I am currently using hashlib library in python to encrypt a URL using SHA256. Following is the code.
import hashlib
url='https://booking.com'
hs = hashlib.sha256(url.encode('utf-8')).hexdigest()
print(hs) # 037c89f2570ac1cff92d67643f570bec93ebea7f0222e105616590a9673be21f
Now, I want to decrypt and get back the url. Can someone tell me how to do this?
You can't do that with a hash
You should use a Cipher for example the AES Cipher
Example:
from Crypto.Cipher import AES
def resize_length(string):
#resizes the String to a size divisible by 16 (needed for this Cipher)
return string.rjust((len(string) // 16 + 1) * 16)
def encrypt(url, cipher):
# Converts the string to bytes and encodes them with your Cipher
return cipher.encrypt(resize_length(url).encode())
def decrypt(text, cipher):
# Converts the string to bytes and decodes them with your Cipher
return cipher.decrypt(text).decode().lstrip()
# It is important to use 2 ciphers with the same information, else the system breaks (at least for me)
# Define the Cipher with your data (Encryption Key and IV)
cipher1 = AES.new('This is a key123', AES.MODE_CBC, 'This is an IV456')
cipher2 = AES.new('This is a key123', AES.MODE_CBC, 'This is an IV456')
decrypt(encrypt("https://booking.com", cipher1), cipher2)
This should return https://booking.com.
Edit: If you want to have an encoded string in the hex format you could use the join and the format command in combination.
For exmple:
#For encoding
cipherstring = cipher.encrypt(resize_length(url).encode())
cipherstring = "".join("{:02x}".format(c) for c in cipherstring)
#For decoding
text = bytes.fromhex(text)
original_url = cipher.decrypt(text).decode().lstrip()
The
"".join("{:02x}".format(c) for c in cipherstring)
means every character gets encoded in hexadecimal format and the list of characters gets joined with the seperator "" (it is beeing converted to a string)
