recvauth.c revision 102644 
1/*
2 * Copyright (c) 1997-2002 Kungliga Tekniska H�gskolan
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
36RCSID("$Id: recvauth.c,v 1.16 2002/04/18 09:41:33 joda Exp $");
37
38/*
39 * See `sendauth.c' for the format.
40 */
41
42static krb5_boolean
43match_exact(const void *data, const char *appl_version)
44{
45    return strcmp(data, appl_version) == 0;
46}
47
48krb5_error_code
49krb5_recvauth(krb5_context context,
50	      krb5_auth_context *auth_context,
51	      krb5_pointer p_fd,
52	      const char *appl_version,
53	      krb5_principal server,
54	      int32_t flags,
55	      krb5_keytab keytab,
56	      krb5_ticket **ticket)
57{
58    return krb5_recvauth_match_version(context, auth_context, p_fd,
59				       match_exact, appl_version,
60				       server, flags,
61				       keytab, ticket);
62}
63
64krb5_error_code
65krb5_recvauth_match_version(krb5_context context,
66			    krb5_auth_context *auth_context,
67			    krb5_pointer p_fd,
68			    krb5_boolean (*match_appl_version)(const void *,
69							       const char*),
70			    const void *match_data,
71			    krb5_principal server,
72			    int32_t flags,
73			    krb5_keytab keytab,
74			    krb5_ticket **ticket)
75{
76  krb5_error_code ret;
77  const char *version = KRB5_SENDAUTH_VERSION;
78  char her_version[sizeof(KRB5_SENDAUTH_VERSION)];
79  char *her_appl_version;
80  u_int32_t len;
81  u_char repl;
82  krb5_data data;
83  krb5_flags ap_options;
84  ssize_t n;
85
86  /*
87   * If there are no addresses in auth_context, get them from `fd'.
88   */
89
90  if (*auth_context == NULL) {
91      ret = krb5_auth_con_init (context, auth_context);
92      if (ret)
93	  return ret;
94  }
95
96  ret = krb5_auth_con_setaddrs_from_fd (context,
97					*auth_context,
98					p_fd);
99  if (ret)
100      return ret;
101
102  if(!(flags & KRB5_RECVAUTH_IGNORE_VERSION)) {
103    n = krb5_net_read (context, p_fd, &len, 4);
104    if (n < 0) {
105	ret = errno;
106	krb5_set_error_string (context, "read: %s", strerror(errno));
107	return ret;
108    }
109    if (n == 0) {
110	krb5_clear_error_string (context);
111	return KRB5_SENDAUTH_BADAUTHVERS;
112    }
113    len = ntohl(len);
114    if (len != sizeof(her_version)
115	|| krb5_net_read (context, p_fd, her_version, len) != len
116	|| strncmp (version, her_version, len)) {
117      repl = 1;
118      krb5_net_write (context, p_fd, &repl, 1);
119	krb5_clear_error_string (context);
120      return KRB5_SENDAUTH_BADAUTHVERS;
121    }
122  }
123
124  n = krb5_net_read (context, p_fd, &len, 4);
125  if (n < 0) {
126      ret = errno;
127      krb5_set_error_string (context, "read: %s", strerror(errno));
128      return ret;
129  }
130  if (n == 0) {
131      krb5_clear_error_string (context);
132      return KRB5_SENDAUTH_BADAPPLVERS;
133  }
134  len = ntohl(len);
135  her_appl_version = malloc (len);
136  if (her_appl_version == NULL) {
137      repl = 2;
138      krb5_net_write (context, p_fd, &repl, 1);
139      krb5_set_error_string (context, "malloc: out of memory");
140      return ENOMEM;
141  }
142  if (krb5_net_read (context, p_fd, her_appl_version, len) != len
143      || !(*match_appl_version)(match_data, her_appl_version)) {
144    repl = 2;
145    krb5_net_write (context, p_fd, &repl, 1);
146    krb5_set_error_string (context, "wrong sendauth version (%s)",
147			   her_appl_version);
148    free (her_appl_version);
149    return KRB5_SENDAUTH_BADAPPLVERS;
150  }
151  free (her_appl_version);
152
153  repl = 0;
154  if (krb5_net_write (context, p_fd, &repl, 1) != 1) {
155    ret = errno;
156    krb5_set_error_string (context, "write: %s", strerror(errno));
157    return ret;
158  }
159
160  krb5_data_zero (&data);
161  ret = krb5_read_message (context, p_fd, &data);
162  if (ret)
163      return ret;
164
165  ret = krb5_rd_req (context,
166		     auth_context,
167		     &data,
168		     server,
169		     keytab,
170		     &ap_options,
171		     ticket);
172  krb5_data_free (&data);
173  if (ret) {
174      krb5_data error_data;
175      krb5_error_code ret2;
176
177      ret2 = krb5_mk_error (context,
178			    ret,
179			    NULL,
180			    NULL,
181			    NULL,
182			    server,
183			    NULL,
184			    NULL,
185			    &error_data);
186      if (ret2 == 0) {
187	  krb5_write_message (context, p_fd, &error_data);
188	  krb5_data_free (&error_data);
189      }
190      return ret;
191  }
192
193  len = 0;
194  if (krb5_net_write (context, p_fd, &len, 4) != 4) {
195      ret = errno;
196      krb5_set_error_string (context, "write: %s", strerror(errno));
197      return ret;
198  }
199
200  if (ap_options & AP_OPTS_MUTUAL_REQUIRED) {
201    ret = krb5_mk_rep (context, *auth_context, &data);
202    if (ret)
203      return ret;
204
205    ret = krb5_write_message (context, p_fd, &data);
206    if (ret)
207	return ret;
208    krb5_data_free (&data);
209  }
210  return 0;
211}
212