Commit Graph

19 Commits

Author SHA1 Message Date
Jason A. Donenfeld c2176f0098 crypto: rng - ensure that the RNG is ready before using
Otherwise, we might be seeding the RNG using bad randomness, which is
dangerous. The one use of this function from within the kernel -- not
from userspace -- is being removed (keys/big_key), so that call site
isn't relevant in assessing this.

Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-07-28 17:56:00 +08:00
Matthias Kaehlcke 1e6adff449 crypto: rng - Remove unused function __crypto_rng_cast()
This fixes the following warning when building with clang:

crypto/rng.c:35:34: error: unused function '__crypto_rng_cast'
    [-Werror,-Wunused-function]

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-06-10 12:04:11 +08:00
Gideon Israel Dsouza d8c34b949d crypto: Replaced gcc specific attributes with macros from compiler.h
Continuing from this commit: 52f5684c8e
("kernel: use macros from compiler.h instead of __attribute__((...))")

I submitted 4 total patches. They are part of task I've taken up to
increase compiler portability in the kernel. I've cleaned up the
subsystems under /kernel /mm /block and /security, this patch targets
/crypto.

There is <linux/compiler.h> which provides macros for various gcc specific
constructs. Eg: __weak for __attribute__((weak)). I've cleaned all
instances of gcc specific attributes with the right macros for the crypto
subsystem.

I had to make one additional change into compiler-gcc.h for the case when
one wants to use this: __attribute__((aligned) and not specify an alignment
factor. From the gcc docs, this will result in the largest alignment for
that data type on the target machine so I've named the macro
__aligned_largest. Please advise if another name is more appropriate.

Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-01-13 00:24:39 +08:00
Herbert Xu 7cecadb7cc crypto: rng - Do not free default RNG when it becomes unused
Currently we free the default RNG when its use count hits zero.
This was OK when the IV generators would latch onto the RNG at
instance creation time and keep it until the instance is torn
down.

Now that IV generators only keep the RNG reference during init
time this scheme causes the default RNG to come and go at a high
frequencey.  This is highly undesirable as we want to keep a single
RNG in use unless the admin wants it to be removed.

This patch changes the scheme so that the system RNG once allocated
is never removed unless a specifically requested.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-06-22 15:49:18 +08:00
Herbert Xu b617b702da crypto: rng - Zero seed in crypto_rng_reset
If we allocate a seed on behalf ot the user in crypto_rng_reset,
we must ensure that it is zeroed afterwards or the RNG may be
compromised.

Reported-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-22 09:30:21 +08:00
Herbert Xu 94f1bb15be crypto: rng - Remove old low-level rng interface
Now that all rng implementations have switched over to the new
interface, we can remove the old low-level interface.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-22 09:30:20 +08:00
Herbert Xu 881cd6c570 crypto: rng - Add multiple algorithm registration interface
This patch adds the helpers that allow the registration and removal
of multiple RNG algorithms.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-22 09:30:16 +08:00
Herbert Xu acec27ff35 crypto: rng - Convert low-level crypto_rng to new style
This patch converts the low-level crypto_rng interface to the
"new" style.

This allows existing implementations to be converted over one-
by-one.  Once that is complete we can then remove the old rng
interface.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-22 09:30:14 +08:00
Herbert Xu 3c5d8fa9f5 crypto: rng - Mark crypto_rng_reset seed as const
There is no reason why crypto_rng_reset should modify the seed
so this patch marks it as const.  Since our algorithms don't
export a const seed function yet we have to go through some
contortions for now.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-22 09:30:07 +08:00
Herbert Xu ff030b099a crypto: rng - Introduce crypto_rng_generate
This patch adds the new top-level function crypto_rng_generate
which generates random numbers with additional input.  It also
extends the mid-level rng_gen_random function to take additional
data as input.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-21 10:19:58 +08:00
Herbert Xu d0e83059a6 crypto: rng - Convert crypto_rng to new style crypto_type
This patch converts the top-level crypto_rng to the "new" style.
It was the last algorithm type added before we switched over
to the new way of doing things exemplified by shash.

All users will automatically switch over to the new interface.

Note that this patch does not touch the low-level interface to
rng implementations.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2015-04-21 10:19:57 +08:00
Mathias Krause 9a5467bf7b crypto: user - fix info leaks in report API
Three errors resulting in kernel memory disclosure:

1/ The structures used for the netlink based crypto algorithm report API
are located on the stack. As snprintf() does not fill the remainder of
the buffer with null bytes, those stack bytes will be disclosed to users
of the API. Switch to strncpy() to fix this.

2/ crypto_report_one() does not initialize all field of struct
crypto_user_alg. Fix this to fix the heap info leak.

3/ For the module name we should copy only as many bytes as
module_name() returns -- not as much as the destination buffer could
hold. But the current code does not and therefore copies random data
from behind the end of the module name, as the module name is always
shorter than CRYPTO_MAX_ALG_NAME.

Also switch to use strncpy() to copy the algorithm's name and
driver_name. They are strings, after all.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2013-02-19 20:27:03 +08:00
David S. Miller 6662df33f8 crypto: Stop using NLA_PUT*().
These macros contain a hidden goto, and are thus extremely error
prone and make code hard to audit.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-02 04:33:42 -04:00
Herbert Xu 3acc84739d crypto: algapi - Fix build problem with NET disabled
The report functions use NLA_PUT so we need to ensure that NET
is enabled.

Reported-by: Luis Henriques <henrix@camandro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2011-11-11 06:57:06 +08:00
Steffen Klassert 792608e9c2 crypto: Add userspace report for rng type algorithms
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2011-10-21 14:24:06 +02:00
Arun Sharma 60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:47 -07:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Christian Kujau a8ccc393dd crypto: rng - Fix typo
Correct a typo in crypto/rng.c

Signed-off-by: Christian Kujau <lists@nerdbynature.de>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2009-08-13 11:53:56 +10:00
Neil Horman 17f0f4a47d crypto: rng - RNG interface and implementation
This patch adds a random number generator interface as well as a
cryptographic pseudo-random number generator based on AES.  It is
meant to be used in cases where a deterministic CPRNG is required.

One of the first applications will be as an input in the IPsec IV
generation process.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2008-08-29 15:50:04 +10:00