This patch adds the random number generator support for AF_ALG.
A random number generator's purpose is to generate data without
requiring the caller to provide any data. Therefore, the AF_ALG
interface handler for RNGs only implements a callback handler for
recvmsg.
The following parameters provided with a recvmsg are processed by the
RNG callback handler:
* sock - to resolve the RNG context data structure accessing the
RNG instance private to the socket
* len - this parameter allows userspace callers to specify how
many random bytes the RNG shall produce and return. As the
kernel context for the RNG allocates a buffer of 128 bytes to
store random numbers before copying them to userspace, the len
parameter is checked that it is not larger than 128. If a
caller wants more random numbers, a new request for recvmsg
shall be made.
The size of 128 bytes is chose because of the following considerations:
* to increase the memory footprint of the kernel too much (note,
that would be 128 bytes per open socket)
* 128 is divisible by any typical cryptographic block size an
RNG may have
* A request for random numbers typically only shall supply small
amount of data like for keys or IVs that should only require
one invocation of the recvmsg function.
Note, during instantiation of the RNG, the code checks whether the RNG
implementation requires seeding. If so, the RNG is seeded with output
from get_random_bytes.
A fully working example using all aspects of the RNG interface is
provided at http://www.chronox.de/libkcapi.html
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
algif_skcipher sends 127 sgl buffers for encryption regardless of how
many buffers acctually have data to process, where the few first with
valid len and the rest with zero len. This is not very eficient.
This patch marks the last one with data as the last one to process.
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Use setsockopt on the tfm FD to provide the authentication tag size for
an AEAD cipher. This is achieved by adding a callback function which is
intended to be used by the AEAD AF_ALG implementation.
The optlen argument of the setsockopt specifies the authentication tag
size to be used with the AEAD tfm.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch adds a panic if the FIPS 140-2 self test error failed.
Note, that entire code is only executed with fips_enabled (i.e. when the
kernel is booted with fips=1. It is therefore not executed for 99.9% of
all user base.
As mathematically such failure cannot occur, this panic should never be
triggered. But to comply with NISTs current requirements, an endless
loop must be replaced with the panic.
When the new version of FIPS 140 will be released, this entire
continuous self test function will be ripped out as it will not be
needed any more.
This patch is functionally equivalent as implemented in ansi_cprng.c and drivers/char/random.c.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fixed style error identified by checkpatch.
WARNING: Missing a blank line after declarations
+ int err = crypto_remove_alg(&inst->alg, &users);
+ BUG_ON(err);
Signed-off-by: Joshua I. James <joshua@cybercrimetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fixed style error identified by checkpatch.
WARNING: Missing a blank line after declarations
+ unsigned int unaligned = alignmask + 1 - (offset & alignmask);
+ if (nbytes > unaligned)
Signed-off-by: Joshua I. James <joshua@cybercrimetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fixed style error identified by checkpatch.
ERROR: space required before the open parenthesis '('
+ switch(cmsg->cmsg_type) {
Signed-off-by: Joshua I. James <joshua@cybercrimetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fixed style error identified by checkpatch.
ERROR: do not use assignment in if condition
+ if ((err = crypto_register_instance(tmpl, inst))) {
Signed-off-by: Joshua I. James <joshua@cybercrimetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fixed style errors reported by checkpatch.
WARNING: Missing a blank line after declarations
+ u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
+ return max(start, end_page);
WARNING: line over 80 characters
+ scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg));
WARNING: Missing a blank line after declarations
+ int err = ablkcipher_copy_iv(walk, tfm, alignmask);
+ if (err)
ERROR: do not use assignment in if condition
+ if ((err = crypto_register_instance(tmpl, inst))) {
Signed-off-by: Joshua I. James <joshua@cybercrimetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
If a request is backlogged, it's complete() handler will get called
twice: once with -EINPROGRESS, and once with the final error code.
af_alg's complete handler, unlike other users, does not handle the
-EINPROGRESS but instead always completes the completion that recvmsg()
is waiting on. This can lead to a return to user space while the
request is still pending in the driver. If userspace closes the sockets
before the requests are handled by the driver, this will lead to
use-after-frees (and potential crashes) in the kernel due to the tfm
having been freed.
The crashes can be easily reproduced (for example) by reducing the max
queue length in cryptod.c and running the following (from
http://www.chronox.de/libkcapi.html) on AES-NI capable hardware:
$ while true; do kcapi -x 1 -e -c '__ecb-aes-aesni' \
-k 00000000000000000000000000000000 \
-p 00000000000000000000000000000000 >/dev/null & done
Cc: stable@vger.kernel.org
Signed-off-by: Rabin Vincent <rabin.vincent@axis.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Pull crypto update from Herbert Xu:
- The crypto API is now documented :)
- Disallow arbitrary module loading through crypto API.
- Allow get request with empty driver name through crypto_user.
- Allow speed testing of arbitrary hash functions.
- Add caam support for ctr(aes), gcm(aes) and their derivatives.
- nx now supports concurrent hashing properly.
- Add sahara support for SHA1/256.
