Last active
May 19, 2021 08:27
-
-
Save twkang/4417903 to your computer and use it in GitHub Desktop.
Python: Simple AES with zlib
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| #!/data/local/bin/python | |
| # AES encryption/decryption with zlib compression | |
| from Crypto.Cipher import AES | |
| from Crypto import Random | |
| import hashlib | |
| import zlib | |
| import base64 | |
| _block_size = 16 | |
| _key_size = 32 | |
| _mode = AES.MODE_CBC | |
| # MODE_B64 : encryption result as base64 encoded string (default) | |
| # MODE_BIN : raw encryption result | |
| MODE_B64, MODE_BIN = 0, 1 | |
| def encrypt(s, pass_string, mode=MODE_B64): | |
| h = hashlib.sha256() | |
| h.update(pass_string) | |
| key_bytes = h.digest() | |
| s = zlib.compress(s) | |
| pad = _block_size - len(s) % _block_size | |
| data = s + bytes(pad*[pad]) | |
| iv_bytes = Random.get_random_bytes(_block_size) | |
| encrypted_bytes = iv_bytes + AES.new(key_bytes, _mode, iv_bytes).encrypt(data) | |
| if mode == MODE_B64: | |
| encrypted_bytes = base64.urlsafe_b64encode(encrypted_bytes) | |
| return encrypted_bytes | |
| def decrypt(s, pass_string, mode=MODE_B64): | |
| h = hashlib.sha256() | |
| h.update(pass_string) | |
| key_bytes = h.digest() | |
| if mode == MODE_B64: | |
| s = base64.urlsafe_b64decode(s) | |
| encrypted_bytes = s | |
| iv_bytes = encrypted_bytes[:_block_size] | |
| encrypted_bytes = encrypted_bytes[_block_size:] | |
| plain_text = AES.new(key_bytes, _mode, iv_bytes).decrypt(encrypted_bytes) | |
| pad = plain_text[-1] | |
| return zlib.decompress(plain_text[:-pad]) | |
| if __name__ == "__main__": | |
| org_str = b"Some test data for simple AES encryption 1234567890" | |
| enc_str = encrypt(org_str, b'password') | |
| print("ENC STR[%d:%s]" % (len(enc_str), enc_str)) | |
| dec_str = decrypt(enc_str, b'password') | |
| assert(org_str == dec_str) | |
| print("DEC STR[%d:%s]" % (len(dec_str), dec_str)) |
not working , give error message in line 22 ( h.update(pass_string)
TypeError: Unicode-objects must be encoded before hashing)
h.update(pass_string.encode("utf-8"))
Thank you so much. I was struggling entire day to compress and encrypt in python 3 and it was not working. Magic was hidden in the way you are adding padding in string to make sure its multiple of 16
s = zlib.compress(s)
pad = _block_size - len(s) % _block_size
data = s + bytes(pad*[pad])
Thanks again.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
not working , give error message in line 22 ( h.update(pass_string)
TypeError: Unicode-objects must be encoded before hashing)