Hi,
This patch set adds AEAD support to the AF_ALG interface
exported by the kernel crypto API.
The AEAD implementation uses the same approach as provided with
skcipher by offering the following interfaces:
* sendmsg and recvmsg interfaces allowing multiple
invocations supporting a threaded user space. To support
multi-threaded user space, kernel-side buffering
is implemented similarly to skcipher.
* splice / vmsplice interfaces allowing a zero-copy
invocation
The new AEAD interface is fully tested with the test application
provided at [1]. That test application exercises all newly added user space
interfaces. The testing covers:
* use of the sendmsg/recvmsg interface
* use of the splice / vmsplice interface
* invocation of all AF_ALG types (aead, rng, skcipher, hash)
* using all types of operation (encryption, decryption, keyed MD,
MD, random numbers, AEAD decryption with positive and negative
authentication verification)
* stress testing by running all tests for 30 minutes in an
endless loop
* test execution on 64 bit and 32 bit
[1] http://www.chronox.de/libkcapi.html
Changes v2:
* rebase to current cryptodev-2.6 tree
* use memzero_explicit to zeroize AEAD associated data
* use sizeof for determining length of AEAD associated data
* update algif_rng.c covering all suggestions from Daniel Borkmann
<[email protected]>
* addition of patch 9: add digestsize interface for hashes
* addition of patch to update documentation covering the userspace interface
* change numbers of getsockopt options: separate them from sendmsg interface
definitions
Changes v3:
* remove getsockopt interface
* AEAD: associated data is set prepended to the plain/ciphertext
* AEAD: allowing arbitrary associated data lengths
* remove setkey patch as protection was already in the existing code
Changes v4:
* stand-alone implementation of AEAD
* testing of all interfaces offered by AEAD
* stress testing of AEAD and RNG
Changes v5:
* AEAD: add outer while(size) loop in aead_sendmsg to ensure all data is
copied into the kernel (reporter Herbert Xu)
* AEAD: aead_sendmsg bug fix: change size -= len; to size -= plen;
* AF_ALG / AEAD: add aead_setauthsize and associated extension to
struct af_alg_type as well as alg_setsockopt (reporter Herbert Xu)
* RNG: rng_recvmsg: use 128 byte stack variable for output of RNG instead
of ctx->result (reporter Herbert Xu)
* RNG / AF_ALG: allow user space to seed RNG via setsockopt
* RNG: rng_recvmsg bug fix: use genlen as result variable for
crypto_rng_get_bytes as previously no negative errors were obtained
* AF_ALG: alg_setop: zeroize buffer before free
Changes v6:
* AEAD/RNG: port to 3.19-rc1 with the iov_iter handling
* RNG: use the setkey interface to obtain the seed and drop the patch adding
a separate reseeding interface
* extract the zeroization patch for alg_setkey into a stand-alone patch
submission
* fix bug in aead_sufficient_data (reporter Herbert Xu)
* testing of all interfaces with test application provided with libkcapi version
0.6.2
Changes v7:
* AEAD: aead_recvmsg: change error code from ENOMEM to EINVAL
* AEAD: drop aead_readable/aead_sufficient_data and only use ctx->more to decide
whether the read side shall become active. This change requires that the
patch for crypto_aead_decrypt ensuring that the ciphertext contains the
authentication tag was added -- see https://lkml.org/lkml/2014/12/30/200.
Otherwise, user space can trigger a kernel crash.
* RNG: patch dropped as it was applied
* AEAD: port Kconfig/Makefile patch forward to current code base
Changes v8:
* Removed check for aead_assoclen in aead_sendmsg
* Fix endless loop bug in aead_sendmsg (check for sgl->cur > ALG_MAX_PAGES in
while condition removed -- this condition is checked within the loop already)
* Resurrect aead_sufficient_data and call it in aead_sendmsg, aead_sendpage to
notify caller about wrong invocation
* Re-add aead_sufficient_data to aead_recvmsg to verify user input data before
using them to ensure the kernel protects against malicious parameters
* Allow arbitrary size of AD (i.e. up to the maximum buffer size of
ALG_MAX_PAGES)
* When aead_recvmsg receives an error from decryption, release all pages if the
error is EBADMSG -- this error implies that a proper decryption was performed
but the integrity of the message is lost. This error is considered to be a
valid decryption result.