- Add ARM64 version of CRC32.
- Misc fixes.
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (77 commits)
crypto: tcrypt - Allow speed testing of arbitrary hash functions
crypto: af_alg - add user space interface for AEAD
crypto: qat - fix problem with coalescing enable logic
crypto: sahara - add support for SHA1/256
crypto: sahara - replace tasklets with kthread
crypto: sahara - add support for i.MX53
crypto: sahara - fix spinlock initialization
crypto: arm - replace memset by memzero_explicit
crypto: powerpc - replace memset by memzero_explicit
crypto: sha - replace memset by memzero_explicit
crypto: sparc - replace memset by memzero_explicit
crypto: algif_skcipher - initialize upon init request
crypto: algif_skcipher - removed unneeded code
crypto: algif_skcipher - Fixed blocking recvmsg
crypto: drbg - use memzero_explicit() for clearing sensitive data
crypto: drbg - use MODULE_ALIAS_CRYPTO
crypto: include crypto- module prefix in template
crypto: user - add MODULE_ALIAS
crypto: sha-mb - remove a bogus NULL check
crytpo: qat - Fix 64 bytes requests
...
Introduce helper macro for_each_cmsghdr as a wrapper of the enumerating
cmsghdr from msghdr, just cleanup.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Note that the code _using_ ->msg_iter at that point will be very
unhappy with anything other than unshifted iovec-backed iov_iter.
We still need to convert users to proper primitives.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This patch allows the testing of arbitrary hash functions specified
by the alg module parameter by using them in mode 300 (for sync hash)
and mode 400 (for async hash).
For example, you could do
modprobe tcrypt mode=300 alg='vmac(aes)'
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
AEAD requires the caller to specify the following information separate
from the data stream. This information allows the AEAD interface handler
to identify the AAD, ciphertext/plaintext and the authentication tag:
* Associated authentication data of arbitrary length and
length
* Length of authentication tag for encryption
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
When using the algif_skcipher, the following call sequence causess a
re-initialization:
1. sendmsg with ALG_SET_OP and iov == NULL, iovlen == 0 (i.e
initializing the cipher, but not sending data)
2. sendmsg with msg->msg-controllen == 0 and iov != NULL (using the initalized
cipher handle by sending data)
In step 2, the cipher operation type (encryption or decryption) is reset
to always decryption, because the local variable of enc is put into
ctx->enc as ctx->user is still zero.
The same applies when all send data is processed and ctx->used falls to
zero followed by user space to send new data.
This patch changes the behavior to only reset the cipher operation type
(and the IV) if such configuration request is received.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As most (all?) users of algif_skcipher are single-threaded and
therefore always write before reading from an algif_skcipher
socket, they never block and exercise that code-path.
It turns out that code path doesn't even work because we never
reload ctx->used after waking up so we never even see the new
data and immediately return an error (and a loud WARN_ON).
This patch fixes this by always reloading ctx->used.
Reported-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Stephan Mueller <smueller@chronox.de>
Compiler dead store optimization can sometimes remove final calls
to memset() used to clear sensitive data at the end of a function.
Replace trailing memset() calls with memzero_explicit() to
preclude unwanted removal.
Signed-off-by: Nickolaus Woodruff <nickolauswoodruff@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This adds the module loading prefix "crypto-" to the template lookup
as well.
For example, attempting to load 'vfat(blowfish)' via AF_ALG now correctly
includes the "crypto-" prefix at every level, correctly rejecting "vfat":
net-pf-38
algif-hash
crypto-vfat(blowfish)
crypto-vfat(blowfish)-all
crypto-vfat
Reported-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
To allow automatic loading of the crypto_user kernel module, the netlink
MODULE_ALIAS is added.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Commit e1bd95bf7c ("crypto: algif - zeroize IV buffer") and
2a6af25bef ("crypto: algif - zeroize message digest buffer")
added memzero_explicit() calls on buffers that are later on
passed back to sock_kfree_s().
This is a discussed follow-up that, instead, extends the sock
API and adds sock_kzfree_s(), which internally uses kzfree()
instead of kfree() for passing the buffers back to slab.
Having sock_kzfree_s() allows to keep the changes more minimal
by just having a drop-in replacement instead of adding
memzero_explicit() calls everywhere before sock_kfree_s().
In kzfree(), the compiler is not allowed to optimize the memset()
away and thus there's no need for memzero_explicit(). Both,
sock_kfree_s() and sock_kzfree_s() are wrappers for
__sock_kfree_s() and call into kfree() resp. kzfree(); here,
__sock_kfree_s() needs to be explicitly inlined as we want the
compiler to optimize the call and condition away and thus it
produces e.g. on x86_64 the _same_ assembler output for
sock_kfree_s() before and after, and thus also allows for
avoiding code duplication.
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Stephan Mueller
Aaro Koskinen
Tadeusz Struk
Joshua I. James
Rabin Vincent
Linus Torvalds
Gu Zheng
Al Viro
Herbert Xu
Nickolaus Woodruff
Kees Cook
Daniel Borkmann