1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* RxRPC key management 3 * 4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 5 * Written by David Howells (dhowells@redhat.com) 6 * 7 * RxRPC keys should have a description of describing their purpose: 8 * "afs@CAMBRIDGE.REDHAT.COM> 9 */ 10 11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 12 13 #include <crypto/skcipher.h> 14 #include <linux/module.h> 15 #include <linux/net.h> 16 #include <linux/skbuff.h> 17 #include <linux/key-type.h> 18 #include <linux/ctype.h> 19 #include <linux/slab.h> 20 #include <net/sock.h> 21 #include <net/af_rxrpc.h> 22 #include <keys/rxrpc-type.h> 23 #include <keys/user-type.h> 24 #include "ar-internal.h" 25 26 static int rxrpc_vet_description_s(const char *); 27 static int rxrpc_preparse_s(struct key_preparsed_payload *); 28 static void rxrpc_free_preparse_s(struct key_preparsed_payload *); 29 static void rxrpc_destroy_s(struct key *); 30 static void rxrpc_describe_s(const struct key *, struct seq_file *); 31 32 /* 33 * rxrpc server keys take "<serviceId>:<securityIndex>[:<sec-specific>]" as the 34 * description and the key material as the payload. 35 */ 36 struct key_type key_type_rxrpc_s = { 37 .name = "rxrpc_s", 38 .flags = KEY_TYPE_NET_DOMAIN, 39 .vet_description = rxrpc_vet_description_s, 40 .preparse = rxrpc_preparse_s, 41 .free_preparse = rxrpc_free_preparse_s, 42 .instantiate = generic_key_instantiate, 43 .destroy = rxrpc_destroy_s, 44 .describe = rxrpc_describe_s, 45 }; 46 47 /* 48 * Vet the description for an RxRPC server key. 49 */ 50 static int rxrpc_vet_description_s(const char *desc) 51 { 52 unsigned long service, sec_class; 53 char *p; 54 55 service = simple_strtoul(desc, &p, 10); 56 if (*p != ':' || service > 65535) 57 return -EINVAL; 58 sec_class = simple_strtoul(p + 1, &p, 10); 59 if ((*p && *p != ':') || sec_class < 1 || sec_class > 255) 60 return -EINVAL; 61 return 0; 62 } 63 64 /* 65 * Preparse a server secret key. 66 */ 67 static int rxrpc_preparse_s(struct key_preparsed_payload *prep) 68 { 69 const struct rxrpc_security *sec; 70 unsigned int service, sec_class; 71 int n; 72 73 _enter("%zu", prep->datalen); 74 75 if (!prep->orig_description) 76 return -EINVAL; 77 78 if (sscanf(prep->orig_description, "%u:%u%n", &service, &sec_class, &n) != 2) 79 return -EINVAL; 80 81 sec = rxrpc_security_lookup(sec_class); 82 if (!sec) 83 return -ENOPKG; 84 85 prep->payload.data[1] = (struct rxrpc_security *)sec; 86 87 if (!sec->preparse_server_key) 88 return -EINVAL; 89 90 return sec->preparse_server_key(prep); 91 } 92 93 static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep) 94 { 95 const struct rxrpc_security *sec = prep->payload.data[1]; 96 97 if (sec && sec->free_preparse_server_key) 98 sec->free_preparse_server_key(prep); 99 } 100 101 static void rxrpc_destroy_s(struct key *key) 102 { 103 const struct rxrpc_security *sec = key->payload.data[1]; 104 105 if (sec && sec->destroy_server_key) 106 sec->destroy_server_key(key); 107 } 108 109 static void rxrpc_describe_s(const struct key *key, struct seq_file *m) 110 { 111 const struct rxrpc_security *sec = key->payload.data[1]; 112 113 seq_puts(m, key->description); 114 if (sec && sec->describe_server_key) 115 sec->describe_server_key(key, m); 116 } 117 118 /* 119 * grab the security keyring for a server socket 120 */ 121 int rxrpc_server_keyring(struct rxrpc_sock *rx, sockptr_t optval, int optlen) 122 { 123 struct key *key; 124 char *description; 125 126 _enter(""); 127 128 if (rx->securities) 129 return -EINVAL; 130 131 if (optlen <= 0 || optlen > PAGE_SIZE - 1) 132 return -EINVAL; 133 134 description = memdup_sockptr_nul(optval, optlen); 135 if (IS_ERR(description)) 136 return PTR_ERR(description); 137 138 key = request_key(&key_type_keyring, description, NULL); 139 if (IS_ERR(key)) { 140 kfree(description); 141 _leave(" = %ld", PTR_ERR(key)); 142 return PTR_ERR(key); 143 } 144 145 rx->securities = key; 146 kfree(description); 147 _leave(" = 0 [key %x]", key->serial); 148 return 0; 149 } 150 151 /** 152 * rxrpc_sock_set_security_keyring - Set the security keyring for a kernel service 153 * @sk: The socket to set the keyring on 154 * @keyring: The keyring to set 155 * 156 * Set the server security keyring on an rxrpc socket. This is used to provide 157 * the encryption keys for a kernel service. 158 * 159 * Return: %0 if successful and a negative error code otherwise. 160 */ 161 int rxrpc_sock_set_security_keyring(struct sock *sk, struct key *keyring) 162 { 163 struct rxrpc_sock *rx = rxrpc_sk(sk); 164 int ret = 0; 165 166 lock_sock(sk); 167 if (rx->securities) 168 ret = -EINVAL; 169 else if (rx->sk.sk_state != RXRPC_UNBOUND) 170 ret = -EISCONN; 171 else 172 rx->securities = key_get(keyring); 173 release_sock(sk); 174 return ret; 175 } 176 EXPORT_SYMBOL(rxrpc_sock_set_security_keyring); 177 178 /** 179 * rxrpc_sock_set_manage_response - Set the manage-response flag for a kernel service 180 * @sk: The socket to set the keyring on 181 * @set: True to set, false to clear the flag 182 * 183 * Set the flag on an rxrpc socket to say that the caller wants to manage the 184 * RESPONSE packet and the user-defined data it may contain. Setting this 185 * means that recvmsg() will return messages with RXRPC_CHALLENGED in the 186 * control message buffer containing information about the challenge. 187 * 188 * The user should respond to the challenge by passing RXRPC_RESPOND or 189 * RXRPC_RESPOND_ABORT control messages with sendmsg() to the same call. 190 * Supplementary control messages, such as RXRPC_RESP_RXGK_APPDATA, may be 191 * included to indicate the parts the user wants to supply. 192 * 193 * The server will be passed the response data with a RXRPC_RESPONDED control 194 * message when it gets the first data from each call. 195 * 196 * Note that this is only honoured by security classes that need auxiliary data 197 * (e.g. RxGK). Those that don't offer the facility (e.g. RxKAD) respond 198 * without consulting userspace. 199 * 200 * Return: The previous setting. 201 */ 202 int rxrpc_sock_set_manage_response(struct sock *sk, bool set) 203 { 204 struct rxrpc_sock *rx = rxrpc_sk(sk); 205 int ret; 206 207 lock_sock(sk); 208 ret = !!test_bit(RXRPC_SOCK_MANAGE_RESPONSE, &rx->flags); 209 if (set) 210 set_bit(RXRPC_SOCK_MANAGE_RESPONSE, &rx->flags); 211 else 212 clear_bit(RXRPC_SOCK_MANAGE_RESPONSE, &rx->flags); 213 release_sock(sk); 214 return ret; 215 } 216 EXPORT_SYMBOL(rxrpc_sock_set_manage_response); 217