* Add test cases for sendmsg and splice interface to test large AD sizes (in
case of sendmsg, use 65504 bytes AD and 32 bytes plaintext; in case of splice
use 15 pages AD and 32 bytes in the 16th page for plaintext). See [1] for
updated test case.
Changes v9:
* if socket is not writable during sendmsg/sendpage due to insufficient memory
and a recvmsg operation is forced, inform userspace about truncated operation
via MSG_TRUNC
* use -EMSGSIZE in case insufficient data was provided in sendmsg/sendpage
* release all buffers in case insufficient data was provided in sendmsg/sendpage
* bug fix in sendmsg: when a new page is allocated, reset sg->offset to 0 --
the error is visible with the new tests in [1] when using the -d flag
with the test application
Changes v10:
* initialize ctx->trunc in aead_accept_parent to zero
* fix one line with code formatting problems
Changes v11:
* return an error if user space sends too much data instead of waiting until
reader side catches up with operation (suggested by Herbert Xu)
* remove now unneeded aead_wait_for_wmem service function
* remove now unneeded ctx->trunc and MSG_TRUNC error return
Changes v12:
* check ctx->used in aead_data_wakeup (reported by Herbert Xu)
* free socket buffers in case userspace sends too much data (reported by
Herbert Xu)
* allow up to 16 IOVECs in recvmsg for the output buffer -- the code can handle
an arbitrary number of IOVECs (just change RSGL_MAX_ENTRIES). Though, when
changing the value, the maximum memory user space can cause the kernel to
allocate should be considered as documented in the comment. The test code in
[1] is updated to invoke recvmsg with 16 IOVECs (reported by Herbert Xu)
* prevent an edge condition error case in sendmsg (reported by Herbert Xu)
* correct some formatting as suggested by checkpatch.pl
Changes v13:
* convert recvmsg to use the iov_iter API
Stephan Mueller (2):
crypto: AF_ALG: add AEAD support
crypto: AF_ALG: enable AEAD interface compilation
crypto/Kconfig | 9 +
crypto/Makefile | 1 +
crypto/algif_aead.c | 666 ++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 676 insertions(+)
create mode 100644 crypto/algif_aead.c
--
2.1.0
Enable compilation of the AEAD AF_ALG support and provide a Kconfig
option to compile the AEAD AF_ALG support.
Signed-off-by: Stephan Mueller <[email protected]>
---
crypto/Kconfig | 9 +++++++++
crypto/Makefile | 1 +
2 files changed, 10 insertions(+)
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 2ca8d15..f3d1c24 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -1532,6 +1532,15 @@ config CRYPTO_USER_API_RNG
This option enables the user-spaces interface for random
number generator algorithms.
+config CRYPTO_USER_API_AEAD
+ tristate "User-space interface for AEAD cipher algorithms"
+ depends on NET
+ select CRYPTO_AEAD
+ select CRYPTO_USER_API
+ help
+ This option enables the user-spaces interface for AEAD
+ cipher algorithms.
+
config CRYPTO_HASH_INFO
bool
diff --git a/crypto/Makefile b/crypto/Makefile
index ba19465..97b7d3a 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -100,6 +100,7 @@ obj-$(CONFIG_CRYPTO_USER_API) += af_alg.o
obj-$(CONFIG_CRYPTO_USER_API_HASH) += algif_hash.o
obj-$(CONFIG_CRYPTO_USER_API_SKCIPHER) += algif_skcipher.o
obj-$(CONFIG_CRYPTO_USER_API_RNG) += algif_rng.o
+obj-$(CONFIG_CRYPTO_USER_API_AEAD) += algif_aead.o
#
# generic algorithms and the async_tx api
--
2.1.0
This patch adds the AEAD support for AF_ALG.
