Commit Graph

63 Commits

Author SHA1 Message Date
Daniel P. Berrange
a090187de1 crypto: introduce new base module for TLS credentials
Introduce a QCryptoTLSCreds class to act as the base class for
storing TLS credentials. This will be later subclassed to provide
handling of anonymous and x509 credential types. The subclasses
will be user creatable objects, so instances can be created &
deleted via 'object-add' and 'object-del' QMP commands respectively,
or via the -object command line arg.

If the credentials cannot be initialized an error will be reported
as a QMP reply, or on stderr respectively.

The idea is to make it possible to represent and manage TLS
credentials independently of the network service that is using
them. This will enable multiple services to use the same set of
credentials and minimize code duplication. A later patch will
convert the current VNC server TLS code over to use this object.

The representation of credentials will be functionally equivalent
to that currently implemented in the VNC server with one exception.
The new code has the ability to (optionally) load a pre-generated
set of diffie-hellman parameters, if the file dh-params.pem exists,
whereas the current VNC server will always generate them on startup.
This is beneficial for admins who wish to avoid the (small) time
sink of generating DH parameters at startup and/or avoid depleting
entropy.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-09-15 14:47:37 +01:00
Daniel P. Berrange
fb37726db7 crypto: move crypto objects out of libqemuutil.la
Future patches will be adding more crypto related APIs which
rely on QOM infrastructure. This creates a problem, because
QOM relies on library constructors to register objects. When
you have a file in a static .a library though which is only
referenced by a constructor the linker is dumb and will drop
that file when linking to the final executable :-( The only
workaround for this is to link the .a library to the executable
using the -Wl,--whole-archive flag, but this creates its own
set of problems because QEMU is relying on lazy linking for
libqemuutil.a. Using --whole-archive majorly increases the
size of final executables as they now contain a bunch of
object code they don't actually use.

The least bad option is to thus not include the crypto objects
in libqemuutil.la, and instead define a crypto-obj-y variable
that is referenced directly by all the executables that need
this code (tools + softmmu, but not qemu-ga). We avoid pulling
entire of crypto-obj-y into the userspace emulators as that
would force them to link to gnutls too, which is not required.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2015-09-15 14:18:18 +01:00
Daniel P. Berrange
6775e2c429 crypto: fix built-in AES decrypt function
The qcrypto_cipher_decrypt_aes method was using the wrong
key material, and passing the wrong mode. This caused it
to incorrectly decrypt ciphertext.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1437740634-6261-1-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-27 12:22:01 +02:00
Kevin Wolf
bd09594603 crypto: Fix aes_decrypt_wrapper()
Commit d3462e3 broke qcow2's encryption functionality by using encrypt
instead of decrypt in the wrapper function it introduces. This was found
by qemu-iotests case 134.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
2015-07-20 13:35:45 +02:00
Radim Krčmář
d3462e378f crypto: avoid undefined behavior in nettle calls
Calling a function pointer that was cast from an incompatible function
results in undefined behavior.  'void *' isn't compatible with 'struct
XXX *', so we can't cast to nettle_cipher_func, but have to provide a
wrapper.  (Conversion from 'void *' to 'struct XXX *' might require
computation, which won't be done if we drop argument's true type, and
pointers can have different sizes so passing arguments on stack would
bug.)

Having two different prototypes based on nettle version doesn't make
this solution any nicer.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Message-Id: <1437062641-12684-3-git-send-email-rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-16 20:00:21 +02:00
Radim Krčmář
becaeb726a crypto: fix build with nettle >= 3.0.0
In nettle 3, cbc_encrypt() accepts 'nettle_cipher_func' instead of
'nettle_crypt_func' and these two differ in 'const' qualifier of the
first argument.  The build fails with:

  In file included from crypto/cipher.c:71:0:
  ./crypto/cipher-nettle.c: In function ‘qcrypto_cipher_encrypt’:
  ./crypto/cipher-nettle.c:154:38: error: passing argument 2 of
  ‘nettle_cbc_encrypt’ from incompatible pointer type
           cbc_encrypt(ctx->ctx_encrypt, ctx->alg_encrypt,
                                               ^
  In file included from ./crypto/cipher-nettle.c:24:0,
                   from crypto/cipher.c:71:
  /usr/include/nettle/cbc.h:48:1: note: expected
  ‘void (*)(const void *, size_t, uint8_t *, const uint8_t *)
  but argument is of type
  ‘void (*)(      void *, size_t, uint8_t *, const uint8_t *)

To allow both versions, we switch to the new definition and #if typedef
it for old versions.

Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Message-Id: <1436548682-9315-2-git-send-email-rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-16 20:00:20 +02:00
Paolo Bonzini
4f4f6976d8 crypto: fix builtin qcrypto_cipher_free
This was dereferencing a pointer before checking if it was NULL.

Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reported-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-09 16:53:45 +02:00
Daniel P. Berrange
ed754746fe crypto: add a nettle cipher implementation
If we are linking to gnutls already and gnutls is built against
nettle, then we should use nettle as a cipher backend in
preference to our built-in backend.

This will be used when linking against some GNUTLS 2.x versions
and all GNUTLS 3.x versions.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-7-git-send-email-berrange@redhat.com>
[Change "#elif" to "#elif defined". - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-08 13:11:01 +02:00
Daniel P. Berrange
62893b67cd crypto: add a gcrypt cipher implementation
If we are linking to gnutls already and gnutls is built against
gcrypt, then we should use gcrypt as a cipher backend in
preference to our built-in backend.

This will be used when linking against GNUTLS 1.x and many
GNUTLS 2.x versions.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-6-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-08 13:11:01 +02:00
Daniel P. Berrange
ca38a4cc9e crypto: introduce generic cipher API & built-in implementation
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>
2015-07-08 13:11:01 +02:00
Daniel P. Berrange
9fd72468df crypto: move built-in D3DES implementation into crypto/
To prepare for a generic internal cipher API, move the
built-in D3DES implementation into the crypto/ directory.

This is not in fact a normal D3DES implementation, it is
D3DES with double & triple length modes removed, and the
key bytes in reversed bit order. IOW it is crippled
specifically for the "benefit" of RFB, so call the new
files desrfb.c instead of d3des.c to make it clear that
it isn't a generally useful impl.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-4-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-07 12:04:31 +02:00
Daniel P. Berrange
6f2945cde6 crypto: move built-in AES implementation into crypto/
To prepare for a generic internal cipher API, move the
built-in AES implementation into the crypto/ directory

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-3-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-07 12:04:13 +02:00
Daniel P. Berrange
ddbb0d0966 crypto: introduce new module for computing hash digests
Introduce a new crypto/ directory that will (eventually) contain
all the cryptographic related code. This initially defines a
wrapper for initializing gnutls and for computing hashes with
gnutls. The former ensures that gnutls is guaranteed to be
initialized exactly once in QEMU regardless of CLI args. The
block quorum code currently fails to initialize gnutls so it
only works by luck, if VNC server TLS is not requested. The
hash APIs avoids the need to litter the rest of the code with
preprocessor checks and simplifies callers by allocating the
correct amount of memory for the requested hash.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1435770638-25715-2-git-send-email-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-07-07 12:04:07 +02:00