----
|
|
*
|
|
* 4 bytes tkt_len length of ticket or -1
|
|
* if error occurred
|
|
*
|
|
* priv_len tmp_buf "private" message created
|
|
* by krb_mk_priv() which
|
|
* contains the incremented
|
|
* checksum sent by the client
|
|
* encrypted in the session
|
|
* key. (This field is not
|
|
* present in case of error.)
|
|
*
|
|
* If all goes well, KSUCCESS is returned; otherwise KFAILURE or some
|
|
* other error code is returned.
|
|
*/
|
|
|
|
#ifndef max
|
|
#define max(a,b) (((a) > (b)) ? (a) : (b))
|
|
#endif /* max */
|
|
|
|
int
|
|
krb_recvauth(long options, int fd, KTEXT ticket, char *service, char *instance,
|
|
struct sockaddr_in *faddr, struct sockaddr_in *laddr, AUTH_DAT *kdata,
|
|
char *filename, des_key_schedule schedule, char *version)
|
|
{
|
|
|
|
int i, cc, old_vers = 0;
|
|
char krb_vers[KRB_SENDAUTH_VLEN + 1]; /* + 1 for the null terminator */
|
|
char *cp = NULL;
|
|
int rem;
|
|
long tkt_len, priv_len;
|
|
u_long cksum;
|
|
u_char tmp_buf[MAX_KTXT_LEN+max(KRB_SENDAUTH_VLEN+1,21)];
|
|
|
|
/* read the protocol version number */
|
|
if (krb_net_read(fd, krb_vers, KRB_SENDAUTH_VLEN) !=
|
|
KRB_SENDAUTH_VLEN)
|
|
return(errno);
|
|
krb_vers[KRB_SENDAUTH_VLEN] = '\0';
|
|
|
|
/* check version string */
|
|
if (strcmp(krb_vers,KRB_SENDAUTH_VERS)) {
|
|
/* Assume the old version of sendkerberosdata: send ascii
|
|
length, ' ', and ticket. */
|
|
if (options & KOPT_DO_MUTUAL)
|
|
return(KFAILURE); /* XXX can't do old style with mutual auth */
|
|
old_vers = 1;
|
|
|
|
/* copy what we have read into tmp_buf */
|
|
(void) bcopy(krb_vers, (char *) tmp_buf, KRB_SENDAUTH_VLEN);
|
|
|
|
/* search for space, and make it a null */
|
|
for (i = 0; i < KRB_SENDAUTH_VLEN; i++)
|
|
if (tmp_buf[i]== ' ') {
|
|
tmp_buf[i] = '\0';
|
|
/* point cp to the beginning of the real ticket */
|
|
cp = (char *) &tmp_buf[i+1];
|
|
break;
|
|
}
|
|
|
|
if (i == KRB_SENDAUTH_VLEN)
|
|
/* didn't find the space, keep reading to find it */
|
|
for (; i<20; i++) {
|
|
if (read(fd, (char *)&tmp_buf[i], 1) != 1) {
|
|
return(KFAILURE);
|
|
}
|
|
if (tmp_buf[i] == ' ') {
|
|
tmp_buf[i] = '\0';
|
|
/* point cp to the beginning of the real ticket */
|
|
cp = (char *) &tmp_buf[i+1];
|
|
break;
|
|
}
|
|
}
|
|
|
|
tkt_len = (long) atoi((char *) tmp_buf);
|
|
|
|
/* sanity check the length */
|
|
if ((i==20)||(tkt_len<=0)||(tkt_len>MAX_KTXT_LEN))
|
|
return(KFAILURE);
|
|
|
|
if (i < KRB_SENDAUTH_VLEN) {
|
|
/* since we already got the space, and part of the ticket,
|
|
we read fewer bytes to get the rest of the ticket */
|
|
if (krb_net_read(fd, (char *)(tmp_buf+KRB_SENDAUTH_VLEN),
|
|
(int) (tkt_len - KRB_SENDAUTH_VLEN + 1 + i))
|
|
!= (int)(tkt_len - KRB_SENDAUTH_VLEN + 1 + i))
