Python get string hash

Create MD5 Hash of a string in Python

As a Python enthusiast, I’m always on the lookout for powerful and practical techniques to incorporate into my projects. One such technique that has proven invaluable in ensuring data integrity is creating an MD5 hash of a string. Whether it’s for password storage, data validation, or checksum verification, MD5 hashing has become a go-to method for developers worldwide. In this blog post, I’m excited to guide you through the process of creating an MD5 hash of a string in Python. So, let’s dive in and discover the wonders of MD5 hashing!

MD5 is (atleast when it was created) a standardized 1-way function that takes in data input of any form and maps it to a fixed-size output string, irrespective of the size of the input string.

Though it is used as a cryptographygraphic hash function, it has been found to suffer from a lot of vulnerabilities.

The hash function generates the same output hash for the same input string. This means that, you can use this string to validate files or text or anything when you pass it across the network or even otherwise. MD5 can act as a stamp or for checking if the data is valid or not.

Input String	Output Hash
hi	49f68a5c8493ec2c0bf489821c21fc3b
debugpointer	d16220bc73b8c7176a3971c7f73ac8aa
computer science is amazing! I love it.	f3c5a497380310d828cdfc1737e8e2a3

MD5 hash of a String in Python

MD5 hash can be created using the python’s default module hashlib . There are many more hash functions defined in the hashlib library.

The process of creating an MD5 hash in python is very simple. First import hashlib, then encode your string that you want to hash i.e., converts the string into the byte equivalent using encode(), then pass it through the hashlib.md5() function. We print the hexdigest value of the hash m , which is the hexadecimal equivalent encoded string.

import hashlib text = 'Hello!'  m = hashlib.md5(text.encode('UTF-8')) print(m.hexdigest()) 

d41d8cd98f00b204e9800998ecf8427e 

The value you see here d41d8cd98f00b204e9800998ecf8427e is the MD5 hash of the string Hello! .

The functions used in the above code-

• encode() : Converts the string into bytes to be acceptable by hash function.
• hexdigest() : Returns the encoded data in hexadecimal format.

You can also update the value of the string and check it as well if needed. This can be used to strengthen the hash logic in your workflow where you can append strings in certain order and see if your hash matched the source hash.

import hashlib text = 'Hello!'  m = hashlib.md5() print(m.hexdigest()) m.update(b"Have Fun!") print(m.hexdigest()) m.update(text.encode('UTF-8')) print(m.hexdigest()) 

24187a7aa74385955a8546c99e0c2b6a 

As you see, the MD5 hash of a string using Python is as simple as this code.

The above code just produced MD5 hash of the string alone, but, to strengthen the security you can also generate MD5 hash with salt as well.

NOTE : Please do not use this to hash passwords and store it in your databases, prefer SHA-256 or SHA-512 or other superior cryptographygraphic hash functions for the same.

I’m glad that you found the content useful. And there you have it! We’ve successfully explored the world of MD5 hashing in Python. By learning how to create an MD5 hash of a string, you’ve added a powerful tool to your Python arsenal. From securing passwords to verifying data integrity, MD5 hashing offers a range of applications in various domains. As you continue your programming journey, remember the importance of data integrity and the role that MD5 hashing plays in ensuring it. Keep exploring, keep learning, and may your Python projects be secure and robust! Happy Coding.

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Hashing Strings with Python

A hash function is a function that takes input of a variable length sequence of bytes and converts it to a fixed length sequence. It is a one way function. This means if f is the hashing function, calculating f(x) is pretty fast and simple, but trying to obtain x again will take years. The value returned by a hash function is often called a hash, message digest, hash value, or checksum. Most of the time a hash function will produce unique output for a given input. However depending on the algorithm, there is a possibility to find a collision due to the mathematical theory behind these functions.

Now suppose you want to hash the string «Hello Word» with the SHA1 Function, the result is 0a4d55a8d778e5022fab701977c5d840bbc486d0 .

Hash functions are used inside some cryptographic algorithms, in digital signatures, message authentication codes, manipulation detection, fingerprints, checksums (message integrity check), hash tables, password storage and much more. As a Python programmer you may need these functions to check for duplicate data or files, to check data integrity when you transmit information over a network, to securely store passwords in databases, or maybe some work related to cryptography.

