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 #ifdef CONFIG_RXGK
24 	[RXRPC_SECURITY_YFS_RXGK] = &rxgk_yfs,
25 #endif
26 };
27 
28 int __init rxrpc_init_security(void)
29 {
30 	int i, ret;
31 
32 	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++) {
33 		if (rxrpc_security_types[i]) {
34 			ret = rxrpc_security_types[i]->init();
35 			if (ret < 0)
36 				goto failed;
37 		}
38 	}
39 
40 	return 0;
41 
42 failed:
43 	for (i--; i >= 0; i--)
44 		if (rxrpc_security_types[i])
45 			rxrpc_security_types[i]->exit();
46 	return ret;
47 }
48 
49 void rxrpc_exit_security(void)
50 {
51 	int i;
52 
53 	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++)
54 		if (rxrpc_security_types[i])
55 			rxrpc_security_types[i]->exit();
56 }
57 
58 /*
59  * look up an rxrpc security module
60  */
61 const struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
62 {
63 	if (security_index >= ARRAY_SIZE(rxrpc_security_types))
64 		return NULL;
65 	return rxrpc_security_types[security_index];
66 }
67 
68 /*
69  * Initialise the security on a client call.
70  */
71 int rxrpc_init_client_call_security(struct rxrpc_call *call)
72 {
73 	const struct rxrpc_security *sec = &rxrpc_no_security;
74 	struct rxrpc_key_token *token;
75 	struct key *key = call->key;
76 	int ret;
77 
78 	if (!key)
79 		goto found;
80 
81 	ret = key_validate(key);
82 	if (ret < 0)
83 		return ret;
84 
85 	for (token = key->payload.data[0]; token; token = token->next) {
86 		sec = rxrpc_security_lookup(token->security_index);
87 		if (sec)
88 			goto found;
89 	}
90 	return -EKEYREJECTED;
91 
92 found:
93 	call->security = sec;
94 	call->security_ix = sec->security_index;
95 	return 0;
96 }
97 
98 /*
99  * initialise the security on a client connection
100  */
101 int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
102 {
103 	struct rxrpc_key_token *token;
104 	struct key *key = conn->key;
105 	int ret = 0;
106 
107 	_enter("{%d},{%x}", conn->debug_id, key_serial(key));
108 
109 	for (token = key->payload.data[0]; token; token = token->next) {
110 		if (token->security_index == conn->security->security_index)
111 			goto found;
112 	}
113 	return -EKEYREJECTED;
114 
115 found:
116 	mutex_lock(&conn->security_lock);
117 	if (conn->state == RXRPC_CONN_CLIENT_UNSECURED) {
118 		ret = conn->security->init_connection_security(conn, token);
119 		if (ret == 0) {
120 			spin_lock_irq(&conn->state_lock);
121 			if (conn->state == RXRPC_CONN_CLIENT_UNSECURED)
122 				conn->state = RXRPC_CONN_CLIENT;
123 			spin_unlock_irq(&conn->state_lock);
124 		}
125 	}
126 	mutex_unlock(&conn->security_lock);
127 	return ret;
128 }
129 
130 /*
131  * Set the ops a server connection.
132  */
133 const struct rxrpc_security *rxrpc_get_incoming_security(struct rxrpc_sock *rx,
134 							 struct sk_buff *skb)
135 {
136 	const struct rxrpc_security *sec;
137 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
138 
139 	_enter("");
140 
141 	sec = rxrpc_security_lookup(sp->hdr.securityIndex);
142 	if (!sec) {
143 		rxrpc_direct_abort(skb, rxrpc_abort_unsupported_security,
144 				   RX_INVALID_OPERATION, -EKEYREJECTED);
145 		return NULL;
146 	}
147 
148 	if (sp->hdr.securityIndex != RXRPC_SECURITY_NONE &&
149 	    !rx->securities) {
150 		rxrpc_direct_abort(skb, rxrpc_abort_no_service_key,
151 				   sec->no_key_abort, -EKEYREJECTED);
152 		return NULL;
153 	}
154 
155 	return sec;
156 }
157 
158 /*
159  * Find the security key for a server connection.
160  */
161 struct key *rxrpc_look_up_server_security(struct rxrpc_connection *conn,
162 					  struct sk_buff *skb,
163 					  u32 kvno, u32 enctype)
164 {
165 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
166 	struct rxrpc_sock *rx;
167 	struct key *key = ERR_PTR(-EKEYREJECTED);
168 	key_ref_t kref = NULL;
169 	char kdesc[5 + 1 + 3 + 1 + 12 + 1 + 12 + 1];
170 	int ret;
171 
172 	_enter("");
173 
174 	if (enctype)
175 		sprintf(kdesc, "%u:%u:%u:%u",
176 			sp->hdr.serviceId, sp->hdr.securityIndex, kvno, enctype);
177 	else if (kvno)
178 		sprintf(kdesc, "%u:%u:%u",
179 			sp->hdr.serviceId, sp->hdr.securityIndex, kvno);
180 	else
181 		sprintf(kdesc, "%u:%u",
182 			sp->hdr.serviceId, sp->hdr.securityIndex);
183 
184 	read_lock(&conn->local->services_lock);
185 
186 	rx = conn->local->service;
187 	if (!rx)
188 		goto out;
189 
190 	/* look through the service's keyring */
191 	kref = keyring_search(make_key_ref(rx->securities, 1UL),
192 			      &key_type_rxrpc_s, kdesc, true);
193 	if (IS_ERR(kref)) {
194 		key = ERR_CAST(kref);
195 		goto out;
196 	}
197 
198 	key = key_ref_to_ptr(kref);
199 
200 	ret = key_validate(key);
201 	if (ret < 0) {
202 		key_put(key);
203 		key = ERR_PTR(ret);
204 		goto out;
205 	}
206 
207 out:
208 	read_unlock(&conn->local->services_lock);
209 	return key;
210 }
211