algif_hash.c 9.5 KB

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  1. // SPDX-License-Identifier: GPL-2.0-or-later
  2. /*
  3. * algif_hash: User-space interface for hash algorithms
  4. *
  5. * This file provides the user-space API for hash algorithms.
  6. *
  7. * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
  8. */
  9. #include <crypto/hash.h>
  10. #include <crypto/if_alg.h>
  11. #include <linux/init.h>
  12. #include <linux/kernel.h>
  13. #include <linux/mm.h>
  14. #include <linux/module.h>
  15. #include <linux/net.h>
  16. #include <net/sock.h>
  17. struct hash_ctx {
  18. struct af_alg_sgl sgl;
  19. u8 *result;
  20. struct crypto_wait wait;
  21. unsigned int len;
  22. bool more;
  23. struct ahash_request req;
  24. };
  25. static int hash_alloc_result(struct sock *sk, struct hash_ctx *ctx)
  26. {
  27. unsigned ds;
  28. if (ctx->result)
  29. return 0;
  30. ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
  31. ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
  32. if (!ctx->result)
  33. return -ENOMEM;
  34. memset(ctx->result, 0, ds);
  35. return 0;
  36. }
  37. static void hash_free_result(struct sock *sk, struct hash_ctx *ctx)
  38. {
  39. unsigned ds;
  40. if (!ctx->result)
  41. return;
  42. ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
  43. sock_kzfree_s(sk, ctx->result, ds);
  44. ctx->result = NULL;
  45. }
  46. static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
  47. size_t ignored)
  48. {
  49. int limit = ALG_MAX_PAGES * PAGE_SIZE;
  50. struct sock *sk = sock->sk;
  51. struct alg_sock *ask = alg_sk(sk);
  52. struct hash_ctx *ctx = ask->private;
  53. long copied = 0;
  54. int err;
  55. if (limit > sk->sk_sndbuf)
  56. limit = sk->sk_sndbuf;
  57. lock_sock(sk);
  58. if (!ctx->more) {
  59. if ((msg->msg_flags & MSG_MORE))
  60. hash_free_result(sk, ctx);
  61. err = crypto_wait_req(crypto_ahash_init(&ctx->req), &ctx->wait);
  62. if (err)
  63. goto unlock;
  64. }
  65. ctx->more = false;
  66. while (msg_data_left(msg)) {
  67. int len = msg_data_left(msg);
  68. if (len > limit)
  69. len = limit;
  70. len = af_alg_make_sg(&ctx->sgl, &msg->msg_iter, len);
  71. if (len < 0) {
  72. err = copied ? 0 : len;
  73. goto unlock;
  74. }
  75. ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, NULL, len);
  76. err = crypto_wait_req(crypto_ahash_update(&ctx->req),
  77. &ctx->wait);
  78. af_alg_free_sg(&ctx->sgl);
  79. if (err)
  80. goto unlock;
  81. copied += len;
  82. iov_iter_advance(&msg->msg_iter, len);
  83. }
  84. err = 0;
  85. ctx->more = msg->msg_flags & MSG_MORE;
  86. if (!ctx->more) {
  87. err = hash_alloc_result(sk, ctx);
  88. if (err)
  89. goto unlock;
  90. ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
  91. err = crypto_wait_req(crypto_ahash_final(&ctx->req),
  92. &ctx->wait);
  93. }
  94. unlock:
  95. release_sock(sk);
  96. return err ?: copied;
  97. }
  98. static ssize_t hash_sendpage(struct socket *sock, struct page *page,
  99. int offset, size_t size, int flags)
  100. {
  101. struct sock *sk = sock->sk;
  102. struct alg_sock *ask = alg_sk(sk);
  103. struct hash_ctx *ctx = ask->private;
  104. int err;
  105. if (flags & MSG_SENDPAGE_NOTLAST)
  106. flags |= MSG_MORE;
  107. lock_sock(sk);
  108. sg_init_table(ctx->sgl.sg, 1);
  109. sg_set_page(ctx->sgl.sg, page, size, offset);
  110. if (!(flags & MSG_MORE)) {
  111. err = hash_alloc_result(sk, ctx);
  112. if (err)
  113. goto unlock;
  114. } else if (!ctx->more)
  115. hash_free_result(sk, ctx);
  116. ahash_request_set_crypt(&ctx->req, ctx->sgl.sg, ctx->result, size);
  117. if (!(flags & MSG_MORE)) {
  118. if (ctx->more)
  119. err = crypto_ahash_finup(&ctx->req);
  120. else
  121. err = crypto_ahash_digest(&ctx->req);
  122. } else {
  123. if (!ctx->more) {
  124. err = crypto_ahash_init(&ctx->req);
