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 <linux/sched.h> 25 #include <net/netlink.h> 26 #include <linux/security.h> 27 #include <net/net_namespace.h> 28 #include <crypto/internal/skcipher.h> 29 #include <crypto/internal/rng.h> 30 #include <crypto/akcipher.h> 31 #include <crypto/kpp.h> 32 #include <crypto/internal/cryptouser.h> 33 34 #include "internal.h" 35 36 #define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x)) 37 38 static DEFINE_MUTEX(crypto_cfg_mutex); 39 40 /* The crypto netlink socket */ 41 struct sock *crypto_nlsk; 42 43 struct crypto_dump_info { 44 struct sk_buff *in_skb; 45 struct sk_buff *out_skb; 46 u32 nlmsg_seq; 47 u16 nlmsg_flags; 48 }; 49 50 struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact) 51 { 52 struct crypto_alg *q, *alg = NULL; 53 54 down_read(&crypto_alg_sem); 55 56 list_for_each_entry(q, &crypto_alg_list, cra_list) { 57 int match = 0; 58 59 if ((q->cra_flags ^ p->cru_type) & p->cru_mask) 60 continue; 61 62 if (strlen(p->cru_driver_name)) 63 match = !strcmp(q->cra_driver_name, 64 p->cru_driver_name); 65 else if (!exact) 66 match = !strcmp(q->cra_name, p->cru_name); 67 68 if (!match) 69 continue; 70 71 if (unlikely(!crypto_mod_get(q))) 72 continue; 73 74 alg = q; 75 break; 76 } 77 78 up_read(&crypto_alg_sem); 79 80 return alg; 81 } 82 83 static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg) 84 { 85 struct crypto_report_cipher rcipher; 86 87 strncpy(rcipher.type, "cipher", sizeof(rcipher.type)); 88 89 rcipher.blocksize = alg->cra_blocksize; 90 rcipher.min_keysize = alg->cra_cipher.cia_min_keysize; 91 rcipher.max_keysize = alg->cra_cipher.cia_max_keysize; 92 93 if (nla_put(skb, CRYPTOCFGA_REPORT_CIPHER, 94 sizeof(struct crypto_report_cipher), &rcipher)) 95 goto nla_put_failure; 96 return 0; 97 98 nla_put_failure: 99 return -EMSGSIZE; 100 } 101 102 static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg) 103 { 104 struct crypto_report_comp rcomp; 105 106 strncpy(rcomp.type, "compression", sizeof(rcomp.type)); 107 if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, 108 sizeof(struct crypto_report_comp), &rcomp)) 109 goto nla_put_failure; 110 return 0; 111 112 nla_put_failure: 113 return -EMSGSIZE; 114 } 115 116 static int crypto_report_one(struct crypto_alg *alg, 117 struct crypto_user_alg *ualg, struct sk_buff *skb) 118 { 119 strncpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name)); 120 strncpy(ualg->cru_driver_name, alg->cra_driver_name, 121 sizeof(ualg->cru_driver_name)); 122 strncpy(ualg->cru_module_name, module_name(alg->cra_module), 123 sizeof(ualg->cru_module_name)); 124 125 ualg->cru_type = 0; 126 ualg->cru_mask = 0; 127 ualg->cru_flags = alg->cra_flags; 128 ualg->cru_refcnt = refcount_read(&alg->cra_refcnt); 129 130 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority)) 131 goto nla_put_failure; 132 if (alg->cra_flags & CRYPTO_ALG_LARVAL) { 133 struct crypto_report_larval rl; 134 135 strncpy(rl.type, "larval", sizeof(rl.type)); 136 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, 137 sizeof(struct crypto_report_larval), &rl)) 138 goto nla_put_failure; 139 goto out; 140 } 141 142 if (alg->cra_type && alg->cra_type->report) { 143 if (alg->cra_type->report(skb, alg)) 144 goto nla_put_failure; 145 146 goto out; 147 } 148 149 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) { 150 case CRYPTO_ALG_TYPE_CIPHER: 151 if (crypto_report_cipher(skb, alg)) 152 goto nla_put_failure; 153 154 break; 155 case CRYPTO_ALG_TYPE_COMPRESS: 156 if (crypto_report_comp(skb, alg)) 157 goto nla_put_failure; 158 159 break; 160 } 161 162 out: 163 return 0; 164 165 nla_put_failure: 166 return -EMSGSIZE; 167 } 168 169 static int crypto_report_alg(struct crypto_alg *alg, 170 struct crypto_dump_info *info) 171 { 172 struct sk_buff *in_skb = info->in_skb; 173 struct sk_buff *skb = info->out_skb; 174 struct nlmsghdr *nlh; 175 struct crypto_user_alg *ualg; 176 int err = 0; 177 178 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq, 179 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags); 180 if (!nlh) { 181 err = -EMSGSIZE; 182 goto out; 183 } 184 185 ualg = nlmsg_data(nlh); 