linux/crypto/crypto_user.c
<<
>>
Prefs
   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/aead.h>
  29#include <crypto/internal/skcipher.h>
  30
  31#include "internal.h"
  32
  33DEFINE_MUTEX(crypto_cfg_mutex);
  34
  35/* The crypto netlink socket */
  36static struct sock *crypto_nlsk;
  37
  38struct crypto_dump_info {
  39        struct sk_buff *in_skb;
  40        struct sk_buff *out_skb;
  41        u32 nlmsg_seq;
  42        u16 nlmsg_flags;
  43};
  44
  45static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
  46{
  47        struct crypto_alg *q, *alg = NULL;
  48
  49        down_read(&crypto_alg_sem);
  50
  51        list_for_each_entry(q, &crypto_alg_list, cra_list) {
  52                int match = 0;
  53
  54                if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
  55                        continue;
  56
  57                if (strlen(p->cru_driver_name))
  58                        match = !strcmp(q->cra_driver_name,
  59                                        p->cru_driver_name);
  60                else if (!exact)
  61                        match = !strcmp(q->cra_name, p->cru_name);
  62
  63                if (match) {
  64                        alg = q;
  65                        break;
  66                }
  67        }
  68
  69        up_read(&crypto_alg_sem);
  70
  71        return alg;
  72}
  73
  74static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
  75{
  76        struct crypto_report_cipher rcipher;
  77
  78        snprintf(rcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "cipher");
  79
  80        rcipher.blocksize = alg->cra_blocksize;
  81        rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
  82        rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
  83
  84        if (nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
  85                    sizeof(struct crypto_report_cipher), &rcipher))
  86                goto nla_put_failure;
  87        return 0;
  88
  89nla_put_failure:
  90        return -EMSGSIZE;
  91}
  92
  93static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
  94{
  95        struct crypto_report_comp rcomp;
  96
  97        snprintf(rcomp.type, CRYPTO_MAX_ALG_NAME, "%s", "compression");
  98
  99        if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
 100                    sizeof(struct crypto_report_comp), &rcomp))
 101                goto nla_put_failure;
 102        return 0;
 103
 104nla_put_failure:
 105        return -EMSGSIZE;
 106}
 107
 108static int crypto_report_one(struct crypto_alg *alg,
 109                             struct crypto_user_alg *ualg, struct sk_buff *skb)
 110{
 111        memcpy(&ualg->cru_name, &alg->cra_name, sizeof(ualg->cru_name));
 112        memcpy(&ualg->cru_driver_name, &alg->cra_driver_name,
 113               sizeof(ualg->cru_driver_name));
 114        memcpy(&ualg->cru_module_name, module_name(alg->cra_module),
 115               CRYPTO_MAX_ALG_NAME);
 116
 117        ualg->cru_flags = alg->cra_flags;
 118        ualg->cru_refcnt = atomic_read(&alg->cra_refcnt);
 119
 120        if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
 121                goto nla_put_failure;
 122        if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
 123                struct crypto_report_larval rl;
 124
 125                snprintf(rl.type, CRYPTO_MAX_ALG_NAME, "%s", "larval");
 126
 127                if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL,
 128                            sizeof(struct crypto_report_larval), &rl))
 129                        goto nla_put_failure;
 130                goto out;
 131        }
 132
 133        if (alg->cra_type && alg->cra_type->report) {
 134                if (alg->cra_type->report(skb, alg))
 135                        goto nla_put_failure;
 136
 137                goto out;
 138        }
 139
 140        switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
 141        case CRYPTO_ALG_TYPE_CIPHER:
 142                if (crypto_report_cipher(skb, alg))
 143                        goto nla_put_failure;
 144
 145                break;
 146        case CRYPTO_ALG_TYPE_COMPRESS:
 147                if (crypto_report_comp(skb, alg))
 148                        goto nla_put_failure;
 149
 150                break;
 151        }
 152
 153out:
 154        return 0;
 155
 156nla_put_failure:
 157        return -EMSGSIZE;
 158}
 159
 160static int crypto_report_alg(struct crypto_alg *alg,
 161                             struct crypto_dump_info *info)
 162{
 163        struct sk_buff *in_skb = info->in_skb;
 164        struct sk_buff *skb = info->out_skb;
 165        struct nlmsghdr *nlh;
 166        struct crypto_user_alg *ualg;
 167        int err = 0;
 168
 169        nlh = nlmsg_put(skb, NETLINK_CB(in_skb).pid, info->nlmsg_seq,
 170                        CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
 171        if (!nlh) {
 172                err = -EMSGSIZE;
 173                goto out;
 174        }
 175
 176        ualg = nlmsg_data(nlh);
 177
 178        err = crypto_report_one(alg, ualg, skb);
 179        if (err) {
 180                nlmsg_cancel(skb, nlh);
 181                goto out;
 182        }
 183
 184        nlmsg_end(skb, nlh);
 185
 186out:
 187        return err;
 188}
 189
 190static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
 191                         struct nlattr **attrs)
 192{
 193        struct crypto_user_alg *p = nlmsg_data(in_nlh);