  125. err = crypto_wait_req(err, &ctx->wait);
  126. if (err)
  127. goto unlock;
  128. }
  129. err = crypto_ahash_update(&ctx->req);
  130. }
  131. err = crypto_wait_req(err, &ctx->wait);
  132. if (err)
  133. goto unlock;
  134. ctx->more = flags & MSG_MORE;
  135. unlock:
  136. release_sock(sk);
  137. return err ?: size;
  138. }
  139. static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
  140. int flags)
  141. {
  142. struct sock *sk = sock->sk;
  143. struct alg_sock *ask = alg_sk(sk);
  144. struct hash_ctx *ctx = ask->private;
  145. unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
  146. bool result;
  147. int err;
  148. if (len > ds)
  149. len = ds;
  150. else if (len < ds)
  151. msg->msg_flags |= MSG_TRUNC;
  152. lock_sock(sk);
  153. result = ctx->result;
  154. err = hash_alloc_result(sk, ctx);
  155. if (err)
  156. goto unlock;
  157. ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
  158. if (!result && !ctx->more) {
  159. err = crypto_wait_req(crypto_ahash_init(&ctx->req),
  160. &ctx->wait);
  161. if (err)
  162. goto unlock;
  163. }
  164. if (!result || ctx->more) {
  165. ctx->more = false;
  166. err = crypto_wait_req(crypto_ahash_final(&ctx->req),
  167. &ctx->wait);
  168. if (err)
  169. goto unlock;
  170. }
  171. err = memcpy_to_msg(msg, ctx->result, len);
  172. unlock:
  173. hash_free_result(sk, ctx);
  174. release_sock(sk);
  175. return err ?: len;
  176. }
  177. static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
  178. bool kern)
  179. {
  180. struct sock *sk = sock->sk;
  181. struct alg_sock *ask = alg_sk(sk);
  182. struct hash_ctx *ctx = ask->private;
  183. struct ahash_request *req = &ctx->req;
  184. char state[HASH_MAX_STATESIZE];
  185. struct sock *sk2;
  186. struct alg_sock *ask2;
  187. struct hash_ctx *ctx2;
  188. bool more;
  189. int err;
  190. lock_sock(sk);
  191. more = ctx->more;
  192. err = more ? crypto_ahash_export(req, state) : 0;
  193. release_sock(sk);
  194. if (err)
  195. return err;
  196. err = af_alg_accept(ask->parent, newsock, kern);
  197. if (err)
  198. return err;
  199. sk2 = newsock->sk;
  200. ask2 = alg_sk(sk2);
  201. ctx2 = ask2->private;
  202. ctx2->more = more;
  203. if (!more)
  204. return err;
  205. err = crypto_ahash_import(&ctx2->req, state);
  206. if (err) {
  207. sock_orphan(sk2);
  208. sock_put(sk2);
  209. }
  210. return err;
  211. }
  212. static struct proto_ops algif_hash_ops = {
  213. .family = PF_ALG,
  214. .connect = sock_no_connect,
  215. .socketpair = sock_no_socketpair,
  216. .getname = sock_no_getname,
  217. .ioctl = sock_no_ioctl,
  218. .listen = sock_no_listen,
  219. .shutdown = sock_no_shutdown,
  220. .mmap = sock_no_mmap,
  221. .bind = sock_no_bind,
  222. .release = af_alg_release,
  223. .sendmsg = hash_sendmsg,
  224. .sendpage = hash_sendpage,
  225. .recvmsg = hash_recvmsg,
  226. .accept = hash_accept,
  227. };
  228. static int hash_check_key(struct socket *sock)
  229. {
  230. int err = 0;
  231. struct sock *psk;
  232. struct alg_sock *pask;
  233. struct crypto_ahash *tfm;
  234. struct sock *sk = sock->sk;
  235. struct alg_sock *ask = alg_sk(sk);
  236. lock_sock(sk);
  237. if (!atomic_read(&ask->nokey_refcnt))
  238. goto unlock_child;
  239. psk = ask->parent;
  240. pask = alg_sk(ask->parent);
  241. tfm = pask->private;
  242. err = -ENOKEY;
  243. lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
  244. if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
  245. goto unlock;
  246. atomic_dec(&pask->nokey_refcnt);
  247. atomic_set(&ask->nokey_refcnt, 0);
  248. err = 0;
  249. unlock:
  250. release_sock(psk);
  251. unlock_child:
  252. release_sock(sk);
  253. return err;
  254. }
  255. static int hash_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
  256. size_t size)
  257. {
