Log Message:
security/ruby-ed25519: add version 1.2.4 package

Add ruby-ed25519 version 1.2.4 package.

# ed25519.rb

A Ruby binding to the Ed25519 elliptic curve public-key signature system
described in [RFC 8032].

Two implementations are provided: a MRI C extension which uses the "ref10"
implementation from the SUPERCOP benchmark suite, and a pure Java version
based on [str4d/ed25519-java].

Ed25519 is one of two notable algorithms implemented atop the Curve25519
elliptic curve. The [x25519 gem] is a related project of this one,
and implements the X25519 Diffie-Hellman key exchange algorithm on the
Montgomery form of Curve25519.

[RFC 8032]: https://tools.ietf.org/html/rfc8032
[str4d/ed25519-java]: https://github.com/str4d/ed25519-java
[x25519 gem]: https://github.com/crypto-rb/x25519