It can't guarantee all cipher modes are supported
if one cipher algorithm is supported by a backend.
Let's extend qcrypto_cipher_supports() to take both
the algorithm and mode as parameters.
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Several error messages print out the raw enum value, which
is less than helpful to users, as these values are not
documented, nor stable across QEMU releases. Switch to use
the enum string instead.
The nettle impl also had two typos where it mistakenly
said "algorithm" instead of "mode", and actually reported
the algorithm value too.
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Introduce 'XTS' as a permitted mode for the cipher APIs.
With XTS the key provided must be twice the size of the
key normally required for any given algorithm. This is
because the key will be split into two pieces for use
in XTS mode.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The built-in and nettle cipher backends for AES maintain
two separate AES contexts, one for encryption and one for
decryption. This is going to be inconvenient for the future
code dealing with XTS, so wrap them up in a single struct
so there is just one pointer to pass around for both
encryption and decryption.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
When encrypting/decrypting data, the plaintext/ciphertext
buffers are required to be a multiple of the cipher block
size. If this is not done, nettle will abort and gcrypt
will report an error. To get consistent behaviour add
explicit checks upfront for the buffer sizes.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
If no IV is provided, then use a default IV of all-zeros
instead of crashing. This gives parity with gcrypt and
nettle backends.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Introduce a generic cipher API and an implementation of it that
supports only the built-in AES and DES-RFB algorithms.
The test suite checks the supported algorithms + modes to
validate that every backend implementation is actually correctly
complying with the specs.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-5-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
