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 struct crypto_alg *alg; 235 struct crypto_dump_info info; 236 int err; 237 238 if (cb->args[0]) 239 goto out; 240 241 cb->args[0] = 1; 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 list_for_each_entry(alg, &crypto_alg_list, cra_list) { 249 err = crypto_report_alg(alg, &info); 250 if (err) 251 goto out_err; 252 } 253 254 out: 255 return skb->len; 256 out_err: 257 return err; 258 } 259 260 static int crypto_dump_report_done(struct netlink_callback *cb) 261 { 262 return 0; 263 } 264 265 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 266 struct nlattr **attrs) 267 { 268 struct crypto_alg *alg; 269 struct crypto_user_alg *p = nlmsg_data(nlh); 270 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 271 LIST_HEAD(list); 272 273 if (!netlink_capable(skb, CAP_NET_ADMIN)) 274 return -EPERM; 275 276 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 277 return -EINVAL; 278 279 if (priority && !strlen(p->cru_driver_name)) 280 return -EINVAL; 281 282 alg = crypto_alg_match(p, 1); 283 if (!alg) 284 return -ENOENT; 285 286 down_write(&crypto_alg_sem); 287 288 crypto_remove_spawns(alg, &list, NULL); 289 290 if (priority) 291 alg->cra_priority = nla_get_u32(priority); 292 293 up_write(&crypto_alg_sem); 294 295 crypto_mod_put(alg); 296 crypto_remove_final(&list); 297 298 return 0; 299 } 300 301 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 302 struct nlattr **attrs) 303 { 304 struct crypto_alg *alg; 305 struct crypto_user_alg *p = nlmsg_data(nlh); 306 int err; 307 308 if (!netlink_capable(skb, CAP_NET_ADMIN)) 309 return -EPERM; 310 311 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 312 return -EINVAL; 313 314 alg = crypto_alg_match(p, 1); 315 if (!alg) 316 return -ENOENT; 317 318 /* We can not unregister core algorithms such as aes-generic. 319 * We would loose the reference in the crypto_alg_list to this algorithm 320 * if we try to unregister. Unregistering such an algorithm without 321 * removing the module is not possible, so we restrict to crypto 322 * instances that are build from templates. */ 323 err = -EINVAL; 324 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE)) 325 goto drop_alg; 326 327 err = -EBUSY; 328 if (refcount_read(&alg->cra_refcnt) > 2) 329 goto drop_alg; 330 331 err = crypto_unregister_instance((struct crypto_instance *)alg); 332 333 drop_alg: 334 crypto_mod_put(alg); 335 return err; 336 } 337 338 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh, 339 struct nlattr **attrs) 340 { 341 int exact = 0; 342 const char *name; 343 struct crypto_alg *alg; 344 struct crypto_user_alg *p = nlmsg_data(nlh); 345 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; 346 347 if (!netlink_capable(skb, CAP_NET_ADMIN)) 348 return -EPERM; 349 350 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name)) 351 return -EINVAL; 352 353 if (strlen(p->cru_driver_name)) 354 exact = 1; 355 356 if (priority && !exact) 357 return -EINVAL; 358 359 alg = crypto_alg_match(p, exact); 360 if (alg) { 361 crypto_mod_put(alg); 362 return -EEXIST; 363 } 364 365 if (strlen(p->cru_driver_name)) 366 name = p->cru_driver_name; 367 else 368 name = p->cru_name; 369 370 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask); 371 if (IS_ERR(alg)) 372 return PTR_ERR(alg); 373 374 down_write(&crypto_alg_sem); 375 376 if (priority) 377 alg->cra_priority = nla_get_u32(priority); 378 379 up_write(&crypto_alg_sem); 380 381 crypto_mod_put(alg); 382 383 return 0; 384 } 385 386 static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh, 387 struct nlattr **attrs) 388 { 389 if (!netlink_capable(skb, CAP_NET_ADMIN)) 390 return -EPERM; 391 return crypto_del_default_rng(); 392 } 393 394 #define MSGSIZE(type) sizeof(struct type) 395 396 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = { 397 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 398 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 399 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 400 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 401 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0, 402 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), 403 }; 404 405 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = { 406 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32}, 407 }; 408 409 #undef MSGSIZE 410 411 static const struct crypto_link { 412 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **); 413 int (*dump)(struct sk_buff *, struct netlink_callback *); 414 int (*done)(struct netlink_callback *); 415 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = { 416 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg}, 417 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg}, 418 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg}, 419 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report, 420 .dump = crypto_dump_report, 421 .done = crypto_dump_report_done}, 422 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng }, 423 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat, 424 .dump = crypto_dump_reportstat, 425 .done = crypto_dump_reportstat_done}, 426 }; 427 428 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, 429 struct netlink_ext_ack *extack) 430 { 431 struct nlattr *attrs[CRYPTOCFGA_MAX+1]; 432 const struct crypto_link *link; 433 int type, err; 434 435 type = nlh->nlmsg_type; 436 if (type > CRYPTO_MSG_MAX) 437 return -EINVAL; 438 439 type -= CRYPTO_MSG_BASE; 440 link = &crypto_dispatch[type]; 441 442 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) && 443 (nlh->nlmsg_flags & NLM_F_DUMP))) { 444 struct crypto_alg *alg; 445 u16 dump_alloc = 0; 446 447 if (link->dump == NULL) 448 return -EINVAL; 449 450 down_read(&crypto_alg_sem); 451 list_for_each_entry(alg, &crypto_alg_list, cra_list) 452 dump_alloc += CRYPTO_REPORT_MAXSIZE; 453 454 { 455 struct netlink_dump_control c = { 456 .dump = link->dump, 457 .done = link->done, 458 .min_dump_alloc = dump_alloc, 459 }; 460 err = netlink_dump_start(crypto_nlsk, skb, nlh, &c); 461 } 462 up_read(&crypto_alg_sem); 463 464 return err; 465 } 466 467 err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX, 468 crypto_policy, extack); 469 if (err < 0) 470 return err; 471 472 if (link->doit == NULL) 473 return -EINVAL; 474 475 return link->doit(skb, nlh, attrs); 476 } 477 478 static void crypto_netlink_rcv(struct sk_buff *skb) 479 { 480 mutex_lock(&crypto_cfg_mutex); 481 netlink_rcv_skb(skb, &crypto_user_rcv_msg); 482 mutex_unlock(&crypto_cfg_mutex); 483 } 484 485 static int __init crypto_user_init(void) 486 { 487 struct netlink_kernel_cfg cfg = { 488 .input = crypto_netlink_rcv, 489 }; 490 491 crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg); 492 if (!crypto_nlsk) 493 return -ENOMEM; 494 495 return 0; 496 } 497 498 static void __exit crypto_user_exit(void) 499 { 500 netlink_kernel_release(crypto_nlsk); 501 } 502 503 module_init(crypto_user_init); 504 module_exit(crypto_user_exit); 505 MODULE_LICENSE("GPL"); 506 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); 507 MODULE_DESCRIPTION("Crypto userspace configuration API"); 508 MODULE_ALIAS("net-pf-16-proto-21"); 509