https://github.com/torvalds/linux
Tip revision: ffc253263a1375a65fa6c9f62a893e9767fbebfa authored by Linus Torvalds on 30 October 2023, 02:31:08 UTC
Linux 6.6
Linux 6.6
Tip revision: ffc2532
algif_hash.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* algif_hash: User-space interface for hash algorithms
*
* This file provides the user-space API for hash algorithms.
*
* Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
*/
#include <crypto/hash.h>
#include <crypto/if_alg.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/net.h>
#include <net/sock.h>
struct hash_ctx {
struct af_alg_sgl sgl;
u8 *result;
struct crypto_wait wait;
unsigned int len;
bool more;
struct ahash_request req;
};
static int hash_alloc_result(struct sock *sk, struct hash_ctx *ctx)
{
unsigned ds;
if (ctx->result)
return 0;
ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);
if (!ctx->result)
return -ENOMEM;
memset(ctx->result, 0, ds);
return 0;
}
static void hash_free_result(struct sock *sk, struct hash_ctx *ctx)
{
unsigned ds;
if (!ctx->result)
return;
ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
sock_kzfree_s(sk, ctx->result, ds);
ctx->result = NULL;
}
static int hash_sendmsg(struct socket *sock, struct msghdr *msg,
size_t ignored)
{
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
struct hash_ctx *ctx = ask->private;
ssize_t copied = 0;
size_t len, max_pages, npages;
bool continuing, need_init = false;
int err;
max_pages = min_t(size_t, ALG_MAX_PAGES,
DIV_ROUND_UP(sk->sk_sndbuf, PAGE_SIZE));
lock_sock(sk);
continuing = ctx->more;
if (!continuing) {
/* Discard a previous request that wasn't marked MSG_MORE. */
hash_free_result(sk, ctx);
if (!msg_data_left(msg))
goto done; /* Zero-length; don't start new req */
need_init = true;
} else if (!msg_data_left(msg)) {
/*
* No data - finalise the prev req if MSG_MORE so any error
* comes out here.
*/
if (!(msg->msg_flags & MSG_MORE)) {
err = hash_alloc_result(sk, ctx);
if (err)
goto unlock_free;
ahash_request_set_crypt(&ctx->req, NULL,
ctx->result, 0);
err = crypto_wait_req(crypto_ahash_final(&ctx->req),
&ctx->wait);
if (err)
goto unlock_free;
}
goto done_more;
}
while (msg_data_left(msg)) {
ctx->sgl.sgt.sgl = ctx->sgl.sgl;
ctx->sgl.sgt.nents = 0;
ctx->sgl.sgt.orig_nents = 0;
err = -EIO;
npages = iov_iter_npages(&msg->msg_iter, max_pages);
if (npages == 0)
goto unlock_free;
sg_init_table(ctx->sgl.sgl, npages);
ctx->sgl.need_unpin = iov_iter_extract_will_pin(&msg->msg_iter);
err = extract_iter_to_sg(&msg->msg_iter, LONG_MAX,
&ctx->sgl.sgt, npages, 0);
if (err < 0)
goto unlock_free;
len = err;
sg_mark_end(ctx->sgl.sgt.sgl + ctx->sgl.sgt.nents - 1);
if (!msg_data_left(msg)) {
err = hash_alloc_result(sk, ctx);
if (err)
goto unlock_free;
}
ahash_request_set_crypt(&ctx->req, ctx->sgl.sgt.sgl,
ctx->result, len);
if (!msg_data_left(msg) && !continuing &&
!(msg->msg_flags & MSG_MORE)) {
err = crypto_ahash_digest(&ctx->req);
} else {
if (need_init) {
err = crypto_wait_req(
crypto_ahash_init(&ctx->req),
&ctx->wait);
if (err)
goto unlock_free;
need_init = false;
}
if (msg_data_left(msg) || (msg->msg_flags & MSG_MORE))
err = crypto_ahash_update(&ctx->req);
else
err = crypto_ahash_finup(&ctx->req);
continuing = true;
}
err = crypto_wait_req(err, &ctx->wait);
if (err)
goto unlock_free;
copied += len;
af_alg_free_sg(&ctx->sgl);
}
done_more:
ctx->more = msg->msg_flags & MSG_MORE;
done:
err = 0;
unlock:
release_sock(sk);
return copied ?: err;
unlock_free:
af_alg_free_sg(&ctx->sgl);
hash_free_result(sk, ctx);
ctx->more = false;
goto unlock;
}
static int hash_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
int flags)
{
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
struct hash_ctx *ctx = ask->private;
unsigned ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));
bool result;
int err;
if (len > ds)
len = ds;
else if (len < ds)
msg->msg_flags |= MSG_TRUNC;
lock_sock(sk);
result = ctx->result;
err = hash_alloc_result(sk, ctx);
if (err)
goto unlock;
ahash_request_set_crypt(&ctx->req, NULL, ctx->result, 0);
if (!result && !ctx->more) {
err = crypto_wait_req(crypto_ahash_init(&ctx->req),
&ctx->wait);
if (err)
goto unlock;
}
if (!result || ctx->more) {
ctx->more = false;
err = crypto_wait_req(crypto_ahash_final(&ctx->req),
&ctx->wait);
if (err)
goto unlock;
}
err = memcpy_to_msg(msg, ctx->result, len);
unlock:
hash_free_result(sk, ctx);
release_sock(sk);
return err ?: len;
}
static int hash_accept(struct socket *sock, struct socket *newsock, int flags,
bool kern)
{
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
struct hash_ctx *ctx = ask->private;
struct ahash_request *req = &ctx->req;
