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Decrypt Text

Decrypts cipher text that was encrypted using symmetric encryption algorithms (AES or 3DES), converting it back to the original plain text. The node accepts hexadecimal-encoded cipher text and returns the decrypted plain text.

Common Properties​

  • Name - The custom name of the node.
  • Color - The custom color of the node.
  • Delay Before (sec) - Waits in seconds before executing the node.
  • Delay After (sec) - Waits in seconds after executing node.
  • Continue On Error - Automation will continue regardless of any error. The default value is false.
info

If the ContinueOnError property is true, no error is caught when the project is executed, even if a Catch node is used.

Inputs​

  • Cipher Text - The encrypted text in hexadecimal format to decrypt.
  • Key - The decryption key in hexadecimal format. Must be the same key used for encryption.
    • AES: 16, 24, or 32 bytes (128, 192, or 256 bits)
    • 3DES: 24 bytes (192 bits)

Options​

  • Decryption Algorithm - The decryption algorithm to use (must match encryption):
    • aes - Advanced Encryption Standard
    • 3Des - Triple Data Encryption Standard

Output​

  • text - The decrypted plain text in its original form.

How It Works​

The Decrypt Text node reverses the encryption process to recover the original plain text:

  1. Receives the hexadecimal cipher text and decryption key
  2. Decodes both the cipher text and key from hexadecimal format
  3. Applies the selected decryption algorithm:
    • AES: Uses ECB mode for block-by-block decryption
    • 3DES: Uses CBC mode with the initialization vector from cipher text
  4. Removes PKCS7 padding from the decrypted data
  5. Returns the original plain text

Example Usage​

Basic AES Decryption​

// Decrypt cipher text using the same key that was used for encryption
const cipherText = "3a7c2f1e4d9b8a6c5e7f2d1a4b9c8e7f3a6d2c5e8f1b4a7c9e2d5f8a1b4c7e";
const key = "a1b2c3d4e5f6g7h8i9j0k1l2m3n4o5p6q7r8s9t0u1v2w3x4y5z6a7b8c9d0e1f2";

// Use Decrypt Text node
// Output: text = "Secret password: MyP@ssw0rd123"

Decrypting User Credentials​

// Retrieve encrypted credentials from storage
const encryptedData = "7f3e9a2b8c1d4e5f6a7b8c9d0e1f2a3b4c5d6e7f8a9b0c1d2e3f4a5b6c7d8e9f";
const encryptionKey = "{{vault.encryption_key}}"; // From Robomotion Vault

// Use Decrypt Text node
// Parse the decrypted JSON
const credentials = JSON.parse(decryptedText);
// Access: credentials.username, credentials.password

Decrypting API Keys​

// Decrypt stored API key for use in API calls
const encryptedApiKey = "{{msg.encrypted_api_key}}";
const masterKey = "{{vault.master_encryption_key}}";

// Use Decrypt Text node
// Use decrypted API key in subsequent API nodes

Batch Decryption​

// Decrypt multiple encrypted values
const encryptedItems = [
  "a1b2c3d4e5f6...",
  "7f8e9d0c1b2a...",
  "3e4f5a6b7c8d..."
];

// Loop through array using ForEach node
// Decrypt each item with Decrypt Text node
// Store results in array

Requirements​

  • Valid hexadecimal cipher text
  • Correct decryption key matching the encryption key
  • Algorithm must match the one used for encryption
  • Cipher text must be properly formatted and not corrupted

Error Handling​

The node will return errors in the following cases:

  • Invalid cipher text format - Cipher text is not valid hexadecimal
  • Invalid key format - Key is not valid hexadecimal
  • Invalid key length - Key length doesn't match algorithm requirements
  • Wrong key - Decryption fails because key doesn't match
  • Corrupted data - Cipher text has been modified or corrupted
  • Algorithm mismatch - Wrong algorithm selected for the cipher text
  • Padding error - Invalid PKCS7 padding detected

Security Best Practices​

  • Protect encryption keys - Store keys securely in Robomotion Vault
  • Match algorithms - Always use the same algorithm for encryption and decryption
  • Verify data integrity - Use HMAC or hash verification to detect tampering
  • Limit key access - Only authorized flows should access decryption keys
  • Audit decryption operations - Log when sensitive data is decrypted
  • Clear memory - Don't keep decrypted sensitive data in memory longer than needed
  • Secure logging - Never log decrypted sensitive data

Common Use Cases​

  • Password Retrieval - Decrypt stored passwords for authentication
  • Data Processing - Decrypt data for processing in RPA workflows
  • Configuration Loading - Decrypt API keys and credentials from config files
  • Secure Data Exchange - Decrypt data received from external systems
  • Compliance - Decrypt data when needed for authorized access
  • Backup Recovery - Decrypt encrypted backup data

Tips for Effective Use​

  • Always use the same key that was used for encryption
  • Ensure the algorithm matches the encryption algorithm
  • Store cipher text securely - tampering will cause decryption to fail
  • Consider implementing retry logic for transient decryption errors
  • Validate decrypted data format before using it
  • Clear or overwrite decrypted sensitive data after use
  • Test decryption in development before production deployment

Troubleshooting​

Decryption Fails​

  • Verify the key - Ensure you're using the exact same key used for encryption
  • Check algorithm - Confirm algorithm matches encryption algorithm
  • Validate cipher text - Ensure cipher text hasn't been modified or corrupted
  • Test with known data - Encrypt and decrypt test data to verify setup

Unexpected Output​

  • Wrong encoding - Ensure cipher text is hexadecimal encoded
  • Partial decryption - Check for data truncation in storage/transmission
  • Character encoding issues - Verify UTF-8 encoding for text data

Performance Issues​

  • Large data - Consider using Decrypt File for large amounts of data
  • Batch operations - Process decryption in parallel when possible
  • Encrypt Text - Encrypt plain text to create cipher text
  • Decrypt File - Decrypt entire encrypted files
  • Generate Key - Generate secure encryption keys
  • Verify - Verify encrypted data hasn't been tampered with using signatures