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 33 #include "internal.h" 34 35 #define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x)) 36 37 static DEFINE_MUTEX(crypto_cfg_mutex); 38 39 /* The crypto netlink socket */ 40 static struct sock *crypto_nlsk; 41 42 struct crypto_dump_info { 43 struct sk_buff *in_skb; 44 struct sk_buff *out_skb; 45 u32 nlmsg_seq; 46 u16 nlmsg_flags; 47 }; 48 49 static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact) 50 { 51 struct crypto_alg *q, *alg = NULL; 52 53 down_read(&crypto_alg_sem); 54 55 list_for_each_entry(q, &crypto_alg_list, cra_list) { 56 int match = 0; 57 58 if ((q->cra_flags ^ p->cru_type) & p->cru_mask) 59 continue; 60 61 if (strlen(p->cru_driver_name)) 62 match = !strcmp(q->cra_driver_name, 63 p->cru_driver_name); 64 else if (!exact) 65 match = !strcmp(q->cra_name, p->cru_name); 66 67 if (!match) 68 continue; 69 70 if (unlikely(!crypto_mod_get(q))) 71 continue; 72 73 alg = q; 74 break; 75 } 76 77 up_read(&crypto_alg_sem); 78 79 return alg; 80 } 81 82 static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg) 83 { 84 struct crypto_report_cipher rcipher; 85 86 strncpy(rcipher.type, "cipher", sizeof(rcipher.type)); 87 88 rcipher.blocksize = alg->cra_blocksize; 89 rcipher.min_keysize = alg->cra_cipher.cia_min_keysize; 90 rcipher.max_keysize = alg->cra_cipher.cia_max_keysize; 91 92 if (nla_put(skb, CRYPTOCFGA_REPORT_CIPHER, 93 sizeof(struct crypto_report_cipher), &rcipher)) 94 goto nla_put_failure; 95 return 0; 96 97 nla_put_failure: 98 return -EMSGSIZE; 99 } 100 101 static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg) 102 { 103 struct crypto_report_comp rcomp; 104 105 strncpy(rcomp.type, "compression", sizeof(rcomp.type)); 106 if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, 107 sizeof(struct crypto_report_comp), &rcomp)) 108 goto nla_put_failure; 109 return 0; 110 111 nla_put_failure: 112 return -EMSGSIZE; 113 } 114 115 static int crypto_report_acomp(struct sk_buff *skb, struct crypto_alg *alg) 116 { 117 struct crypto_report_acomp racomp; 118 119 strncpy(racomp.type, "acomp", sizeof(racomp.type)); 120 121 if (nla_put(skb, CRYPTOCFGA_REPORT_ACOMP, 122 sizeof(struct crypto_report_acomp), &racomp)) 123 goto nla_put_failure; 124 return 0; 125 126 nla_put_failure: 127 return -EMSGSIZE; 128 } 129 130 static int crypto_report_akcipher(struct sk_buff *skb, struct crypto_alg *alg) 131 { 132 struct crypto_report_akcipher rakcipher; 133 134 strncpy(rakcipher.type, "akcipher", sizeof(rakcipher.type)); 135 136 if (nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER, 137 sizeof(struct crypto_report_akcipher), &rakcipher)) 138 goto nla_put_failure; 139 return 0; 140 141 nla_put_failure: 142 return -EMSGSIZE; 143 } 144 145 static int crypto_report_kpp(struct sk_buff *skb, struct crypto_alg *alg) 146 { 147 struct crypto_report_kpp rkpp; 148 149 strncpy(rkpp.type, "kpp", sizeof(rkpp.type)); 150 151 if (nla_put(skb, CRYPTOCFGA_REPORT_KPP, 152 sizeof(struct crypto_report_kpp), &rkpp)) 153 goto nla_put_failure; 154 return 0; 155 156 nla_put_failure: 157 return -EMSGSIZE; 158 } 159 160 static int crypto_report_one(struct crypto_alg *alg, 161 struct crypto_user_alg *ualg, struct sk_buff *skb) 162 { 163 strncpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name)); 164 strncpy(ualg->cru_driver_name, alg->cra_driver_name, 165 sizeof(ualg->cru_driver_name)); 166 strncpy(ualg->cru_module_name, module_name(alg->cra_module), 167 sizeof(ualg->cru_module_name)); 168 169 ualg->cru_type = 0; 170 ualg->cru_mask = 0; 171 ualg->cru_flags = alg->cra_flags; 172 ualg->cru_refcnt = atomic_read(&alg->cra_refcnt); 173 174 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority)) 175 goto nla_put_failure; 176 if (alg->cra_flags & CRYPTO_ALG_LARVAL) { 177 struct crypto_report_larval rl; 178 179 strncpy(rl.type, "larval", sizeof(rl.type)); 180 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, 181 sizeof(struct crypto_report_larval), &rl)) 182 goto nla_put_failure; 183 goto out; 184 } 185 186 if (alg->cra_type && alg->cra_type->report) { 187 if (alg->cra_type->report(skb, alg)) 188 goto nla_put_failure; 189 190 goto out; 191 } 192 193 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) { 194 case CRYPTO_ALG_TYPE_CIPHER: 195 if (crypto_report_cipher(skb, alg)) 196 goto nla_put_failure; 197 198 break; 199 case CRYPTO_ALG_TYPE_COMPRESS: 200 if (crypto_report_comp(skb, alg)) 201 goto nla_put_failure; 202 203 break; 204 