> ## Documentation Index
> Fetch the complete documentation index at: https://waasapi.uuwallet.com/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 theme={null}
  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 DecryptionExample.js theme={null}
  const RSAUtils = require('./RSAUtils');
  const JsonUtils = require('./JsonUtils');
  const Base64Util = require('./Base64Util');

  /**
  * Decryption Response Example
  *
  * Demonstrates how to decrypt and parse responses from WaaS API
  */
  class DecryptionExample {
    /**
     * Decrypts and parses API response
     * @param {string} encryptedResponse - Base64 encoded encrypted response
     * @param {string} publicKey - Base64 encoded public key
     * @returns {Object} Parsed business object
     */
    static decryptResponse(encryptedResponse, publicKey) {
        try {
            console.log('Starting decryption response example...');

            // ===================== 1. Base64 Decoding =====================
            console.log('Base64 decoding response...');
            const decodedBytes = Base64Util.decodeString(encryptedResponse);

            // ===================== 2. RSA Public Key Decryption =====================
            console.log('RSA decrypting response...');
            const decryptedBytes = RSAUtils.decryptByPublicKey(
                decodedBytes,
                publicKey
            );

            // ===================== 3. Parse Business Object =====================
            console.log('Parsing JSON response...');
            const responseObj = JsonUtils.fromJson(decryptedBytes.toString('utf8'));

            // ===================== 4. Validate and Output Results =====================
            if (!responseObj.address || typeof responseObj.address !== 'string') {
                throw new Error('API returned invalid address information');
            }

            console.log('\n✅ Successfully retrieved wallet address information:');
            console.log('------------------------');
            console.log('Tenant User ID:', responseObj.tenantUserId);
            console.log('Chain Name:   ', responseObj.chainName);
            console.log('Wallet Address:', responseObj.address);
            console.log('------------------------');

            return responseObj;
        } catch (error) {
            throw new Error(`Decryption failed: ${error.message}`);
        }
    }

    /**
     * Executes the complete example
     */
    static executeExample() {
        try {
            // Configuration parameters
            const config = {
                PUBLIC_KEY: `YOUR_PUBLIC_KEY`
            };

            // Sample encrypted response from EncryptionExample
            const encryptedResponse = 'BOvLMndpkzbXuESD5nysm7YYMYGamewDpszbfnHxVFVsllzKvaib/BlJ9Z7gxRpLqZ2O1bIg0oTPwVLqbi2pPqlAtb2cICa4rIrv80mXDoxs9ErP6DkFDDExzo6O/5ZVSd++RMDtYhXLyD6HmTSeJeZ94T34t+G1s/gYL1E0i6R0x9AyrzL7hEja0wiqobc5HVd2KjHhhVH2mxGcTGOMup/4s/3U3fd5xLBGX3pGfI4ljVLoTBITAMssG/adn5/iT0S58EcRU4GOLjMaNumh0ZxYd1fBQLNoqJ/htonmmOdV6KhO9XpvyRhMx4iXZRogNCdN+XeWFJ57HT5bLKHQ7g==';

            console.log('Starting WaaS API decryption process...');

            // Decrypt and parse response
            const responseObj = this.decryptResponse(
                encryptedResponse,
                config.PUBLIC_KEY
            );

            return responseObj;
        } catch (error) {
            console.error('\n❌ Decryption failed:', error.message);
            throw error;
        }
    }
  }

  if (require.main === module) {
    (async () => {
        try {
            await DecryptionExample.executeExample();
        } catch (error) {
            console.error('Decryption example execution failed:', error.message);
        }
    })();
  }

  module.exports = DecryptionExample;
  ```

  ```python DecryptionExample.py theme={null}
  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>