The implementation is based on algif_skcipher, but contains heavy
modifications to streamline the interface for AEAD uses.
To use AEAD, the user space consumer has to use the salg_type named
"aead".
The AEAD implementation includes some overhead to calculate the size of
the ciphertext, because the AEAD implementation of the kernel crypto API
makes implied assumption on the location of the authentication tag. When
performing an encryption, the tag will be added to the created
ciphertext (note, the tag is placed adjacent to the ciphertext). For
decryption, the caller must hand in the ciphertext with the tag appended
to the ciphertext. Therefore, the selection of the used memory
needs to add/subtract the tag size from the source/destination buffers
depending on the encryption type. The code is provided with comments
explaining when and how that operation is performed.
A fully working example using all aspects of AEAD is provided at
http://www.chronox.de/libkcapi.html
Signed-off-by: Stephan Mueller <[email protected]>
---
crypto/algif_aead.c | 666 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 666 insertions(+)
create mode 100644 crypto/algif_aead.c
diff --git a/crypto/algif_aead.c b/crypto/algif_aead.c
new file mode 100644
index 0000000..527d27b
--- /dev/null
+++ b/crypto/algif_aead.c
@@ -0,0 +1,666 @@
+/*
+ * algif_aead: User-space interface for AEAD algorithms
+ *
+ * Copyright (C) 2014, Stephan Mueller <[email protected]>
+ *
+ * This file provides the user-space API for AEAD ciphers.
+ *
+ * This file is derived from algif_skcipher.c.
+ *
+ * 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/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 aead_sg_list {
+ unsigned int cur;
+ struct scatterlist sg[ALG_MAX_PAGES];
+};
+
+struct aead_ctx {
+ struct aead_sg_list tsgl;
+ /*
+ * RSGL_MAX_ENTRIES is an artificial limit where user space at maximum
+ * can cause the kernel to allocate RSGL_MAX_ENTRIES * ALG_MAX_PAGES
+ * bytes
+ */
+#define RSGL_MAX_ENTRIES ALG_MAX_PAGES
+ struct af_alg_sgl rsgl[RSGL_MAX_ENTRIES];
+
+ void *iv;
+
+ struct af_alg_completion completion;
+
+ unsigned long used;
+
+ unsigned int len;
+ bool more;
+ bool merge;
+ bool enc;
+
+ size_t aead_assoclen;
+ struct aead_request aead_req;
+};
+
+static inline int aead_sndbuf(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct aead_ctx *ctx = ask->private;
+
+ return max_t(int, max_t(int, sk->sk_sndbuf & PAGE_MASK, PAGE_SIZE) -
+ ctx->used, 0);
+}
+
+static inline bool aead_writable(struct sock *sk)
+{
+ return PAGE_SIZE <= aead_sndbuf(sk);
+}
+
+static inline bool aead_sufficient_data(struct aead_ctx *ctx)
+{
+ unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
+
+ return (ctx->used >= (ctx->aead_assoclen + (ctx->enc ? 0 : as)));
+}
+
+static void aead_put_sgl(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct aead_ctx *ctx = ask->private;
+ struct aead_sg_list *sgl = &ctx->tsgl;
+ struct scatterlist *sg = sgl->sg;
+ unsigned int i;
+
+ for (i = 0; i < sgl->cur; i++) {
+ if (!sg_page(sg + i))
