Signature Generation

Follow the steps below to generate your signature:

Retrieve your clientId (one which you are passing through the header X-Client-Id)
Append this with CURRENT UNIX timestamp separated by a period (.)
Encrypt this data using RSA encrypt with Public key you received – this is the signature.
Pass this signature through the header X-Cf-Signature.

In the case of using our library, go through the libraries section. During the initialization process, you need to pass the key as a parameter.

<?php
public static function getSignature() {
    $clientId = "<your clientId here>";
    $publicKey =
openssl_pkey_get_public(file_get_contents("/path/to/certificate/public
_key.pem"));
    $encodedData = $clientId.".".strtotime("now");
    return static::encrypt_RSA($encodedData, $publicKey);
  }
private static function encrypt_RSA($plainData, $publicKey) { if (openssl_public_encrypt($plainData, $encrypted, $publicKey,
OPENSSL_PKCS1_OAEP_PADDING))
      $encryptedData = base64_encode($encrypted);
    else return NULL;
    return $encryptedData;
  }
?>

private static String generateEncryptedSignature(String clientIdWithEpochTimestamp) {
    // String clientIdWithEpochTimeStamp = clientId+"."+Instant.now().getEpochSecond();
    String encrytedSignature = "";
    try {
        byte[] keyBytes = Files
            .readAllBytes(new File("/Users/sameera/Downloads/payout_test_public_key.pem").toPath()); // Absolute Path to be replaced
        String publicKeyContent = new String(keyBytes);
        System.out.println(publicKeyContent);
        publicKeyContent = publicKeyContent.replaceAll("[\\t\\n\\r]", "")
            .replace("-----BEGIN PUBLIC KEY-----", "").replace("-----END PUBLIC KEY-----", "");
        KeyFactory kf = KeyFactory.getInstance("RSA");
        System.out.println(publicKeyContent);
        X509EncodedKeySpec keySpecX509 = new X509EncodedKeySpec(
            Base64.getDecoder().decode(publicKeyContent));
        RSAPublicKey pubKey = (RSAPublicKey) kf.generatePublic(keySpecX509);
        final Cipher cipher = Cipher.getInstance("RSA/ECB/OAEPWithSHA-1AndMGF1Padding");
        cipher.init(Cipher.ENCRYPT_MODE, pubKey);
        encrytedSignature = Base64.getEncoder().encodeToString(cipher.doFinal(clientIdWithEpochTimestamp.getBytes()));
        System.out.println(encrytedSignature);
    } catch (Exception e) {
        e.printStackTrace();
    }
    return encrytedSignature;
}