Code for How to Build a Password Manager in Python Tutorial
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password_manager.py
import json, hashlib, getpass, os, pyperclip, sys
from cryptography.fernet import Fernet
# Function for Hashing the Master Password.
def hash_password(password):
sha256 = hashlib.sha256()
sha256.update(password.encode())
return sha256.hexdigest()
# Generate a secret key. This should be done only once as you'll see.
def generate_key():
return Fernet.generate_key()
# Initialize Fernet cipher with the provided key.
def initialize_cipher(key):
return Fernet(key)
# Function to encrypt a password.
def encrypt_password(cipher, password):
return cipher.encrypt(password.encode()).decode()
# Function to decrypt a password.
def decrypt_password(cipher, encrypted_password):
return cipher.decrypt(encrypted_password.encode()).decode()
# Function to register you.
def register(username, master_password):
# Encrypt the master password before storing it
hashed_master_password = hash_password(master_password)
user_data = {'username': username, 'master_password': hashed_master_password}
file_name = 'user_data.json'
if os.path.exists(file_name) and os.path.getsize(file_name) == 0:
with open(file_name, 'w') as file:
json.dump(user_data, file)
print("\n[+] Registration complete!!\n")
else:
with open(file_name, 'x') as file:
json.dump(user_data, file)
print("\n[+] Registration complete!!\n")
# Function to log you in.
def login(username, entered_password):
try:
with open('user_data.json', 'r') as file:
user_data = json.load(file)
stored_password_hash = user_data.get('master_password')
entered_password_hash = hash_password(entered_password)
if entered_password_hash == stored_password_hash and username == user_data.get('username'):
print("\n[+] Login Successful..\n")
else:
print("\n[-] Invalid Login credentials. Please use the credentials you used to register.\n")
sys.exit()
except Exception:
print("\n[-] You have not registered. Please do that.\n")
sys.exit()
# Function to view saved websites.
def view_websites():
try:
with open('passwords.json', 'r') as data:
view = json.load(data)
print("\nWebsites you saved...\n")
for x in view:
print(x['website'])
print('\n')
except FileNotFoundError:
print("\n[-] You have not saved any passwords!\n")
# Load or generate the encryption key.
key_filename = 'encryption_key.key'
if os.path.exists(key_filename):
with open(key_filename, 'rb') as key_file:
key = key_file.read()
else:
key = generate_key()
with open(key_filename, 'wb') as key_file:
key_file.write(key)
cipher = initialize_cipher(key)
# Function to add (save password).
def add_password(website, password):
# Check if passwords.json exists
if not os.path.exists('passwords.json'):
# If passwords.json doesn't exist, initialize it with an empty list
data = []
else:
# Load existing data from passwords.json
try:
with open('passwords.json', 'r') as file:
data = json.load(file)
except json.JSONDecodeError:
# Handle the case where passwords.json is empty or invalid JSON.
data = []
# Encrypt the password
encrypted_password = encrypt_password(cipher, password)
# Create a dictionary to store the website and password
password_entry = {'website': website, 'password': encrypted_password}
data.append(password_entry)
# Save the updated list back to passwords.json
with open('passwords.json', 'w') as file:
json.dump(data, file, indent=4)
# Function to retrieve a saved password.
def get_password(website):
# Check if passwords.json exists
if not os.path.exists('passwords.json'):
return None
# Load existing data from passwords.json
try:
with open('passwords.json', 'r') as file:
data = json.load(file)
except json.JSONDecodeError:
data = []
# Loop through all the websites and check if the requested website exists.
for entry in data:
if entry['website'] == website:
# Decrypt and return the password
decrypted_password = decrypt_password(cipher, entry['password'])
return decrypted_password
return None
# Infinite loop to keep the program running until the user chooses to quit.
while True:
print("1. Register")
print("2. Login")
print("3. Quit")
choice = input("Enter your choice: ")
if choice == '1': # If a user wants to register
file = 'user_data.json'
if os.path.exists(file) and os.path.getsize(file) != 0:
print("\n[-] Master user already exists!!")
sys.exit()
else:
username = input("Enter your username: ")
master_password = getpass.getpass("Enter your master password: ")
register(username, master_password)
elif choice == '2': # If a User wants to log in
file = 'user_data.json'
if os.path.exists(file):
username = input("Enter your username: ")
master_password = getpass.getpass("Enter your master password: ")
login(username, master_password)
else:
print("\n[-] You have not registered. Please do that.\n")
sys.exit()
# Various options after a successful Login.
while True:
print("1. Add Password")
print("2. Get Password")
print("3. View Saved websites")
print("4. Quit")
password_choice = input("Enter your choice: ")
if password_choice == '1': # If a user wants to add a password
website = input("Enter website: ")
password = getpass.getpass("Enter password: ")
# Encrypt and add the password
add_password(website, password)
print("\n[+] Password added!\n")
elif password_choice == '2': # If a User wants to retrieve a password
website = input("Enter website: ")
decrypted_password = get_password(website)
if website and decrypted_password:
# Copy password to clipboard for convenience
pyperclip.copy(decrypted_password)
print(f"\n[+] Password for {website}: {decrypted_password}\n[+] Password copied to clipboard.\n")
else:
print("\n[-] Password not found! Did you save the password?"
"\n[-] Use option 3 to see the websites you saved.\n")
elif password_choice == '3': # If a user wants to view saved websites
view_websites()
elif password_choice == '4': # If a user wants to quit the password manager
break
elif choice == '3': # If a user wants to quit the program
break
