Dart Requires Chilkat v11.0.0+

Ibanity HTTP Signature for XS2A, Isabel Connect, Ponto Connect

See more Ibanity Examples

Demonstrates how to add a Signature header for Ibanity HTTP requests. Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // 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
  final json = CkJsonObject();
  json.updateString('data.type', 'customerAccessToken');
  json.updateString('data.attributes.applicationCustomerReference', '15874569');

  final payload = json.emit();
  print('payload = $payload');

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

  final dtNow = CkDateTime();
  dtNow.setFromCurrentSystemTime();
  final created = dtNow.getAsUnixTimeStr(false);
  print('created = $created');

  // Step 2: Build the Digest header
  final crypt = CkCrypt2();
  crypt.hashAlgorithm = 'sha512';
  crypt.encodingMode = 'base64';
  crypt.charset = 'utf-8';

  final sbDigestHdrValue = CkStringBuilder();
  sbDigestHdrValue.append('SHA-512=');
  sbDigestHdrValue.append(crypt.hashStringENC(json.emit()));

  print(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.
  final requestTarget = '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. 

  final sbSigningString = CkStringBuilder();
  sbSigningString.append('(request-target): ');
  sbSigningString.appendLine(requestTarget, 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: ');
  final 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. 
  final signedHeadersList = '(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.

  final privKey = CkPrivateKey();
  try {
    privKey.loadEncryptedPemFile('my_ibanity_signature_private_key.pem', 'pem_password');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final rsa = CkRsa();
  rsa.pssSaltLen = 32;
  rsa.encodingMode = 'base64';
  // Use the RSASSA-PSS signature algorithm
  rsa.pkcsPadding = false;

  try {
    rsa.usePrivateKey(privKey);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Sign the signing string.
  final String sigBase64;
  try {
    sigBase64 = rsa.signStringENC(sbSigningString.getAsString(), 'sha-256');
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  // Build the signature header value.
  final sbSigHeaderValue = CkStringBuilder();
  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(signedHeadersList);
  sbSigHeaderValue.append('",signature="');
  sbSigHeaderValue.append(sigBase64);
  sbSigHeaderValue.append('"');

  print(sbSigHeaderValue.getAsString());
}