Type Definition winapi::um::wincrypt::PFN_CMSG_GEN_CONTENT_ENCRYPT_KEY

type PFN_CMSG_GEN_CONTENT_ENCRYPT_KEY = Option<unsafe extern "system" fn(pContentEncryptInfo: PCMSG_CONTENT_ENCRYPT_INFO, dwFlags: DWORD, pvReserved: *mut c_void) -> BOOL>;