x25519 - 0~20241004-1 main

microlibrary for the X25519 encryption system and the Ed25519 signature system,
both of which use the Curve25519 elliptic curve. Curve25519 is the fastest
curve in TLS 1.3, and the only curve in Wireguard, Signal, and many other
applications.
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lib25519 has a very simple stateless API based on the SUPERCOP API, with
wire-format inputs and outputs, providing functions that directly match the
central cryptographic operations in X25519 and Ed25519:
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lib25519_dh_keypair(pk, sk): X25519 key generation
lib25519_dh(k, pk, sk): shared-secret generation
lib25519_sign_keypair(pk, sk): Ed25519 key generation
lib25519_sign(sm, &smlen, m, mlen, sk): signing
lib25519_sign_open(m, &mlen, sm, smlen, pk): verification + message recovery
Internally, lib25519 includes implementations designed for performance on
various CPUs, implementations designed to work portably across CPUs, and
automatic run-time selection of implementations.
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lib25519 is intended to be called by larger multi-function libraries, including
libraries in other languages via FFI. The idea is that lib25519 will take
responsibility for the details of X25519/Ed25519 computation, including
optimization, timing-attack protection, and eventually verification, freeing up
the calling libraries to concentrate on application-specific needs such as
protocol integration. Applications can also call lib25519 directly.
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X25519 command line tools.