+ continue;
+
+ put_page(sg_page(sg + i));
+ sg_assign_page(sg + i, NULL);
+ }
+ sgl->cur = 0;
+ ctx->used = 0;
+ ctx->more = 0;
+ ctx->merge = 0;
+}
+
+static void aead_wmem_wakeup(struct sock *sk)
+{
+ struct socket_wq *wq;
+
+ if (!aead_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 aead_wait_for_data(struct sock *sk, unsigned flags)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct aead_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->more)) {
+ err = 0;
+ break;
+ }
+ }
+ finish_wait(sk_sleep(sk), &wait);
+
+ clear_bit(SOCK_ASYNC_WAITDATA, &sk->sk_socket->flags);
+
+ return err;
+}
+
+static void aead_data_wakeup(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct aead_ctx *ctx = ask->private;
+ struct socket_wq *wq;
+
+ if (ctx->more)
+ return;
+ 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 aead_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 aead_ctx *ctx = ask->private;
+ unsigned ivsize =
+ crypto_aead_ivsize(crypto_aead_reqtfm(&ctx->aead_req));
+ struct aead_sg_list *sgl = &ctx->tsgl;
+ struct af_alg_control con = {};
+ long copied = 0;
+ bool enc = 0;
+ bool init = 0;
+ int err = -EINVAL;
+
+ if (msg->msg_controllen) {
+ err = af_alg_cmsg_send(msg, &con);
+ if (err)
+ return err;
+
+ init = 1;
+ 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;
+ }
+
+ lock_sock(sk);
+ if (!ctx->more && ctx->used)
+ goto unlock;
+
+ if (init) {
+ ctx->enc = enc;
+ if (con.iv)
+ memcpy(ctx->iv, con.iv->iv, ivsize);
+
+ ctx->aead_assoclen = con.aead_assoclen;
+ }
+
+ while (size) {
+ unsigned long len = size;
+ struct scatterlist *sg = NULL;
+
+ /* use the existing memory in an allocated page */
+ if (ctx->merge) {
+ sg = sgl->sg + sgl->cur - 1;
+ len = min_t(unsigned long, len,
+ PAGE_SIZE - sg->offset - sg->length);
+ err = memcpy_from_msg(page_address(sg_page(sg)) +
+ sg->offset + sg->length,
+ msg, len);
+ if (err)
+ goto unlock;
+
+ sg->length += len;
+ ctx->merge = (sg->offset + sg->length) &
+ (PAGE_SIZE - 1);
+
+ ctx->used += len;
+ copied += len;
+ size -= len;
+ continue;
+ }
+
+ if (!aead_writable(sk)) {
+ /* user space sent too much data */
+ aead_put_sgl(sk);
+ err = -EMSGSIZE;
+ goto unlock;
+ }
+
+ /* allocate a new page */
+ len = min_t(unsigned long, size, aead_sndbuf(sk));
+ while (len) {
+ int plen = 0;
+
+ if (sgl->cur >= ALG_MAX_PAGES) {
+ aead_put_sgl(sk);
+ err = -E2BIG;
+ goto unlock;
+ }
+
+ sg = sgl->sg + sgl->cur;
+ plen = min_t(int, len, PAGE_SIZE);
+
+ sg_assign_page(sg, alloc_page(GFP_KERNEL));
+ err = -ENOMEM;
+ if (!sg_page(sg))
+ goto unlock;
+
+ err = memcpy_from_msg(page_address(sg_page(sg)),
+ msg, plen);
+ if (err) {
+ __free_page(sg_page(sg));
+ sg_assign_page(sg, NULL);
+ goto unlock;
+ }
+
+ sg->offset = 0;
+ sg->length = plen;
+ len -= plen;
+ ctx->used += plen;
+ copied += plen;
+ sgl->cur++;
+ size -= plen;
+ ctx->merge = plen & (PAGE_SIZE - 1);
+ }
+ }
+
+ err = 0;
+
+ ctx->more = msg->msg_flags & MSG_MORE;
+ if (!ctx->more && !aead_sufficient_data(ctx)) {
+ aead_put_sgl(sk);
+ err = -EMSGSIZE;
+ }
+