186 187 err = crypto_report_one(alg, ualg, skb); 188 if (err) { 189 nlmsg_cancel(skb, nlh); 190 goto out; 191 } 192 193 nlmsg_end(skb, nlh); 194 195 out: 196 return err; 197 } 198 199 static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, 200 struct nlattr **attrs) 201 { 202 struct crypto_user_alg *p = nlmsg_data(in_nlh); 203 struct crypto_alg *alg; 204 struct sk_buff *skb; 205 struct crypto_dump_info info; 206 int err; 207 208 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 209 return -EINVAL; 210 211 alg = crypto_alg_match(p, 0); 212 if (!alg) 213 return -ENOENT; 214 215 err = -ENOMEM; 216 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 217 if (!skb) 218 goto drop_alg; 219 220 info.in_skb = in_skb; 221 info.out_skb = skb; 222 info.nlmsg_seq = in_nlh->nlmsg_seq; 223 info.nlmsg_flags = 0; 224 225 err = crypto_report_alg(alg, &info); 226 227 drop_alg: 228 crypto_mod_put(alg); 229 230 if (err) 231 return err; 232 233 return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid); 234 } 235 236 static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb) 237 { 238 struct crypto_alg *alg; 239 struct crypto_dump_info info; 240 int err; 241 242 if (cb->args[0]) 243 goto out; 244 245 cb->args[0] = 1; 246 247 info.in_skb = cb->skb; 248 info.out_skb = skb; 249 info.nlmsg_seq = cb->nlh->nlmsg_seq; 250 info.nlmsg_flags = NLM_F_MULTI; 251 252 list_for_each_entry(alg, &crypto_alg_list, cra_list) { 253 err = crypto_report_alg(alg, &info); 254 if (err) 255 goto out_err; 256 } 257 258 out: 259 return skb->len; 260 out_err: 261 return err; 262 } 263 264 static int crypto_dump_report_done(struct netlink_callback *cb) 265 { 266 return 0; 267 } 268 269 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 270 struct nlattr **attrs) 271 { 272 struct crypto_alg *alg; 273 struct crypto_user_alg *p = nlmsg_data(nlh); 274 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 275 LIST_HEAD(list); 276 277 if (!netlink_capable(skb, CAP_NET_ADMIN)) 278 return -EPERM; 279 280 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 281 return -EINVAL; 282 283 if (priority && !strlen(p->cru_driver_name)) 284 return -EINVAL; 285 286 alg = crypto_alg_match(p, 1); 287 if (!alg) 288 return -ENOENT; 289 290 down_write(&crypto_alg_sem); 291 292 crypto_remove_spawns(alg, &list, NULL); 293 294 if (priority) 295 alg->cra_priority = nla_get_u32(priority); 296 297 up_write(&crypto_alg_sem); 298 299 crypto_mod_put(alg); 300 crypto_remove_final(&list); 301 302 return 0; 303 } 304 305 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 306 struct nlattr **attrs) 307 { 308 struct crypto_alg *alg; 309 struct crypto_user_alg *p = nlmsg_data(nlh); 310 int err; 311 312 if (!netlink_capable(skb, CAP_NET_ADMIN)) 313 return -EPERM; 314 315 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 316 return -EINVAL; 317 318 alg = crypto_alg_match(p, 1); 319 if (!alg) 320 return -ENOENT; 321 322 /* We can not unregister core algorithms such as aes-generic. 323 * We would loose the reference in the crypto_alg_list to this algorithm 324 * if we try to unregister. Unregistering such an algorithm without 325 * removing the module is not possible, so we restrict to crypto 326 * instances that are build from templates. */ 327 err = -EINVAL; 328 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE)) 329 goto drop_alg; 330 331 err = -EBUSY; 332 if (refcount_read(&alg->cra_refcnt) > 2) 333 goto drop_alg; 334 335 err = crypto_unregister_instance((struct crypto_instance *)alg); 336 337 drop_alg: 338 crypto_mod_put(alg); 339 return err; 340 } 341 342 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 343 struct nlattr **attrs) 344 { 345 int exact = 0; 346 const char *name; 347 struct crypto_alg *alg; 348 struct crypto_user_alg *p = nlmsg_data(nlh); 349 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 350 351 if (!netlink_capable(skb, CAP_NET_ADMIN)) 352 return -EPERM; 353 354 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 355 return -EINVAL; 356 357 if (strlen(p->cru_driver_name)) 358 exact = 1; 359 360 if (priority && !exact) 361 return -EINVAL; 362 363 alg = crypto_alg_match(p, exact); 