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 memset(&rcipher, 0, sizeof(rcipher)); 88 89 strscpy(rcipher.type, "cipher", sizeof(rcipher.type)); 90 91 rcipher.blocksize = alg->cra_blocksize; 92 rcipher.min_keysize = alg->cra_cipher.cia_min_keysize; 93 rcipher.max_keysize = alg->cra_cipher.cia_max_keysize; 94 95 return nla_put(skb, CRYPTOCFGA_REPORT_CIPHER, 96 sizeof(rcipher), &rcipher); 97 } 98 99 static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg) 100 { 101 struct crypto_report_comp rcomp; 102 103 memset(&rcomp, 0, sizeof(rcomp)); 104 105 strscpy(rcomp.type, "compression", sizeof(rcomp.type)); 106 107 return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(rcomp), &rcomp); 108 } 109 110 static int crypto_report_one(struct crypto_alg *alg, 111 struct crypto_user_alg *ualg, struct sk_buff *skb) 112 { 113 memset(ualg, 0, sizeof(*ualg)); 114 115 strscpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name)); 116 strscpy(ualg->cru_driver_name, alg->cra_driver_name, 117 sizeof(ualg->cru_driver_name)); 118 strscpy(ualg->cru_module_name, module_name(alg->cra_module), 119 sizeof(ualg->cru_module_name)); 120 121 ualg->cru_type = 0; 122 ualg->cru_mask = 0; 123 ualg->cru_flags = alg->cra_flags; 124 ualg->cru_refcnt = refcount_read(&alg->cra_refcnt); 125 126 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority)) 127 goto nla_put_failure; 128 if (alg->cra_flags & CRYPTO_ALG_LARVAL) { 129 struct crypto_report_larval rl; 130 131 memset(&rl, 0, sizeof(rl)); 132 strscpy(rl.type, "larval", sizeof(rl.type)); 133 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl)) 134 goto nla_put_failure; 135 goto out; 136 } 137 138 if (alg->cra_type && alg->cra_type->report) { 139 if (alg->cra_type->report(skb, alg)) 140 goto nla_put_failure; 141 142 goto out; 143 } 144 145 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) { 146 case CRYPTO_ALG_TYPE_CIPHER: 147 if (crypto_report_cipher(skb, alg)) 148 goto nla_put_failure; 149 150 break; 151 case CRYPTO_ALG_TYPE_COMPRESS: 152 if (crypto_report_comp(skb, alg)) 153 goto nla_put_failure; 154 155 break; 156 } 157 158 out: 159 return 0; 160 161 nla_put_failure: 162 return -EMSGSIZE; 163 } 164 165 static int crypto_report_alg(struct crypto_alg *alg, 166 struct crypto_dump_info *info) 167 { 168 struct sk_buff *in_skb = info->in_skb; 169 struct sk_buff *skb = info->out_skb; 170 struct nlmsghdr *nlh; 171 struct crypto_user_alg *ualg; 172 int err = 0; 173 174 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq, 175 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags); 176 if (!nlh) { 177 err = -EMSGSIZE; 178 goto out; 179 } 180 181 ualg = nlmsg_data(nlh); 182 183 err = crypto_report_one(alg, ualg, skb); 184 if (err) { 185 nlmsg_cancel(skb, nlh); 186 goto out; 187 } 188 189 nlmsg_end(skb, nlh); 190 191 out: 192 return err; 193 } 194 195 static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, 196 struct nlattr **attrs) 197 { 198 struct crypto_user_alg *p = nlmsg_data(in_nlh); 199 struct crypto_alg *alg; 200 struct sk_buff *skb; 201 struct crypto_dump_info info; 202 int err; 203 204 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 205 return -EINVAL; 206 207 alg = crypto_alg_match(p, 0); 208 if (!alg) 209 return -ENOENT; 210 211 err = -ENOMEM; 212 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 213 if (!skb) 214 goto drop_alg; 215 216 info.in_skb = in_skb; 217 info.out_skb = skb; 218 info.nlmsg_seq = in_nlh->nlmsg_seq; 219 info.nlmsg_flags = 0; 220 221 err = crypto_report_alg(alg, &info); 222 223 drop_alg: 224 crypto_mod_put(alg); 225 226 if (err) 227 return err; 228 229 return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid); 