struct crypto_ahash *tfm;
struct sock *sk2;
struct alg_sock *ask2;
struct hash_ctx *ctx2;
char *state;
bool more;
int err;
tfm = crypto_ahash_reqtfm(req);
state = kmalloc(crypto_ahash_statesize(tfm), GFP_KERNEL);
err = -ENOMEM;
if (!state)
goto out;
lock_sock(sk);
more = ctx->more;
err = more ? crypto_ahash_export(req, state) : 0;
release_sock(sk);
if (err)
goto out_free_state;
err = af_alg_accept(ask->parent, newsock, kern);
if (err)
goto out_free_state;
sk2 = newsock->sk;
ask2 = alg_sk(sk2);
ctx2 = ask2->private;
ctx2->more = more;
if (!more)
goto out_free_state;
err = crypto_ahash_import(&ctx2->req, state);
if (err) {
sock_orphan(sk2);
sock_put(sk2);
}
out_free_state:
kfree_sensitive(state);
out:
return err;
}
static struct proto_ops algif_hash_ops = {
.family = PF_ALG,
.connect = sock_no_connect,
.socketpair = sock_no_socketpair,
.getname = sock_no_getname,
.ioctl = sock_no_ioctl,
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.mmap = sock_no_mmap,
.bind = sock_no_bind,
.release = af_alg_release,
.sendmsg = hash_sendmsg,
.recvmsg = hash_recvmsg,
.accept = hash_accept,
};
static int hash_check_key(struct socket *sock)
{
int err = 0;
struct sock *psk;
struct alg_sock *pask;
struct crypto_ahash *tfm;
struct sock *sk = sock->sk;
struct alg_sock *ask = alg_sk(sk);
lock_sock(sk);
if (!atomic_read(&ask->nokey_refcnt))
goto unlock_child;
psk = ask->parent;
pask = alg_sk(ask->parent);
tfm = pask->private;
err = -ENOKEY;
lock_sock_nested(psk, SINGLE_DEPTH_NESTING);
if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
goto unlock;
atomic_dec(&pask->nokey_refcnt);
atomic_set(&ask->nokey_refcnt, 0);
err = 0;
unlock:
release_sock(psk);
unlock_child:
release_sock(sk);
return err;
}
static int hash_sendmsg_nokey(struct socket *sock, struct msghdr *msg,
size_t size)
{
int err;
err = hash_check_key(sock);
if (err)
return err;
return hash_sendmsg(sock, msg, size);
}
static int hash_recvmsg_nokey(struct socket *sock, struct msghdr *msg,
size_t ignored, int flags)
{
int err;
err = hash_check_key(sock);
if (err)
return err;
return hash_recvmsg(sock, msg, ignored, flags);
}
static int hash_accept_nokey(struct socket *sock, struct socket *newsock,
int flags, bool kern)
{
int err;
err = hash_check_key(sock);
if (err)
return err;
return hash_accept(sock, newsock, flags, kern);
}
static struct proto_ops algif_hash_ops_nokey = {
.family = PF_ALG,
.connect = sock_no_connect,
.socketpair = sock_no_socketpair,
.getname = sock_no_getname,
.ioctl = sock_no_ioctl,
.listen = sock_no_listen,
.shutdown = sock_no_shutdown,
.mmap = sock_no_mmap,
.bind = sock_no_bind,
.release = af_alg_release,
.sendmsg = hash_sendmsg_nokey,
.recvmsg = hash_recvmsg_nokey,
.accept = hash_accept_nokey,
};
static void *hash_bind(const char *name, u32 type, u32 mask)
{
return crypto_alloc_ahash(name, type, mask);
}
static void hash_release(void *private)
{
crypto_free_ahash(private);
}
static int hash_setkey(void *private, const u8 *key, unsigned int keylen)
{
return crypto_ahash_setkey(private, key, keylen);
}
static void hash_sock_destruct(struct sock *sk)
{
struct alg_sock *ask = alg_sk(sk);
struct hash_ctx *ctx = ask->private;
hash_free_result(sk, ctx);
sock_kfree_s(sk, ctx, ctx->len);
af_alg_release_parent(sk);
}
static int hash_accept_parent_nokey(void *private, struct sock *sk)
{
struct crypto_ahash *tfm = private;
struct alg_sock *ask = alg_sk(sk);
struct hash_ctx *ctx;
unsigned int len = sizeof(*ctx) + crypto_ahash_reqsize(tfm);
ctx = sock_kmalloc(sk, len, GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->result = NULL;
ctx->len = len;
ctx->more = false;
crypto_init_wait(&ctx->wait);
ask->private = ctx;
ahash_request_set_tfm(&ctx->req, tfm);
ahash_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG,
crypto_req_done, &ctx->wait);
sk->sk_destruct = hash_sock_destruct;
return 0;
}
static int hash_accept_parent(void *private, struct sock *sk)
{
struct crypto_ahash *tfm = private;
if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
return -ENOKEY;
return hash_accept_parent_nokey(private, sk);
}
static const struct af_alg_type algif_type_hash = {
.bind = hash_bind,
.release = hash_release,
.setkey = hash_setkey,
.accept = hash_accept_parent,
.accept_nokey = hash_accept_parent_nokey,
.ops = &algif_hash_ops,
.ops_nokey = &algif_hash_ops_nokey,
.name = "hash",
.owner = THIS_MODULE
};
static int __init algif_hash_init(void)
{
return af_alg_register_type(&algif_type_hash);
}
static void __exit algif_hash_exit(void)
{
int err = af_alg_unregister_type(&algif_type_hash);
BUG_ON(err);
}
module_init(algif_hash_init);
module_exit(algif_hash_exit);
MODULE_LICENSE("GPL");