1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * algif_hash: User-space interface for hash algorithms
5 * This file provides the user-space API for hash algorithms.
7 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
10 #include <crypto/hash.h>
11 #include <crypto/if_alg.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/net.h>
20 struct af_alg_sgl sgl;
24 struct crypto_wait wait;
29 struct ahash_request req;
32 static int hash_alloc_result(struct sock *sk, struct hash_ctx *ctx)
39 ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
41 ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
45 memset(ctx->result, 0, ds);
50 static void hash_free_result(struct sock *sk, struct hash_ctx *ctx)
57 ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
59 sock_kzfree_s(sk, ctx->result, ds);
63 static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
66 struct sock *sk = sock->sk;
67 struct alg_sock *ask = alg_sk(sk);
68 struct hash_ctx *ctx = ask->private;
70 size_t len, max_pages, npages;
71 bool continuing, need_init = false;
74 max_pages = min_t(size_t, ALG_MAX_PAGES,
75 DIV_ROUND_UP(sk->sk_sndbuf, PAGE_SIZE));
78 continuing = ctx->more;
81 /* Discard a previous request that wasn't marked MSG_MORE. */
82 hash_free_result(sk, ctx);
83 if (!msg_data_left(msg))
84 goto done; /* Zero-length; don't start new req */
86 } else if (!msg_data_left(msg)) {
88 * No data - finalise the prev req if MSG_MORE so any error
91 if (!(msg->msg_flags & MSG_MORE)) {
92 err = hash_alloc_result(sk, ctx);
94 goto unlock_free_result;
95 ahash_request_set_crypt(&ctx->req, NULL,
97 err = crypto_wait_req(crypto_ahash_final(&ctx->req),
100 goto unlock_free_result;
105 while (msg_data_left(msg)) {
106 ctx->sgl.sgt.sgl = ctx->sgl.sgl;
107 ctx->sgl.sgt.nents = 0;
108 ctx->sgl.sgt.orig_nents = 0;
111 npages = iov_iter_npages(&msg->msg_iter, max_pages);
115 sg_init_table(ctx->sgl.sgl, npages);
117 ctx->sgl.need_unpin = iov_iter_extract_will_pin(&msg->msg_iter);
119 err = extract_iter_to_sg(&msg->msg_iter, LONG_MAX,
120 &ctx->sgl.sgt, npages, 0);
124 sg_mark_end(ctx->sgl.sgt.sgl + ctx->sgl.sgt.nents - 1);
126 if (!msg_data_left(msg)) {
127 err = hash_alloc_result(sk, ctx);
132 ahash_request_set_crypt(&ctx->req, ctx->sgl.sgt.sgl,
135 if (!msg_data_left(msg) && !continuing &&
136 !(msg->msg_flags & MSG_MORE)) {
137 err = crypto_ahash_digest(&ctx->req);
140 err = crypto_wait_req(
141 crypto_ahash_init(&ctx->req),
148 if (msg_data_left(msg) || (msg->msg_flags & MSG_MORE))
149 err = crypto_ahash_update(&ctx->req);
151 err = crypto_ahash_finup(&ctx->req);
155 err = crypto_wait_req(err, &ctx->wait);
160 af_alg_free_sg(&ctx->sgl);
164 ctx->more = msg->msg_flags & MSG_MORE;
169 return copied ?: err;
172 af_alg_free_sg(&ctx->sgl);
174 hash_free_result(sk, ctx);
179 static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
182 struct sock *sk = sock->sk;
183 struct alg_sock *ask = alg_sk(sk);
184 struct hash_ctx *ctx = ask->private;
185 unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
192 msg->msg_flags |= MSG_TRUNC;
195 result = ctx->result;
196 err = hash_alloc_result(sk, ctx);
200 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
202 if (!result && !ctx->more) {
203 err = crypto_wait_req(crypto_ahash_init(&ctx->req),
209 if (!result || ctx->more) {
211 err = crypto_wait_req(crypto_ahash_final(&ctx->req),
217 err = memcpy_to_msg(msg, ctx->result, len);
220 hash_free_result(sk, ctx);
226 static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
229 struct sock *sk = sock->sk;
230 struct alg_sock *ask = alg_sk(sk);
231 struct hash_ctx *ctx = ask->private;
232 struct ahash_request *req = &ctx->req;
233 struct crypto_ahash *tfm;
235 struct alg_sock *ask2;
236 struct hash_ctx *ctx2;
241 tfm = crypto_ahash_reqtfm(req);
242 state = kmalloc(crypto_ahash_statesize(tfm), GFP_KERNEL);