case CRYPTO_ALG_TYPE_ACOMPRESS: 205 if (crypto_report_acomp(skb, alg)) 206 goto nla_put_failure; 207 208 break; 209 case CRYPTO_ALG_TYPE_AKCIPHER: 210 if (crypto_report_akcipher(skb, alg)) 211 goto nla_put_failure; 212 213 break; 214 case CRYPTO_ALG_TYPE_KPP: 215 if (crypto_report_kpp(skb, alg)) 216 goto nla_put_failure; 217 break; 218 } 219 220 out: 221 return 0; 222 223 nla_put_failure: 224 return -EMSGSIZE; 225 } 226 227 static int crypto_report_alg(struct crypto_alg *alg, 228 struct crypto_dump_info *info) 229 { 230 struct sk_buff *in_skb = info->in_skb; 231 struct sk_buff *skb = info->out_skb; 232 struct nlmsghdr *nlh; 233 struct crypto_user_alg *ualg; 234 int err = 0; 235 236 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq, 237 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags); 238 if (!nlh) { 239 err = -EMSGSIZE; 240 goto out; 241 } 242 243 ualg = nlmsg_data(nlh); 244 245 err = crypto_report_one(alg, ualg, skb); 246 if (err) { 247 nlmsg_cancel(skb, nlh); 248 goto out; 249 } 250 251 nlmsg_end(skb, nlh); 252 253 out: 254 return err; 255 } 256 257 static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, 258 struct nlattr **attrs) 259 { 260 struct crypto_user_alg *p = nlmsg_data(in_nlh); 261 struct crypto_alg *alg; 262 struct sk_buff *skb; 263 struct crypto_dump_info info; 264 int err; 265 266 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 267 return -EINVAL; 268 269 alg = crypto_alg_match(p, 0); 270 if (!alg) 271 return -ENOENT; 272 273 err = -ENOMEM; 274 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); 275 if (!skb) 276 goto drop_alg; 277 278 info.in_skb = in_skb; 279 info.out_skb = skb; 280 info.nlmsg_seq = in_nlh->nlmsg_seq; 281 info.nlmsg_flags = 0; 282 283 err = crypto_report_alg(alg, &info); 284 285 drop_alg: 286 crypto_mod_put(alg); 287 288 if (err) 289 return err; 290 291 return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid); 292 } 293 294 static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb) 295 { 296 struct crypto_alg *alg; 297 struct crypto_dump_info info; 298 int err; 299 300 if (cb->args[0]) 301 goto out; 302 303 cb->args[0] = 1; 304 305 info.in_skb = cb->skb; 306 info.out_skb = skb; 307 info.nlmsg_seq = cb->nlh->nlmsg_seq; 308 info.nlmsg_flags = NLM_F_MULTI; 309 310 list_for_each_entry(alg, &crypto_alg_list, cra_list) { 311 err = crypto_report_alg(alg, &info); 312 if (err) 313 goto out_err; 314 } 315 316 out: 317 return skb->len; 318 out_err: 319 return err; 320 } 321 322 static int crypto_dump_report_done(struct netlink_callback *cb) 323 { 324 return 0; 325 } 326 327 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 328 struct nlattr **attrs) 329 { 330 struct crypto_alg *alg; 331 struct crypto_user_alg *p = nlmsg_data(nlh); 332 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 333 LIST_HEAD(list); 334 335 if (!netlink_capable(skb, CAP_NET_ADMIN)) 336 return -EPERM; 337 338 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 339 return -EINVAL; 340 341 if (priority && !strlen(p->cru_driver_name)) 342 return -EINVAL; 343 344 alg = crypto_alg_match(p, 1); 345 if (!alg) 346 return -ENOENT; 347 348 down_write(&crypto_alg_sem); 349 350 crypto_remove_spawns(alg, &list, NULL); 351 352 if (priority) 353 alg->cra_priority = nla_get_u32(priority); 354 355 up_write(&crypto_alg_sem); 356 357 crypto_mod_put(alg); 358 crypto_remove_final(&list); 359 360 return 0; 361 } 362 363 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 364 struct nlattr **attrs) 365 { 366 struct crypto_alg *alg; 367 struct crypto_user_alg *p = nlmsg_data(nlh); 368 int err; 369 370 if (!netlink_capable(skb, CAP_NET_ADMIN)) 371 return -EPERM; 372 373 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 374 return -EINVAL; 375 376 alg = crypto_alg_match(p, 1); 377 if (!alg) 378 return -ENOENT; 379 380 /* We can not unregister core algorithms such as aes-generic. 