> ## Documentation Index
> Fetch the complete documentation index at: https://xaferapi.apacx.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Decryption Operation Guide

> WaaS API Response Data Decryption Operation Guide

### c. Decryption Operation Guide

This guide details how to decrypt encrypted response data obtained from WaaS APIs.

#### i. Decryption Process Step-by-Step Explanation

The following are the steps for decryption operations:

1. Obtain <span className="text-blue-600 font-semibold"> encrypted data </span> from the API response
2. Perform <span className="text-blue-600 font-semibold"> Base64 decoding </span> of the data
3. Decrypt using the <span className="text-blue-600 font-semibold"> RSA public key </span>
4. Parse the decrypted result into the <span className="text-blue-600 font-semibold"> business object </span>

#### ii. Decryption Code Examples

<CodeGroup>
  ```java DecryptionExample.java
  class DecryptionExample {
      class AddressVO {
          private String tenantUserId;
          private String chainName;
          private String address;

          // TODO: Add getter and setter methods
      }
      public static void main(String[] args) {
          try {
              // ===================== 1. Get API response =====================
              // Send API request and get response
              APIResult<String> response = restTemplate.postForObject(
                  "https://waas2-out-api.powersafe-rel.cc/api/v1/api/user/getUserAddress",
                  httpEntity,
                  APIResult.class
              );

              // Extract encrypted data (ensure response format matches API)
              String encryptedData = response.getData();

              // ===================== 2. Base64 decoding =====================
              // Decode using Base64 utility class (implementation reference utility classes)
              byte[] decodedBytes = Base64Util.decodeString(encryptedData);

              // ===================== 3. RSA public key decryption =====================
              // Use the same public key as for requests
              String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQ...";

              // Perform RSA decryption
              byte[] decryptedBytes = RSAUtils.decryptByPublicKey(
                  decodedBytes,
                  publicKey
              );

              // ===================== 4. Parse business object =====================
              // Convert decrypted JSON data to business object
              AddressVO address = JsonUtils.fromJson(
                  new String(decryptedBytes, StandardCharsets.UTF_8),
                  AddressVO.class
              );

              // ===================== 5. Use decrypted data =====================
              System.out.println("Parsed address information:");
              System.out.println("Merchant user ID: " + address.getTenantUserId());
              System.out.println("Chain name: " + address.getChainName());
              System.out.println("Wallet address: " + address.getAddress());

          } catch (Exception e) {
              System.err.println("\nError occurred during decryption: " + e.getMessage());
              e.printStackTrace();
          }
      }
  }
  ```

  ```javascript EncryptionExample.js
  async function main() {
  try {
      // ===================== 1. Simulate getting API response =====================
      // Assume request was sent and response received
      const response = await axios.post(
          'https://waas2-out-api.powersafe-rel.cc/api/v1/api/user/getUserAddress',
          { /* Request body */ },
          { headers: { 'X-API-KEY': 'MERCHANT_123456' } }
      );

      // Get encrypted data (assume response structure is { data: "encrypted data", ... })
      const encryptedData = response.data.data;

      // ===================== 2. Base64 decoding =====================
      const decodedBytes = Base64Util.decodeString(encryptedData);

      // ===================== 3. RSA public key decryption =====================
      const publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQ...";

      // Decrypt data
      const decryptedBytes = await RSAUtils.decryptByPublicKey(
          decodedBytes.buffer,
          publicKey
      );

      // Convert to string
      const decryptedText = new TextDecoder().decode(decryptedBytes);

      // ===================== 4. Parse business object =====================
      // Deserialize to AddressVO instance using JsonUtils
      const address = JsonUtils.fromJson(decryptedText, AddressVO);

      // ===================== 5. Use decrypted data =====================
      console.log("Parsed address information:");
      console.log("Merchant user ID: " + address.getTenantUserId());
      console.log("Chain name: " + address.getChainName());
      console.log("Wallet address: " + address.getAddress());

  } catch (error) {
      console.error("\nError occurred during decryption: " + error.message);
      console.error(error.stack);
  }
  }

  // Execute main function
  main();
  ```

  ```python EncryptionExample.py
  import requests
  from JsonUtils import JsonUtils
  from RSAUtils import RSAUtils
  from Base64Util import Base64Util

  def main():
  try:
      # ===================== 1. Simulate getting API response =====================
      # Assume request was sent and response received
      response = requests.post(
          'https://waas2-out-api.powersafe-rel.cc/api/v1/api/user/getUserAddress',
          data={},
          headers={'X-API-KEY': 'MERCHANT_123456'}
      )

      # Parse JSON response and get encrypted data
      response_data = response.json()
      encrypted_data = response_data['data']

      # ===================== 2. Base64 decoding =====================
      decoded_bytes = Base64Util.decode_string(encrypted_data)

      # ===================== 3. RSA public key decryption =====================
      public_key = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQ..."
      decrypted_bytes = RSAUtils.decrypt_by_public_key(
          decoded_bytes,
          public_key
      )

      # Convert to string
      decrypted_text = decrypted_bytes.decode('utf-8')

      # ===================== 4. Parse business object =====================
      # Deserialize to AddressVO instance using JsonUtils
      address_data = JsonUtils.from_json(decrypted_text)
      address = AddressVO(address_data)

      # ===================== 5. Use decrypted data =====================
      print("\nParsed address information:")
      print("Merchant user ID:", address.get_tenant_user_id())
      print("Chain name:", address.get_chain_name())
      print("Wallet address:", address.get_address())

  except Exception as e:
      print("\nError occurred during decryption:", str(e))
      import traceback
      traceback.print_exc()

  if __name__ == "__main__":
  main();
  ```
</CodeGroup>