249 err = more ? crypto_ahash_export(req, state) : 0;
255 err = af_alg_accept(ask->parent, newsock, kern);
261 ctx2 = ask2->private;
267 err = crypto_ahash_import(&ctx2->req, state);
274 kfree_sensitive(state);
280 static struct proto_ops algif_hash_ops = {
283 .connect = sock_no_connect,
284 .socketpair = sock_no_socketpair,
285 .getname = sock_no_getname,
286 .ioctl = sock_no_ioctl,
287 .listen = sock_no_listen,
288 .shutdown = sock_no_shutdown,
289 .mmap = sock_no_mmap,
290 .bind = sock_no_bind,
292 .release = af_alg_release,
293 .sendmsg = hash_sendmsg,
294 .recvmsg = hash_recvmsg,
295 .accept = hash_accept,
298 static int hash_check_key(struct socket *sock)
302 struct alg_sock *pask;
303 struct crypto_ahash *tfm;
304 struct sock *sk = sock->sk;
305 struct alg_sock *ask = alg_sk(sk);
308 if (!atomic_read(&ask->nokey_refcnt))
312 pask = alg_sk(ask->parent);
316 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
317 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
320 atomic_dec(&pask->nokey_refcnt);
321 atomic_set(&ask->nokey_refcnt, 0);
333 static int hash_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
338 err = hash_check_key(sock);
342 return hash_sendmsg(sock, msg, size);
345 static int hash_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
346 size_t ignored, int flags)
350 err = hash_check_key(sock);
354 return hash_recvmsg(sock, msg, ignored, flags);
357 static int hash_accept_nokey(struct socket *sock, struct socket *newsock,
358 int flags, bool kern)
362 err = hash_check_key(sock);
366 return hash_accept(sock, newsock, flags, kern);
369 static struct proto_ops algif_hash_ops_nokey = {
372 .connect = sock_no_connect,
373 .socketpair = sock_no_socketpair,
374 .getname = sock_no_getname,
375 .ioctl = sock_no_ioctl,
376 .listen = sock_no_listen,
377 .shutdown = sock_no_shutdown,
378 .mmap = sock_no_mmap,
379 .bind = sock_no_bind,
381 .release = af_alg_release,
382 .sendmsg = hash_sendmsg_nokey,
383 .recvmsg = hash_recvmsg_nokey,
384 .accept = hash_accept_nokey,
387 static void *hash_bind(const char *name, u32 type, u32 mask)
389 return crypto_alloc_ahash(name, type, mask);
392 static void hash_release(void *private)
394 crypto_free_ahash(private);
397 static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
399 return crypto_ahash_setkey(private, key, keylen);
402 static void hash_sock_destruct(struct sock *sk)
404 struct alg_sock *ask = alg_sk(sk);
405 struct hash_ctx *ctx = ask->private;
407 hash_free_result(sk, ctx);
408 sock_kfree_s(sk, ctx, ctx->len);
409 af_alg_release_parent(sk);
412 static int hash_accept_parent_nokey(void *private, struct sock *sk)
414 struct crypto_ahash *tfm = private;
415 struct alg_sock *ask = alg_sk(sk);
416 struct hash_ctx *ctx;
417 unsigned int len = sizeof(*ctx) + crypto_ahash_reqsize(tfm);
419 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
426 crypto_init_wait(&ctx->wait);
430 ahash_request_set_tfm(&ctx->req, tfm);
431 ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
432 crypto_req_done, &ctx->wait);
434 sk->sk_destruct = hash_sock_destruct;
439 static int hash_accept_parent(void *private, struct sock *sk)
441 struct crypto_ahash *tfm = private;
443 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
446 return hash_accept_parent_nokey(private, sk);
449 static const struct af_alg_type algif_type_hash = {
451 .release = hash_release,
452 .setkey = hash_setkey,
453 .accept = hash_accept_parent,
454 .accept_nokey = hash_accept_parent_nokey,
455 .ops = &algif_hash_ops,
456 .ops_nokey = &algif_hash_ops_nokey,
461 static int __init algif_hash_init(void)
463 return af_alg_register_type(&algif_type_hash);
466 static void __exit algif_hash_exit(void)
468 int err = af_alg_unregister_type(&algif_type_hash);
472 module_init(algif_hash_init);
473 module_exit(algif_hash_exit);
474 MODULE_LICENSE("GPL");