364 if (alg) { 365 crypto_mod_put(alg); 366 return -EEXIST; 367 } 368 369 if (strlen(p->cru_driver_name)) 370 name = p->cru_driver_name; 371 else 372 name = p->cru_name; 373 374 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask); 375 if (IS_ERR(alg)) 376 return PTR_ERR(alg); 377 378 down_write(&crypto_alg_sem); 379 380 if (priority) 381 alg->cra_priority = nla_get_u32(priority); 382 383 up_write(&crypto_alg_sem); 384 385 crypto_mod_put(alg); 386 387 return 0; 388 } 389 390 static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh, 391 struct nlattr **attrs) 392 { 393 if (!netlink_capable(skb, CAP_NET_ADMIN)) 394 return -EPERM; 395 return crypto_del_default_rng(); 396 } 397 398 #define MSGSIZE(type) sizeof(struct type) 399 400 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = { 401 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 402 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 403 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 404 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 405 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0, 406 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 407 }; 408 409 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = { 410 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32}, 411 }; 412 413 #undef MSGSIZE 414 415 static const struct crypto_link { 416 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **); 417 int (*dump)(struct sk_buff *, struct netlink_callback *); 418 int (*done)(struct netlink_callback *); 419 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = { 420 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg}, 421 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg}, 422 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg}, 423 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report, 424 .dump = crypto_dump_report, 425 .done = crypto_dump_report_done}, 426 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng }, 427 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat, 428 .dump = crypto_dump_reportstat, 429 .done = crypto_dump_reportstat_done}, 430 }; 431 432 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, 433 struct netlink_ext_ack *extack) 434 { 435 struct nlattr *attrs[CRYPTOCFGA_MAX+1]; 436 const struct crypto_link *link; 437 int type, err; 438 439 type = nlh->nlmsg_type; 440 if (type > CRYPTO_MSG_MAX) 441 return -EINVAL; 442 443 type -= CRYPTO_MSG_BASE; 444 link = &crypto_dispatch[type]; 445 446 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) && 447 (nlh->nlmsg_flags & NLM_F_DUMP))) { 448 struct crypto_alg *alg; 449 u16 dump_alloc = 0; 450 451 if (link->dump == NULL) 452 return -EINVAL; 453 454 down_read(&crypto_alg_sem); 455 list_for_each_entry(alg, &crypto_alg_list, cra_list) 456 dump_alloc += CRYPTO_REPORT_MAXSIZE; 457 458 { 459 struct netlink_dump_control c = { 460 .dump = link->dump, 461 .done = link->done, 462 .min_dump_alloc = dump_alloc, 463 }; 464 err = netlink_dump_start(crypto_nlsk, skb, nlh, &c); 465 } 466 up_read(&crypto_alg_sem); 467 468 return err; 469 } 470 471 err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX, 472 crypto_policy, extack); 473 if (err < 0) 474 return err; 475 476 if (link->doit == NULL) 477 return -EINVAL; 478 479 return link->doit(skb, nlh, attrs); 480 } 481 482 static void crypto_netlink_rcv(struct sk_buff *skb) 483 { 484 mutex_lock(&crypto_cfg_mutex); 485 netlink_rcv_skb(skb, &crypto_user_rcv_msg); 486 mutex_unlock(&crypto_cfg_mutex); 487 } 488 489 static int __init crypto_user_init(void) 490 { 491 struct netlink_kernel_cfg cfg = { 492 .input = crypto_netlink_rcv, 493 }; 494 495 crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg); 496 if (!crypto_nlsk) 497 return -ENOMEM; 498 499 return 0; 500 } 501 502 static void __exit crypto_user_exit(void) 503 { 504 netlink_kernel_release(crypto_nlsk); 505 } 506 507 module_init(crypto_user_init); 508 module_exit(crypto_user_exit); 509 MODULE_LICENSE("GPL"); 510 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); 511 MODULE_DESCRIPTION("Crypto userspace configuration API"); 512 MODULE_ALIAS("net-pf-16-proto-21"); 513