230 } 231 232 static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb) 233 { 234 const size_t start_pos = cb->args[0]; 235 size_t pos = 0; 236 struct crypto_dump_info info; 237 struct crypto_alg *alg; 238 int res; 239 240 info.in_skb = cb->skb; 241 info.out_skb = skb; 242 info.nlmsg_seq = cb->nlh->nlmsg_seq; 243 info.nlmsg_flags = NLM_F_MULTI; 244 245 down_read(&crypto_alg_sem); 246 list_for_each_entry(alg, &crypto_alg_list, cra_list) { 247 if (pos >= start_pos) { 248 res = crypto_report_alg(alg, &info); 249 if (res == -EMSGSIZE) 250 break; 251 if (res) 252 goto out; 253 } 254 pos++; 255 } 256 cb->args[0] = pos; 257 res = skb->len; 258 out: 259 up_read(&crypto_alg_sem); 260 return res; 261 } 262 263 static int crypto_dump_report_done(struct netlink_callback *cb) 264 { 265 return 0; 266 } 267 268 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 269 struct nlattr **attrs) 270 { 271 struct crypto_alg *alg; 272 struct crypto_user_alg *p = nlmsg_data(nlh); 273 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 274 LIST_HEAD(list); 275 276 if (!netlink_capable(skb, CAP_NET_ADMIN)) 277 return -EPERM; 278 279 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 280 return -EINVAL; 281 282 if (priority && !strlen(p->cru_driver_name)) 283 return -EINVAL; 284 285 alg = crypto_alg_match(p, 1); 286 if (!alg) 287 return -ENOENT; 288 289 down_write(&crypto_alg_sem); 290 291 crypto_remove_spawns(alg, &list, NULL); 292 293 if (priority) 294 alg->cra_priority = nla_get_u32(priority); 295 296 up_write(&crypto_alg_sem); 297 298 crypto_mod_put(alg); 299 crypto_remove_final(&list); 300 301 return 0; 302 } 303 304 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 305 struct nlattr **attrs) 306 { 307 struct crypto_alg *alg; 308 struct crypto_user_alg *p = nlmsg_data(nlh); 309 int err; 310 311 if (!netlink_capable(skb, CAP_NET_ADMIN)) 312 return -EPERM; 313 314 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 315 return -EINVAL; 316 317 alg = crypto_alg_match(p, 1); 318 if (!alg) 319 return -ENOENT; 320 321 /* We can not unregister core algorithms such as aes-generic. 322 * We would loose the reference in the crypto_alg_list to this algorithm 323 * if we try to unregister. Unregistering such an algorithm without 324 * removing the module is not possible, so we restrict to crypto 325 * instances that are build from templates. */ 326 err = -EINVAL; 327 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE)) 328 goto drop_alg; 329 330 err = -EBUSY; 331 if (refcount_read(&alg->cra_refcnt) > 2) 332 goto drop_alg; 333 334 err = crypto_unregister_instance((struct crypto_instance *)alg); 335 336 drop_alg: 337 crypto_mod_put(alg); 338 return err; 339 } 340 341 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 342 struct nlattr **attrs) 343 { 344 int exact = 0; 345 const char *name; 346 struct crypto_alg *alg; 347 struct crypto_user_alg *p = nlmsg_data(nlh); 348 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 349 350 if (!netlink_capable(skb, CAP_NET_ADMIN)) 351 return -EPERM; 352 353 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 354 return -EINVAL; 355 356 if (strlen(p->cru_driver_name)) 357 exact = 1; 358 359 if (priority && !exact) 360 return -EINVAL; 361 362 alg = crypto_alg_match(p, exact); 363 if (alg) { 364 crypto_mod_put(alg); 365 return -EEXIST; 366 } 367 368 if (strlen(p->cru_driver_name)) 369 name = p->cru_driver_name; 370 else 371 name = p->cru_name; 372 373 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask); 374 if (IS_ERR(alg)) 375 return PTR_ERR(alg); 376 377 down_write(&crypto_alg_sem); 378 379 if (priority) 380 alg->cra_priority = nla_get_u32(priority); 381 382 