1 /* 2 * Crypto user configuration API. 3 * 4 * Copyright (C) 2011 secunet Security Networks AG 5 * Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com> 6 * 7 * This program is free software; you can redistribute it and/or modify it 8 * under the terms and conditions of the GNU General Public License, 9 * version 2, as published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 * more details. 15 * 16 * You should have received a copy of the GNU General Public License along with 17 * this program; if not, write to the Free Software Foundation, Inc., 18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. 19 */ 20 21 #include <linux/module.h> 22 #include <linux/crypto.h> 23 #include <linux/cryptouser.h> 24 #include <net/netlink.h> 25 #include <linux/security.h> 26 #include <net/net_namespace.h> 27 #include "internal.h" 28 29 DEFINE_MUTEX(crypto_cfg_mutex); 30 31 /* The crypto netlink socket */ 32 static struct sock *crypto_nlsk; 33 34 struct crypto_dump_info { 35 struct sk_buff *in_skb; 36 struct sk_buff *out_skb; 37 u32 nlmsg_seq; 38 u16 nlmsg_flags; 39 }; 40 41 static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact) 42 { 43 struct crypto_alg *q, *alg = NULL; 44 45 down_read(&crypto_alg_sem); 46 47 if (list_empty(&crypto_alg_list)) 48 return NULL; 49 50 list_for_each_entry(q, &crypto_alg_list, cra_list) { 51 int match = 0; 52 53 if ((q->cra_flags ^ p->cru_type) & p->cru_mask) 54 continue; 55 56 if (strlen(p->cru_driver_name)) 57 match = !strcmp(q->cra_driver_name, 58 p->cru_driver_name); 59 else if (!exact) 60 match = !strcmp(q->cra_name, p->cru_name); 61 62 if (match) { 63 alg = q; 64 break; 65 } 66 } 67 68 up_read(&crypto_alg_sem); 69 70 return alg; 71 } 72 73 static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg) 74 { 75 struct crypto_report_cipher rcipher; 76 77 snprintf(rcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "cipher"); 78 79 rcipher.blocksize = alg->cra_blocksize; 80 rcipher.min_keysize = alg->cra_cipher.cia_min_keysize; 81 rcipher.max_keysize = alg->cra_cipher.cia_max_keysize; 82 83 NLA_PUT(skb, CRYPTOCFGA_REPORT_CIPHER, 84 sizeof(struct crypto_report_cipher), &rcipher); 85 86 return 0; 87 88 nla_put_failure: 89 return -EMSGSIZE; 90 } 91 92 static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg) 93 { 94 struct crypto_report_comp rcomp; 95 96 snprintf(rcomp.type, CRYPTO_MAX_ALG_NAME, "%s", "compression"); 97 98 NLA_PUT(skb, CRYPTOCFGA_REPORT_COMPRESS, 99 sizeof(struct crypto_report_comp), &rcomp); 100 101 return 0; 102 103 nla_put_failure: 104 return -EMSGSIZE; 105 } 106 107 static int crypto_report_one(struct crypto_alg *alg, 108 struct crypto_user_alg *ualg, struct sk_buff *skb) 109 { 110 memcpy(&ualg->cru_name, &alg->cra_name, sizeof(ualg->cru_name)); 111 memcpy(&ualg->cru_driver_name, &alg->cra_driver_name, 112 sizeof(ualg->cru_driver_name)); 113 memcpy(&ualg->cru_module_name, module_name(alg->cra_module), 114 CRYPTO_MAX_ALG_NAME); 115 116 ualg->cru_flags = alg->cra_flags; 117 ualg->cru_refcnt = atomic_read(&alg->cra_refcnt); 118 119 NLA_PUT_U32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority); 120 121 if (alg->cra_flags & CRYPTO_ALG_LARVAL) { 122 struct crypto_report_larval rl; 123 124 snprintf(rl.type, CRYPTO_MAX_ALG_NAME, "%s", "larval"); 125 126 NLA_PUT(skb, CRYPTOCFGA_REPORT_LARVAL, 127 sizeof(struct crypto_report_larval), &rl); 128 129 goto out; 130 } 131 132 if (alg->cra_type && alg->cra_type->report) { 133 if (alg->cra_type->report(skb, alg)) 134 goto nla_put_failure; 135 136 goto out; 137 } 138 139 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) { 140 case CRYPTO_ALG_TYPE_CIPHER: 141 if (crypto_report_cipher(skb, alg)) 