xref: /openbmc/linux/net/rxrpc/security.c (revision b9b77222)
1 /* RxRPC security handling
2  *
3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/net.h>
14 #include <linux/skbuff.h>
15 #include <linux/udp.h>
16 #include <linux/crypto.h>
17 #include <net/sock.h>
18 #include <net/af_rxrpc.h>
19 #include <keys/rxrpc-type.h>
20 #include "ar-internal.h"
21 
22 static const struct rxrpc_security *rxrpc_security_types[] = {
23 	[RXRPC_SECURITY_NONE]	= &rxrpc_no_security,
24 #ifdef CONFIG_RXKAD
25 	[RXRPC_SECURITY_RXKAD]	= &rxkad,
26 #endif
27 };
28 
29 int __init rxrpc_init_security(void)
30 {
31 	int i, ret;
32 
33 	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++) {
34 		if (rxrpc_security_types[i]) {
35 			ret = rxrpc_security_types[i]->init();
36 			if (ret < 0)
37 				goto failed;
38 		}
39 	}
40 
41 	return 0;
42 
43 failed:
44 	for (i--; i >= 0; i--)
45 		if (rxrpc_security_types[i])
46 			rxrpc_security_types[i]->exit();
47 	return ret;
48 }
49 
50 void rxrpc_exit_security(void)
51 {
52 	int i;
53 
54 	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++)
55 		if (rxrpc_security_types[i])
56 			rxrpc_security_types[i]->exit();
57 }
58 
59 /*
60  * look up an rxrpc security module
61  */
62 static const struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
63 {
64 	if (security_index >= ARRAY_SIZE(rxrpc_security_types))
65 		return NULL;
66 	return rxrpc_security_types[security_index];
67 }
68 
69 /*
70  * initialise the security on a client connection
71  */
72 int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
73 {
74 	const struct rxrpc_security *sec;
75 	struct rxrpc_key_token *token;
76 	struct key *key = conn->params.key;
77 	int ret;
78 
79 	_enter("{%d},{%x}", conn->debug_id, key_serial(key));
80 
81 	if (!key)
82 		return 0;
83 
84 	ret = key_validate(key);
85 	if (ret < 0)
86 		return ret;
87 
88 	token = key->payload.data[0];
89 	if (!token)
90 		return -EKEYREJECTED;
91 
92 	sec = rxrpc_security_lookup(token->security_index);
93 	if (!sec)
94 		return -EKEYREJECTED;
95 	conn->security = sec;
96 
97 	ret = conn->security->init_connection_security(conn);
98 	if (ret < 0) {
99 		conn->security = &rxrpc_no_security;
100 		return ret;
101 	}
102 
103 	_leave(" = 0");
104 	return 0;
105 }
106 
107 /*
108  * initialise the security on a server connection
109  */
110 int rxrpc_init_server_conn_security(struct rxrpc_connection *conn)
111 {
112 	const struct rxrpc_security *sec;
113 	struct rxrpc_local *local = conn->params.local;
114 	struct rxrpc_sock *rx;
115 	struct key *key;
116 	key_ref_t kref;
117 	char kdesc[5 + 1 + 3 + 1];
118 
119 	_enter("");
120 
121 	sprintf(kdesc, "%u:%u", conn->service_id, conn->security_ix);
122 
123 	sec = rxrpc_security_lookup(conn->security_ix);
124 	if (!sec) {
125 		_leave(" = -ENOKEY [lookup]");
126 		return -ENOKEY;
127 	}
128 
129 	/* find the service */
130 	read_lock(&local->services_lock);
131 	rx = rcu_dereference_protected(local->service,
132 				       lockdep_is_held(&local->services_lock));
133 	if (rx && (rx->srx.srx_service == conn->service_id ||
134 		   rx->second_service == conn->service_id))
135 		goto found_service;
136 
137 	/* the service appears to have died */
138 	read_unlock(&local->services_lock);
139 	_leave(" = -ENOENT");
140 	return -ENOENT;
141 
142 found_service:
143 	if (!rx->securities) {
144 		read_unlock(&local->services_lock);
145 		_leave(" = -ENOKEY");
146 		return -ENOKEY;
147 	}
148 
149 	/* look through the service's keyring */
150 	kref = keyring_search(make_key_ref(rx->securities, 1UL),
151 			      &key_type_rxrpc_s, kdesc);
152 	if (IS_ERR(kref)) {
153 		read_unlock(&local->services_lock);
154 		_leave(" = %ld [search]", PTR_ERR(kref));
155 		return PTR_ERR(kref);
156 	}
157 
158 	key = key_ref_to_ptr(kref);
159 	read_unlock(&local->services_lock);
160 
161 	conn->server_key = key;
162 	conn->security = sec;
163 
164 	_leave(" = 0");
165 	return 0;
166 }
167