diff options
| -rw-r--r-- | crypto/Kconfig | 8 | ||||
| -rw-r--r-- | crypto/Makefile | 1 | ||||
| -rw-r--r-- | crypto/algif_skcipher.c | 640 |
3 files changed, 649 insertions, 0 deletions
diff --git a/crypto/Kconfig b/crypto/Kconfig index 6db27d7..69437e2 100644 --- a/crypto/Kconfig +++ b/crypto/Kconfig @@ -852,6 +852,14 @@ config CRYPTO_USER_API_HASH This option enables the user-spaces interface for hash algorithms. +config CRYPTO_USER_API_SKCIPHER + tristate "User-space interface for symmetric key cipher algorithms" + select CRYPTO_BLKCIPHER + select CRYPTO_USER_API + help + This option enables the user-spaces interface for symmetric + key cipher algorithms. + source "drivers/crypto/Kconfig" endif # if CRYPTO diff --git a/crypto/Makefile b/crypto/Makefile index 14ab405..efc0f18 100644 --- a/crypto/Makefile +++ b/crypto/Makefile @@ -87,6 +87,7 @@ obj-$(CONFIG_CRYPTO_TEST) += tcrypt.o obj-$(CONFIG_CRYPTO_GHASH) += ghash-generic.o obj-$(CONFIG_CRYPTO_USER_API) += af_alg.o obj-$(CONFIG_CRYPTO_USER_API_HASH) += algif_hash.o +obj-$(CONFIG_CRYPTO_USER_API_SKCIPHER) += algif_skcipher.o # # generic algorithms and the async_tx api diff --git a/crypto/algif_skcipher.c b/crypto/algif_skcipher.c new file mode 100644 index 0000000..211c956 --- /dev/null +++ b/crypto/algif_skcipher.c @@ -0,0 +1,640 @@ +/* + * algif_skcipher: User-space interface for skcipher algorithms + * + * This file provides the user-space API for symmetric key ciphers. + * + * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + */ + +#include <crypto/scatterwalk.h> +#include <crypto/skcipher.h> +#include <crypto/if_alg.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/net.h> +#include <net/sock.h> + +struct skcipher_sg_list { + struct list_head list; + + int cur; + + struct scatterlist sg[0]; +}; + +struct skcipher_ctx { + struct list_head tsgl; + struct af_alg_sgl rsgl; + + void *iv; + + struct af_alg_completion completion; + + unsigned used; + + unsigned int len; + bool more; + bool merge; + bool enc; + + struct ablkcipher_request req; +}; + +#define MAX_SGL_ENTS ((PAGE_SIZE - sizeof(struct skcipher_sg_list)) / \ + sizeof(struct scatterlist) - 1) + +static inline bool skcipher_writable(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + struct skcipher_ctx *ctx = ask->private; + + return ctx->used + PAGE_SIZE <= max_t(int, sk->sk_sndbuf, PAGE_SIZE); +} + +static int skcipher_alloc_sgl(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + struct skcipher_ctx *ctx = ask->private; + struct skcipher_sg_list *sgl; + struct scatterlist *sg = NULL; + + sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list); + if (!list_empty(&ctx->tsgl)) + sg = sgl->sg; + + if (!sg || sgl->cur >= MAX_SGL_ENTS) { + sgl = sock_kmalloc(sk, sizeof(*sgl) + + sizeof(sgl->sg[0]) * (MAX_SGL_ENTS + 1), + GFP_KERNEL); + if (!sgl) + return -ENOMEM; + + sg_init_table(sgl->sg, MAX_SGL_ENTS + 1); + sgl->cur = 0; + + if (sg) + scatterwalk_sg_chain(sg, MAX_SGL_ENTS + 1, sgl->sg); + + list_add_tail(&sgl->list, &ctx->tsgl); + } + + return 0; +} + +static void skcipher_pull_sgl(struct sock *sk, int used) +{ + struct alg_sock *ask = alg_sk(sk); + struct skcipher_ctx *ctx = ask->private; + struct skcipher_sg_list *sgl; + struct scatterlist *sg; + int i; + + while (!list_empty(&ctx->tsgl)) { + sgl = list_first_entry(&ctx->tsgl, struct skcipher_sg_list, + list); + sg = sgl->sg; + + for (i = 0; i < sgl->cur; i++) { + int plen = min_t(int, used, sg[i].length); + + if (!sg_page(sg + i)) + continue; + + sg[i].length -= plen; + sg[i].offset += plen; + + used -= plen; + ctx->used -= plen; + + if (sg[i].length) + return; + + put_page(sg_page(sg + i)); + sg_assign_page(sg + i, NULL); + } + + list_del(&sgl->list); + sock_kfree_s(sk, sgl, + sizeof(*sgl) + sizeof(sgl->sg[0]) * + (MAX_SGL_ENTS + 1)); + } + + if (!ctx->used) + ctx->merge = 0; +} + +static void skcipher_free_sgl(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + struct skcipher_ctx *ctx = ask->private; + + skcipher_pull_sgl(sk, ctx->used); +} + +static int skcipher_wait_for_wmem(struct sock *sk, unsigned flags) +{ + long timeout; + DEFINE_WAIT(wait); + int err = -ERESTARTSYS; + + if (flags & MSG_DONTWAIT) + return -EAGAIN; + + set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags); + + for (;;) { + if (signal_pending(current)) + break; + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + timeout = MAX_SCHEDULE_TIMEOUT; + if (sk_wait_event(sk, &timeout, skcipher_writable(sk))) { + err = 0; + break; + } + } + finish_wait(sk_sleep(sk), &wait); + + return err; +} + +static void skcipher_wmem_wakeup(struct sock *sk) +{ + struct socket_wq *wq; + + if (!skcipher_writable(sk)) + return; + + rcu_read_lock(); + wq = rcu_dereference(sk->sk_wq); + if (wq_has_sleeper(wq)) + wake_up_interruptible_sync_poll(&wq->wait, POLLIN | + POLLRDNORM | + POLLRDBAND); + sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); + rcu_read_unlock(); +} + +static int skcipher_wait_for_data(struct sock *sk, unsigned flags) +{ + struct alg_sock *ask = alg_sk(sk); + struct skcipher_ctx *ctx = ask->private; + long timeout; + DEFINE_WAIT(wait); + int err = -ERESTARTSYS; + + if (flags & MSG_DONTWAIT) { + return -EAGAIN; + } + + set_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); + + for (;;) { + if (signal_pending(current)) + break; + prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); + timeout = MAX_SCHEDULE_TIMEOUT; + if (sk_wait_event(sk, &timeout, ctx->used)) { + err = 0; + break; + } + } + finish_wait(sk_sleep(sk), &wait); + + clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags); + + return err; +} + +static void skcipher_data_wakeup(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + struct skcipher_ctx *ctx = ask->private; + struct socket_wq *wq; + + if (!ctx->used) + return; + + rcu_read_lock(); + wq = rcu_dereference(sk->sk_wq); + if (wq_has_sleeper(wq)) + wake_up_interruptible_sync_poll(&wq->wait, POLLOUT | + POLLRDNORM | + POLLRDBAND); + sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); + rcu_read_unlock(); +} + +static int skcipher_sendmsg(struct kiocb *unused, struct socket *sock, + struct msghdr *msg, size_t size) +{ + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + struct skcipher_ctx *ctx = ask->private; + struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req); + unsigned ivsize = crypto_ablkcipher_ivsize(tfm); + struct skcipher_sg_list *sgl; + struct af_alg_control con = {}; + long copied = 0; + bool enc = 0; + int limit; + int err; + int i; + + if (msg->msg_controllen) { + err = af_alg_cmsg_send(msg, &con); + if (err) + return err; + + switch (con.op) { + case ALG_OP_ENCRYPT: + enc = 1; + break; + case ALG_OP_DECRYPT: + enc = 0; + break; + default: + return -EINVAL; + } + + if (con.iv && con.iv->ivlen != ivsize) + return -EINVAL; + } + + err = -EINVAL; + + lock_sock(sk); + if (!ctx->more && ctx->used) + goto unlock; + + if (!ctx->used) { + ctx->enc = enc; + if (con.iv) + memcpy(ctx->iv, con.iv->iv, ivsize); + } + + limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE); + limit -= ctx->used; + + while (size) { + struct scatterlist *sg; + unsigned long len = size; + int plen; + + if (ctx->merge) { + sgl = list_entry(ctx->tsgl.prev, + struct skcipher_sg_list, list); + sg = sgl->sg + sgl->cur - 1; + len = min_t(unsigned long, len, + PAGE_SIZE - sg->offset - sg->length); + + err = memcpy_fromiovec(page_address(sg_page(sg)) + + sg->offset + sg->length, + msg->msg_iov, len); + if (err) + goto unlock; + + sg->length += len; + ctx->merge = (sg->offset + sg->length) & + (PAGE_SIZE - 1); + + ctx->used += len; + copied += len; + size -= len; + limit -= len; + continue; + } + + if (limit < PAGE_SIZE) { + err = skcipher_wait_for_wmem(sk, msg->msg_flags); + if (err) + goto unlock; + + limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE); + limit -= ctx->used; + } + + len = min_t(unsigned long, len, limit); + + err = skcipher_alloc_sgl(sk); + if (err) + goto unlock; + + sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list); + sg = sgl->sg; + do { + i = sgl->cur; + plen = min_t(int, len, PAGE_SIZE); + + sg_assign_page(sg + i, alloc_page(GFP_KERNEL)); + err = -ENOMEM; + if (!sg_page(sg + i)) + goto unlock; + + err = memcpy_fromiovec(page_address(sg_page(sg + i)), + msg->msg_iov, plen); + if (err) { + __free_page(sg_page(sg + i)); + sg_assign_page(sg + i, NULL); + goto unlock; + } + + sg[i].length = plen; + len -= plen; + ctx->used += plen; + copied += plen; + size -= plen; + limit -= plen; + sgl->cur++; + } while (len && sgl->cur < MAX_SGL_ENTS); + + ctx->merge = plen & (PAGE_SIZE - 1); + } + + err = 0; + + ctx->more = msg->msg_flags & MSG_MORE; + if (!ctx->more && !list_empty(&ctx->tsgl)) + sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list); + +unlock: + skcipher_data_wakeup(sk); + release_sock(sk); + + return copied ?: err; +} + +static ssize_t skcipher_sendpage(struct socket *sock, struct page *page, + int offset, size_t size, int flags) +{ + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + struct skcipher_ctx *ctx = ask->private; + struct skcipher_sg_list *sgl; + int err = -EINVAL; + int limit; + + lock_sock(sk); + if (!ctx->more && ctx->used) + goto unlock; + + if (!size) + goto done; + + limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE); + limit -= ctx->used; + + if (limit < PAGE_SIZE) { + err = skcipher_wait_for_wmem(sk, flags); + if (err) + goto unlock; + + limit = max_t(int, sk->sk_sndbuf, PAGE_SIZE); + limit -= ctx->used; + } + + err = skcipher_alloc_sgl(sk); + if (err) + goto unlock; + + ctx->merge = 0; + sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list); + + get_page(page); + sg_set_page(sgl->sg + sgl->cur, page, size, offset); + sgl->cur++; + ctx->used += size; + +done: + ctx->more = flags & MSG_MORE; + if (!ctx->more && !list_empty(&ctx->tsgl)) + sgl = list_entry(ctx->tsgl.prev, struct skcipher_sg_list, list); + +unlock: + skcipher_data_wakeup(sk); + release_sock(sk); + + return err ?: size; +} + +static int skcipher_recvmsg(struct kiocb *unused, struct socket *sock, + struct msghdr *msg, size_t ignored, int flags) +{ + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + struct skcipher_ctx *ctx = ask->private; + unsigned bs = crypto_ablkcipher_blocksize(crypto_ablkcipher_reqtfm( + &ctx->req)); + struct skcipher_sg_list *sgl; + struct scatterlist *sg; + unsigned long iovlen; + struct iovec *iov; + int err = -EAGAIN; + int used; + long copied = 0; + + lock_sock(sk); + for (iov = msg->msg_iov, iovlen = msg->msg_iovlen; iovlen > 0; + iovlen--, iov++) { + unsigned long seglen = iov->iov_len; + char __user *from = iov->iov_base; + + while (seglen) { + sgl = list_first_entry(&ctx->tsgl, + struct skcipher_sg_list, list); + sg = sgl->sg; + + while (!sg->length) + sg++; + + used = ctx->used; + if (!used) { + err = skcipher_wait_for_data(sk, flags); + if (err) + goto unlock; + } + + used = min_t(unsigned long, used, seglen); + + if (ctx->more || used < ctx->used) + used -= used % bs; + + err = -EINVAL; + if (!used) + goto unlock; + + used = af_alg_make_sg(&ctx->rsgl, from, used, 1); + if (used < 0) + goto unlock; + + ablkcipher_request_set_crypt(&ctx->req, sg, + ctx->rsgl.sg, used, + ctx->iv); + + err = af_alg_wait_for_completion( + ctx->enc ? + crypto_ablkcipher_encrypt(&ctx->req) : + crypto_ablkcipher_decrypt(&ctx->req), + &ctx->completion); + + af_alg_free_sg(&ctx->rsgl); + + if (err) + goto unlock; + + copied += used; + from += used; + seglen -= used; + skcipher_pull_sgl(sk, used); + } + } + + err = 0; + +unlock: + skcipher_wmem_wakeup(sk); + release_sock(sk); + + return copied ?: err; +} + + +static unsigned int skcipher_poll(struct file *file, struct socket *sock, + poll_table *wait) +{ + struct sock *sk = sock->sk; + struct alg_sock *ask = alg_sk(sk); + struct skcipher_ctx *ctx = ask->private; + unsigned int mask; + + sock_poll_wait(file, sk_sleep(sk), wait); + mask = 0; + + if (ctx->used) + mask |= POLLIN | POLLRDNORM; + + if (skcipher_writable(sk)) + mask |= POLLOUT | POLLWRNORM | POLLWRBAND; + + return mask; +} + +static struct proto_ops algif_skcipher_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, + .getsockopt = sock_no_getsockopt, + .mmap = sock_no_mmap, + .bind = sock_no_bind, + .accept = sock_no_accept, + .setsockopt = sock_no_setsockopt, + + .release = af_alg_release, + .sendmsg = skcipher_sendmsg, + .sendpage = skcipher_sendpage, + .recvmsg = skcipher_recvmsg, + .poll = skcipher_poll, +}; + +static void *skcipher_bind(const char *name, u32 type, u32 mask) +{ + return crypto_alloc_ablkcipher(name, type, mask); +} + +static void skcipher_release(void *private) +{ + crypto_free_ablkcipher(private); +} + +static int skcipher_setkey(void *private, const u8 *key, unsigned int keylen) +{ + return crypto_ablkcipher_setkey(private, key, keylen); +} + +static void skcipher_sock_destruct(struct sock *sk) +{ + struct alg_sock *ask = alg_sk(sk); + struct skcipher_ctx *ctx = ask->private; + struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(&ctx->req); + + skcipher_free_sgl(sk); + sock_kfree_s(sk, ctx->iv, crypto_ablkcipher_ivsize(tfm)); + sock_kfree_s(sk, ctx, ctx->len); + af_alg_release_parent(sk); +} + +static int skcipher_accept_parent(void *private, struct sock *sk) +{ + struct skcipher_ctx *ctx; + struct alg_sock *ask = alg_sk(sk); + unsigned int len = sizeof(*ctx) + crypto_ablkcipher_reqsize(private); + + ctx = sock_kmalloc(sk, len, GFP_KERNEL); + if (!ctx) + return -ENOMEM; + + ctx->iv = sock_kmalloc(sk, crypto_ablkcipher_ivsize(private), + GFP_KERNEL); + if (!ctx->iv) { + sock_kfree_s(sk, ctx, len); + return -ENOMEM; + } + + memset(ctx->iv, 0, crypto_ablkcipher_ivsize(private)); + + INIT_LIST_HEAD(&ctx->tsgl); + ctx->len = len; + ctx->used = 0; + ctx->more = 0; + ctx->merge = 0; + ctx->enc = 0; + af_alg_init_completion(&ctx->completion); + + ask->private = ctx; + + ablkcipher_request_set_tfm(&ctx->req, private); + ablkcipher_request_set_callback(&ctx->req, CRYPTO_TFM_REQ_MAY_BACKLOG, + af_alg_complete, &ctx->completion); + + sk->sk_destruct = skcipher_sock_destruct; + + return 0; +} + +static const struct af_alg_type algif_type_skcipher = { + .bind = skcipher_bind, + .release = skcipher_release, + .setkey = skcipher_setkey, + .accept = skcipher_accept_parent, + .ops = &algif_skcipher_ops, + .name = "skcipher", + .owner = THIS_MODULE +}; + +static int __init algif_skcipher_init(void) +{ + return af_alg_register_type(&algif_type_skcipher); +} + +static void __exit algif_skcipher_exit(void) +{ + int err = af_alg_unregister_type(&algif_type_skcipher); + BUG_ON(err); +} + +module_init(algif_skcipher_init); +module_exit(algif_skcipher_exit); +MODULE_LICENSE("GPL"); |
