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Python Create MD5 Hash of String [with Code Examples]

Introduction

A common cryptographic hash function, MD5, generates a hash value of 128 bits. It is used to check the data’s consistency and make sure that it wasn’t altered while being transmitted.

To determine the MD5 hash of a string in Python, use the hashlib package.

What is Python MD5 string ?

The phrase “Python MD5 string” refers to the MD5 hash function as it is used in Python code. A cryptographic algorithm known as the MD5 hash function accepts input data of any size and generates a fixed-length output known as a hash value or message digest.

A number of uses for the MD5 hash function exist, including the saving of passwords, data integrity checks, and the validation of digital signatures.

Because it transforms the user’s password into an unreadable, fixed-length string of characters that can be saved in a database, the MD5 hash algorithm is particularly helpful for saving passwords.

The MD5 hash function is used to hash the user’s password, and the resulting value is compared against a previously stored value.

The user is given access if the two hash values match. As the original passwords cannot be recovered even if an attacker gains access to the database, this method is more safe than storing plaintext passwords there.

The MD5 hash function and other hash functions are implemented in Python through the hashlib module.

You don’t need to install any additional packages in order to use the hashlib module because it is part of the standard library. Data verification, file integrity testing, and other uses for the MD5 hash algorithm are available.

Syntax:

Python’s hashlib module can be used to compute a string’s MD5 hash value. Here is how to use it:

import hashlib
# Create a hashlib object for the MD5 hash function
hash_object = hashlib.md5()
# Update the hash object with the string to be hashed
hash_object.update(b"string to be hashed")
# Get the hexadecimal representation of the hash
hash_hex = hash_object.hexdigest()
# Print the hash
print(hash_hex)

explanation of the syntax and what each line does:

import hashlib

This line imports the hashlib module, which offers MD5 hash function implementations among other hash functions.

hash_object = hashlib.md5()

Using the hashlib.md5() method, this line produces an instance of the MD5 hash object. The supplied data’s hash will be calculated using this object.

hash_object.update(b"string to be hashed")

This line updates the hash object with the input data, which in this case is the bytes literal b”string to be hashed”. The update() method can be called multiple times with different input data to incrementally compute the hash.

hash_hex = hash_object.hexdigest()

Using the hexdigest() technique, this line returns the hash value’s hexadecimal form. A fixed-length string of 32 hexadecimal characters known as the hash value is produced in order to represent the input data’s distinct hash.

print(hash_hex)

This line outputs the hash value obtained to the console. A 32-character hexadecimal string representing the precise hash of the supplied data will be the output.

Example 1: Python create MD5 Hash of string

Here is an illustration showing how to compute a string’s MD5 hash using the hashlib module:

import hashlib
# Create a hashlib object for the MD5 hash function
hash_object = hashlib.md5()
# Update the hash object with the string to be hashed
hash_object.update(b"Hello, world!")
# Get the hexadecimal representation of the hash
hash_hex = hash_object.hexdigest()
# Print the hash
print(hash_hex)

output:

b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9

We import the hashlib module first in the aforementioned example. The hashlib.md5() method is then used to construct a hashlib object for the MD5 hash algorithm.

The next step is to use the hash object.update() method to update the hash object with the string to be hashed. Notably, since hashlib only accepts bytes, we encode the string as bytes using the b prefix before providing it to the update() method.

The hash object.hexdigest() method is then used to obtain the hash’s hexadecimal form, which is then printed to the console.

Example 2: Hashing a Password

In this example, we’ll hash a password using the MD5 hash method. This is a typical application for the MD5 hash function since it enables secure database password storage without saving the actual password in plain text.

import hashlib
# Get password from user
password = input("Enter your password: ")
# Create a hashlib object for the MD5 hash function
hash_object = hashlib.md5()
# Update the hash object with the password
hash_object.update(password.encode())
# Get the hexadecimal representation of the hash
password_hash = hash_object.hexdigest()
# Print the hash
print("Hashed password:", password_hash)

In this example, we first utilise the input() function to obtain the user’s password.

Finally, using the hash_object.update() method, we construct a hashlib object for the MD5 hash function and update it with the password. The encode() method is used to transform the password from a string to bytes.

After updating the hash object, we use the hash_object.hexdigest() function to obtain the hash’s hexadecimal equivalent and save it in the password hash variable. The hashed password is then printed to the terminal.

