signature/s:
Algorithm Before After
---------------+---------+-------
ecdsa-p256 3707 4396
ecdsa-p384 1067 1332
ecdsa-secp256k1 4490 5147
Add ECDSA to the benchmark by the way.
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!
Most of this migration was performed automatically with `zig fmt`. There
were a few exceptions which I had to manually fix:
* `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten
* `@truncate`'s fixup is incorrect for vectors
* Test cases are not formatted, and their error locations change
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.