signature

func Sign(
	src io.Reader,
	isRegular bool,
	signatureFormat string,
	identity interface{},
) (io.Reader, func() (string, error), error)

func SignHeader(
	hdr *tar.Header,
	isRegular bool,
	signatureFormat string,
	identity interface{},
) error

func SignString(
	src string,
	isRegular bool,
	signatureFormat string,
	identity interface{},
) (string, error)

func Verify(
	src io.Reader,
	isRegular bool,
	signatureFormat string,
	recipient interface{},
	signature string,
) (io.Reader, func() error, error)

func VerifyHeader(
	hdr *tar.Header,
	isRegular bool,
	signatureFormat string,
	recipient interface{},
) error

func VerifyString(
	src string,
	isRegular bool,
	signatureFormat string,
	recipient interface{},
	signature string,
) error