+unlock:
+ aead_data_wakeup(sk);
+ release_sock(sk);
+
+ return err ?: copied;
+}
+
+static ssize_t aead_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 aead_ctx *ctx = ask->private;
+ struct aead_sg_list *sgl = &ctx->tsgl;
+ int err = -EINVAL;
+
+ if (flags & MSG_SENDPAGE_NOTLAST)
+ flags |= MSG_MORE;
+
+ if (sgl->cur >= ALG_MAX_PAGES)
+ return -E2BIG;
+
+ lock_sock(sk);
+ if (!ctx->more && ctx->used)
+ goto unlock;
+
+ if (!size)
+ goto done;
+
+ if (!aead_writable(sk)) {
+ /* user space sent too much data */
+ aead_put_sgl(sk);
+ err = -EMSGSIZE;
+ goto unlock;
+ }
+
+ ctx->merge = 0;
+
+ get_page(page);
+ sg_set_page(sgl->sg + sgl->cur, page, size, offset);
+ sgl->cur++;
+ ctx->used += size;
+
+ err = 0;
+
+done:
+ ctx->more = flags & MSG_MORE;
+ if (!ctx->more && !aead_sufficient_data(ctx)) {
+ aead_put_sgl(sk);
+ err = -EMSGSIZE;
+ }
+
+unlock:
+ aead_data_wakeup(sk);
+ release_sock(sk);
+
+ return err ?: size;
+}
+
+static int aead_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 aead_ctx *ctx = ask->private;
+ unsigned bs = crypto_aead_blocksize(crypto_aead_reqtfm(&ctx->aead_req));
+ unsigned as = crypto_aead_authsize(crypto_aead_reqtfm(&ctx->aead_req));
+ struct aead_sg_list *sgl = &ctx->tsgl;
+ struct scatterlist *sg = NULL;
+ struct scatterlist assoc[ALG_MAX_PAGES];
+ size_t assoclen = 0;
+ unsigned int i = 0;
+ int err = -EINVAL;
+ unsigned long used = 0;
+ size_t outlen = 0;
+ size_t usedpages = 0;
+ unsigned int cnt = 0;
+
+ /* Limit number of IOV blocks to be accessed below */
+ if (msg->msg_iter.nr_segs > RSGL_MAX_ENTRIES)
+ return -ENOMSG;
+
+ lock_sock(sk);
+
+ /*
+ * AEAD memory structure: For encryption, the tag is appended to the
+ * ciphertext which implies that the memory allocated for the ciphertext
+ * must be increased by the tag length. For decryption, the tag
+ * is expected to be concatenated to the ciphertext. The plaintext
+ * therefore has a memory size of the ciphertext minus the tag length.
+ *
+ * The memory structure for cipher operation has the following
+ * structure:
+ * AEAD encryption input: assoc data || plaintext
+ * AEAD encryption output: cipherntext || auth tag
+ * AEAD decryption input: assoc data || ciphertext || auth tag
+ * AEAD decryption output: plaintext
+ */
+
+ if (ctx->more) {
+ err = aead_wait_for_data(sk, flags);
+ if (err)
+ goto unlock;
+ }
+
+ used = ctx->used;
+
+ /*
+ * Make sure sufficient data is present -- note, the same check is
+ * is also present in sendmsg/sendpage. The checks in sendpage/sendmsg
+ * shall provide an information to the data sender that something is
+ * wrong, but they are irrelevant to maintain the kernel integrity.
+ * We need this check here too in case user space decides to not honor
+ * the error message in sendmsg/sendpage and still call recvmsg. This
+ * check here protects the kernel integrity.
+ */
+ if (!aead_sufficient_data(ctx))
+ goto unlock;
+
+ /*
+ * The cipher operation input data is reduced by the associated data
+ * length as this data is processed separately later on.
