recursively replace base64-encoded strings in a JSON file with the decoded string

ub64.py

# recursively replace base64-encoded strings in a JSON file with the decoded string
# usage: python main.py <input_file> <output_file>

import sys
import json
import base64

def decode_json(data):
    if isinstance(data, dict):
        return {decode_json(key): decode_json(value) for key, value in data.items()}
    elif isinstance(data, list):
        return [decode_json(element) for element in data]
    elif isinstance(data, str):
        try:
            return decode_json(json.loads(base64.b64decode(data)))
        except:
            return data
    else:
        return data

def main():
    if len(sys.argv) != 3:
        print('usage: python main.py <input_file> <output_file>')
        exit(1)

    with open(sys.argv[1], 'r') as f:
        data = json.load(f)

    with open(sys.argv[2], 'w') as f:
        json.dump(decode_json(data), f, indent=4)

if __name__ == '__main__':
    main()