Move x509_request_asymmetric_key() to asymmetric_type.c so that it can be
generalised.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Generalise system_verify_data() to provide access to internal content
through a callback.  This allows all the PKCS#7 stuff to be hidden inside
this function and removed from the PE file parser and the PKCS#7 test key.

If external content is not required, NULL should be passed as data to the
function.  If the callback is not required, that can be set to NULL.

The function is now called verify_pkcs7_signature() to contrast with
verify_pefile_signature() and the definitions of both have been moved into
linux/verification.h along with the key_being_used_for enum.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Allow authentication data to be stored in an asymmetric key in the 4th
element of the key payload and provide a way for it to be destroyed.

For the public key subtype, this will be a public_key_signature struct.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Merge the type-specific data with the payload data into one four-word chunk
as it seems pointless to keep them separate.

Use user_key_payload() for accessing the payloads of overloaded
user-defined keys.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: linux-cifs@vger.kernel.org
cc: ecryptfs@vger.kernel.org
cc: linux-ext4@vger.kernel.org
cc: linux-f2fs-devel@lists.sourceforge.net
cc: linux-nfs@vger.kernel.org
cc: ceph-devel@vger.kernel.org
cc: linux-ima-devel@lists.sourceforge.net

Bring back the functionality whereby an asymmetric key can be matched with a
partial match on one of its IDs.

Whilst we're at it, allow for the possibility of having an increased number of
IDs.
Reported-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Implement the first step in using binary key IDs for asymmetric keys rather
than hex string keys.

The previously added match data preparsing will be able to convert hex
criterion strings into binary which can then be compared more rapidly.

Further, we actually want more then one ID string per public key.  The problem
is that X.509 certs refer to other X.509 certs by matching Issuer + AuthKeyId
to Subject + SubjKeyId, but PKCS#7 messages match against X.509 Issuer +
SerialNumber.

This patch just provides facilities for a later patch to make use of.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NVivek Goyal <vgoyal@redhat.com>

Create a key type that can be used to represent an asymmetric key type for use
in appropriate cryptographic operations, such as encryption, decryption,
signature generation and signature verification.

The key type is "asymmetric" and can provide access to a variety of
cryptographic algorithms.

Possibly, this would be better as "public_key" - but that has the disadvantage
that "public key" is an overloaded term.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>