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/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* appl/simple/client/sim_client.c */
/*
* Copyright 1989,1991 by the Massachusetts Institute of Technology.
* All Rights Reserved.
*
* Export of this software from the United States of America may
* 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. Furthermore if you modify this software you must label
* your software as modified software and not distribute it in such a
* fashion that it might be confused with the original M.I.T. software.
* 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.
*/
/*
* Simple UDP-based sample client program. For demonstration.
* This program performs no useful function.
*/
#include <krb5.h>
#include "com_err.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <netdb.h>
#include <getopt.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "simple.h"
/* for old Unixes and friends ... */
#ifndef MAXHOSTNAMELEN
#define MAXHOSTNAMELEN 64
#endif
#define MSG "hi there!" /* message text */
void usage (char *);
void
usage(char *name)
{
fprintf(stderr, "usage: %s [-p port] [-h host] [-m message] [-s service] [host]\n", name);
}
int
main(int argc, char *argv[])
{
int sock, i;
socklen_t len;
int flags = 0; /* flags for sendto() */
struct servent *serv;
struct hostent *host;
#ifdef BROKEN_STREAMS_SOCKETS
char my_hostname[MAXHOSTNAMELEN];
#endif
struct sockaddr_in s_sock; /* server address */
struct sockaddr_in c_sock; /* client address */
extern int opterr, optind;
extern char * optarg;
int ch;
short port = 0;
char *message = MSG;
char *hostname = 0;
char *service = SIMPLE_SERVICE;
char *progname = 0;
krb5_error_code retval;
krb5_data packet, inbuf;
krb5_ccache ccdef;
krb5_address addr;
krb5_context context;
krb5_auth_context auth_context = NULL;
retval = krb5_init_context(&context);
if (retval) {
com_err(argv[0], retval, "while initializing krb5");
exit(1);
}
progname = argv[0];
/*
* Parse command line arguments
*
*/
opterr = 0;
while ((ch = getopt(argc, argv, "p:m:h:s:")) != -1)
switch (ch) {
case 'p':
port = atoi(optarg);
break;
case 'm':
message = optarg;
break;
case 'h':
hostname = optarg;
break;
case 's':
service = optarg;
break;
case '?':
default:
usage(progname);
exit(1);
break;
}
argc -= optind;
argv += optind;
if (argc > 0) {
if (hostname)
usage(progname);
hostname = argv[0];
}
if (hostname == 0) {
fprintf(stderr, "You must specify a hostname to contact.\n\n");
usage(progname);
exit(1);
}
/* Look up server host */
if ((host = gethostbyname(hostname)) == (struct hostent *) 0) {
fprintf(stderr, "%s: unknown host\n", hostname);
exit(1);
}
/* Set server's address */
(void) memset(&s_sock, 0, sizeof(s_sock));
memcpy(&s_sock.sin_addr, host->h_addr, sizeof(s_sock.sin_addr));
#ifdef DEBUG
printf("s_sock.sin_addr is %s\n", inet_ntoa(s_sock.sin_addr));
#endif
s_sock.sin_family = AF_INET;
if (port == 0) {
/* Look up service */
if ((serv = getservbyname(SIMPLE_PORT, "udp")) == NULL) {
fprintf(stderr, "service unknown: %s/udp\n", SIMPLE_PORT);
exit(1);
}
s_sock.sin_port = serv->s_port;
} else {
s_sock.sin_port = htons(port);
}
/* Open a socket */
if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
com_err(progname, errno, "opening datagram socket");
exit(1);
}
memset(&c_sock, 0, sizeof(c_sock));
c_sock.sin_family = AF_INET;
#ifdef BROKEN_STREAMS_SOCKETS
if (gethostname(my_hostname, sizeof(my_hostname)) < 0) {
perror("gethostname");
exit(1);
}
if ((host = gethostbyname(my_hostname)) == (struct hostent *)0) {
fprintf(stderr, "%s: unknown host\n", hostname);
exit(1);
}
memcpy(&c_sock.sin_addr, host->h_addr, sizeof(c_sock.sin_addr));
#endif
/* Bind it to set the address; kernel will fill in port # */
if (bind(sock, (struct sockaddr *)&c_sock, sizeof(c_sock)) < 0) {
com_err(progname, errno, "while binding datagram socket");
exit(1);
}
/* PREPARE KRB_AP_REQ MESSAGE */
inbuf.data = hostname;
inbuf.length = strlen(hostname);
/* Get credentials for server */
if ((retval = krb5_cc_default(context, &ccdef))) {
com_err(progname, retval, "while getting default ccache");
exit(1);
}
retval = krb5_mk_req(context, &auth_context, AP_OPTS_USE_SUBKEY, service,
hostname, &inbuf, ccdef, &packet);
if (retval) {
com_err(progname, retval, "while preparing AP_REQ");
exit(1);
}
printf("Got credentials for %s.\n", service);
/* "connect" the datagram socket; this is necessary to get a local address
properly bound for getsockname() below. */
if (connect(sock, (struct sockaddr *)&s_sock, sizeof(s_sock)) == -1) {
com_err(progname, errno, "while connecting to server");
exit(1);
}
/* Send authentication info to server */
if ((i = send(sock, (char *)packet.data, (unsigned) packet.length,
flags)) < 0)
com_err(progname, errno, "while sending KRB_AP_REQ message");
printf("Sent authentication data: %d bytes\n", i);
krb5_free_data_contents(context, &packet);
/* PREPARE KRB_SAFE MESSAGE */
/* Get my address */
memset(&c_sock, 0, sizeof(c_sock));
len = sizeof(c_sock);
if (getsockname(sock, (struct sockaddr *)&c_sock, &len) < 0) {
com_err(progname, errno, "while getting socket name");
exit(1);
}
addr.addrtype = ADDRTYPE_IPPORT;
addr.length = sizeof(c_sock.sin_port);
addr.contents = (krb5_octet *)&c_sock.sin_port;
if ((retval = krb5_auth_con_setports(context, auth_context,
&addr, NULL))) {
com_err(progname, retval, "while setting local port\n");
exit(1);
}
addr.addrtype = ADDRTYPE_INET;
addr.length = sizeof(c_sock.sin_addr);
addr.contents = (krb5_octet *)&c_sock.sin_addr;
if ((retval = krb5_auth_con_setaddrs(context, auth_context,
&addr, NULL))) {
com_err(progname, retval, "while setting local addr\n");
exit(1);
}
/* Make the safe message */
inbuf.data = message;
inbuf.length = strlen(message);
if ((retval = krb5_mk_safe(context, auth_context, &inbuf, &packet, NULL))){
com_err(progname, retval, "while making KRB_SAFE message");
exit(1);
}
/* Send it */
if ((i = send(sock, (char *)packet.data, (unsigned) packet.length,
flags)) < 0)
com_err(progname, errno, "while sending SAFE message");
printf("Sent checksummed message: %d bytes\n", i);
krb5_free_data_contents(context, &packet);
/* PREPARE KRB_PRIV MESSAGE */
/* Make the encrypted message */
if ((retval = krb5_mk_priv(context, auth_context, &inbuf,
&packet, NULL))) {
com_err(progname, retval, "while making KRB_PRIV message");
exit(1);
}
/* Send it */
if ((i = send(sock, (char *)packet.data, (unsigned) packet.length,
flags)) < 0)
com_err(progname, errno, "while sending PRIV message");
printf("Sent encrypted message: %d bytes\n", i);
krb5_free_data_contents(context, &packet);
krb5_auth_con_free(context, auth_context);
krb5_free_context(context);
exit(0);
}
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