linux-stable.git/crypto/shash.c, branch linux-5.7.y

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

crypto: algapi - remove obsoleted instance creation helpers

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

Remove lots of helper functions that were previously used for
instantiating crypto templates, but are now unused:

- crypto_get_attr_alg() and similar functions looked up an inner
  algorithm directly from a template parameter.  These were replaced
  with getting the algorithm's name, then calling crypto_grab_*().

- crypto_init_spawn2() and similar functions initialized a spawn, given
  an algorithm.  Similarly, these were replaced with crypto_grab_*().

- crypto_alloc_instance() and similar functions allocated an instance
  with a single spawn, given the inner algorithm.  These aren't useful
  anymore since crypto_grab_*() need the instance allocated first.

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

crypto: shash - introduce crypto_grab_shash()

2020-01-09T03:30:54+00:00

Currently, shash spawns are initialized by using shash_attr_alg() or
crypto_alg_mod_lookup() to look up the shash algorithm, then calling
crypto_init_shash_spawn().

This is different from how skcipher, aead, and akcipher spawns are
initialized (they use crypto_grab_*()), and for no good reason.  This
difference introduces unnecessary complexity.

The crypto_grab_*() functions used to have some problems, like not
holding a reference to the algorithm and requiring the caller to
initialize spawn->base.inst.  But those problems are fixed now.

So, let's introduce crypto_grab_shash() so that we can convert all
templates to the same way of initializing their spawns.

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

crypto: algapi - make unregistration functions return void

2019-12-20T06:58:35+00:00

Some of the algorithm unregistration functions return -ENOENT when asked
to unregister a non-registered algorithm, while others always return 0
or always return void.  But no users check the return value, except for
two of the bulk unregistration functions which print a message on error
but still always return 0 to their caller, and crypto_del_alg() which
calls crypto_unregister_instance() which always returns 0.

Since unregistering a non-registered algorithm is always a kernel bug
but there isn't anything callers should do to handle this situation at
runtime, let's simplify things by making all the unregistration
functions return void, and moving the error message into
crypto_unregister_alg() and upgrading it to a WARN().

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

crypto: shash - Add init_tfm/exit_tfm and verify descsize

2019-12-11T08:48:39+00:00

The shash interface supports a dynamic descsize field because of
the presence of fallbacks (it's just padlock-sha actually, perhaps
we can remove it one day).  As it is the API does not verify the
setting of descsize at all.  It is up to the individual algorithms
to ensure that descsize does not exceed the specified maximum value
of HASH_MAX_DESCSIZE (going above would cause stack corruption).

In order to allow the API to impose this limit directly, this patch
adds init_tfm/exit_tfm hooks to the shash_alg structure.  We can
then verify the descsize setting in the API directly.

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

crypto: shash - allow essiv and hmac to use OPTIONAL_KEY algorithms

2019-12-11T08:36:57+00:00

The essiv and hmac templates refuse to use any hash algorithm that has a
->setkey() function, which includes not just algorithms that always need
a key, but also algorithms that optionally take a key.

Previously the only optionally-keyed hash algorithms in the crypto API
were non-cryptographic algorithms like crc32, so this didn't really
matter.  But that's changed with BLAKE2 support being added.  BLAKE2
should work with essiv and hmac, just like any other cryptographic hash.

Fix this by allowing the use of both algorithms without a ->setkey()
function and algorithms that have the OPTIONAL_KEY flag set.

Signed-off-by: Eric Biggers 
Acked-by: Ard Biesheuvel 
Signed-off-by: Herbert Xu

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

2019-05-30T18:26:32+00:00

Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman