xref: /freebsd/crypto/heimdal/lib/krb5/recvauth.c (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
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 
40 static krb5_boolean
41 match_exact(const void *data, const char *appl_version)
42 {
43     return strcmp(data, appl_version) == 0;
44 }
45 
46 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
47 krb5_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 
62 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
63 krb5_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, bytes;
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) != 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     her_appl_version = malloc (len);
135     if (her_appl_version == NULL) {
136 	repl = 2;
137 	krb5_net_write (context, p_fd, &repl, 1);
138 	krb5_set_error_message(context, ENOMEM,
139 			       N_("malloc: out of memory", ""));
140 	return ENOMEM;
141     }
142     if ((bytes = krb5_net_read (context, p_fd, her_appl_version, len))) {
143 	/* PR/267884: String read must always conatain a terminating NUL */
144 	if (strnlen(her_appl_version, len) == len)
145 		her_appl_version[len-1] = '\0';
146 
147 	    if (bytes != 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     }
158     free (her_appl_version);
159 
160     repl = 0;
161     if (krb5_net_write (context, p_fd, &repl, 1) != 1) {
162 	ret = errno;
163 	krb5_set_error_message(context, ret, "write: %s", strerror(ret));
164 	return ret;
165     }
166 
167     krb5_data_zero (&data);
168     ret = krb5_read_message (context, p_fd, &data);
169     if (ret)
170 	return ret;
171 
172     ret = krb5_rd_req (context,
173 		       auth_context,
174 		       &data,
175 		       server,
176 		       keytab,
177 		       &ap_options,
178 		       ticket);
179     krb5_data_free (&data);
180     if (ret) {
181 	krb5_data error_data;
182 	krb5_error_code ret2;
183 
184 	ret2 = krb5_mk_error (context,
185 			      ret,
186 			      NULL,
187 			      NULL,
188 			      NULL,
189 			      server,
190 			      NULL,
191 			      NULL,
192 			      &error_data);
193 	if (ret2 == 0) {
194 	    krb5_write_message (context, p_fd, &error_data);
195 	    krb5_data_free (&error_data);
196 	}
197 	return ret;
198     }
199 
200     len = 0;
201     if (krb5_net_write (context, p_fd, &len, 4) != 4) {
202 	ret = errno;
203 	krb5_set_error_message(context, ret, "write: %s", strerror(ret));
204 	krb5_free_ticket(context, *ticket);
205 	*ticket = NULL;
206 	return ret;
207     }
208 
209     if (ap_options & AP_OPTS_MUTUAL_REQUIRED) {
210 	ret = krb5_mk_rep (context, *auth_context, &data);
211 	if (ret) {
212 	    krb5_free_ticket(context, *ticket);
213 	    *ticket = NULL;
214 	    return ret;
215 	}
216 
217 	ret = krb5_write_message (context, p_fd, &data);
218 	if (ret) {
219 	    krb5_free_ticket(context, *ticket);
220 	    *ticket = NULL;
221 	    return ret;
222 	}
223 	krb5_data_free (&data);
224     }
225     return 0;
226 }
227