Specifies an opaque user context pointer to be passed to the
DNS callback set by
||dkim_set_user_context() can be called at any time prior to
DNS operations while verifying.
||Message-specific signing handle, returned by
Note that since DNS operations only take place while verifying,
this is really only meaningful in the latter case.
||A pointer to a user-generated context handle referencing
data specific to the message being signed or verified by the
handle provided above.
- The context pointer, if set, will be passed as-is to the DNS callback,
if any. It can also be retrieved by the caller at any time using the