Changes from v1:
* removed the default implementation from set_pub_key: it is assumed that
an implementation must always have this callback defined as there are
no use case for an algorithm, which doesn't need a public key
Many akcipher implementations (like ECDSA) support only signature
verifications, so they don't have all callbacks defined.
Commit 78a0324f4a ("crypto: akcipher - default implementations for
request callbacks") introduced default callbacks for sign/verify
operations, which just return an error code.
However, these are not enough, because before calling sign the caller would
likely call set_priv_key first on the instantiated transform (as the
in-kernel testmgr does). This function does not have a default stub, so the
kernel crashes, when trying to set a private key on an akcipher, which
doesn't support signature generation.
I've noticed this, when trying to add a KAT vector for ECDSA signature to
the testmgr.
With this patch the testmgr returns an error in dmesg (as it should)
instead of crashing the kernel NULL ptr dereference.
Fixes: 78a0324f4a ("crypto: akcipher - default implementations for request callbacks")
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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 <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently, crypto_spawn::inst is first used temporarily to pass the
instance to crypto_grab_spawn(). Then crypto_init_spawn() overwrites it
with crypto_spawn::next, which shares the same union. Finally,
crypto_spawn::inst is set again when the instance is registered.
Make this less convoluted by just passing the instance as an argument to
crypto_grab_spawn() instead.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Initializing a crypto_akcipher_spawn currently requires:
1. Set spawn->base.inst to point to the instance.
2. Call crypto_grab_akcipher().
But there's no reason for these steps to be separate, and in fact this
unneeded complication has caused at least one bug, the one fixed by
commit 6db4341017 ("crypto: adiantum - initialize crypto_spawn::inst")
So just make crypto_grab_akcipher() take the instance as an argument.
To keep the function call from getting too unwieldy due to this extra
argument, also introduce a 'mask' variable into pkcs1pad_create().
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
Because with the introduction of EC-RDSA and change in workings of RSA
in regard to sign/verify, akcipher could have not all callbacks defined,
check the presence of callbacks in crypto_register_akcipher() and
provide default implementation if the callback is not implemented.
This is suggested by Herbert Xu instead of checking the presence of the
callback on every request.
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
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>
Add a struct akcipher_instance and struct akcipher_spawn similar to
how AEAD declares them and the macros for converting to/from
crypto_instance/crypto_spawn. Also add register functions to
avoid exposing crypto_akcipher_type.
Signed-off-by: Andrew Zaborowski <andrew.zaborowski@intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Don't #include crypto/public_key.h in akcipher as the contents of the
header aren't used and changes in a future patch cause it to fail to
compile if CONFIG_KEYS=n.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Add Public Key Encryption API.
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Made CRYPTO_AKCIPHER invisible like other type config options.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