+ */
+ used -= ctx->aead_assoclen;
+
+ if (ctx->enc) {
+ /* round up output buffer to multiple of block size */
+ outlen = ((used + bs - 1) / bs * bs);
+ /* add the size needed for the auth tag to be created */
+ outlen += as;
+ } else {
+ /* output data size is input without the authentication tag */
+ outlen = used - as;
+ /* round up output buffer to multiple of block size */
+ outlen = ((outlen + bs - 1) / bs * bs);
+ }
+
+ /* convert iovecs of output buffers into scatterlists */
+ while (iov_iter_count(&msg->msg_iter)) {
+ size_t seglen = min_t(size_t, iov_iter_count(&msg->msg_iter),
+ (outlen - usedpages));
+
+ /* make one iovec available as scatterlist */
+ err = af_alg_make_sg(&ctx->rsgl[cnt], &msg->msg_iter,
+ seglen);
+ if (err < 0)
+ goto unlock;
+ usedpages += err;
+ /* chain the new scatterlist with initial list */
+ if (cnt)
+ scatterwalk_crypto_chain(ctx->rsgl[0].sg,
+ ctx->rsgl[cnt].sg, 1,
+ sg_nents(ctx->rsgl[cnt-1].sg));
+ /* we do not need more iovecs as we have sufficient memory */
+ if (outlen <= usedpages)
+ break;
+ iov_iter_advance(&msg->msg_iter, err);
+ cnt++;
+ }
+
+ err = -EINVAL;
+ /* ensure output buffer is sufficiently large */
+ if (usedpages < outlen)
+ goto unlock;
+
+ sg_init_table(assoc, ALG_MAX_PAGES);
+ assoclen = ctx->aead_assoclen;
+ /*
+ * Split scatterlist into two: first part becomes AD, second part
+ * is plaintext / ciphertext. The first part is assigned to assoc
+ * scatterlist. When this loop finishes, sg points to the start of the
+ * plaintext / ciphertext.
+ */
+ for (i = 0; i < ctx->tsgl.cur; i++) {
+ sg = sgl->sg + i;
+ if (sg->length <= assoclen) {
+ /* AD is larger than one page */
+ sg_set_page(assoc + i, sg_page(sg),
+ sg->length, sg->offset);
+ assoclen -= sg->length;
+ if (i >= ctx->tsgl.cur)
+ goto unlock;
+ } else if (!assoclen) {
+ /* current page is to start of plaintext / ciphertext */
+ if (i)
+ /* AD terminates at page boundary */
+ sg_mark_end(assoc + i - 1);
+ else
+ /* AD size is zero */
+ sg_mark_end(assoc);
+ break;
+ } else {
+ /* AD does not terminate at page boundary */
+ sg_set_page(assoc + i, sg_page(sg),
+ assoclen, sg->offset);
+ sg_mark_end(assoc + i);
+ /* plaintext / ciphertext starts after AD */
+ sg->length -= assoclen;
+ sg->offset += assoclen;
+ break;
+ }
+ }
+
+ aead_request_set_assoc(&ctx->aead_req, assoc, ctx->aead_assoclen);
+ aead_request_set_crypt(&ctx->aead_req, sg, ctx->rsgl[0].sg, used,
+ ctx->iv);
+
+ err = af_alg_wait_for_completion(ctx->enc ?
