Pascal (Lazarus/Delphi)

Ibanity HTTP Signature for XS2A, Isabel Connect, Ponto Connect

See more Ibanity Examples

Demonstrates how to add a Signature header for Ibanity HTTP requests. 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.CkDateTime,
  Chilkat.Rsa,
  Chilkat.StringBuilder,
  Chilkat.JsonObject,
  Chilkat.PrivateKey,
  Chilkat.Crypt2;

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

procedure RunDemo;
var
  success: Boolean;
  json: TJsonObject;
  payload: string;
  dtNow: TCkDateTime;
  created: string;
  crypt: TCrypt2;
  sbDigestHdrValue: TStringBuilder;
  request_target: string;
  sbSigningString: TStringBuilder;
  idempotencyKey: string;
  signed_headers_list: string;
  privKey: TPrivateKey;
  rsa: TRsa;
  sigBase64: string;
  sbSigHeaderValue: TStringBuilder;

begin
  success := False;

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

  //  In order to sign your HTTP requests, you have to add 2 headers to the HTTP request: Digest: the digest of the request payload and Signature: the actual signature of the request. 

  //  POST /xs2a/customer-access-tokens HTTP/1.1
  //  Host: api.ibanity.com
  //  Content-Type: application/json
  //  Digest: SHA-512=z4PhNX7vuL3xVChQ1m2AB9Yg5AULVxXcg/SpIdNs6c5H0NE8XYXysP+DGNKHfuwvY7kxvUdBeoGlODJ6+SfaPg==
  //  Ibanity-Idempotency-Key: 61f02718-eeee-46e1-b5eb-e8fd6e799c2d
  //  Signature: keyId="62f02718-eeee-46e1-b5eb-e8fd6e799c2e",created=1599659223,algorithm="hs2019",headers="(request-target) host digest (created) ibanity-idempotency-key",signature="SjWJWbWN7i0...zsbM="
  //  
  //  {"data":{"type":"customerAccessToken", "attributes":{"applicationCustomerReference":"15874569"}}}

  //  The payload (body) of the above HTTP request is the JSON.
  //  Build the JSON above.
  //  Use this online tool to generate code from sample JSON: 
  //  Generate Code to Create JSON
  json := TJsonObject.Create;
  json.UpdateString('data.type','customerAccessToken');
  json.UpdateString('data.attributes.applicationCustomerReference','15874569');

  payload := json.Emit();
  WriteLn('payload = ' + payload);

  //  Step 1: Build the (created) virtual header

  dtNow := TCkDateTime.Create;
  dtNow.SetFromCurrentSystemTime();
  created := dtNow.GetAsUnixTimeStr(False);
  WriteLn('created = ' + created);

  //  Step 2: Build the Digest header
  crypt := TCrypt2.Create;
  crypt.HashAlgorithm := 'sha512';
  crypt.EncodingMode := 'base64';
  crypt.Charset := 'utf-8';

  sbDigestHdrValue := TStringBuilder.Create;
  sbDigestHdrValue.Append('SHA-512=');
  sbDigestHdrValue.Append(crypt.HashStringENC(json.Emit()));

  WriteLn(sbDigestHdrValue.GetAsString());

  //  Step 3: Build the (request target) virtual header

  //  In order to build the signature you will need a virtual header named (request-target) (the parentheses are important). 
  //  The (request-target) is the string concatenation of the HTTP method (in lowercase) with the path and query parameters.
  request_target := 'post /xs2a/customer-access-tokens';

  //  Step 4: Build the signing string

  //  The signing string is the concatenation of the signed header names (in lowercase) and values separated by a LF.

  //  You must always sign the following headers: (request-target), host, (created), digest. 
  //  If used, you must also sign the authorization header and any ibanity-* headers, such as ibanity-idempotency-key. 

  sbSigningString := TStringBuilder.Create;
  sbSigningString.Append('(request-target): ');
  sbSigningString.AppendLine(request_target,False);
  sbSigningString.Append('host: ');
  sbSigningString.AppendLine('api.ibanity.com',False);
  sbSigningString.Append('digest: ');
  sbSigningString.AppendLine(sbDigestHdrValue.GetAsString(),False);
  sbSigningString.Append('(created): ');
  sbSigningString.AppendLine(created,False);
  sbSigningString.Append('ibanity-idempotency-key: ');
  idempotencyKey := crypt.GenerateUuid();
  sbSigningString.Append(idempotencyKey);

  //  Step 5: Build the signed headers list

  //  To allow Ibanity to check the signed headers, you must provide a list of the header names. They should be lowercase and in the same order used to create the signing string. 
  signed_headers_list := '(request-target) host digest (created) ibanity-idempotency-key';

  //  Step 6: Build the Signature header

  //  This is where the real signing happens. The signature header is a combination of several sub-headers -
  //  
  //      keyId: the identifier for the application's signature certificate, obtained from the Developer Portal
  //      algorithm: the digital signature algorithm used to generate the signature (must be hs2019)
  //      headers: The list of HTTP headers created in step 5
  //      signature: the Base64-encoded digital signature of the signing string created in step 4.

  privKey := TPrivateKey.Create;
  success := privKey.LoadEncryptedPemFile('my_ibanity_signature_private_key.pem','pem_password');
  if (success = False) then
    begin
      WriteLn(privKey.LastErrorText);
      Exit;
    end;

  rsa := TRsa.Create;
  rsa.PssSaltLen := 32;
  rsa.EncodingMode := 'base64';
  //  Use the RSASSA-PSS signature algorithm
  rsa.PkcsPadding := False;

  success := rsa.UsePrivateKey(privKey);
  if (success = False) then
    begin
      WriteLn(rsa.LastErrorText);
      Exit;
    end;

  //  Sign the signing string.
  sigBase64 := rsa.SignStringENC(sbSigningString.GetAsString(),'sha-256');
  if (rsa.LastMethodSuccess = False) then
    begin
      WriteLn(rsa.LastErrorText);
      Exit;
    end;

  //  Build the signature header value.
  sbSigHeaderValue := TStringBuilder.Create;
  sbSigHeaderValue.Append('keyId="');
  //  Use your identifier for the application's signature certificate, obtained from the Developer Portal
  sbSigHeaderValue.Append('62f02718-eeee-46e1-b5eb-e8fd6e799c2e');
  sbSigHeaderValue.Append('",created=');
  sbSigHeaderValue.Append(created);
  sbSigHeaderValue.Append(',algorithm="hs2019",headers="');
  sbSigHeaderValue.Append(signed_headers_list);
  sbSigHeaderValue.Append('",signature="');
  sbSigHeaderValue.Append(sigBase64);
  sbSigHeaderValue.Append('"');

  WriteLn(sbSigHeaderValue.GetAsString());


  json.Free;
  dtNow.Free;
  crypt.Free;
  sbDigestHdrValue.Free;
  sbSigningString.Free;
  privKey.Free;
  rsa.Free;
  sbSigHeaderValue.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.