|
|
return(errno);
|
|
} else {
|
|
if (krb_net_read(fd, (char *)(tmp_buf+i), (int)tkt_len) !=
|
|
(int) tkt_len)
|
|
return(errno);
|
|
}
|
|
ticket->length = tkt_len;
|
|
/* copy the ticket into the struct */
|
|
(void) bcopy(cp, (char *) ticket->dat, ticket->length);
|
|
|
|
} else {
|
|
/* read the application version string */
|
|
if (krb_net_read(fd, version, KRB_SENDAUTH_VLEN) !=
|
|
KRB_SENDAUTH_VLEN)
|
|
return(errno);
|
|
version[KRB_SENDAUTH_VLEN] = '\0';
|
|
|
|
/* get the length of the ticket */
|
|
if (krb_net_read(fd, (char *)&tkt_len, sizeof(tkt_len)) !=
|
|
sizeof(tkt_len))
|
|
return(errno);
|
|
|
|
/* sanity check */
|
|
ticket->length = ntohl((unsigned long)tkt_len);
|
|
if ((ticket->length <= 0) || (ticket->length > MAX_KTXT_LEN)) {
|
|
if (options & KOPT_DO_MUTUAL) {
|
|
rem = KFAILURE;
|
|
goto mutual_fail;
|
|
} else
|
|
return(KFAILURE); /* XXX there may still be junk on the fd? */
|
|
}
|
|
|
|
/* read the ticket */
|
|
if (krb_net_read(fd, (char *) ticket->dat, ticket->length)
|
|
!= ticket->length)
|
|
return(errno);
|
|
}
|
|
/*
|
|
* now have the ticket. decrypt it to get the authenticated
|
|
* data.
|
|
*/
|
|
rem = krb_rd_req(ticket,service,instance,faddr->sin_addr.s_addr,
|
|
kdata,filename);
|
|
|
|
if (old_vers) return(rem); /* XXX can't do mutual with old client */
|
|
|
|
/* if we are doing mutual auth, compose a response */
|
|
if (options & KOPT_DO_MUTUAL) {
|
|
if (rem != KSUCCESS)
|
|
/* the krb_rd_req failed */
|
|
goto mutual_fail;
|
|
|
|
/* add one to the (formerly) sealed checksum, and re-seal it
|
|
for return to the client */
|
|
cksum = kdata->checksum + 1;
|
|
cksum = htonl(cksum);
|
|
#ifndef NOENCRYPTION
|
|
key_sched((des_cblock *)kdata->session,schedule);
|
|
#endif
|
|
priv_len = krb_mk_priv((unsigned char *)&cksum,
|
|
tmp_buf,
|
|
(unsigned long) sizeof(cksum),
|
|
schedule,
|
|
kdata->session,
|
|
laddr,
|
|
faddr);
|
|
if (priv_len < 0) {
|
|
/* re-sealing failed; notify the client */
|
|
rem = KFAILURE; /* XXX */
|
|
mutual_fail:
|
|
priv_len = -1;
|
|
tkt_len = htonl((unsigned long) priv_len);
|
|
/* a length of -1 is interpreted as an authentication
|
|
failure by the client */
|
|
if ((cc = krb_net_write(fd, (char *)&tkt_len, sizeof(tkt_len)))
|
|
!= sizeof(tkt_len))
|
|
return(cc);
|
|
return(rem);
|
|
} else {
|
|
/* re-sealing succeeded, send the private message */
|
|
tkt_len = htonl((unsigned long)priv_len);
|
|
if ((cc = krb_net_write(fd, (char *)&tkt_len, sizeof(tkt_len)))
|
|
!= sizeof(tkt_len))
|
|
return(cc);
|
|
if ((cc = krb_net_write(fd, (char *)tmp_buf, (int) priv_len))
|
|
!= (int) priv_len)
|
|
return(cc);
|
|
}
|
|
}
|
|
return(rem);
|
|
}
|