cipher_canonical_to_stream

Writes a part to a stream in a canonicalised format, suitable for signing/encrypting.

The transfer encoding paramaters for the part may be changed by this function.

Parameters:

part	Part to write.
flags	flags for the canonicalisation filter (CamelMimeFilterCanon)
ostream	stream to write canonicalised output to.
cancellable	optional Cancellable object, or null

Returns:

-1 on error;