credentials

type AuthInfo interface {
	AuthType() string
}

type PerRPCCredentials interface {
	// GetRequestMetadata gets the current request metadata, refreshing
	// tokens if required. This should be called by the transport layer on
	// each request, and the data should be populated in headers or other
	// context. uri is the URI of the entry point for the request. When
	// supported by the underlying implementation, ctx can be used for
	// timeout and cancellation.
	// TODO(zhaoq): Define the set of the qualified keys instead of leaving
	// it as an arbitrary string.
	GetRequestMetadata(ctx context.Context, uri ...string) (map[string]string, error)
	// RequireTransportSecurity indicates whether the credentials requires
	// transport security.
	RequireTransportSecurity() bool
}

type ProtocolInfo struct {
	// ProtocolVersion is the gRPC wire protocol version.
	ProtocolVersion string
	// SecurityProtocol is the security protocol in use.
	SecurityProtocol string
	// SecurityVersion is the security protocol version.
	SecurityVersion string
	// ServerName is the user-configured server name.
	ServerName string
}

type TLSInfo struct {
	State tls.ConnectionState
}

type TransportCredentials interface {
	// ClientHandshake does the authentication handshake specified by the corresponding
	// authentication protocol on rawConn for clients. It returns the authenticated
	// connection and the corresponding auth information about the connection.
	// Implementations must use the provided context to implement timely cancellation.
	// gRPC will try to reconnect if the error returned is a temporary error
	// (io.EOF, context.DeadlineExceeded or err.Temporary() == true).
	// If the returned error is a wrapper error, implementations should make sure that
	// the error implements Temporary() to have the correct retry behaviors.
	//
	// If the returned net.Conn is closed, it MUST close the net.Conn provided.
	ClientHandshake(context.Context, string, net.Conn) (net.Conn, AuthInfo, error)
	// ServerHandshake does the authentication handshake for servers. It returns
	// the authenticated connection and the corresponding auth information about
	// the connection.
	//
	// If the returned net.Conn is closed, it MUST close the net.Conn provided.
	ServerHandshake(net.Conn) (net.Conn, AuthInfo, error)
	// Info provides the ProtocolInfo of this TransportCredentials.
	Info() ProtocolInfo
	// Clone makes a copy of this TransportCredentials.
	Clone() TransportCredentials
	// OverrideServerName overrides the server name used to verify the hostname on the returned certificates from the server.
	// gRPC internals also use it to override the virtual hosting name if it is set.
	// It must be called before dialing. Currently, this is only used by grpclb.
	OverrideServerName(string) error
}