a #GMimeCryptoContext
MIME part to encrypt
true if the content should also be signed or false otherwise
user id to use for signing (only used if sign is true)
a #GMimeEncryptFlags
an array of recipients to encrypt to
a new #GMimeMultipartEncrypted object on success or null on fail. If encrypting fails, an exception will be set on err to provide information as to why the failure occurred.
Attempts to encrypt (and conditionally sign) the entity MIME part to the public keys of recipients using the ctx encryption context. If successful, a new multipart/encrypted object is returned.