142 goto nla_put_failure; 143 144 break; 145 case CRYPTO_ALG_TYPE_COMPRESS: 146 if (crypto_report_comp(skb, alg)) 147 goto nla_put_failure; 148 149 break; 150 } 151 152 out: 153 return 0; 154 155 nla_put_failure: 156 return -EMSGSIZE; 157 } 158 159 static int crypto_report_alg(struct crypto_alg *alg, 160 struct crypto_dump_info *info) 161 { 162 struct sk_buff *in_skb = info->in_skb; 163 struct sk_buff *skb = info->out_skb; 164 struct nlmsghdr *nlh; 165 struct crypto_user_alg *ualg; 166 int err = 0; 167 168 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).pid, info->nlmsg_seq, 169 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags); 170 if (!nlh) { 171 err = -EMSGSIZE; 172 goto out; 173 } 174 175 ualg = nlmsg_data(nlh); 176 177 err = crypto_report_one(alg, ualg, skb); 178 if (err) { 179 nlmsg_cancel(skb, nlh); 180 goto out; 181 } 182 183 nlmsg_end(skb, nlh); 184 185 out: 186 return err; 187 } 188 189 static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, 190 struct nlattr **attrs) 191 { 192 struct crypto_user_alg *p = nlmsg_data(in_nlh); 193 struct crypto_alg *alg; 194 struct sk_buff *skb; 195 struct crypto_dump_info info; 196 int err; 197 198 if (!p->cru_driver_name) 199 return -EINVAL; 200 201 alg = crypto_alg_match(p, 1); 202 if (!alg) 203 return -ENOENT; 204 205 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); 206 if (!skb) 207 return -ENOMEM; 208 209 info.in_skb = in_skb; 210 info.out_skb = skb; 211 info.nlmsg_seq = in_nlh->nlmsg_seq; 212 info.nlmsg_flags = 0; 213 214 err = crypto_report_alg(alg, &info); 215 if (err) 216 return err; 217 218 return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).pid); 219 } 220 221 static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb) 222 { 223 struct crypto_alg *alg; 224 struct crypto_dump_info info; 225 int err; 226 227 if (cb->args[0]) 228 goto out; 229 230 cb->args[0] = 1; 231 232 info.in_skb = cb->skb; 233 info.out_skb = skb; 234 info.nlmsg_seq = cb->nlh->nlmsg_seq; 235 info.nlmsg_flags = NLM_F_MULTI; 236 237 list_for_each_entry(alg, &crypto_alg_list, cra_list) { 238 err = crypto_report_alg(alg, &info); 239 if (err) 240 goto out_err; 241 } 242 243 out: 244 return skb->len; 245 out_err: 246 return err; 247 } 248 249 static int crypto_dump_report_done(struct netlink_callback *cb) 250 { 251 return 0; 252 } 253 254 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 255 struct nlattr **attrs) 256 { 257 struct crypto_alg *alg; 258 struct crypto_user_alg *p = nlmsg_data(nlh); 259 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 260 LIST_HEAD(list); 261 262 if (priority && !strlen(p->cru_driver_name)) 263 return -EINVAL; 264 265 alg = crypto_alg_match(p, 1); 266 if (!alg) 267 return -ENOENT; 268 269 down_write(&crypto_alg_sem); 270 271 crypto_remove_spawns(alg, &list, NULL); 272 273 if (priority) 274 alg->cra_priority = nla_get_u32(priority); 275 276 up_write(&crypto_alg_sem); 277 278 crypto_remove_final(&list); 279 280 return 0; 281 } 282 283 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 284 struct nlattr **attrs) 285 { 286 struct crypto_alg *alg; 287 struct crypto_user_alg *p = nlmsg_data(nlh); 288 289 alg = crypto_alg_match(p, 1); 290 if (!alg) 291 return -ENOENT; 292 293 /* We can not unregister core algorithms such as aes-generic. 