Pascal (Lazarus/Delphi)

Get Firebase Access Token from JSON Service Account Private Key

See more Firebase Examples

Demonstrates how to get a Firebase access token using a JSON service account private key. Your Firebase service account can be used to authenticate multiple Firebase features, such as Database, Storage and Auth, programmatically.

A Firebase JSON service account private key can be created in the Firebase settings/admin portion of the console.firebase.google.com site as shown here:

Scroll down to see the example code...

Pascal (Lazarus/Delphi)

program ChilkatDemo;

// Demonstrates using the Chilkat Pascal wrapper via the C bridge DLL.
// Builds as a console application under Lazarus (FPC) or Delphi.

{$IFDEF FPC}
  {$MODE DELPHI}
{$ENDIF}
{$APPTYPE CONSOLE}

uses
  {$IFDEF UNIX}
  cthreads,
  {$ENDIF}
  SysUtils,
  CkDllLoader,
  Chilkat.FileAccess,
  Chilkat.AuthGoogle,
  Chilkat.Socket;

// ---------------------------------------------------------------------------

procedure RunDemo;
var
  success: Boolean;
  fac: TFileAccess;
  jsonKey: string;
  gAuth: TAuthGoogle;
  tlsSock: TSocket;

begin
  success := False;

  //  This example requires the Chilkat API to have been previously unlocked.
  //  See Global Unlock Sample for sample code.

  //  First load the Firebase JSON private key into a string.
  fac := TFileAccess.Create;
  jsonKey := fac.ReadEntireTextFile('qa_data/firebase/firebase-chilkat-firebase-adminsdk-n28n4-1b664ee163.json','utf-8');
  if (fac.LastMethodSuccess <> True) then
    begin
      WriteLn(fac.LastErrorText);
      Exit;
    end;

  //  A Firebase JSON private key should look something like this:

  //  { 
  //    "type": "service_account",
  //    "project_id": "firebase-chilkat",
  //    "private_key_id": "1c664ee164907413c91ddefcf5b765ecba8779e2",
  //    "private_key": "-----BEGIN PRIVATE KEY-----\nMIIEvQIBA ... Ya2UZii/lXn73/ZOK8=\n-----END PRIVATE KEY-----\n",
  //    "client_email": "firebase-adminsdk-n28n4@firebase-chilkat.iam.gserviceaccount.com",
  //    "client_id": "134846322329335418431",
  //    "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  //    "token_uri": "https://accounts.google.com/o/oauth2/token",
  //    "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  //    "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/firebase-adminsdk-n28n4%40firebase-chilkat.iam.gserviceaccount.com"
  //  } 
  //  

  gAuth := TAuthGoogle.Create;
  gAuth.JsonKey := jsonKey;

  //  Choose a scope.
  //  The scope could be "https://www.googleapis.com/auth/firebase.database"
  //  or a space-delimited list of scopes:
  //  "https://www.googleapis.com/auth/firebase.database https://www.googleapis.com/auth/userinfo.email"

  gAuth.Scope := 'https://www.googleapis.com/auth/firebase.database https://www.googleapis.com/auth/userinfo.email';

  //  Request an access token that is valid for this many seconds.
  gAuth.ExpireNumSeconds := 3600;

  //  If the application is requesting delegated access:
  //  The email address of the user for which the application is requesting delegated access,
  //  then set the email address here. (Otherwise leave it empty.)
  gAuth.SubEmailAddress := '';

  //  Connect to www.googleapis.com using TLS (TLS 1.2 is the default.)
  //  The Chilkat socket object is used so that the connection can be established
  //  through proxies or an SSH tunnel if desired.
  tlsSock := TSocket.Create;
  success := tlsSock.Connect('www.googleapis.com',443,True,5000);
  if (success <> True) then
    begin
      WriteLn(tlsSock.LastErrorText);
      Exit;
    end;

  //  Send the request to obtain the access token.
  success := gAuth.ObtainAccessToken(tlsSock);
  if (success <> True) then
    begin
      WriteLn(gAuth.LastErrorText);
      Exit;
    end;

  //  Examine the access token:
  WriteLn('Firebase Access Token: ' + gAuth.AccessToken);

  //  Save the token to a file (or wherever desired).  This token is valid for 1 hour.
  fac.WriteEntireTextFile('qa_data/tokens/firebaseToken.txt',gAuth.AccessToken,'utf-8',False);


  fac.Free;
  gAuth.Free;
  tlsSock.Free;

end;

// ---------------------------------------------------------------------------

begin

  try
    RunDemo;
  except
    on E: Exception do
      WriteLn('Unhandled exception: ', E.ClassName, ': ', E.Message);
  end;

  WriteLn;
  {$IFDEF MSWINDOWS}
  WriteLn('Press Enter to exit...');
  ReadLn;
  {$ENDIF}
end.