Currently the crypto layer exposes support for a 'des-rfb'
algorithm which is just normal single-DES, with the bits
in each key byte reversed. This special key munging is
required by the RFB protocol password authentication
mechanism.
Since the crypto layer is generic shared code, it makes
more sense to do the key byte munging in the VNC server
code, and expose normal single-DES support.
Replacing cipher 'des-rfb' by 'des' looks like an incompatible
interface change, but it doesn't matter. While the QMP schema
allows any QCryptoCipherAlgorithm for the 'cipher-alg' field
in QCryptoBlockCreateOptionsLUKS, the code restricts what can
be used at runtime. Thus the only effect is a change in error
message.
Original behaviour:
$ qemu-img create -f luks --object secret,id=sec0,data=123 -o cipher-alg=des-rfb,key-secret=sec0 demo.luks 1G
Formatting 'demo.luks', fmt=luks size=1073741824 key-secret=sec0 cipher-alg=des-rfb
qemu-img: demo.luks: Algorithm 'des-rfb' not supported
New behaviour:
$ qemu-img create -f luks --object secret,id=sec0,data=123 -o cipher-alg=des-rfb,key-secret=sec0 demo.luks 1G
Formatting 'demo.luks', fmt=luks size=1073741824 key-secret=sec0 cipher-alg=des-fish
qemu-img: demo.luks: Invalid parameter 'des-rfb'
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The GNUTLS crypto provider doesn't support DES-ECB, only DES-CBC.
We can use the latter to simulate the former, if we encrypt only
1 block (8 bytes) of data at a time, using an all-zeros IV. This
is a very inefficient way to use the QCryptoCipher APIs, but
since the VNC authentication challenge is only 16 bytes, this
is acceptable. No other part of QEMU should be using DES. This
test case demonstrates the equivalence of ECB and CBC for the
single-block case.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The main method checks whether the cipher choice is supported
at runtime, so there is no need for compile time conditions.
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The main tests directory still looks very crowded, and it's not
clear which files are part of a unit tests and which belong to
a different test subsystem. Let's clean up the mess and move the
unit tests to a separate directory.
Message-Id: <20210310063314.1049838-1-thuth@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
