package cybersecurity

import "crypto/ed25519"

// SignEd25519 signs msg with an Ed25519 private key and returns the 64-byte signature.
// priv must be a valid Ed25519 private key (64 bytes as returned by GenerateIdentity or ed25519.GenerateKey).
// This function is pure: same inputs always produce the same output (ed25519 is deterministic).
func SignEd25519(priv, msg []byte) []byte {
	return ed25519.Sign(ed25519.PrivateKey(priv), msg)
}