anchor.diff:  %% @doc The underlying implementation of {@link grpca:sign_provider_req/2}.
   %% ====================================================================
   -spec sign_provider_req_imp(ProviderId :: binary(), CSRPem :: binary(),
  -                            CaDir :: string()) -> {ok, Pem :: binary()}.
  +    CaDir :: string()) -> {ok, Pem :: binary()}.
   %% ====================================================================
   sign_provider_req_imp(ProviderId, CSRPem, CaDir) ->
       TmpDir = mochitemp:mkdtemp(),
  
positive.code: %% @doc The underlying implementation of {@link grpca:verify_provider_imp/1}.
  %% ====================================================================
  -spec verify_provider_imp(PeerCertDer :: public_key:der_encoded(),
                            CaDir :: string()) -> {ok, ProviderId :: binary()}.
  %% ====================================================================
  verify_provider_imp(PeerCertDer, CaDir) -> %% @todo: CRLs
      CaCertFile = cacert_path(CaDir),
  
negative.code: 
      ?info("~s", [RequestOutput]),
      ?info("Signing the Global Resistry REST interface CSR..."),
  
      ?dump(CaConfigFile),
      ?dump(CSRFile),
      ?dump(CertPath),
  
      SigningOutput = os:cmd(["openssl ca",
          " -config ", CaConfigFile,
  