Function gpgme_sys::gpgme_op_revsig_start

pub unsafe extern "C" fn gpgme_op_revsig_start(
    ctx: gpgme_ctx_t,
    key: gpgme_key_t,
    signing_key: gpgme_key_t,
    userid: *const c_char,
    flags: c_uint
) -> gpgme_error_t