Commit graph

6 commits

Author SHA1 Message Date
Nicolai Stange
46ed5269bf crypto: kpp - provide support for KPP spawns
The upcoming support for the RFC 7919 ffdhe group parameters will be
made available in the form of templates like "ffdhe2048(dh)",
"ffdhe3072(dh)" and so on. Template instantiations thereof would wrap the
inner "dh" kpp_alg and also provide kpp_alg services to the outside again.

The primitves needed for providing kpp_alg services from template instances
have been introduced with the previous patch. Continue this work now and
implement everything needed for enabling template instances to make use
of inner KPP algorithms like "dh".

More specifically, define a struct crypto_kpp_spawn in close analogy to
crypto_skcipher_spawn, crypto_shash_spawn and alike. Implement a
crypto_grab_kpp() and crypto_drop_kpp() pair for binding such a spawn to
some inner kpp_alg and for releasing it respectively. Template
implementations can instantiate transforms from the underlying kpp_alg by
means of the new crypto_spawn_kpp(). Finally, provide the
crypto_spawn_kpp_alg() helper for accessing a spawn's underlying kpp_alg
during template instantiation.

Annotate everything with proper kernel-doc comments, even though
include/crypto/internal/kpp.h is not considered for the generated docs.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-03-03 10:47:50 +12:00
Nicolai Stange
1038fd78a1 crypto: kpp - provide support for KPP template instances
The upcoming support for the RFC 7919 ffdhe group parameters will be
made available in the form of templates like "ffdhe2048(dh)",
"ffdhe3072(dh)" and so on. Template instantiations thereof would wrap the
inner "dh" kpp_alg and also provide kpp_alg services to the outside again.
Furthermore, it might be perhaps be desirable to provide KDF templates in
the future, which would similarly wrap an inner kpp_alg and present
themselves to the outside as another kpp_alg, transforming the shared
secret on its way out.

Introduce the bits needed for supporting KPP template instances. Everything
related to inner kpp_alg spawns potentially being held by such template
instances will be deferred to a subsequent patch in order to facilitate
review.

Define struct struct kpp_instance in close analogy to the already existing
skcipher_instance, shash_instance and alike, but wrapping a struct kpp_alg.
Implement the new kpp_register_instance() template instance registration
primitive. Provide some helper functions for
- going back and forth between a generic struct crypto_instance and the new
  struct kpp_instance,
- obtaining the instantiating kpp_instance from a crypto_kpp transform and
- for accessing a given kpp_instance's implementation specific context
  data.

Annotate everything with proper kernel-doc comments, even though
include/crypto/internal/kpp.h is not considered for the generated docs.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-03-03 10:47:49 +12:00
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
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 <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Eric Biggers
37db69e0b4 crypto: user - clean up report structure copying
There have been a pretty ridiculous number of issues with initializing
the report structures that are copied to userspace by NETLINK_CRYPTO.
Commit 4473710df1 ("crypto: user - Prepare for CRYPTO_MAX_ALG_NAME
expansion") replaced some strncpy()s with strlcpy()s, thereby
introducing information leaks.  Later two other people tried to replace
other strncpy()s with strlcpy() too, which would have introduced even
more information leaks:

    - https://lore.kernel.org/patchwork/patch/954991/
    - https://patchwork.kernel.org/patch/10434351/

Commit cac5818c25 ("crypto: user - Implement a generic crypto
statistics") also uses the buggy strlcpy() approach and therefore leaks
uninitialized memory to userspace.  A fix was proposed, but it was
originally incomplete.

Seeing as how apparently no one can get this right with the current
approach, change all the reporting functions to:

- Start by memsetting the report structure to 0.  This guarantees it's
  always initialized, regardless of what happens later.
- Initialize all strings using strscpy().  This is safe after the
  memset, ensures null termination of long strings, avoids unnecessary
  work, and avoids the -Wstringop-truncation warnings from gcc.
- Use sizeof(var) instead of sizeof(type).  This is more robust against
  copy+paste errors.

For simplicity, also reuse the -EMSGSIZE return value from nla_put().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-11-09 17:41:39 +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
Salvatore Benedetto
4e5f2c4007 crypto: kpp - Key-agreement Protocol Primitives API (KPP)
Add key-agreement protocol primitives (kpp) API which allows to
implement primitives required by protocols such as DH and ECDH.
The API is composed mainly by the following functions
 * set_secret() - It allows the user to set his secret, also
   referred to as his private key, along with the parameters
   known to both parties involved in the key-agreement session.
 * generate_public_key() - It generates the public key to be sent to
   the other counterpart involved in the key-agreement session. The
   function has to be called after set_params() and set_secret()
 * generate_secret() - It generates the shared secret for the session

Other functions such as init() and exit() are provided for allowing
cryptographic hardware to be inizialized properly before use

Signed-off-by: Salvatore Benedetto <salvatore.benedetto@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2016-06-23 18:29:56 +08:00