294 * We would loose the reference in the crypto_alg_list to this algorithm 295 * if we try to unregister. Unregistering such an algorithm without 296 * removing the module is not possible, so we restrict to crypto 297 * instances that are build from templates. */ 298 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE)) 299 return -EINVAL; 300 301 if (atomic_read(&alg->cra_refcnt) != 1) 302 return -EBUSY; 303 304 return crypto_unregister_alg(alg); 305 } 306 307 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 308 struct nlattr **attrs) 309 { 310 int exact; 311 const char *name; 312 struct crypto_alg *alg; 313 struct crypto_user_alg *p = nlmsg_data(nlh); 314 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 315 316 if (strlen(p->cru_driver_name)) 317 exact = 1; 318 319 if (priority && !exact) 320 return -EINVAL; 321 322 alg = crypto_alg_match(p, exact); 323 if (alg) 324 return -EEXIST; 325 326 if (strlen(p->cru_driver_name)) 327 name = p->cru_driver_name; 328 else 329 name = p->cru_name; 330 331 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask); 332 if (IS_ERR(alg)) 333 return PTR_ERR(alg); 334 335 down_write(&crypto_alg_sem); 336 337 if (priority) 338 alg->cra_priority = nla_get_u32(priority); 339 340 up_write(&crypto_alg_sem); 341 342 crypto_mod_put(alg); 343 344 return 0; 345 } 346 347 #define MSGSIZE(type) sizeof(struct type) 348 349 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = { 350 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 351 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 352 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 353 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 354 }; 355 356 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = { 357 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32}, 358 }; 359 360 #undef MSGSIZE 361 362 static struct crypto_link { 363 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **); 364 int (*dump)(struct sk_buff *, struct netlink_callback *); 365 int (*done)(struct netlink_callback *); 366 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = { 367 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg}, 368 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg}, 369 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg}, 370 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report, 371 .dump = crypto_dump_report, 372 .done = crypto_dump_report_done}, 373 }; 374 375 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 376 { 377 struct nlattr *attrs[CRYPTOCFGA_MAX+1]; 378 struct crypto_link *link; 379 int type, err; 380 381 type = nlh->nlmsg_type; 382 if (type > CRYPTO_MSG_MAX) 383 return -EINVAL; 384 385 type -= CRYPTO_MSG_BASE; 386 link = &crypto_dispatch[type]; 387 388 if (security_netlink_recv(skb, CAP_NET_ADMIN)) 389 return -EPERM; 390 391 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) && 392 (nlh->nlmsg_flags & NLM_F_DUMP))) { 393 if (link->dump == NULL) 394 return -EINVAL; 395 396 return netlink_dump_start(crypto_nlsk, skb, nlh, 397 link->dump, link->done, 0); 398 } 399 400 err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX, 401 crypto_policy); 402 if (err < 0) 403 return err; 404 405 if (link->doit == NULL) 406 return -EINVAL; 407 408 return link->doit(skb, nlh, attrs); 409 } 410 411 static void crypto_netlink_rcv(struct sk_buff *skb) 412 { 413 mutex_lock(&crypto_cfg_mutex); 414 netlink_rcv_skb(skb, &crypto_user_rcv_msg); 415 mutex_unlock(&crypto_cfg_mutex); 416 } 417 418 static int __init crypto_user_init(void) 419 { 420 crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, 421 0, crypto_netlink_rcv, 422 NULL, THIS_MODULE); 423 if (!crypto_nlsk) 424 return -ENOMEM; 425 426 return 0; 427 } 428 429 static void __exit crypto_user_exit(void) 430 { 431 netlink_kernel_release(crypto_nlsk); 432 } 433 434 module_init(crypto_user_init); 435 module_exit(crypto_user_exit); 436 MODULE_LICENSE("GPL"); 437 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); 438 MODULE_DESCRIPTION("Crypto userspace configuration API"); 439