* tests: Remove if-pyramids
* tests: Switch run_command arguments
* tests: Make run_command a vararg function
* tests: Xcode doesn't obey CMake's test working directory
* openssl: move manual AES-CTR cipher into crypto init
* cmake: Move our include dir before all other include paths
Not all backends feature the low level API needed to compute a Diffie-Hellman
secret, but some of them directly implement Diffie-Hellman support with opaque
private data. The later approach is now generalized and backends are
responsible for all Diffie Hellman computations.
As a side effect, procedures/macros _libssh2_bn_rand and _libssh2_bn_mod_exp
are no longer needed outside the backends.
* os400: minimum supported OS version is now V6R1.
Do not log compiler informational messages.
* Implement crypto backend specific Diffie-Hellman computation.
This feature is now needed on os400 because the QC3 library does not
implement bn_mod_exp() natively. Up to now, this function was emulated using
an RSA encryption, but commits ca5222ea819cc5ed797860070b4c6c1aeeb28420 and
7934c9ce2a029c43e3642a492d3b9e494d1542be (CVE-2016-0787) broke the emulation
because QC3 only supports RSA exponents up to 512 bits.
Happily, QC3 supports a native API for Diffie-Hellman computation, with
opaque random value: this commit implements the use of this API and, as a
side effect, enables support of this feature for any other crypto backend that
would use it.
A "generic" Diffie-Hellman computation internal API supports crypto backends
not implementing their own: this generic API uses the same functions as before.
* Fix typos in docs/HACKING.CRYPTO.
The new --with-crypto option replaces the previous backend-specific
--with-{openssl,libgcrypt,mbedtls,wincng} options and fixes some issues.
* libgcrypt or mbedtls would previously be used whenever found, even
if configure was passed --without-libgcrypt or --without-mbedtls.
* If --with-$backend was specified then configure would not fail even
if that library could not be found, and would instead use whichever
crypto library was found first.
The new option defaults to `auto`, which makes configure check for all
supported crypto libraries in turn, choosing the first one found, or
exiting with an error if none can be found.
