winapi::wincrypt::PFN_CRYPT_GET_SIGNER_CERTIFICATE

type PFN_CRYPT_GET_SIGNER_CERTIFICATE = Option<unsafe extern "system" fn(pvGetArg: *mut c_void, dwCertEncodingType: DWORD, pSignerId: PCERT_INFO, hMsgCertStore: HCERTSTORE) -> PCCERT_CONTEXT>;