CallbackForPassword implements https://godoc.org/golang.org/x/crypto/openpgp#PromptFunction.

CopyMetadata copies custom meta data from a remote object to another.

CopyObject copies a remote object to a different remote key.

CreateMetadata create metadata to be stored along with GCS objects.

DecryptBytes decrypts and verifies a byte sequence.

EncryptBytes encrypts and signs a byte sequence.

GetUserPassword promtps for a user password to decrypt private keys.

LoadArmoredKey loads an armored GPG keys from local disk.

QueryStorage queries the remote storage to find keys.

ReadMetadata reads remote metadata for an object.

ReadObject reads a remote object.

RemoveObject removes an object from remote storage.

WriteMetadata writes a set of tags on a remote object.

WriteObject write a byte sequence to remote storage.