This code was part of Dolphin's relicensing from v2 to v2+ a while back,
we just never updated these copyright headers. I double-checked that
segher gave us permission to relicense this code to v2+ on 2015-05-16.
SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
UNUSED is quite a generic macro name and has potential to clash with
other libraries, so rename it to DOLPHIN_UNUSED to prevent that, as well
as make its naming consistent with the force inline macro
Instead of globbing things under an ambiguous Common.h header, move
compiler-specifics over to Compiler.h. This gives us a dedicated home
for anything related to compilers that we want to make functional across
all compilers that we support.
This moves us a little closer to eliminating Common.h entirely.
This makes it easier to generate random numbers or fill a buffer with
random data in a cryptographically secure way.
This also replaces existing usages of RNG functions in the codebase:
* <random> is pretty hard to use correctly, and std::random_device does
not give enough guarantees about its results (it's
implementation-defined, non cryptographically secure and could be
deterministic on some platforms).
Doing things correctly is error prone and verbose.
* rand() is terrible and should not be used especially in crypto code.
- Move all of the ec functions into the Common::ec namespace.
- Give the public functions better names and some usage information.
- Move all of the "elt" related functions into an "elt" class including
all of the arithmetic operations, so that the logic becomes clearer
and feels less like assembly.
This also makes it much more obvious what the parameters are, instead
of only using unsigned char* (which doesn't tell anything about what
the pointer is used for or the size).
- Similarly, add a new "Point" class and move point functions there.
Overload the arithmetic operators to make calculations easier to read