+ crypto_aead_encrypt(&ctx->aead_req) :
+ crypto_aead_decrypt(&ctx->aead_req),
+ &ctx->completion);
+
+ if (err) {
+ /* EBADMSG implies a valid cipher operation took place */
+ if (err == -EBADMSG)
+ aead_put_sgl(sk);
+ goto unlock;
+ }
+
+ aead_put_sgl(sk);
+
+ err = 0;
+
+unlock:
+ for (i = 0; i < cnt; i++)
+ af_alg_free_sg(&ctx->rsgl[i]);
+
+ aead_wmem_wakeup(sk);
+ release_sock(sk);
+
+ return err ? err : outlen;
+}
+
+static unsigned int aead_poll(struct file *file, struct socket *sock,
+ poll_table *wait)
+{
+ struct sock *sk = sock->sk;
+ struct alg_sock *ask = alg_sk(sk);
+ struct aead_ctx *ctx = ask->private;
+ unsigned int mask;
+
+ sock_poll_wait(file, sk_sleep(sk), wait);
+ mask = 0;
+
+ if (!ctx->more)
+ mask |= POLLIN | POLLRDNORM;
+
+ if (aead_writable(sk))
+ mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
+
+ return mask;
+}
+
+static struct proto_ops algif_aead_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 = aead_sendmsg,
+ .sendpage = aead_sendpage,
+ .recvmsg = aead_recvmsg,
+ .poll = aead_poll,
+};
+
+static void *aead_bind(const char *name, u32 type, u32 mask)
+{
+ return crypto_alloc_aead(name, type, mask);
+}
+
+static void aead_release(void *private)
+{
+ crypto_free_aead(private);
+}
+
+static int aead_setauthsize(void *private, unsigned int authsize)
+{
+ return crypto_aead_setauthsize(private, authsize);
+}
+
+static int aead_setkey(void *private, const u8 *key, unsigned int keylen)
+{
+ return crypto_aead_setkey(private, key, keylen);
+}
+
+static void aead_sock_destruct(struct sock *sk)
+{
+ struct alg_sock *ask = alg_sk(sk);
+ struct aead_ctx *ctx = ask->private;
+ unsigned int ivlen = crypto_aead_ivsize(
+ crypto_aead_reqtfm(&ctx->aead_req));
+
+ aead_put_sgl(sk);
+ sock_kzfree_s(sk, ctx->iv, ivlen);
+ sock_kfree_s(sk, ctx, ctx->len);
+ af_alg_release_parent(sk);
+}
+
+static int aead_accept_parent(void *private, struct sock *sk)
+{
+ struct aead_ctx *ctx;
+ struct alg_sock *ask = alg_sk(sk);
+ unsigned int len = sizeof(*ctx) + crypto_aead_reqsize(private);
+ unsigned int ivlen = crypto_aead_ivsize(private);
+
+ ctx = sock_kmalloc(sk, len, GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+ memset(ctx, 0, len);
+
+ ctx->iv = sock_kmalloc(sk, ivlen, GFP_KERNEL);
+ if (!ctx->iv) {
+ sock_kfree_s(sk, ctx, len);
+ return -ENOMEM;
+ }
+ memset(ctx->iv, 0, ivlen);
+
+ ctx->len = len;
+ ctx->used = 0;
+ ctx->more = 0;
+ ctx->merge = 0;
+ ctx->enc = 0;
+ ctx->tsgl.cur = 0;
+ ctx->aead_assoclen = 0;
+ af_alg_init_completion(&ctx->completion);
+ sg_init_table(ctx->tsgl.sg, ALG_MAX_PAGES);
+
+ ask->private = ctx;
+
+ aead_request_set_tfm(&ctx->aead_req, private);
+ aead_request_set_callback(&ctx->aead_req, CRYPTO_TFM_REQ_MAY_BACKLOG,
+ af_alg_complete, &ctx->completion);
+
+ sk->sk_destruct = aead_sock_destruct;
+
+ return 0;
+}
+
+static const struct af_alg_type algif_type_aead = {
+ .bind = aead_bind,
+ .release = aead_release,
+ .setkey = aead_setkey,
+ .setauthsize = aead_setauthsize,
+ .accept = aead_accept_parent,
+ .ops = &algif_aead_ops,
+ .name = "aead",
+ .owner = THIS_MODULE
+};
+
+static int __init algif_aead_init(void)
+{
+ return af_alg_register_type(&algif_type_aead);
+}
+
+static void __exit algif_aead_exit(void)
+{
+ int err = af_alg_unregister_type(&algif_type_aead);
+ BUG_ON(err);
+}
+
+module_init(algif_aead_init);
+module_exit(algif_aead_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Stephan Mueller <[email protected]>");
+MODULE_DESCRIPTION("AEAD kernel crypto API user space interface");
--
2.1.0
On Sat, Feb 28, 2015 at 08:49:22PM +0100, Stephan Mueller wrote:
> Hi,
>
> This patch set adds AEAD support to the AF_ALG interface
> exported by the kernel crypto API.