 194        struct crypto_alg *alg;
 195        struct sk_buff *skb;
 196        struct crypto_dump_info info;
 197        int err;
 198
 199        if (!p->cru_driver_name)
 200                return -EINVAL;
 201
 202        alg = crypto_alg_match(p, 1);
 203        if (!alg)
 204                return -ENOENT;
 205
 206        skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
 207        if (!skb)
 208                return -ENOMEM;
 209
 210        info.in_skb = in_skb;
 211        info.out_skb = skb;
 212        info.nlmsg_seq = in_nlh->nlmsg_seq;
 213        info.nlmsg_flags = 0;
 214
 215        err = crypto_report_alg(alg, &info);
 216        if (err)
 217                return err;
 218
 219        return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).pid);
 220}
 221
 222static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
 223{
 224        struct crypto_alg *alg;
 225        struct crypto_dump_info info;
 226        int err;
 227
 228        if (cb->args[0])
 229                goto out;
 230
 231        cb->args[0] = 1;
 232
 233        info.in_skb = cb->skb;
 234        info.out_skb = skb;
 235        info.nlmsg_seq = cb->nlh->nlmsg_seq;
 236        info.nlmsg_flags = NLM_F_MULTI;
 237
 238        list_for_each_entry(alg, &crypto_alg_list, cra_list) {
 239                err = crypto_report_alg(alg, &info);
 240                if (err)
 241                        goto out_err;
 242        }
 243
 244out:
 245        return skb->len;
 246out_err:
 247        return err;
 248}
 249
 250static int crypto_dump_report_done(struct netlink_callback *cb)
 251{
 252        return 0;
 253}
 254
 255static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
 256                             struct nlattr **attrs)
 257{
 258        struct crypto_alg *alg;
 259        struct crypto_user_alg *p = nlmsg_data(nlh);
 260        struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
 261        LIST_HEAD(list);
 262
 263        if (priority && !strlen(p->cru_driver_name))
 264                return -EINVAL;
 265
 266        alg = crypto_alg_match(p, 1);
 267        if (!alg)
 268                return -ENOENT;
 269
 270        down_write(&crypto_alg_sem);
 271
 272        crypto_remove_spawns(alg, &list, NULL);
 273
 274        if (priority)
 275                alg->cra_priority = nla_get_u32(priority);
 276
 277        up_write(&crypto_alg_sem);
 278
 279        crypto_remove_final(&list);
 280
 281        return 0;
 282}
 283
 284static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
 285                          struct nlattr **attrs)
 286{
 287        struct crypto_alg *alg;
 288        struct crypto_user_alg *p = nlmsg_data(nlh);
 289
 290        alg = crypto_alg_match(p, 1);
 291        if (!alg)
 292                return -ENOENT;
 293
 294        /* We can not unregister core algorithms such as aes-generic.
 295         * We would loose the reference in the crypto_alg_list to this algorithm
 296         * if we try to unregister. Unregistering such an algorithm without
 297         * removing the module is not possible, so we restrict to crypto
 298         * instances that are build from templates. */
 299        if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
 300                return -EINVAL;
 301
 302        if (atomic_read(&alg->cra_refcnt) != 1)
 303                return -EBUSY;
 304
 305        return crypto_unregister_instance(alg);
 306}
 307
 308static struct crypto_alg *crypto_user_skcipher_alg(const char *name, u32 type,
 309                                                   u32 mask)
 310{
 311        int err;
 312        struct crypto_alg *alg;
 313
 314        type = crypto_skcipher_type(type);
 315        mask = crypto_skcipher_mask(mask);
 316
 317        for (;;) {
 318                alg = crypto_lookup_skcipher(name,  type, mask);
 319                if (!IS_ERR(alg))
 320                        return alg;
 321
 322                err = PTR_ERR(alg);
 323                if (err != -EAGAIN)
 324                        break;
 325                if (signal_pending(current)) {
 326                        err = -EINTR;
 327                        break;
 328                }
 329        }
 330
 331        return ERR_PTR(err);
 332}
 333
 334static struct crypto_alg *crypto_user_aead_alg(const char *name, u32 type,
 335                                               u32 mask)
 336{
 337        int err;
 338        struct crypto_alg *alg;
 339
 340        type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 341        type |= CRYPTO_ALG_TYPE_AEAD;
 342        mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 343        mask |= CRYPTO_ALG_TYPE_MASK;
 344
 345        for (;;) {
 346                alg = crypto_lookup_aead(name,  type, mask);
 347                if (!IS_ERR(alg))
 348                        return alg;
 349
 350                err = PTR_ERR(alg);
 351                if (err != -EAGAIN)
 352                        break;
 353                if (signal_pending(current)) {
 354                        err = -EINTR;
 355                        break;
 356                }
 357        }
 358
 359        return ERR_PTR(err);
 360}
 361
 362static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
 363                          struct nlattr **attrs)
 364{
 365        int exact = 0;
 366        const char *name;
 367        struct crypto_alg *alg;
 368        struct crypto_user_alg *p = nlmsg_data(nlh);
 369        struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
