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 = ctx->more, need_init = false;
74 max_pages = min_t(size_t, ALG_MAX_PAGES,
75 DIV_ROUND_UP(sk->sk_sndbuf, PAGE_SIZE));
79 /* Discard a previous request that wasn't marked MSG_MORE. */
80 hash_free_result(sk, ctx);
81 if (!msg_data_left(msg))
82 goto done; /* Zero-length; don't start new req */
84 } else if (!msg_data_left(msg)) {
86 * No data - finalise the prev req if MSG_MORE so any error
89 if (!(msg->msg_flags & MSG_MORE)) {
90 err = hash_alloc_result(sk, ctx);
93 ahash_request_set_crypt(&ctx->req, NULL,
95 err = crypto_wait_req(crypto_ahash_final(&ctx->req),
103 while (msg_data_left(msg)) {
104 ctx->sgl.sgt.sgl = ctx->sgl.sgl;
105 ctx->sgl.sgt.nents = 0;
106 ctx->sgl.sgt.orig_nents = 0;
109 npages = iov_iter_npages(&msg->msg_iter, max_pages);
113 sg_init_table(ctx->sgl.sgl, npages);
115 ctx->sgl.need_unpin = iov_iter_extract_will_pin(&msg->msg_iter);
117 err = extract_iter_to_sg(&msg->msg_iter, LONG_MAX,
118 &ctx->sgl.sgt, npages, 0);
122 sg_mark_end(ctx->sgl.sgt.sgl + ctx->sgl.sgt.nents - 1);
124 if (!msg_data_left(msg)) {
125 err = hash_alloc_result(sk, ctx);
130 ahash_request_set_crypt(&ctx->req, ctx->sgl.sgt.sgl,
133 if (!msg_data_left(msg) && !continuing &&
134 !(msg->msg_flags & MSG_MORE)) {
135 err = crypto_ahash_digest(&ctx->req);
138 err = crypto_wait_req(
139 crypto_ahash_init(&ctx->req),
146 if (msg_data_left(msg) || (msg->msg_flags & MSG_MORE))
147 err = crypto_ahash_update(&ctx->req);
149 err = crypto_ahash_finup(&ctx->req);
153 err = crypto_wait_req(err, &ctx->wait);
158 af_alg_free_sg(&ctx->sgl);
162 ctx->more = msg->msg_flags & MSG_MORE;
167 return copied ?: err;
170 af_alg_free_sg(&ctx->sgl);
171 hash_free_result(sk, ctx);
176 static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
179 struct sock *sk = sock->sk;
180 struct alg_sock *ask = alg_sk(sk);
181 struct hash_ctx *ctx = ask->private;
182 unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
189 msg->msg_flags |= MSG_TRUNC;
192 result = ctx->result;
193 err = hash_alloc_result(sk, ctx);
197 ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
199 if (!result && !ctx->more) {
200 err = crypto_wait_req(crypto_ahash_init(&ctx->req),
206 if (!result || ctx->more) {
208 err = crypto_wait_req(crypto_ahash_final(&ctx->req),
214 err = memcpy_to_msg(msg, ctx->result, len);
217 hash_free_result(sk, ctx);
223 static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
226 struct sock *sk = sock->sk;
227 struct alg_sock *ask = alg_sk(sk);
228 struct hash_ctx *ctx = ask->private;
229 struct ahash_request *req = &ctx->req;
230 struct crypto_ahash *tfm;
232 struct alg_sock *ask2;
233 struct hash_ctx *ctx2;
238 tfm = crypto_ahash_reqtfm(req);
239 state = kmalloc(crypto_ahash_statesize(tfm), GFP_KERNEL);
246 err = more ? crypto_ahash_export(req, state) : 0;
252 err = af_alg_accept(ask->parent, newsock, kern);
258 ctx2 = ask2->private;
264 err = crypto_ahash_import(&ctx2->req, state);
271 kfree_sensitive(state);
277 static struct proto_ops algif_hash_ops = {
280 .connect = sock_no_connect,
281 .socketpair = sock_no_socketpair,
282 .getname = sock_no_getname,
283 .ioctl = sock_no_ioctl,
284 .listen = sock_no_listen,
285 .shutdown = sock_no_shutdown,
286 .mmap = sock_no_mmap,
287 .bind = sock_no_bind,
289 .release = af_alg_release,
