MultipartSigned.sign

gmime.multipart_signed.MultipartSigned sign(gmime.crypto_context.CryptoContext ctx,  gmime.object.ObjectWrap entity,  string userid)

Attempts to sign the content MIME part with userid's private key using the ctx signing context. If successful, a new multipart/signed object is returned.

Parameters

`ctx`	a #GMimeCryptoContext
`entity`	MIME part to sign
`userid`	user id to sign with

Returns

a new #GMimeMultipartSigned object on success

or null on fail. If signing fails, an exception will be set on err to provide information as to why the failure occurred.

Throws

[ErrorWrap]