Example 3: Comparing Hashed Passwords

In this example, we’ll check to determine if two hashed passwords match. The MD5 hash function is used frequently in situations like this because it enables password verification without saving the actual password in plain text.

import hashlib
# Get password from user
password = input("Enter your password: ")
# Create a hashlib object for the MD5 hash function
hash_object = hashlib.md5()
# Update the hash object with the password
hash_object.update(password.encode())
# Get the hexadecimal representation of the hash
password_hash = hash_object.hexdigest()
# Simulate getting the hashed password from a database
database_password_hash = '5f4dcc3b5aa765d61d8327deb882cf99'
# Compare the two hashes
if password_hash == database_password_hash:
    print("Passwords match!")
else:
    print("Passwords do not match.")

In this example, we first utilise the input() function to obtain the user’s password. Finally, using the hash_object.update() method, we construct a hashlib object for the MD5 hash function and update it with the password.

The encode() method is used to transform the password from a string to bytes.

After updating the hash object, we use the hash_object.hexdigest() function to obtain the hash’s hexadecimal equivalent and save it in the password_hash variable.

The database_password_hash_variable then contains the hashed password as a string to imitate retrieving it from a database. We then use an if statement to compare the two hashes. We output “Passwords match!” if the hashes match. If not, “Passwords do not match.” is printed.

Example 4: Hashing a Large File

We’ll hash a big file in this example using the MD5 hash method. This is a practical method for making sure a file hasn’t been altered during storage or delivery.

import hashlib
# Open file for reading in binary mode
with open('large_file.bin', 'rb') as f:
    # Create a hashlib object for the MD5 hash function
    hash_object = hashlib.md5()
    # Loop through file in chunks and update hash object
    for chunk in iter(lambda: f.read(4096), b''):
        hash_object.update(chunk)
    # Get the hexadecimal representation of the hash
    file_hash = hash_object.hexdigest()
    # Print the hash
    print("Hashed file:", file_hash)

In this example, we first use the open() method to open the file “large_file.bin” for reading in binary mode. When we’re finished with a file, we make sure it is properly closed by using the with statement.

The hashlib.md5() method is then used to construct a hashlib object for the MD5 hash algorithm.

The lambda function and iter() are then used to create a loop that reads 4096 bytes at a time through the file until we reach the file’s end (b”). We use the hash_object.update() function to update the hash object for each piece.

After analysing the entire file, we use the hash_object.hexdigest() method to obtain the hash’s hexadecimal form, which we then save in the file_hash variable.

The hashed file is then printed to the terminal. This makes it possible for us to confirm that the file hasn’t been altered since it was first hashed.

Advantages and disadvantages of using the MD5 hash function in Python:

Advantages

  • The MD5 hash function offers a distinct, fixed-length representation of all input data, making it practical for password storing, data integrity checking, and the validation of digital signatures.
  • The hashlib module, which comes with built-in support for salted password hashing and other features, offers a quick and secure solution to implement the MD5 hash function in Python.
  • It is simple to integrate the MD5 hash function with other systems because it is widely used and supported across a wide range of computer languages and operating systems.
  • Since MD5 hashing is comparatively quick and effective, it is appropriate for use in large-scale applications.

Disadvantages

  • Collision attacks, where diverse input data generates the same hash value, are possible using the MD5 hash function. This could jeopardise the security of programmes that store passwords and other sensitive data that depend on the hash’s uniqueness.
  • MD5 is being phased out in favour of more robust hash algorithms like SHA-2 and SHA-3 since it is no longer regarded as secure for cryptographic applications.
  • The MD5 hash function is vulnerable to brute-force assaults, in which a perpetrator attempts numerous inputs until they discover a hash value that matches. For this reason, using salted password hashing and other security measures to thwart such attacks is crucial.
  • It is crucial to employ high-quality random data and secure coding techniques since the security of the MD5 hash function depends on the implementation of the algorithm and the quality of the input data.

Conclusion

In conclusion, the widely used MD5 hash algorithm is a cryptographic hash function that protects data integrity and thwarts tampering. Using the hashlib module of Python, it is simple to determine a string’s MD5 hash value.

You may quickly create a secure and distinctive hash value for your data by creating a hashlib object for the MD5 hash function, updating it with the string to be hashed, and receiving the hexadecimal representation of the hash.

Always encode your strings as bytes before providing them to hashlib, it’s vital to keep in mind. You can use the MD5 hash function with confidence in your Python projects to protect your data by employing these methods.