290 .sendmsg = hash_sendmsg,
291 .recvmsg = hash_recvmsg,
292 .accept = hash_accept,
295 static int hash_check_key(struct socket *sock)
299 struct alg_sock *pask;
300 struct crypto_ahash *tfm;
301 struct sock *sk = sock->sk;
302 struct alg_sock *ask = alg_sk(sk);
305 if (!atomic_read(&ask->nokey_refcnt))
309 pask = alg_sk(ask->parent);
313 lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
314 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
317 atomic_dec(&pask->nokey_refcnt);
318 atomic_set(&ask->nokey_refcnt, 0);
330 static int hash_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
335 err = hash_check_key(sock);
339 return hash_sendmsg(sock, msg, size);
342 static int hash_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
343 size_t ignored, int flags)
347 err = hash_check_key(sock);
351 return hash_recvmsg(sock, msg, ignored, flags);
354 static int hash_accept_nokey(struct socket *sock, struct socket *newsock,
355 int flags, bool kern)
359 err = hash_check_key(sock);
363 return hash_accept(sock, newsock, flags, kern);
366 static struct proto_ops algif_hash_ops_nokey = {
369 .connect = sock_no_connect,
370 .socketpair = sock_no_socketpair,
371 .getname = sock_no_getname,
372 .ioctl = sock_no_ioctl,
373 .listen = sock_no_listen,
374 .shutdown = sock_no_shutdown,
375 .mmap = sock_no_mmap,
376 .bind = sock_no_bind,
378 .release = af_alg_release,
379 .sendmsg = hash_sendmsg_nokey,
380 .recvmsg = hash_recvmsg_nokey,
381 .accept = hash_accept_nokey,
384 static void *hash_bind(const char *name, u32 type, u32 mask)
386 return crypto_alloc_ahash(name, type, mask);
389 static void hash_release(void *private)
391 crypto_free_ahash(private);
394 static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
396 return crypto_ahash_setkey(private, key, keylen);
399 static void hash_sock_destruct(struct sock *sk)
401 struct alg_sock *ask = alg_sk(sk);
402 struct hash_ctx *ctx = ask->private;
404 hash_free_result(sk, ctx);
405 sock_kfree_s(sk, ctx, ctx->len);
406 af_alg_release_parent(sk);
409 static int hash_accept_parent_nokey(void *private, struct sock *sk)
411 struct crypto_ahash *tfm = private;
412 struct alg_sock *ask = alg_sk(sk);
413 struct hash_ctx *ctx;
414 unsigned int len = sizeof(*ctx) + crypto_ahash_reqsize(tfm);
416 ctx = sock_kmalloc(sk, len, GFP_KERNEL);
423 crypto_init_wait(&ctx->wait);
427 ahash_request_set_tfm(&ctx->req, tfm);
428 ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
429 crypto_req_done, &ctx->wait);
431 sk->sk_destruct = hash_sock_destruct;
436 static int hash_accept_parent(void *private, struct sock *sk)
438 struct crypto_ahash *tfm = private;
440 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
443 return hash_accept_parent_nokey(private, sk);
446 static const struct af_alg_type algif_type_hash = {
448 .release = hash_release,
449 .setkey = hash_setkey,
450 .accept = hash_accept_parent,
451 .accept_nokey = hash_accept_parent_nokey,
452 .ops = &algif_hash_ops,
453 .ops_nokey = &algif_hash_ops_nokey,
458 static int __init algif_hash_init(void)
460 return af_alg_register_type(&algif_type_hash);
463 static void __exit algif_hash_exit(void)
465 int err = af_alg_unregister_type(&algif_type_hash);
469 module_init(algif_hash_init);
470 module_exit(algif_hash_exit);
471 MODULE_LICENSE("GPL");