  258. int err;
  259. err = hash_check_key(sock);
  260. if (err)
  261. return err;
  262. return hash_sendmsg(sock, msg, size);
  263. }
  264. static ssize_t hash_sendpage_nokey(struct socket *sock, struct page *page,
  265. int offset, size_t size, int flags)
  266. {
  267. int err;
  268. err = hash_check_key(sock);
  269. if (err)
  270. return err;
  271. return hash_sendpage(sock, page, offset, size, flags);
  272. }
  273. static int hash_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
  274. size_t ignored, int flags)
  275. {
  276. int err;
  277. err = hash_check_key(sock);
  278. if (err)
  279. return err;
  280. return hash_recvmsg(sock, msg, ignored, flags);
  281. }
  282. static int hash_accept_nokey(struct socket *sock, struct socket *newsock,
  283. int flags, bool kern)
  284. {
  285. int err;
  286. err = hash_check_key(sock);
  287. if (err)
  288. return err;
  289. return hash_accept(sock, newsock, flags, kern);
  290. }
  291. static struct proto_ops algif_hash_ops_nokey = {
  292. .family = PF_ALG,
  293. .connect = sock_no_connect,
  294. .socketpair = sock_no_socketpair,
  295. .getname = sock_no_getname,
  296. .ioctl = sock_no_ioctl,
  297. .listen = sock_no_listen,
  298. .shutdown = sock_no_shutdown,
  299. .mmap = sock_no_mmap,
  300. .bind = sock_no_bind,
  301. .release = af_alg_release,
  302. .sendmsg = hash_sendmsg_nokey,
  303. .sendpage = hash_sendpage_nokey,
  304. .recvmsg = hash_recvmsg_nokey,
  305. .accept = hash_accept_nokey,
  306. };
  307. static void *hash_bind(const char *name, u32 type, u32 mask)
  308. {
  309. return crypto_alloc_ahash(name, type, mask);
  310. }
  311. static void hash_release(void *private)
  312. {
  313. crypto_free_ahash(private);
  314. }
  315. static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
  316. {
  317. return crypto_ahash_setkey(private, key, keylen);
  318. }
  319. static void hash_sock_destruct(struct sock *sk)
  320. {
  321. struct alg_sock *ask = alg_sk(sk);
  322. struct hash_ctx *ctx = ask->private;
  323. hash_free_result(sk, ctx);
  324. sock_kfree_s(sk, ctx, ctx->len);
  325. af_alg_release_parent(sk);
  326. }
  327. static int hash_accept_parent_nokey(void *private, struct sock *sk)
  328. {
  329. struct crypto_ahash *tfm = private;
  330. struct alg_sock *ask = alg_sk(sk);
  331. struct hash_ctx *ctx;
  332. unsigned int len = sizeof(*ctx) + crypto_ahash_reqsize(tfm);
  333. ctx = sock_kmalloc(sk, len, GFP_KERNEL);
  334. if (!ctx)
  335. return -ENOMEM;
  336. ctx->result = NULL;
  337. ctx->len = len;
  338. ctx->more = false;
  339. crypto_init_wait(&ctx->wait);
  340. ask->private = ctx;
  341. ahash_request_set_tfm(&ctx->req, tfm);
  342. ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
  343. crypto_req_done, &ctx->wait);
  344. sk->sk_destruct = hash_sock_destruct;
  345. return 0;
  346. }
  347. static int hash_accept_parent(void *private, struct sock *sk)
  348. {
  349. struct crypto_ahash *tfm = private;
  350. if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
  351. return -ENOKEY;
  352. return hash_accept_parent_nokey(private, sk);
  353. }
  354. static const struct af_alg_type algif_type_hash = {
  355. .bind = hash_bind,
  356. .release = hash_release,
  357. .setkey = hash_setkey,
  358. .accept = hash_accept_parent,
  359. .accept_nokey = hash_accept_parent_nokey,
  360. .ops = &algif_hash_ops,
  361. .ops_nokey = &algif_hash_ops_nokey,
  362. .name = "hash",
  363. .owner = THIS_MODULE
  364. };
  365. static int __init algif_hash_init(void)
  366. {
  367. return af_alg_register_type(&algif_type_hash);
  368. }
  369. static void __exit algif_hash_exit(void)
  370. {
  371. int err = af_alg_unregister_type(&algif_type_hash);
  372. BUG_ON(err);
  373. }
  374. module_init(algif_hash_init);
  375. module_exit(algif_hash_exit);
  376. MODULE_LICENSE("GPL");