ASET - Egyptian Tax Authority APIs implementation

Introduction

ASET is a .NET library that implements the invoicing SDK of the Egyptian Tax Authority.

This project is in the early development stage, you're welcome to contribute.

Disclaimer

This library is NOT an official release of ETA, we neither have a relationship with them nor with any sponsoring authority, however, this library will adhere to the official ETA API instructions.

Usage guide

1. Token

A static class used for master token generation and manipulation.

HttpClient

The token class has a singleton HttpClient which serves the purpose of the whole application, it is strongly recommended not to dispose it for the lifetime of the application that uses the library.

Disposing the HttpClient will cause it re-initialized each time a transaction occurs against the API portal, which may - and possibly will - cause a socket exhaustion, so disposing of it should be at the very end of the respective application life.

Token Generation

First, you need to create a class that implements the ISecretVault interface, which is used to get user data such as client ID and client secrets:

• ISecretVault definition

  public interface ISecretVault
  {
      Task<string> GetClientId();
      Task<string> GetClientSecret1();
      Task<string> GetClientSecret2();
  }

• Implementation might look like this snippet

  ///Tip: User data should be encrypted, and then decrypted and retrieved by this class.
  internal class SecretVault : ISecretVault
  {
      private FrmMain fm = Program.fm;
  
      public Task<string> GetClientId()
      {
          var c = fm.txtClientId.Text.Trim(); 
          return Task.FromResult(c);
      }
  
      public Task<string> GetClientSecret1()
      {
          var c = fm.txtClientSecret1.Text.Trim();
          return Task.FromResult(c);
      }
  
      public Task<string> GetClientSecret2()
      {
          throw new NotImplementedException();
      }
  }

  The idea behind the scenes is that the user data is extremely confidential and should be encrypted, a good perspective might be encrypting it using symmetric or asymmetric algorithms and using the implementation to decrypt it, thus passing it to the token securely.

• Configuring and generating a token

  SecretVault s = new SecretVault(); //Create a SecretVault
  Token.Environment = EtEnvironment.PreProduction; //Set ETA Environment
  await Token.GenerateAsync(); //Generate a new token

  Note: EtEnvironment is a public enum in the namespace ASET.Core that holds the environment modes that ETA supports:

  public enum EtEnvironment { PreProduction, SIT, Production }

• Get token value

  If the token is generated without exceptions, then you can get its value like this:

  txtToken.Text = Token.Value

  Also, there are some helpful properties you might want to use:

  lblEnvironment.Text = Token.Environment.ToString();
  txtToken.Text = Token.Value ?? string.Empty;
  lblTokenTimestamp.Text = Token.GenerationTime?.ToString() ?? "N/A";
  lblTokenLiveTime.Text = Token.ExpireIn?.ToString() ?? "N/A";
  lblTokenExpiry.Text = Token.ExpiryTime?.ToString() ?? "N/A";

Token destruction

You can erase all token data by calling Token.Destroy()

Note: by calling the preceding method, the related HttpClient is not disposed and must be disposed manually by calling Token.HttpClient.Dispose().

Token events

There is a bunch of useful token events you can subscribe to:

1. TokenGenerating: Occurs right before the token is successfully generated.
2. TokenGenerated: Occurs after the token is successfully generated.
3. TokenDestroyed: Occurs after the token is destroyed by the user.
4. LifeSpanChanged: Fires each second passed from the lifetime of the generated token.

Documentation

Documentation is currently under development, the link will be stated here once available.