Fixes compilation errors in functions that are syntaxic sugar
to operate on serialized scalars.
Also make it explicit that square roots in fields whose size is
not congruent to 3 modulo 4 are not an error, they are just
not implemented yet.
Reported by @vitalonodo - Thanks!
For 25519, it's very likely that applications would ever need the
serialized representation. Expose the value as an integer as in
other curves. Rename the internal representation from `field_size`
to `field_order` for consistency.
Also fix a common typo in `scalar.sub()`.
After P-256, here comes P-384, also known as secp384r1.
Like P-256, it is required for TLS, and is the current NIST recommendation for key exchange and signatures, for better or for worse.
Like P-256, all the finite field arithmetic has been computed and verified to be correct by fiat-crypto.
We already have a LICENSE file that covers the Zig Standard Library. We
no longer need to remind everyone that the license is MIT in every single
file.
Previously this was introduced to clarify the situation for a fork of
Zig that made Zig's LICENSE file harder to find, and replaced it with
their own license that required annual payments to their company.
However that fork now appears to be dead. So there is no need to
reinforce the copyright notice in every single file.
Functions generated by Fiat-crypto are not prefixed by their description any more. This matches an upstream change.
We can now use a single type for different curves and implementations.
The field type is now generic, so we can properly handle the base field and scalars without code duplication.
Uses verified code generated by fiat-crypto for field arithmetic, and complete formulas to avoid side channels.
There's still plenty of room for optimizations, especially with a fixed base. But this gives us a framework to easily add other similar curves.
