userdb

type UserDB interface {
	// Exists returns true iff the user identified by the username exists.
	Exists([]byte) bool

	// IsValid returns true iff the user identified by the username and
	// public key is valid.
	IsValid([]byte, *ecdh.PublicKey) bool

	// Link returns the user's link layer authentication key.
	Link([]byte) (*ecdh.PublicKey, error)

	// Add adds the user identified by the username and public key
	// to the database.  Existing users will have their public keys
	// updated if specified, otherwise an error will be returned.
	Add([]byte, *ecdh.PublicKey, bool) error

	// SetIdentity sets the optional identity key for the user identified
	// by the user name to the provided public key.  Providing a nil key
	// will remove the user's identity key iff it exists.
	SetIdentity([]byte, *ecdh.PublicKey) error

	// Identity returns the optional identity key for the user identified
	// by the user name.
	Identity([]byte) (*ecdh.PublicKey, error)

	// Remove removes the user identified by the username from the database.
	Remove([]byte) error

	// Close closes the UserDB instance.
	Close()
}