diff options
Diffstat (limited to 'crypto/algif_hash.c')
| -rw-r--r-- | crypto/algif_hash.c | 473 |
1 files changed, 473 insertions, 0 deletions
diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c new file mode 100644 index 000000000..82c44d489 --- /dev/null +++ b/crypto/algif_hash.c @@ -0,0 +1,473 @@ +// 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"); |