I want to make clear that hash functions are not a cryptographic protocol, they do not encrypt or decrypt information, but they are a fundamental part of many cryptographic protocols and tools.

Some of the most used hash functions are:

• MD5: Message digest algorithm producing a 128 bit hash value. This is widely used to check data integrity. It is not suitable for use in other fields due to the security vulnerabilities of MD5.
• SHA: Group of algorithms designed by the U.S’s NSA that are part of the U.S Federal Information processing standard. These algorithms are used widely in several cryptographic applications. The message length ranges from 160 bits to 512 bits.

The hashlib module, included in The Python Standard library is a module containing an interface to the most popular hashing algorithms. hashlib implements some of the algorithms, however if you have OpenSSL installed, hashlib is able to use this algorithms as well.

This code is made to work in Python 3.2 and above. If you want to run this examples in Python 2.x, just remove the algorithms_available and algorithms_guaranteed calls.

First, import the hashlib module:

[python]
import hashlib
[/python]

Now we use algorithms_available or algorithms_guaranteed to list the algorithms available.

[python]
print(hashlib.algorithms_available)
print(hashlib.algorithms_guaranteed)
[/python]

The algorithms_available method lists all the algorithms available in the system, including the ones available trough OpenSSl. In this case you may see duplicate names in the list. algorithms_guaranteed only lists the algorithms present in the module. md5, sha1, sha224, sha256, sha384, sha512 are always present.

MD5

[python]
import hashlib
hash_object = hashlib.md5(b’Hello World’)
print(hash_object.hexdigest())
[/python]

The code above takes the «Hello World» string and prints the HEX digest of that string. hexdigest returns a HEX string representing the hash, in case you need the sequence of bytes you should use digest instead.

It is important to note the «b» preceding the string literal, this converts the string to bytes, because the hashing function only takes a sequence of bytes as a parameter. In previous versions of the library, it used to take a string literal. So, if you need to take some input from the console, and hash this input, do not forget to encode the string in a sequence of bytes:

[python]
import hashlib
mystring = input(‘Enter String to hash: ‘)
# Assumes the default UTF-8
hash_object = hashlib.md5(mystring.encode())
print(hash_object.hexdigest())
[/python]

SHA1

[python]
import hashlib
hash_object = hashlib.sha1(b’Hello World’)
hex_dig = hash_object.hexdigest()
print(hex_dig)
[/python]

SHA224

[python]
import hashlib
hash_object = hashlib.sha224(b’Hello World’)
hex_dig = hash_object.hexdigest()
print(hex_dig)
[/python]

SHA256

[python]
import hashlib
hash_object = hashlib.sha256(b’Hello World’)
hex_dig = hash_object.hexdigest()
print(hex_dig)
[/python]

SHA384

[python]
import hashlib
hash_object = hashlib.sha384(b’Hello World’)
hex_dig = hash_object.hexdigest()
print(hex_dig)
[/python]

SHA512

[python]
import hashlib
hash_object = hashlib.sha512(b’Hello World’)
hex_dig = hash_object.hexdigest()
print(hex_dig)
[/python]

Using OpenSSL Algorithms

Now suppose you need an algorithm provided by OpenSSL. Using algorithms_available , we can find the name of the algorithm you want to use. In this case, «DSA» is available on my computer. You can then use the new and update methods:

[python]
import hashlib
hash_object = hashlib.new(‘DSA’)
hash_object.update(b’Hello World’)
print(hash_object.hexdigest())
[/python]

