go_chacha20poly1305_openssh/consts.go

package cc20p1305ssh

const (
	/*
		FullKeySize is 64, but OpenSSH only uses the first half for the (true) KeySize.
		(Normally in ChaCha20Poly1305, the second half is used for "additional data".
		OpenSSH keys do not have "additional data".)
	*/
	FullKeySize int = 64 // Generated by Poly1305...
	KeySize     int = 32 // The first 32 of which are used by ChaCha20.
	// And for clarity, aliases for the above.
	Poly1305KeySize int = FullKeySize
	ChaCha20KeySize int = KeySize
	// IvSize is 0 because OpenSSH uses a fixed internal constant (see IV).
	IvSize int = 0
	// NonceSize is literally the only reason I need to do this. The only reason.
	NonceSize int = 16
	// TagLen is the length of the Poly1305 tag.
	TagLen int = 16
)

var (
	// iv is the constant fixed IV.
	iv []byte = []byte{
		0x0, 0x0, 0x0, 0x0,
		0x0, 0x0, 0x0, 0x0,
		0x0, 0x0, 0x0, 0x0,
		0x0, 0x0, 0x0, 0x0,
	}
)