Password hash in python

published on: 2025/03/28 by: irfan

categories: CYBERNETICS

keywords: Password Hash Python

Using a strong hashing mechanism like bcrypt can help protect user data. However, remember that no solution is entirely bulletproof, so always follow best practices in security. Additionally, consider using HTTPS to secure the communication between your application and the database.

How to do a password hash in python, for user authentication and for storage in a user database?

Creating a secure password hashing mechanism is crucial when storing passwords in a database to protect them from unauthorized access. In Python, you can use the bcrypt library, which provides bcrypt-based password hashing.

Here’s how you can set up and use bcrypt for both generating hashed passwords during user registration and verifying stored passwords during authentication:

Step 1: Install the Required Library

First, install the bcrypt library if you haven't already. You can do this using pip: `sh pip install bcrypt `

Step 2: Generate Hashed Passwords During User Registration

When a user registers and provides their password, you generate a hashed version of that password.

Example Code:

import bcrypt

def hash_password(password):
    # Convert the plain text password to bytes (bcrypt requires bytes)
    password_bytes = password.encode('utf-8')
    
    # Generate a salt with bcrypt's default cost factor
    salt = bcrypt.gensalt()
    
    # Create a hashed password from the salt and the provided password bytes
    hashed_password = bcrypt.hashpw(password_bytes, salt)
    
    return hashed_password

# Example usage:
password = "my_secure_password123"
hashed_password = hash_password(password)
print(hashed_password)

Step 3: Store Hashed Passwords in Your Database

You would store the hashed_password returned by the above function into your database instead of storing the plain text password.

Step 4: Verify Stored Passwords During Authentication

When a user attempts to log in, you need to compare the provided password with the stored hashed version. If they match, the login attempt is successful.

Example Code:

def verify_password(hashed_password, input_password):
    # Convert both the hashed and plain text passwords into bytes (bcrypt requires bytes)
    hashed_bytes = hashed_password.encode('utf-8')
    input_password_bytes = input_password.encode('utf-8')
    
    # Check if the provided password matches the stored hash
    return bcrypt.checkpw(input_password_bytes, hashed_bytes)

# Example usage:
stored_hashed_password = b'$2b$12$XzCqVW6dIh0uN7RgK3J/EO.'  # This is an example of a hashed password
input_password = "my_secure_password123"

is_correct_password = verify_password(stored_hashed_password, input_password)
print(is_correct_password)  # Should print True if passwords match, False otherwise.

Notes:

• Cost Factor: The bcrypt function's cost factor can be adjusted for security. A higher cost factor makes the hashing process slower and more computationally intensive (less secure), while a lower cost factor is faster but less secure. By default, the cost factor is set to 12.

• Salt: Salt is used in bcrypt to add additional randomness to each password hash, making it very difficult for attackers to use precomputed tables of hashes (like rainbow tables). The salt is generated automatically by bcrypt.gensalt().

Final Thoughts:

Using a strong hashing mechanism like bcrypt can help protect user data. However, remember that no solution is entirely bulletproof, so always follow best practices in security. Additionally, consider using HTTPS to secure the communication between your application and the database.