>
> The AEAD implementation uses the same approach as provided with
> skcipher by offering the following interfaces:
>
> * sendmsg and recvmsg interfaces allowing multiple
> invocations supporting a threaded user space. To support
> multi-threaded user space, kernel-side buffering
> is implemented similarly to skcipher.
>
> * splice / vmsplice interfaces allowing a zero-copy
> invocation
>
> The new AEAD interface is fully tested with the test application
> provided at [1]. That test application exercises all newly added user space
> interfaces. The testing covers:
>
> * use of the sendmsg/recvmsg interface
>
> * use of the splice / vmsplice interface
>
> * invocation of all AF_ALG types (aead, rng, skcipher, hash)
>
> * using all types of operation (encryption, decryption, keyed MD,
> MD, random numbers, AEAD decryption with positive and negative
> authentication verification)
>
> * stress testing by running all tests for 30 minutes in an
> endless loop
>
> * test execution on 64 bit and 32 bit
All applied. Thanks a lot for your hard work!
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
Am Mittwoch, 4. M?rz 2015, 22:16:32 schrieb Herbert Xu:
Hi Herbert,
>On Sat, Feb 28, 2015 at 08:49:22PM +0100, Stephan Mueller wrote:
>> Hi,
>>
>> This patch set adds AEAD support to the AF_ALG interface
>> exported by the kernel crypto API.
>>
>
>All applied. Thanks a lot for your hard work!
And thank you a lot for your patience with me! I am glad that it
received such hard assessment as it is a user space interface.
Ciao
Stephan
Hi Stephan,
On 02/28/2015 11:50 AM, Stephan Mueller wrote:
> + err = af_alg_wait_for_completion(ctx->enc ?
> + crypto_aead_encrypt(&ctx->aead_req) :
> + crypto_aead_decrypt(&ctx->aead_req),
> + &ctx->completion);
> +
> + if (err) {
> + /* EBADMSG implies a valid cipher operation took place */
> + if (err == -EBADMSG)
> + aead_put_sgl(sk);
> + goto unlock;
Shouldn't we free the TX sgl regardless of the error was?
Or do we expect that the user will try to read again and it will be Ok the second time?
Hope you still remember :)
> + }
> +
> + aead_put_sgl(sk);
> +
> + err = 0;
> +
> +unlock:
> + for (i = 0; i < cnt; i++)
> + af_alg_free_sg(&ctx->rsgl[i]);
> +
> + aead_wmem_wakeup(sk);
> + release_sock(sk);
> +
> + return err ? err : outlen;
> +}
Am Thursday 11 June 2015, 15:59:29 schrieb Tadeusz Struk:
Hi Tadeusz,
>Hi Stephan,
>
>On 02/28/2015 11:50 AM, Stephan Mueller wrote:
>> + err = af_alg_wait_for_completion(ctx->enc ?
>> + crypto_aead_encrypt(&ctx->aead_req) :
>> + crypto_aead_decrypt(&ctx->aead_req),
>> + &ctx->completion);
>> +
>> + if (err) {
>> + /* EBADMSG implies a valid cipher operation took place */
>> + if (err == -EBADMSG)
>> + aead_put_sgl(sk);
>> + goto unlock;
>
>Shouldn't we free the TX sgl regardless of the error was?
>Or do we expect that the user will try to read again and it will be Ok the
>second time? Hope you still remember :)
It is the latter: as the crypto was not completed properly, leave the data in
memory. This may allow a user to send more data if he needs to for completing
the AEAD operation.
Ciao
Stephan