CBOR to base64 public key

README.md

Setup

To setup, first create a virtual env

python3 -m virtualenv venv

activate the virtual env

source venv/bin/activate

install the requirements

pip3 install -r requirements.txt

Run

activate the virutal env if not activated

source venv/bin/activate

and run the script

python3 convert.py BASE64_WEBSAFE_ENCODED_CBOR_PUBLIC_KEY

convert.py

import sys
import base64
from fido2 import cbor

def cbor_to_base64_pbk(cbor_pbk):
    padding = "="
    cbor_pbk = cbor_pbk + padding * (len(cbor_pbk) % 4)

    pbk = base64.b64decode(cbor_pbk.replace("_", "/").replace("-", "+").encode("utf-8"))
    data = cbor.decode(pbk)

    return base64.urlsafe_b64encode(bytes([4]) + data[-2] + data[-3]).decode('utf-8').rstrip("=")

if __name__ == "__main__":
    if len(sys.argv) < 2:
        exit("please provide a public key to convert from CBOR")
    cbor_pbk = sys.argv[1]
    print(cbor_to_base64_pbk(cbor_pbk))

requirements.txt

fido2