In preparation libtool "-module" flag removal, add lib prefix to all
mock shared objects.

While at it, introduce VIR_TEST_MOCK macros that makes path out of mock
name to be used with VIR_TEST_PRELOAD or VIR_TEST_MAIN_PRELOAD.  That,
hopefully, improves readability, reduces line length and allows to
tailor VIR_TEST_MOCK for specific platform if it has shared library
suffix different from ".so".
Signed-off-by: NRoman Bolshakov <r.bolshakov@yadro.com>

Now that GnuTLS is a requirement, we can drop a lot of
conditionally built code. However, not all ifdef-s can go because
we still want libvirt_setuid to build without gnutls.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NDaniel P. Berrangé <berrange@redhat.com>

In libvirt when a function wants to return an error code it
should be a negative value. Returning a positive value (or zero)
means success. But virRandomBytes() does not follow this rule.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>

Fix make check without gnutls.
Signed-off-by: NJán Tomko <jtomko@redhat.com>

Right-aligning backslashes when defining macros or using complex
commands in Makefiles looks cute, but as soon as any changes is
required to the code you end up with either distractingly broken
alignment or unnecessarily big diffs where most of the changes
are just pushing all backslashes a few characters to one side.

Generated using

  $ git grep -El '[[:blank:]][[:blank:]]\\$' | \
    grep -E '*\.([chx]|am|mk)$$' | \
    while read f; do \
      sed -Ei 's/[[:blank:]]*[[:blank:]]\\$/ \\/g' "$f"; \
    done
Signed-off-by: NAndrea Bolognani <abologna@redhat.com>

We use the "vir" prefix pretty consistently in our
APIs, both external and internal, which made these
macros stood out.

This function doesn't follow our convention of naming functions.

Document the return value of virRandomBytes as 0 or some errno value and
then make sure all callers make the proper checks.

Introduce virCryptoHaveCipher and virCryptoEncryptData to handle
performing encryption.

 virCryptoHaveCipher:
   Boolean function to determine whether the requested cipher algorithm
   is available. It's expected this API will be called prior to
   virCryptoEncryptdata. It will return true/false.

 virCryptoEncryptData:
   Based on the requested cipher type, call the specific encryption
   API to encrypt the data.

Currently the only algorithm support is the AES 256 CBC encryption.

Adjust tests for the API's

GNULIB provides APIs for calculating md5 and sha256 hashes,
but these APIs only return you raw byte arrays. Most users
in libvirt want the hash in printable string format. Add
some helper APIs in util/vircrypto.{c,h} for doing this.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>