* 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.
Build procedure extproto() did not strip braces from header files, thus
possibly prepended them to true prototypes. This prevented the prototype to
be recognized as such.
The solution implemented here is to map braces to semicolons, effectively
considering them as potential prototype delimiters.
In addition, file os400/macros.h declares all procedures originally
defined as macros. It must not be used for real inclusion and is only
intended to be used as a `database' for macro wrapping procedures generation.
