Python encryption unicode error when converting from Python 2 to python 3

问题

I found some code which I want to incorporate into my Python encryption program. It should encrypt the files in the code's same directory, and I want it to target a directory. But, it's written in Python 2 and when I change around some code to fit Python 3, I get the following error:

Traceback (most recent call last):
  File "/home/pi/Desktop/Projects/FyleCript/Dev Files/encryption.py", line 77, in <module>
    encrypt(SHA256.new(password).digest(), str(Tfiles))
  File "/usr/lib/python3/dist-packages/Crypto/Hash/SHA256.py", line 88, in new
    return SHA256Hash().new(data)
  File "/usr/lib/python3/dist-packages/Crypto/Hash/SHA256.py", line 75, in new
    return SHA256Hash(data)
  File "/usr/lib/python3/dist-packages/Crypto/Hash/SHA256.py", line 72, in __init__
    HashAlgo.__init__(self, hashFactory, data)
  File "/usr/lib/python3/dist-packages/Crypto/Hash/hashalgo.py", line 51, in __init__
    self.update(data)
  File "/usr/lib/python3/dist-packages/Crypto/Hash/hashalgo.py", line 69, in update
    return self._hash.update(data)
TypeError: Unicode-objects must be encoded before hashing

But the code works perfectly in Python 2. I have tried looking for similar questions on SO and Googling, but no help.

---

Code:

#-*- coding:utf-8 -*-

#Python 
from Crypto.Hash import SHA256
from Crypto.Cipher import AES
import os, random, sys, pkg_resources

def encrypt(key, filename):
        chunksize = 64 * 1024
        outFile = os.path.join(os.path.dirname(filename), "(encrypted)"+os.path.basename(filename))
        filesize = str(os.path.getsize(filename)).zfill(16)
        IV = ''

        for i in range(16):
                IV += chr(random.randint(0, 0xFF))

        encryptor = AES.new(key, AES.MODE_CBC, IV)

        with open(filename, "rb") as infile:
                with open(outFile, "wb") as outfile:
                        outfile.write(filesize)
                        outfile.write(IV)
                        while True:
                                chunk = infile.read(chunksize)

                                if len(chunk) == 0:
                                        break

                                elif len(chunk) % 16 !=0:
                                        chunk += ' ' *  (16 - (len(chunk) % 16))

                                outfile.write(encryptor.encrypt(chunk))


def decrypt(key, filename):
        outFile = os.path.join(os.path.dirname(filename), os.path.basename(filename[11:]))
        chunksize = 64 * 1024
        with open(filename, "rb") as infile:
                filesize = infile.read(16)
                IV = infile.read(16)

                decryptor = AES.new(key, AES.MODE_CBC, IV)

                with open(outFile, "wb") as outfile:
                        while True:
                                chunk = infile.read(chunksize)
                                if len(chunk) == 0:
                                        break

                                outfile.write(decryptor.decrypt(chunk))

                        outfile.truncate(int(filesize))

def allfiles():
        allFiles = []
        for root, subfiles, files in os.walk(os.getcwd()):
                for names in files:
                        allFiles.append(os.path.join(root, names))

        return allFiles


choice = input("Do you want to (E)ncrypt or (D)ecrypt? ")
password = input("Enter the password: ") 

encFiles = allfiles()

if choice == "E" or 'e':
        for Tfiles in encFiles:
                if os.path.basename(Tfiles).startswith("(encrypted)"):
                        print("%s is already encrypted" %str(Tfiles))
                        pass

                elif Tfiles == os.path.join(os.getcwd(), sys.argv[0]):
                        pass
                else:
                        encrypt(SHA256.new(password).digest(), str(Tfiles))
                        print("Done encrypting %s" %str(Tfiles))
                        os.remove(Tfiles)


elif choice == "D" or 'd':
        filename = input("Enter the filename to decrypt: ")
        if not os.path.exists(filename):
                print("The file does not exist")
                sys.exit()
        elif not filename.startswith("(encrypted)"):
                print("%s is already not encrypted" %filename)
                sys.exit()
        else:
                decrypt(SHA256.new(password).digest(), filename)
                print("Done decrypting %s" %filename)
                os.remove(filename)

else:
        print("Please choose a valid command.")
        sys.exit()

Can anyone help me with this problem? I have used a Python 2 to 3 tool, but it still didn't work.

Also, could you please fix the directory problem? It isn't necessary, but I would like it.

---

EDIT: I have replaced str with bytes and bytearray but it returns the same error.

回答1:

Your 'password' variable is a string, but SHA256.new expects bytes (to allow for unicode, for example). That you need bytes is listed in the Crypto.Hash.SHA256 documentation.

The solution is to encode the password to bytes before hashing. This is almost literally what the error message says (if you know that all strings in python 3 are unicode objects):

TypeError: Unicode-objects must be encoded before hashing

The solution is for example to encode with utf8 :

SHA256.new(password.encode('utf8')).digest()

来源：https://stackoverflow.com/questions/51350462/python-encryption-unicode-error-when-converting-from-python-2-to-python-3