xref: /openbmc/linux/net/rxrpc/security.c (revision 63705da3)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* RxRPC security handling
3  *
4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #include <linux/module.h>
9 #include <linux/net.h>
10 #include <linux/skbuff.h>
11 #include <linux/udp.h>
12 #include <linux/crypto.h>
13 #include <net/sock.h>
14 #include <net/af_rxrpc.h>
15 #include <keys/rxrpc-type.h>
16 #include "ar-internal.h"
17 
18 static const struct rxrpc_security *rxrpc_security_types[] = {
19 	[RXRPC_SECURITY_NONE]	= &rxrpc_no_security,
20 #ifdef CONFIG_RXKAD
21 	[RXRPC_SECURITY_RXKAD]	= &rxkad,
22 #endif
23 };
24 
25 int __init rxrpc_init_security(void)
26 {
27 	int i, ret;
28 
29 	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++) {
30 		if (rxrpc_security_types[i]) {
31 			ret = rxrpc_security_types[i]->init();
32 			if (ret < 0)
33 				goto failed;
34 		}
35 	}
36 
37 	return 0;
38 
39 failed:
40 	for (i--; i >= 0; i--)
41 		if (rxrpc_security_types[i])
42 			rxrpc_security_types[i]->exit();
43 	return ret;
44 }
45 
46 void rxrpc_exit_security(void)
47 {
48 	int i;
49 
50 	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++)
51 		if (rxrpc_security_types[i])
52 			rxrpc_security_types[i]->exit();
53 }
54 
55 /*
56  * look up an rxrpc security module
57  */
58 const struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
59 {
60 	if (security_index >= ARRAY_SIZE(rxrpc_security_types))
61 		return NULL;
62 	return rxrpc_security_types[security_index];
63 }
64 
65 /*
66  * initialise the security on a client connection
67  */
68 int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
69 {
70 	const struct rxrpc_security *sec;
71 	struct rxrpc_key_token *token;
72 	struct key *key = conn->params.key;
73 	int ret;
74 
75 	_enter("{%d},{%x}", conn->debug_id, key_serial(key));
76 
77 	if (!key)
78 		return 0;
79 
80 	ret = key_validate(key);
81 	if (ret < 0)
82 		return ret;
83 
84 	for (token = key->payload.data[0]; token; token = token->next) {
85 		sec = rxrpc_security_lookup(token->security_index);
86 		if (sec)
87 			goto found;
88 	}
89 	return -EKEYREJECTED;
90 
91 found:
92 	conn->security = sec;
93 
94 	ret = conn->security->init_connection_security(conn, token);
95 	if (ret < 0) {
96 		conn->security = &rxrpc_no_security;
97 		return ret;
98 	}
99 
100 	_leave(" = 0");
101 	return 0;
102 }
103 
104 /*
105  * Set the ops a server connection.
106  */
107 const struct rxrpc_security *rxrpc_get_incoming_security(struct rxrpc_sock *rx,
108 							 struct sk_buff *skb)
109 {
110 	const struct rxrpc_security *sec;
111 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
112 
113 	_enter("");
114 
115 	sec = rxrpc_security_lookup(sp->hdr.securityIndex);
116 	if (!sec) {
117 		trace_rxrpc_abort(0, "SVS",
118 				  sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
119 				  RX_INVALID_OPERATION, EKEYREJECTED);
120 		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
121 		skb->priority = RX_INVALID_OPERATION;
122 		return NULL;
123 	}
124 
125 	if (sp->hdr.securityIndex != RXRPC_SECURITY_NONE &&
126 	    !rx->securities) {
127 		trace_rxrpc_abort(0, "SVR",
128 				  sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
129 				  RX_INVALID_OPERATION, EKEYREJECTED);
130 		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
131 		skb->priority = sec->no_key_abort;
132 		return NULL;
133 	}
134 
135 	return sec;
136 }
137 
138 /*
139  * Find the security key for a server connection.
140  */
141 struct key *rxrpc_look_up_server_security(struct rxrpc_connection *conn,
142 					  struct sk_buff *skb,
143 					  u32 kvno, u32 enctype)
144 {
145 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
146 	struct rxrpc_sock *rx;
147 	struct key *key = ERR_PTR(-EKEYREJECTED);
148 	key_ref_t kref = NULL;
149 	char kdesc[5 + 1 + 3 + 1 + 12 + 1 + 12 + 1];
150 	int ret;
151 
152 	_enter("");
153 
154 	if (enctype)
155 		sprintf(kdesc, "%u:%u:%u:%u",
156 			sp->hdr.serviceId, sp->hdr.securityIndex, kvno, enctype);
157 	else if (kvno)
158 		sprintf(kdesc, "%u:%u:%u",
159 			sp->hdr.serviceId, sp->hdr.securityIndex, kvno);
160 	else
161 		sprintf(kdesc, "%u:%u",
162 			sp->hdr.serviceId, sp->hdr.securityIndex);
163 
164 	rcu_read_lock();
165 
166 	rx = rcu_dereference(conn->params.local->service);
167 	if (!rx)
168 		goto out;
169 
170 	/* look through the service's keyring */
171 	kref = keyring_search(make_key_ref(rx->securities, 1UL),
172 			      &key_type_rxrpc_s, kdesc, true);
173 	if (IS_ERR(kref)) {
174 		key = ERR_CAST(kref);
175 		goto out;
176 	}
177 
178 	key = key_ref_to_ptr(kref);
179 
180 	ret = key_validate(key);
181 	if (ret < 0) {
182 		key_put(key);
183 		key = ERR_PTR(ret);
184 		goto out;
185 	}
186 
187 out:
188 	rcu_read_unlock();
189 	return key;
190 }
191