Package errors contains common error types for the OpenPGP packages.
InvalidArgumentError indicates that the caller is in error and passed an incorrect value.
SignatureError indicates that a syntactically valid signature failed to validate.
A StructuralError is returned when OpenPGP data is found to be syntactically invalid.
UnsupportedError indicates that, although the OpenPGP data is valid, it makes use of currently unimplemented features.