Org.BouncyCastle.Crypto.Signers.Ed25519ctxSigner
Ed25519ctx (RFC 8032 ยง5.1) signature primitive: pure Ed25519 with a domain-separation context
of up to 255 bytes captured at construction.
Construct an Ed25519ctx signer bound to the supplied context. The context
bytes are cloned so the caller may mutate the array afterwards.
Finalise the buffered message and produce the signature. Buffer is reset on return.
Length in bytes of an Ed25519ctx signature (64).
Initialise for signing (private key) or verification (public key).
Clear and rewind the buffered message; the captured context survives.
Finalise the buffered message and verify signature. Buffer is reset on
return.