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 (crypto_is_larval(q)) 60 continue; 61 62 if ((q->cra_flags ^ p->cru_type) & p->cru_mask) 63 continue; 64 65 if (strlen(p->cru_driver_name)) 66 match = !strcmp(q->cra_driver_name, 67 p->cru_driver_name); 68 else if (!exact) 69 match = !strcmp(q->cra_name, p->cru_name); 70 71 if (!match) 72 continue; 73 74 if (unlikely(!crypto_mod_get(q))) 75 continue; 76 77 alg = q; 78 break; 79 } 80 81 up_read(&crypto_alg_sem); 82 83 return alg; 84 } 85 86 static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg) 87 { 88 struct crypto_report_cipher rcipher; 89 90 memset(&rcipher, 0, sizeof(rcipher)); 91 92 strscpy(rcipher.type, "cipher", sizeof(rcipher.type)); 93 94 rcipher.blocksize = alg->cra_blocksize; 95 rcipher.min_keysize = alg->cra_cipher.cia_min_keysize; 96 rcipher.max_keysize = alg->cra_cipher.cia_max_keysize; 97 98 return nla_put(skb, CRYPTOCFGA_REPORT_CIPHER, 99 sizeof(rcipher), &rcipher); 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 memset(&rcomp, 0, sizeof(rcomp)); 107 108 strscpy(rcomp.type, "compression", sizeof(rcomp.type)); 109 110 return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(rcomp), &rcomp); 111 } 112 113 static int crypto_report_one(struct crypto_alg *alg, 114 struct crypto_user_alg *ualg, struct sk_buff *skb) 115 { 116 memset(ualg, 0, sizeof(*ualg)); 117 118 strscpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name)); 119 strscpy(ualg->cru_driver_name, alg->cra_driver_name, 120 sizeof(ualg->cru_driver_name)); 121 strscpy(ualg->cru_module_name, module_name(alg->cra_module), 122 sizeof(ualg->cru_module_name)); 123 124 ualg->cru_type = 0; 125 ualg->cru_mask = 0; 126 ualg->cru_flags = alg->cra_flags; 127 ualg->cru_refcnt = refcount_read(&alg->cra_refcnt); 128 129 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority)) 130 goto nla_put_failure; 131 if (alg->cra_flags & CRYPTO_ALG_LARVAL) { 132 struct crypto_report_larval rl; 133 134 memset(&rl, 0, sizeof(rl)); 135 strscpy(rl.type, "larval", sizeof(rl.type)); 136 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl)) 137 goto nla_put_failure; 138 goto out; 139 } 140 141 if (alg->cra_type && alg->cra_type->report) { 142 if (alg->cra_type->report(skb, alg)) 143 goto nla_put_failure; 144 145 goto out; 146 } 147 148 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) { 149 case CRYPTO_ALG_TYPE_CIPHER: 150 if (crypto_report_cipher(skb, alg)) 151 goto nla_put_failure; 152 153 break; 154 case CRYPTO_ALG_TYPE_COMPRESS: 155 if (crypto_report_comp(skb, alg)) 156 goto nla_put_failure; 157 158 break; 159 } 160 161 out: 162 return 0; 163 164 nla_put_failure: 165 return -EMSGSIZE; 166 } 167 168 static int crypto_report_alg(struct crypto_alg *alg, 169 struct crypto_dump_info *info) 170 { 171 struct sk_buff *in_skb = info->in_skb; 172 struct sk_buff *skb = info->out_skb; 173 struct nlmsghdr *nlh; 174 struct crypto_user_alg *ualg; 175 int err = 0; 176 177 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq, 178 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags); 179 if (!nlh) { 180 err = -EMSGSIZE; 181 goto out; 182 } 183 184 ualg = nlmsg_data(nlh); 185 186 err = crypto_report_one(alg, ualg, skb); 187 if (err) { 188 nlmsg_cancel(skb, nlh); 189 goto out; 190 } 191 192 nlmsg_end(skb, nlh); 193 194 out: 195 return err; 196 } 197 198 static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, 199 struct nlattr **attrs) 200 { 201 struct crypto_user_alg *p = nlmsg_data(in_nlh); 202 struct crypto_alg *alg; 203 struct sk_buff *skb; 204 struct crypto_dump_info info; 205 int err; 206 207 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 208 return -EINVAL; 209 210 alg = crypto_alg_match(p, 0); 211 if (!alg) 212 return -ENOENT; 213 214 err = -ENOMEM; 215 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 216 if (!skb) 217 goto drop_alg; 218 219 info.in_skb = in_skb; 220 info.out_skb = skb; 221 info.nlmsg_seq = in_nlh->nlmsg_seq; 222 info.nlmsg_flags = 0; 223 224 err = crypto_report_alg(alg, &info); 225 226 drop_alg: 227 crypto_mod_put(alg); 228 229 if (err) 230 return err; 231 232 return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid); 233 } 234 235 static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb) 236 { 237 const size_t start_pos = cb->args[0]; 238 size_t pos = 0; 239 struct crypto_dump_info info; 240 struct crypto_alg *alg; 241 int res; 242 243 info.in_skb = cb->skb; 244 info.out_skb = skb; 245 info.nlmsg_seq = cb->nlh->nlmsg_seq; 246 info.nlmsg_flags = NLM_F_MULTI; 247 248 down_read(&crypto_alg_sem); 249 list_for_each_entry(alg, &crypto_alg_list, cra_list) { 250 if (pos >= start_pos) { 251 res = crypto_report_alg(alg, &info); 252 if (res == -EMSGSIZE) 253 break; 254 if (res) 255 goto out; 256 } 257 pos++; 258 } 259 cb->args[0] = pos; 260 res = skb->len; 261 out: 262 up_read(&crypto_alg_sem); 263 return res; 264 } 265 266 static int crypto_dump_report_done(struct netlink_callback *cb) 