Create passwordmanager.py

passwordmanager/passwordmanager.py

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+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC
+from cryptography.hazmat.primitives import hashes
+from cryptography.fernet import Fernet
+import base64
+import csv
+import os
+import getpass
+
+# Step 1: Derive encryption key from master password
+def derive_key_from_password(master_password, salt):
+    # PBKDF2 with SHA-256
+    kdf = PBKDF2HMAC(
+        algorithm=hashes.SHA256(),
+        length=32,
+        salt=salt,
+        iterations=100000,
+        backend=default_backend()
+    )
+    key = base64.urlsafe_b64encode(kdf.derive(master_password.encode()))
+    return key
+
+# Step 2: Encrypt the password
+def encrypt_password(password, key):
+    fernet = Fernet(key)
+    encrypted_password = fernet.encrypt(password.encode())
+    return encrypted_password
+
+# Step 3: Decrypt the password
+def decrypt_password(encrypted_password, key):
+    fernet = Fernet(key)
+    decrypted_password = fernet.decrypt(encrypted_password).decode()
+    return decrypted_password
+
+# Step 4: Store encrypted password in CSV file
+def store_password(site, username, password, master_password):
+    salt = os.urandom(16)  # Random salt for key derivation
+    key = derive_key_from_password(master_password, salt)
+    encrypted_password = encrypt_password(password, key)
+
+    with open('passwords.csv', mode='a', newline='') as file:
+        writer = csv.writer(file)
+        writer.writerow([site, username, encrypted_password.decode(), base64.b64encode(salt).decode()])
+
+# Step 5: Retrieve and decrypt password from CSV file
+def retrieve_password(site, username):
+    # Ask for master password at the time of retrieval
+    master_password = getpass.getpass("Enter your master password: ")
+
+    with open('passwords.csv', mode='r') as file:
+        reader = csv.reader(file)
+        for row in reader:
+            if row[0] == site and row[1] == username:
+                encrypted_password = row[2].encode()
+                salt = base64.b64decode(row[3].encode())
+                key = derive_key_from_password(master_password, salt)
+                try:
+                    decrypted_password = decrypt_password(encrypted_password, key)
+                    return decrypted_password
+                except Exception as e:
+                    print(f"Error decrypting password: {e}")
+                    return None
+    return None
+
+# Step 6: Menu-driven application for user interaction
+def menu():
+    while True:
+        print("\nPassword Manager")
+        print("1. Store new password")
+        print("2. Retrieve password")
+        print("3. Exit")
+        choice = input("Enter your choice: ")
+
+        if choice == '1':
+            # For storing passwords, master password is asked once
+            master_password = getpass.getpass("Enter your master password: ")
+            site = input("Enter the website or application name: ")
+            username = input("Enter your username: ")
+            password = input("Enter your password: ")
+            store_password(site, username, password, master_password)
+            print(f"Password for {site} saved.")
+
+        elif choice == '2':
+            # For retrieving, master password is asked every time
+            site = input("Enter the website or application name: ")
+            username = input("Enter your username: ")
+            password = retrieve_password(site, username)
+            if password:
+                print(f"Password for {site}: {password}")
+            else:
+                print(f"No password found for {site} with username {username}.")
+
+        elif choice == '3':
+            print("Exiting...")
+            break
+
+        else:
+            print("Invalid choice. Please try again.")
+
+# Run the password manager
+if __name__ == "__main__":
+    menu()