| Argument | Description | 
|---|
    | libhandle | DKIM library instance handle, returned by
        an earlier call to dkim_init(). | 
    | id | An opaque, printable string for identifying this message,
            suitable for use in logging or debug output. | 
    | memclosure | Opaque memory closure, passed directly to the caller-provided
            malloc() and/or free() replacement functions. | 
    | secretkey | The private key to be used when signing this message.  This
	must be a NULL-terminated string containing either a PEM-formatted
	private key, or a DER-formatted private key after being encoded
	with base64. | 
    | selector | The name of the selector to be reported in the signature on this
        message. | 
    | domain | The domain doing the signing; this will be the domain whose DNS
        will be queried by the verifier for key data. | 
    | hdrcanon_alg | The canonicalization algorithm to use when preparing the headers
	of this message for signing. | 
    | bodycanon_alg | The canonicalization algorithm to use when preparing the body
	of this message for signing. | 
    | sign_alg | The signing algorithm to use when generating the signature
        to be attached to this message. | 
    | length | The number of bytes of the body to sign.  A value of -1
        will cause the entire message to be signed. | 
    | statp | Pointer to a DKIM_STAT
            object which receives the completion status of this operation. |