1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
/*
* appl/sample/sserver/sserver.c
*
* Copyright 1990,1991 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. 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.
*
*
* Sample Kerberos v5 server.
*
* sample_server:
* A sample Kerberos server, which reads an AP_REQ from a TCP socket,
* decodes it, and writes back the results (in ASCII) to the client.
*
* Usage:
* sample_server servername
*
* file descriptor 0 (zero) should be a socket connected to the requesting
* client (this will be correct if this server is started by inetd).
*/
#include "krb5.h"
#include "com_err.h"
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <syslog.h>
#include "../sample.h"
extern krb5_deltat krb5_clockskew;
#define DEBUG
void
usage(name)
char *name;
{
fprintf(stderr, "usage: %s [-p port] [-s service] [-S keytab]\n",
name);
}
void
main(argc, argv)
int argc;
char *argv[];
{
krb5_context context;
krb5_auth_context auth_context = NULL;
krb5_ticket * ticket;
krb5_address peeraddr;
struct sockaddr_in peername;
int namelen = sizeof(peername);
int sock = -1; /* incoming connection fd */
krb5_data recv_data;
short xmitlen;
krb5_error_code retval;
krb5_principal server, client;
char repbuf[BUFSIZ];
char *cname;
char *service = SAMPLE_SERVICE;
short port = 0; /* If user specifies port */
extern int opterr, optind;
extern char * optarg;
int ch;
krb5_keytab keytab = NULL; /* Allow specification on command line */
char *progname;
int on = 1;
progname = *argv;
krb5_init_context(&context);
krb5_init_ets(context);
/* open a log connection */
openlog("sserver", 0, LOG_DAEMON);
/*
* Parse command line arguments
*
*/
opterr = 0;
while ((ch = getopt(argc, argv, "p:S:s:")) != EOF)
switch (ch) {
case 'p':
port = atoi(optarg);
break;
case 's':
service = optarg;
break;
case 'S':
if (retval = krb5_kt_resolve(context, optarg, &keytab)) {
com_err(progname, retval,
"while resolving keytab file %s", optarg);
exit(2);
}
break;
case '?':
default:
usage(progname);
exit(1);
break;
}
argc -= optind;
argv += optind;
/* Backwards compatibility, allow port to be specified at end */
if (argc > 1) {
port = atoi(argv[1]);
}
if (retval = krb5_sname_to_principal(context, NULL, service,
KRB5_NT_SRV_HST, &server)) {
syslog(LOG_ERR, "while generating service name (%s): %s",
service, error_message(retval));
exit(1);
}
/*
* If user specified a port, then listen on that port; otherwise,
* assume we've been started out of inetd.
*/
if (port) {
int acc;
struct sockaddr_in sin;
if ((sock = socket(PF_INET, SOCK_STREAM, 0)) < 0) {
syslog(LOG_ERR, "socket: %m");
exit(3);
}
/* Let the socket be reused right away */
(void) setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (char *)&on,
sizeof(on));
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = 0;
sin.sin_port = htons(port);
if (bind(sock, (struct sockaddr *) &sin, sizeof(sin))) {
syslog(LOG_ERR, "bind: %m");
exit(3);
}
if (listen(sock, 1) == -1) {
syslog(LOG_ERR, "listen: %m");
exit(3);
}
if ((acc = accept(sock, (struct sockaddr *)&peername, &namelen)) == -1){
syslog(LOG_ERR, "accept: %m");
exit(3);
}
dup2(acc, 0);
close(sock);
sock = 0;
} else {
/*
* To verify authenticity, we need to know the address of the
* client.
*/
if (getpeername(0, (struct sockaddr *)&peername, &namelen) < 0) {
syslog(LOG_ERR, "getpeername: %m");
exit(1);
}
sock = 0;
}
peeraddr.addrtype = peername.sin_family;
peeraddr.length = sizeof(peername.sin_addr);
peeraddr.contents = (krb5_octet *)&peername.sin_addr;
if (retval = krb5_recvauth(context, &auth_context, (krb5_pointer)&sock,
SAMPLE_VERSION, server,
0, /* no flags */
keytab, /* default keytab is NULL */
&ticket)) {
syslog(LOG_ERR, "recvauth failed--%s", error_message(retval));
exit(1);
}
/* Get client name */
if (retval = krb5_unparse_name(context, ticket->enc_part2->client, &cname)){
syslog(LOG_ERR, "unparse failed: %s", error_message(retval));
sprintf(repbuf, "You are <unparse error>\n");
} else {
sprintf(repbuf, "You are %s\n", cname);
free(cname);
}
xmitlen = htons(strlen(repbuf));
recv_data.length = strlen(repbuf);
recv_data.data = repbuf;
if ((retval = krb5_net_write(context, 0, (char *)&xmitlen,
sizeof(xmitlen))) < 0) {
syslog(LOG_ERR, "%m: while writing len to client");
exit(1);
}
if ((retval = krb5_net_write(context, 0, (char *)recv_data.data,
recv_data.length)) < 0) {
syslog(LOG_ERR, "%m: while writing data to client");
exit(1);
}
krb5_auth_con_free(context, auth_context);
krb5_free_context(context);
exit(0);
}
|