381 * We would loose the reference in the crypto_alg_list to this algorithm 382 * if we try to unregister. Unregistering such an algorithm without 383 * removing the module is not possible, so we restrict to crypto 384 * instances that are build from templates. */ 385 err = -EINVAL; 386 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE)) 387 goto drop_alg; 388 389 err = -EBUSY; 390 if (atomic_read(&alg->cra_refcnt) > 2) 391 goto drop_alg; 392 393 err = crypto_unregister_instance((struct crypto_instance *)alg); 394 395 drop_alg: 396 crypto_mod_put(alg); 397 return err; 398 } 399 400 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 401 struct nlattr **attrs) 402 { 403 int exact = 0; 404 const char *name; 405 struct crypto_alg *alg; 406 struct crypto_user_alg *p = nlmsg_data(nlh); 407 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 408 409 if (!netlink_capable(skb, CAP_NET_ADMIN)) 410 return -EPERM; 411 412 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 413 return -EINVAL; 414 415 if (strlen(p->cru_driver_name)) 416 exact = 1; 417 418 if (priority && !exact) 419 return -EINVAL; 420 421 alg = crypto_alg_match(p, exact); 422 if (alg) { 423 crypto_mod_put(alg); 424 return -EEXIST; 425 } 426 427 if (strlen(p->cru_driver_name)) 428 name = p->cru_driver_name; 429 else 430 name = p->cru_name; 431 432 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask); 433 if (IS_ERR(alg)) 434 return PTR_ERR(alg); 435 436 down_write(&crypto_alg_sem); 437 438 if (priority) 439 alg->cra_priority = nla_get_u32(priority); 440 441 up_write(&crypto_alg_sem); 442 443 crypto_mod_put(alg); 444 445 return 0; 446 } 447 448 static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh, 449 struct nlattr **attrs) 450 { 451 if (!netlink_capable(skb, CAP_NET_ADMIN)) 452 return -EPERM; 453 return crypto_del_default_rng(); 454 } 455 456 #define MSGSIZE(type) sizeof(struct type) 457 458 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = { 459 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 460 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 461 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 462 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 463 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0, 464 }; 465 466 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = { 467 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32}, 468 }; 469 470 #undef MSGSIZE 471 472 static const struct crypto_link { 473 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **); 474 int (*dump)(struct sk_buff *, struct netlink_callback *); 475 int (*done)(struct netlink_callback *); 476 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = { 477 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg}, 478 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg}, 479 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg}, 480 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report, 481 .dump = crypto_dump_report, 482 .done = crypto_dump_report_done}, 483 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng }, 484 }; 485 486 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) 487 { 488 struct nlattr *attrs[CRYPTOCFGA_MAX+1]; 489 const struct crypto_link *link; 490 int type, err; 491 492 type = nlh->nlmsg_type; 493 if (type > CRYPTO_MSG_MAX) 494 return -EINVAL; 495 496 type -= CRYPTO_MSG_BASE; 497 link = &crypto_dispatch[type]; 498 499 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) && 500 (nlh->nlmsg_flags & NLM_F_DUMP))) { 501 struct crypto_alg *alg; 502 u16 dump_alloc = 0; 503 504 if (link->dump == NULL) 505 return -EINVAL; 506 507 down_read(&crypto_alg_sem); 508 list_for_each_entry(alg, &crypto_alg_list, cra_list) 509 dump_alloc += CRYPTO_REPORT_MAXSIZE; 510 511 { 512 struct netlink_dump_control c = { 513 .dump = link->dump, 514 .done = link->done, 515 .min_dump_alloc = dump_alloc, 516 }; 517 err = netlink_dump_start(crypto_nlsk, skb, nlh, &c); 518 } 519 up_read(&crypto_alg_sem); 520 521 return err; 522 } 523 524 err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX, 525 crypto_policy); 526 if (err < 0) 527 return err; 528 529 if (link->doit == NULL) 530 return -EINVAL; 531 532 return link->doit(skb, nlh, attrs); 533 } 534 535 static void crypto_netlink_rcv(struct sk_buff *skb) 536 { 537 mutex_lock(&crypto_cfg_mutex); 538 netlink_rcv_skb(skb, &crypto_user_rcv_msg); 539 mutex_unlock(&crypto_cfg_mutex); 540 } 541 542 static int __init crypto_user_init(void) 543 { 544 struct netlink_kernel_cfg cfg = { 545 .input = crypto_netlink_rcv, 546 }; 547 548 crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg); 549 if (!crypto_nlsk) 550 return -ENOMEM; 551 552 return 0; 553 } 554 555 static void __exit crypto_user_exit(void) 556 { 557 netlink_kernel_release(crypto_nlsk); 558 } 559 560 module_init(crypto_user_init); 561 module_exit(crypto_user_exit); 562 MODULE_LICENSE("GPL"); 563 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); 564 MODULE_DESCRIPTION("Crypto userspace configuration API"); 565 MODULE_ALIAS("net-pf-16-proto-21"); 566