Password security is a critical requirement for any organization. It is important to use complex passwords and enforce security policies to prevent unauthorized access to sensitive data. In SQL Server, one way to enhance password security is by encrypting passwords before storing them in a table. This article explores how to encrypt and decrypt passwords in SQL Server using Python scripts.

Overview of Python Language

Python is a high-level programming language that is widely used for complex data analytics and manipulations. It provides a range of libraries and modules that make it easy to perform encryption and decryption tasks. Before diving into the details of encrypting and decrypting passwords in SQL Server, it is important to have a basic understanding of the Python language.

Prerequisites

In order to follow along with the examples in this article, you will need to have Azure Data Studio SQL Notebooks installed. You will also need to have a Python 3 kernel configured in SQL Notebook. If you are not familiar with these tools, you can refer to the documentation provided by Microsoft for more information.

Cryptography in Python

Python provides a cryptography module that can be used to generate symmetric keys for encrypting and decrypting data. Symmetric key encryption involves using the same key for both encryption and decryption. This module allows you to convert plain text passwords into encrypted form (ciphertext) and later decrypt them back to plain text.

Plain Text and Ciphertext

Before we dive into the code examples, let’s understand a few key terms. Plain text refers to the original, readable text that is to be encrypted. Ciphertext, on the other hand, is the output text after applying encryption to the plain text. It is difficult to understand and remember the ciphertext without the decryption key.

Installing the Cryptography Module

In order to use the cryptography module in Python, you will need to install it using the pip command. Open SQL Notebook in Azure Data Studio and change the connection to Python 3 kernel. Then, execute the following command:

pip install cryptography

This command will install the necessary packages for encryption and decryption.

Encrypting Passwords

Once you have the cryptography module installed, you can use it to encrypt passwords before storing them in SQL Server tables. The following Python script demonstrates how to generate a symmetric key and encrypt a password:

from cryptography.fernet import Fernet

# Generate a symmetric key
key = Fernet.generate_key()
print(key)

# Encrypt the password using the symmetric key
cipher_suite = Fernet(key)
ciphered_text = cipher_suite.encrypt(b"SQLShack@DemoPass")
print(ciphered_text)

This script generates a symmetric key using the Fernet module and encrypts the password “SQLShack@DemoPass” using the generated key. The encrypted password (ciphertext) can then be stored in a SQL Server table.

Decrypting Passwords

If you need to retrieve the original password from the encrypted form, you can use the same symmetric key for decryption. The following Python script demonstrates how to decrypt the encrypted password and generate the original password:

from cryptography.fernet import Fernet

# Specify the symmetric key and encrypted password
key = b'PCHl_MjGyEyBxLYha3S-cWg_SDDmjT4YYaKYh4Z7Yug='
cipher_suite = Fernet(key)
ciphered_text = b'gAAAAABd_jcLWEz-fIBt3y2P3IoB3jGdbNnSzeSINZ8BomP9DrKIX2YF4pMLkMCvCxLshmKgKXk7np42xop6QIaiawbhjGayMU0UrbTeUX-6XA8zmo55vwA='

# Decrypt the password and generate the original password
unciphered_text = cipher_suite.decrypt(ciphered_text)
print(unciphered_text)

This script uses the same symmetric key and encrypted password from the previous example to decrypt the password and generate the original plain text password.

Conclusion

In this article, we explored how to use Python scripts to encrypt and decrypt passwords in SQL Server. By encrypting passwords before storing them in a table, you can enhance the security of your SQL Server environment. Python provides a range of libraries and modules that make it easy to perform encryption and decryption tasks. I hope this article has provided you with a useful reference for implementing password encryption in SQL Server.