1/*
2 * Copyright (c) 1997-2007 Kungliga Tekniska Högskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include "krb5_locl.h"
35
36/*
37 * See `sendauth.c' for the format.
38 */
39
40static krb5_boolean
41match_exact(const void *data, const char *appl_version)
42{
43    return strcmp(data, appl_version) == 0;
44}
45
46KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
47krb5_recvauth(krb5_context context,
48	      krb5_auth_context *auth_context,
49	      krb5_pointer p_fd,
50	      const char *appl_version,
51	      krb5_principal server,
52	      int32_t flags,
53	      krb5_keytab keytab,
54	      krb5_ticket **ticket)
55{
56    return krb5_recvauth_match_version(context, auth_context, p_fd,
57				       match_exact, appl_version,
58				       server, flags,
59				       keytab, ticket);
60}
61
62KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
63krb5_recvauth_match_version(krb5_context context,
64			    krb5_auth_context *auth_context,
65			    krb5_pointer p_fd,
66			    krb5_boolean (*match_appl_version)(const void *,
67							       const char*),
68			    const void *match_data,
69			    krb5_principal server,
70			    int32_t flags,
71			    krb5_keytab keytab,
72			    krb5_ticket **ticket)
73{
74    krb5_error_code ret;
75    const char *version = KRB5_SENDAUTH_VERSION;
76    char her_version[sizeof(KRB5_SENDAUTH_VERSION)];
77    char *her_appl_version;
78    uint32_t len;
79    u_char repl;
80    krb5_data data;
81    krb5_flags ap_options;
82    ssize_t n;
83
84    /*
85     * If there are no addresses in auth_context, get them from `fd'.
86     */
87
88    if (*auth_context == NULL) {
89	ret = krb5_auth_con_init (context, auth_context);
90	if (ret)
91	    return ret;
92    }
93
94    ret = krb5_auth_con_setaddrs_from_fd (context,
95					  *auth_context,
96					  p_fd);
97    if (ret)
98	return ret;
99
100    if(!(flags & KRB5_RECVAUTH_IGNORE_VERSION)) {
101	n = krb5_net_read (context, p_fd, &len, 4);
102	if (n < 0) {
103	    ret = errno;
104	    krb5_set_error_message(context, ret, "read: %s", strerror(ret));
105	    return ret;
106	}
107	if (n == 0) {
108	    krb5_set_error_message(context, KRB5_SENDAUTH_BADAUTHVERS,
109				   N_("Failed to receive sendauth data", ""));
110	    return KRB5_SENDAUTH_BADAUTHVERS;
111	}
112	len = ntohl(len);
113	if (len != sizeof(her_version)
114	    || krb5_net_read (context, p_fd, her_version, len) != (ssize_t)len
115	    || strncmp (version, her_version, len)) {
116	    repl = 1;
117	    krb5_net_write (context, p_fd, &repl, 1);
118	    krb5_clear_error_message (context);
119	    return KRB5_SENDAUTH_BADAUTHVERS;
120	}
121    }
122
123    n = krb5_net_read (context, p_fd, &len, 4);
124    if (n < 0) {
125	ret = errno;
126	krb5_set_error_message(context, ret, "read: %s", strerror(ret));
127	return ret;
128    }
129    if (n == 0) {
130	krb5_clear_error_message (context);
131	return KRB5_SENDAUTH_BADAPPLVERS;
132    }
133    len = ntohl(len);
134    if (len > UINT_MAX / 16) {
135	krb5_set_error_message(context, ERANGE,
136			       N_("packet to large", ""));
137	return ERANGE;
138    }
139    her_appl_version = malloc (len);
140    if (her_appl_version == NULL) {
141	repl = 2;
142	krb5_net_write (context, p_fd, &repl, 1);
143	krb5_set_error_message(context, ENOMEM,
144			       N_("malloc: out of memory", ""));
145	return ENOMEM;
146    }
147    if (krb5_net_read (context, p_fd, her_appl_version, len) != (ssize_t)len
148	|| !(*match_appl_version)(match_data, her_appl_version)) {
149	repl = 2;
150	krb5_net_write (context, p_fd, &repl, 1);
151	krb5_set_error_message(context, KRB5_SENDAUTH_BADAPPLVERS,
152			       N_("wrong sendauth version (%s)", ""),
153			       her_appl_version);
154	free (her_appl_version);
155	return KRB5_SENDAUTH_BADAPPLVERS;
156    }
157    free (her_appl_version);
158
159    repl = 0;
160    if (krb5_net_write (context, p_fd, &repl, 1) != 1) {
161	ret = errno;
162	krb5_set_error_message(context, ret, "write: %s", strerror(ret));
163	return ret;
164    }
165
166    krb5_data_zero (&data);
167    ret = krb5_read_message (context, p_fd, &data);
168    if (ret) {
169	krb5_set_error_message(context, ret, "krb5_recvauth: client closed connection");
170	return ret;
171    }
172
173    ret = krb5_rd_req (context,
174		       auth_context,
175		       &data,
176		       server,
177		       keytab,
178		       &ap_options,
179		       ticket);
180    krb5_data_free (&data);
181    if (ret) {
182	krb5_data error_data;
183	krb5_error_code ret2;
184
185	ret2 = krb5_mk_error (context,
186			      ret,
187			      NULL,
188			      NULL,
189			      NULL,
190			      server,
191			      NULL,
192			      NULL,
193			      &error_data);
194	if (ret2 == 0) {
195	    krb5_write_message (context, p_fd, &error_data);
196	    krb5_data_free (&error_data);
197	}
198	return ret;
199    }
200
201    len = 0;
202    if (krb5_net_write (context, p_fd, &len, 4) != 4) {
203	ret = errno;
204	krb5_set_error_message(context, ret, "write: %s", strerror(ret));
205	krb5_free_ticket(context, *ticket);
206	*ticket = NULL;
207	return ret;
208    }
209
210    if (ap_options & AP_OPTS_MUTUAL_REQUIRED) {
211	ret = krb5_mk_rep (context, *auth_context, &data);
212	if (ret) {
213	    krb5_free_ticket(context, *ticket);
214	    *ticket = NULL;
215	    return ret;
216	}
217
218	ret = krb5_write_message (context, p_fd, &data);
219	if (ret) {
220	    krb5_set_error_message(context, ret, "krb5_recvauth: server closed connection");
221	    krb5_free_ticket(context, *ticket);
222	    *ticket = NULL;
223	    return ret;
224	}
225	krb5_data_free (&data);
226    }
227    return 0;
228}
229