linux-stable.git/crypto/shash.c, branch linux-6.2.y

crypto: api - Increase MAX_ALGAPI_ALIGNMASK to 127

2022-12-02T10:12:40+00:00

Previously we limited the maximum alignment mask to 63.  This
is mostly due to stack usage for shash.  This patch introduces
a separate limit for shash algorithms and increases the general
limit to 127 which is the value that we need for DMA allocations
on arm64.

Signed-off-by: Herbert Xu

Revert "crypto: shash - avoid comparing pointers to exported functions under CFI"

2022-11-25T09:39:19+00:00

This reverts commit 22ca9f4aaf431a9413dcc115dd590123307f274f because CFI
no longer breaks cross-module function address equality, so
crypto_shash_alg_has_setkey() can now be an inline function like before.

This commit should not be backported to kernels that don't have the new
CFI implementation.

Acked-by: Peter Zijlstra (Intel) 
Reviewed-by: Sami Tolvanen 
Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: add crypto_has_shash()

2022-08-02T23:14:47+00:00

Add helper function to determine if a given synchronous hash is supported.

Signed-off-by: Hannes Reinecke 
Reviewed-by: Sagi Grimberg 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Himanshu Madhani 
Acked-by: Herbert Xu 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Jens Axboe

crypto: shash - avoid comparing pointers to exported functions under CFI

2021-06-17T07:07:31+00:00

crypto_shash_alg_has_setkey() is implemented by testing whether the
.setkey() member of a struct shash_alg points to the default version,
called shash_no_setkey(). As crypto_shash_alg_has_setkey() is a static
inline, this requires shash_no_setkey() to be exported to modules.

Unfortunately, when building with CFI, function pointers are routed
via CFI stubs which are private to each module (or to the kernel proper)
and so this function pointer comparison may fail spuriously.

Let's fix this by turning crypto_shash_alg_has_setkey() into an out of
line function.

Cc: Sami Tolvanen 
Cc: Eric Biggers 
Signed-off-by: Ard Biesheuvel 
Reviewed-by: Eric Biggers 
Reviewed-by: Sami Tolvanen 
Signed-off-by: Herbert Xu

mm, treewide: rename kzfree() to kfree_sensitive()

2020-08-07T18:33:22+00:00

As said by Linus:

  A symmetric naming is only helpful if it implies symmetries in use.
  Otherwise it's actively misleading.

  In "kzalloc()", the z is meaningful and an important part of what the
  caller wants.

  In "kzfree()", the z is actively detrimental, because maybe in the
  future we really _might_ want to use that "memfill(0xdeadbeef)" or
  something. The "zero" part of the interface isn't even _relevant_.

The main reason that kzfree() exists is to clear sensitive information
that should not be leaked to other future users of the same memory
objects.

Rename kzfree() to kfree_sensitive() to follow the example of the recently
added kvfree_sensitive() and make the intention of the API more explicit.
In addition, memzero_explicit() is used to clear the memory to make sure
that it won't get optimized away by the compiler.

The renaming is done by using the command sequence:

  git grep -w --name-only kzfree |\
  xargs sed -i 's/kzfree/kfree_sensitive/'

followed by some editing of the kfree_sensitive() kerneldoc and adding
a kzfree backward compatibility macro in slab.h.

[akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h]
[akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more]

Suggested-by: Joe Perches 
Signed-off-by: Waiman Long 
Signed-off-by: Andrew Morton 
Acked-by: David Howells 
Acked-by: Michal Hocko 
Acked-by: Johannes Weiner 
Cc: Jarkko Sakkinen 
Cc: James Morris 
Cc: "Serge E. Hallyn" 
Cc: Joe Perches 
Cc: Matthew Wilcox 
Cc: David Rientjes 
Cc: Dan Carpenter 
Cc: "Jason A . Donenfeld" 
Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com
Signed-off-by: Linus Torvalds

crypto: hash - introduce crypto_shash_tfm_digest()

2020-05-08T05:32:12+00:00

Currently the simplest use of the shash API is to use
crypto_shash_digest() to digest a whole buffer.  However, this still
requires allocating a hash descriptor (struct shash_desc).  Many users
don't really want to preallocate one and instead just use a one-off
descriptor on the stack like the following:

	{
		SHASH_DESC_ON_STACK(desc, tfm);
		int err;

		desc->tfm = tfm;

		err = crypto_shash_digest(desc, data, len, out);

		shash_desc_zero(desc);
	}

Wrap this in a new helper function crypto_shash_tfm_digest() that can be
used instead of the above.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: algapi - enforce that all instances have a ->free() method

2020-01-09T03:30:58+00:00

All instances need to have a ->free() method, but people could forget to
set it and then not notice if the instance is never unregistered.  To
help detect this bug earlier, don't allow an instance without a ->free()
method to be registered, and complain loudly if someone tries to do it.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: algapi - remove crypto_template::{alloc,free}()

2020-01-09T03:30:58+00:00

Now that all templates provide a ->create() method which creates an
instance, installs a strongly-typed ->free() method directly to it, and
registers it, the older ->alloc() and ->free() methods in
'struct crypto_template' are no longer used.  Remove them.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: shash - convert shash_free_instance() to new style

2020-01-09T03:30:57+00:00

Convert shash_free_instance() and its users to the new way of freeing
instances, where a ->free() method is installed to the instance struct
itself.  This replaces the weakly-typed method crypto_template::free().

This will allow removing support for the old way of freeing instances.

Also give shash_free_instance() a more descriptive name to reflect that
it's only for instances with a single spawn, not for any instance.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu

crypto: hash - add support for new way of freeing instances

2020-01-09T03:30:57+00:00

Add support to shash and ahash for the new way of freeing instances
(already used for skcipher, aead, and akcipher) where a ->free() method
is installed to the instance struct itself.  These methods are more
strongly-typed than crypto_template::free(), which they replace.

This will allow removing support for the old way of freeing instances.

Signed-off-by: Eric Biggers 
Signed-off-by: Herbert Xu