up_write(&crypto_alg_sem); 383 384 crypto_mod_put(alg); 385 386 return 0; 387 } 388 389 static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh, 390 struct nlattr **attrs) 391 { 392 if (!netlink_capable(skb, CAP_NET_ADMIN)) 393 return -EPERM; 394 return crypto_del_default_rng(); 395 } 396 397 #define MSGSIZE(type) sizeof(struct type) 398 399 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = { 400 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 401 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 402 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 403 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 404 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0, 405 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 406 }; 407 408 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = { 409 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32}, 410 }; 411 412 #undef MSGSIZE 413 414 static const struct crypto_link { 415 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **); 416 int (*dump)(struct sk_buff *, struct netlink_callback *); 417 int (*done)(struct netlink_callback *); 418 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = { 419 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg}, 420 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg}, 421 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg}, 422 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report, 423 .dump = crypto_dump_report, 424 .done = crypto_dump_report_done}, 425 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng }, 426 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat}, 427 }; 428 429 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, 430 struct netlink_ext_ack *extack) 431 { 432 struct nlattr *attrs[CRYPTOCFGA_MAX+1]; 433 const struct crypto_link *link; 434 int type, err; 435 436 type = nlh->nlmsg_type; 437 if (type > CRYPTO_MSG_MAX) 438 return -EINVAL; 439 440 type -= CRYPTO_MSG_BASE; 441 link = &crypto_dispatch[type]; 442 443 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) && 444 (nlh->nlmsg_flags & NLM_F_DUMP))) { 445 struct crypto_alg *alg; 446 unsigned long dump_alloc = 0; 447 448 if (link->dump == NULL) 449 return -EINVAL; 450 451 down_read(&crypto_alg_sem); 452 list_for_each_entry(alg, &crypto_alg_list, cra_list) 453 dump_alloc += CRYPTO_REPORT_MAXSIZE; 454 up_read(&crypto_alg_sem); 455 456 { 457 struct netlink_dump_control c = { 458 .dump = link->dump, 459 .done = link->done, 460 .min_dump_alloc = min(dump_alloc, 65535UL), 461 }; 462 err = netlink_dump_start(crypto_nlsk, skb, nlh, &c); 463 } 464 465 return err; 466 } 467 468 err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX, 469 crypto_policy, extack); 470 if (err < 0) 471 return err; 472 473 if (link->doit == NULL) 474 return -EINVAL; 475 476 return link->doit(skb, nlh, attrs); 477 } 478 479 static void crypto_netlink_rcv(struct sk_buff *skb) 480 { 481 mutex_lock(&crypto_cfg_mutex); 482 netlink_rcv_skb(skb, &crypto_user_rcv_msg); 483 mutex_unlock(&crypto_cfg_mutex); 484 } 485 486 static int __init crypto_user_init(void) 487 { 488 struct netlink_kernel_cfg cfg = { 489 .input = crypto_netlink_rcv, 490 }; 491 492 crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg); 493 if (!crypto_nlsk) 494 return -ENOMEM; 495 496 return 0; 497 } 498 499 static void __exit crypto_user_exit(void) 500 { 501 netlink_kernel_release(crypto_nlsk); 502 } 503 504 module_init(crypto_user_init); 505 module_exit(crypto_user_exit); 506 MODULE_LICENSE("GPL"); 507 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); 508 MODULE_DESCRIPTION("Crypto userspace configuration API"); 509 MODULE_ALIAS("net-pf-16-proto-21"); 510