267 { 268 return 0; 269 } 270 271 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 272 struct nlattr **attrs) 273 { 274 struct crypto_alg *alg; 275 struct crypto_user_alg *p = nlmsg_data(nlh); 276 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 277 LIST_HEAD(list); 278 279 if (!netlink_capable(skb, CAP_NET_ADMIN)) 280 return -EPERM; 281 282 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 283 return -EINVAL; 284 285 if (priority && !strlen(p->cru_driver_name)) 286 return -EINVAL; 287 288 alg = crypto_alg_match(p, 1); 289 if (!alg) 290 return -ENOENT; 291 292 down_write(&crypto_alg_sem); 293 294 crypto_remove_spawns(alg, &list, NULL); 295 296 if (priority) 297 alg->cra_priority = nla_get_u32(priority); 298 299 up_write(&crypto_alg_sem); 300 301 crypto_mod_put(alg); 302 crypto_remove_final(&list); 303 304 return 0; 305 } 306 307 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 308 struct nlattr **attrs) 309 { 310 struct crypto_alg *alg; 311 struct crypto_user_alg *p = nlmsg_data(nlh); 312 int err; 313 314 if (!netlink_capable(skb, CAP_NET_ADMIN)) 315 return -EPERM; 316 317 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 318 return -EINVAL; 319 320 alg = crypto_alg_match(p, 1); 321 if (!alg) 322 return -ENOENT; 323 324 /* We can not unregister core algorithms such as aes-generic. 325 * We would loose the reference in the crypto_alg_list to this algorithm 326 * if we try to unregister. Unregistering such an algorithm without 327 * removing the module is not possible, so we restrict to crypto 328 * instances that are build from templates. */ 329 err = -EINVAL; 330 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE)) 331 goto drop_alg; 332 333 err = -EBUSY; 334 if (refcount_read(&alg->cra_refcnt) > 2) 335 goto drop_alg; 336 337 err = crypto_unregister_instance((struct crypto_instance *)alg); 338 339 drop_alg: 340 crypto_mod_put(alg); 341 return err; 342 } 343 344 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 345 struct nlattr **attrs) 346 { 347 int exact = 0; 348 const char *name; 349 struct crypto_alg *alg; 350 struct crypto_user_alg *p = nlmsg_data(nlh); 351 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 352 353 if (!netlink_capable(skb, CAP_NET_ADMIN)) 354 return -EPERM; 355 356 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 357 return -EINVAL; 358 359 if (strlen(p->cru_driver_name)) 360 exact = 1; 361 362 if (priority && !exact) 363 return -EINVAL; 364 365 alg = crypto_alg_match(p, exact); 366 if (alg) { 367 crypto_mod_put(alg); 368 return -EEXIST; 369 } 370 371 if (strlen(p->cru_driver_name)) 372 name = p->cru_driver_name; 373 else 374 name = p->cru_name; 375 376 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask); 377 if (IS_ERR(alg)) 378 return PTR_ERR(alg); 379 380 down_write(&crypto_alg_sem); 381 382 if (priority) 383 alg->cra_priority = nla_get_u32(priority); 384 385 up_write(&crypto_alg_sem); 386 387 crypto_mod_put(alg); 388 389 return 0; 390 } 391 392 static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh, 393 struct nlattr **attrs) 394 { 395 if (!netlink_capable(skb, CAP_NET_ADMIN)) 396 return -EPERM; 397 return crypto_del_default_rng(); 398 } 399 400 #define MSGSIZE(type) sizeof(struct type) 401 402 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = { 403 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 404 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 405 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 406 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 407 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0, 408 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 409 }; 410 411 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = { 412 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32}, 413 }; 414 415 #undef MSGSIZE 416 417 static const struct crypto_link { 418 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **); 419 int (*dump)(struct sk_buff *, struct netlink_callback *); 420 int (*done)(struct netlink_callback *); 421 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = { 422 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg}, 423 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg}, 424 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg}, 425 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report, 426 .dump = crypto_dump_report, 427 .done = crypto_dump_report_done}, 428 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng }, 429 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat}, 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 unsigned long 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 up_read(&crypto_alg_sem); 458 459 { 460 struct netlink_dump_control c = { 461 .dump = link->dump, 462 .done = link->done, 463 .min_dump_alloc = min(dump_alloc, 65535UL), 464 }; 465 err = netlink_dump_start(crypto_nlsk, skb, nlh, &c); 466 } 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