 370
 371        if (strlen(p->cru_driver_name))
 372                exact = 1;
 373
 374        if (priority && !exact)
 375                return -EINVAL;
 376
 377        alg = crypto_alg_match(p, exact);
 378        if (alg)
 379                return -EEXIST;
 380
 381        if (strlen(p->cru_driver_name))
 382                name = p->cru_driver_name;
 383        else
 384                name = p->cru_name;
 385
 386        switch (p->cru_type & p->cru_mask & CRYPTO_ALG_TYPE_MASK) {
 387        case CRYPTO_ALG_TYPE_AEAD:
 388                alg = crypto_user_aead_alg(name, p->cru_type, p->cru_mask);
 389                break;
 390        case CRYPTO_ALG_TYPE_GIVCIPHER:
 391        case CRYPTO_ALG_TYPE_BLKCIPHER:
 392        case CRYPTO_ALG_TYPE_ABLKCIPHER:
 393                alg = crypto_user_skcipher_alg(name, p->cru_type, p->cru_mask);
 394                break;
 395        default:
 396                alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
 397        }
 398
 399        if (IS_ERR(alg))
 400                return PTR_ERR(alg);
 401
 402        down_write(&crypto_alg_sem);
 403
 404        if (priority)
 405                alg->cra_priority = nla_get_u32(priority);
 406
 407        up_write(&crypto_alg_sem);
 408
 409        crypto_mod_put(alg);
 410
 411        return 0;
 412}
 413
 414#define MSGSIZE(type) sizeof(struct type)
 415
 416static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
 417        [CRYPTO_MSG_NEWALG      - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
 418        [CRYPTO_MSG_DELALG      - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
 419        [CRYPTO_MSG_UPDATEALG   - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
 420        [CRYPTO_MSG_GETALG      - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
 421};
 422
 423static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
 424        [CRYPTOCFGA_PRIORITY_VAL]   = { .type = NLA_U32},
 425};
 426
 427#undef MSGSIZE
 428
 429static struct crypto_link {
 430        int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
 431        int (*dump)(struct sk_buff *, struct netlink_callback *);
 432        int (*done)(struct netlink_callback *);
 433} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
 434        [CRYPTO_MSG_NEWALG      - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
 435        [CRYPTO_MSG_DELALG      - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
 436        [CRYPTO_MSG_UPDATEALG   - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
 437        [CRYPTO_MSG_GETALG      - CRYPTO_MSG_BASE] = { .doit = crypto_report,
 438                                                       .dump = crypto_dump_report,
 439                                                       .done = crypto_dump_report_done},
 440};
 441
 442static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 443{
 444        struct nlattr *attrs[CRYPTOCFGA_MAX+1];
 445        struct crypto_link *link;
 446        int type, err;
 447
 448        type = nlh->nlmsg_type;
 449        if (type > CRYPTO_MSG_MAX)
 450                return -EINVAL;
 451
 452        type -= CRYPTO_MSG_BASE;
 453        link = &crypto_dispatch[type];
 454
 455        if (!capable(CAP_NET_ADMIN))
 456                return -EPERM;
 457
 458        if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
 459            (nlh->nlmsg_flags & NLM_F_DUMP))) {
 460                struct crypto_alg *alg;
 461                u16 dump_alloc = 0;
 462
 463                if (link->dump == NULL)
 464                        return -EINVAL;
 465
 466                list_for_each_entry(alg, &crypto_alg_list, cra_list)
 467                        dump_alloc += CRYPTO_REPORT_MAXSIZE;
 468
 469                {
 470                        struct netlink_dump_control c = {
 471                                .dump = link->dump,
 472                                .done = link->done,
 473                                .min_dump_alloc = dump_alloc,
 474                        };
 475                        return netlink_dump_start(crypto_nlsk, skb, nlh, &c);
 476                }
 477        }
 478
 479        err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX,
 480                          crypto_policy);
 481        if (err < 0)
 482                return err;
 483
 484        if (link->doit == NULL)
 485                return -EINVAL;
 486
 487        return link->doit(skb, nlh, attrs);
 488}
 489
 490static void crypto_netlink_rcv(struct sk_buff *skb)
 491{
 492        mutex_lock(&crypto_cfg_mutex);
 493        netlink_rcv_skb(skb, &crypto_user_rcv_msg);
 494        mutex_unlock(&crypto_cfg_mutex);
 495}
 496
 497static int __init crypto_user_init(void)
 498{
 499        struct netlink_kernel_cfg cfg = {
 500                .input  = crypto_netlink_rcv,
 501        };
 502
 503        crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO,
 504                                            THIS_MODULE, &cfg);
 505        if (!crypto_nlsk)
 506                return -ENOMEM;
 507
 508        return 0;
 509}
 510
 511static void __exit crypto_user_exit(void)
 512{
 513        netlink_kernel_release(crypto_nlsk);
 514}
 515
 516module_init(crypto_user_init);
 517module_exit(crypto_user_exit);
 518MODULE_LICENSE("GPL");
 519MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
 520MODULE_DESCRIPTION("Crypto userspace configuration API");
 521
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.