Cryptography Blowfish decryption

main.py

import base64
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives.ciphers import algorithms, modes, Cipher

key = 'xxx'
iv = b'12345678'

print(type(iv))

inputs = {
  'issuing authority': 'xxx'
}
outputs = {}


algorithm = algorithms.Blowfish(key)

decryptor = Cipher(algorithm, mode=modes.CBC(iv), backend=default_backend()).decryptor()

for field, cipher_text in inputs.items():
    cipher_text = base64.b64decode(cipher_text)
    decryptor.update(cipher_text)
    output = decryptor.finalize()
    outputs[field] = output.strip()

print(outputs)

Output when run:

<class 'bytes'>
Traceback (most recent call last):
  File "decrypt-blowflish-string.py", line 31, in <module>
    decryptor = Cipher(algorithm, mode=modes.CBC(iv), backend=default_backend()).decryptor()
  File "/usr/local/lib/python3.6/site-packages/cryptography/hazmat/primitives/ciphers/base.py", line 127, in decryptor
    self.algorithm, self.mode
  File "/usr/local/lib/python3.6/site-packages/cryptography/hazmat/backends/openssl/backend.py", line 271, in create_symmetric_decryption_ctx
    return _CipherContext(self, cipher, mode, _CipherContext._DECRYPT)
  File "/usr/local/lib/python3.6/site-packages/cryptography/hazmat/backends/openssl/ciphers.py", line 110, in __init__
    operation
TypeError: initializer for ctype 'unsigned char *' must be a bytes or list or tuple, not str