In the modern digital landscape, safeguarding sensitive information, particularly passwords, is paramount. Password managers play a vital role in securely storing and managing credentials for various online services. This case study explores the development of a password manager using Python and the Fernet encryption library, exemplifying how to create a user-friendly command-line tool for storing and retrieving passwords.
from cryptography.fernet import Fernet
import json
PASSWORD_FILE = "passwords.json"
MASTER_PASSWORD = "YourMasterPassword"
def generate_key():
return Fernet.generate_key()
def encrypt_password(key, password):
cipher_suite = Fernet(key)
return cipher_suite.encrypt(password.encode()).decode()
def decrypt_password(key, encrypted_password):
cipher_suite = Fernet(key)
return cipher_suite.decrypt(encrypted_password.encode()).decode()
def read_passwords():
try:
with open(PASSWORD_FILE, "r") as file:
data = json.load(file)
return data
except FileNotFoundError:
return {}
def write_passwords(passwords):
with open(PASSWORD_FILE, "w") as file:
json.dump(passwords, file)
def add_password(master_password, website, username, password):
key = master_password.encode()
passwords = read_passwords()
encrypted_password = encrypt_password(key, password)
passwords[website] = {
"username": username,
"password": encrypted_password
}
write_passwords(passwords)
def get_password(master_password, website):
key = master_password.encode()
passwords = read_passwords()
if website in passwords:
encrypted_password = passwords[website]["password"]
return decrypt_password(key, encrypted_password)
else:
return None
def main():
print("Password Manager")
master_password = input("Enter your master password: ")
while True:
print("\n1. Add a new password")
print("2. Retrieve a password")
print("3. Exit")
choice = input("Enter your choice (1/2/3): ")
if choice == "1":
website = input("Enter the website or service name: ")
username = input("Enter your username: ")
password = input("Enter your password: ")
add_password(master_password, website, username, password)
print("Password added successfully!")
elif choice == "2":
website = input("Enter the website or service name: ")
password = get_password(master_password, website)
if password:
print(f"Password for {website}: {password}")
else:
print("Password not found.")
elif choice == "3":
break
else:
print("Invalid choice. Please try again.")
if __name__ == "__main__":
main()Output:
Code Overview
The provided Python code comprises a collection of functions and a command-line interface (CLI) for users to interact with the password manager. Here’s an overview of its key components:
1. Password Encryption
The core of the password manager relies on the Fernet encryption library to encrypt and decrypt sensitive passwords. These functions facilitate secure storage and retrieval:
generate_key(): Generates a Fernet key, which is a secure encryption key, for encrypting and decrypting passwords.encrypt_password(key, password): Encrypts a plaintext password using the Fernet key, ensuring the stored data remains confidential.decrypt_password(key, encrypted_password): Decrypts an encrypted password, allowing the user to retrieve the original plaintext password securely.
2. Password Storage
The password manager maintains a JSON file, passwords.json, to store encrypted passwords. These functions manage the storage and retrieval of password data:
read_passwords(): Reads and loads encrypted password data frompasswords.json. If the file does not exist, it returns an empty dictionary.write_passwords(passwords): Writes the encrypted password data back topasswords.json, updating the stored passwords.
3. User Interaction
The code provides a straightforward command-line interface (CLI) for users to interact with the password manager. Users can perform the following actions:
- Add a New Password: Users can input a website or service name, a username, and a password. The password manager encrypts and stores these credentials in
passwords.json. - Retrieve a Password: Users can input a website or service name to retrieve the associated password securely. The password manager decrypts and presents the original password to the user.
- Exit: Users can exit the program when they have completed their actions.
Functionality
The password manager, though simple in design, offers fundamental functionalities for secure password management:
1. Password Storage
Users can securely store their passwords for various websites and services, knowing that the data is encrypted using Fernet encryption.
2. Password Retrieval
Users can conveniently retrieve their stored passwords when needed, ensuring easy access to their credentials without compromising security.
Conclusion
In summary, this case study has introduced a basic password manager developed using Python and the Fernet encryption library. While the code represents a foundational implementation, it serves as a starting point for building more advanced password management applications with additional features.
Further Enhancements:
The password manager application can be expanded and improved in various ways:
1. Stronger Authentication
Implement stronger user authentication mechanisms, such as requiring a master password and using multi-factor authentication for enhanced security.
2. Password Generator
Incorporate a password generator feature that creates strong, random passwords to enhance security.
3. Password Policies
Enforce password policies, such as minimum length and character requirements, to ensure that stored passwords are secure.
4. Backup and Recovery
Introduce backup and recovery options to prevent data loss in case of accidental deletion or system failure.
5. Cross-Platform Support
Extend the password manager to support multiple platforms, including mobile devices, to enable seamless access to stored credentials.
6. Cloud Synchronization
Implement cloud synchronization to securely store and access passwords across multiple devices.
7. Password Expiry
Introduce password expiration and reminders to prompt users to update their passwords regularly.
This case study provides a glimpse into the world of password management applications and illustrates how to create a secure foundation for safeguarding sensitive credentials. The journey to building a robust and user-friendly password manager is ripe with opportunities for enhancement and customization to meet the evolving needs of users.