Practical example: hashing passwords

In the following example we are hashing a password in order to store it in a database. In this example we are using a salt. A salt is a random sequence added to the password string before using the hash function. The salt is used in order to prevent dictionary attacks and rainbow tables attacks. However, if you are making real world applications and working with users’ passwords, make sure to be updated about the latest vulnerabilities in this field. I you want to find out more about secure passwords please refer to this article

def hash_password(password):
# uuid is used to generate a random number
salt = uuid.uuid4().hex
return hashlib.sha256(salt.encode() + password.encode()).hexdigest() + ‘:’ + salt

def check_password(hashed_password, user_password):
password, salt = hashed_password.split(‘:’)
return password == hashlib.sha256(salt.encode() + user_password.encode()).hexdigest()

new_pass = input(‘Please enter a password: ‘)
hashed_password = hash_password(new_pass)
print(‘The string to store in the db is: ‘ + hashed_password)
old_pass = input(‘Now please enter the password again to check: ‘)
if check_password(hashed_password, old_pass):
print(‘You entered the right password’)
else:
print(‘I am sorry but the password does not match’)
[/python]

def hash_password(password):
# uuid is used to generate a random number
salt = uuid.uuid4().hex
return hashlib.sha256(salt.encode() + password.encode()).hexdigest() + ‘:’ + salt

def check_password(hashed_password, user_password):
password, salt = hashed_password.split(‘:’)
return password == hashlib.sha256(salt.encode() + user_password.encode()).hexdigest()

new_pass = raw_input(‘Please enter a password: ‘)
hashed_password = hash_password(new_pass)
print(‘The string to store in the db is: ‘ + hashed_password)
old_pass = raw_input(‘Now please enter the password again to check: ‘)
if check_password(hashed_password, old_pass):
print(‘You entered the right password’)
else:
print(‘I am sorry but the password does not match’)
[/python]

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Python hashlib: How to use sha256 and hexdigest

You can get the hash of a string by importing hashlib in Python.

import hashlib a = 'ABC' h = hashlib.sha256(a.encode()).hexdigest() print(h) # b5d4045c3f466fa91fe2cc6abe79232a1a57cdf104f7a26e716e0a1e2789df78 

The hashlib module has md5(), sha256(), sha512() and stuff like that.

The string must be encoded

The argument of sha256() must be encoded. Python raises the TypeError if a string is directly assigned.

import hashlib a = 'ABC' h = hashlib.sha256(a).hexdigest() # TypeError: Unicode-objects must be encoded before hashing 

The sha256() returns a HASH object, not a string

The sha256() returns a HASH object.

import hashlib a = 'ABC' h = hashlib.sha256(a.encode()) print(h) # print(type(h)) #

So if you want to get the hash as a string, use the hexdigest().

import hashlib a = 'ABC' h = hashlib.sha256(a.encode()).hexdigest() print(h) # b5d4045c3f466fa91fe2cc6abe79232a1a57cdf104f7a26e716e0a1e2789df78 

The prefix b substitutes the encode().

import hashlib a = 'ABC' h = hashlib.sha256(b'ABC').hexdigest() print(h) # b5d4045c3f466fa91fe2cc6abe79232a1a57cdf104f7a26e716e0a1e2789df78 

A value with prefix b is a bytes object.

x = b'ABC' print(x) # b'ABC' print(type(x)) #

The sha256() takes a bytes object.

import hashlib x = b'ABC' y = hashlib.sha256(x).hexdigest() print(y) # b5d4045c3f466fa91fe2cc6abe79232a1a57cdf104f7a26e716e0a1e2789df78 

hashlib.new()

import hashlib s = 'ABC' h1 = hashlib.new('sha256', s.encode()).hexdigest() h2 = hashlib.sha256(s.encode()).hexdigest() print(h1) # b5d4045c3f466fa91fe2cc6abe79232a1a57cdf104f7a26e716e0a1e2789df78 print(h2) # b5d4045c3f466fa91fe2cc6abe79232a1a57cdf104f7a26e716e0a1e2789df78 

The new() takes the algorithm name such as sha256 and encoded value. It returns the HASH object that can be expressed as a string by using hexdigest(). The new() and sha256() are basically the same function. The function wrapping the new() is like this.

import hashlib def h(algorithm, text): return hashlib.new(algorithm, text.encode()).hexdigest() print(h('sha256', 'ABC')) # b5d4045c3f466fa91fe2cc6abe79232a1a57cdf104f7a26e716e0a1e2789df78 print(h('sha512', 'ABC')) # 397118fdac8d83ad98813c50759c85b8c47565d8268bf10da483153b747a74743a58a90e85aa9f705ce6984ffc128db567489817e4092d050d8a1cc596ddc119 

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