base64-json-decoder

README.md

base64-json-decoder

Quickstart

Install

pip install -e git+https://gist.github.com/APTy/8dea3010c0b261689339a8cc52e8dc76#egg=base64-json-decoder

This installs: base64-json-decoder, aliased as bjd.

Usage

Decode JSON data with arbitrarily nested base64+JSON within:

$ echo '{"payload":"eyJtZXNzYWdlIjoiSGVsbG8hIiwgImZyb20iOiAiQVBUeSJ9Cg=="}' | bjd
{
  "payload": {
    "message": "Hello!", 
    "from": "APTy"
  }
}

It will even try to turn timestamps into something more readable:

$ echo '{"occurred_at": 1500000000}' | bjd
{
  "occurred_at": "2017-07-13 19:40:00 UTC"
}

main.py

import json
import base64
import datetime
import fileinput


def main():
    """Reads nested base64/json input and prints the decoded version."""
    in_bytes = _get_input()
    out = _decode_all(in_bytes)
    _print_output(out)


def _get_input():
    """Get user input from stdin or from filenames passed as args."""
    inputs = []
    for line in fileinput.input():
        inputs.append(line)
    return ''.join(inputs)


def _decode_all(in_bytes):
    """Decode the nested base64/json combination payload."""
    # attempt to decode the input string
    out = _try_decode(in_bytes)

    # if this isn't nested further, return the value
    if type(out) != dict:
        return out

    # loop over every nested item and try to decode it
    for key, val in out.items():
        # if this value isn't nested further, decode it
        if type(val) != dict:
            out[key] = _decode_all(val)
            continue

        # if this value is nested further, recursively decode its contents
        for nestedKey, nestedVal in val.items():
            val[nestedKey] = _decode_all(nestedVal)

    return out


def _try_decode(in_bytes):
    """Attempts to decode using a variety of different methods.

    Returns the input value if decoding fails.
    """
    # try plain json decode
    try:
        return json.loads(in_bytes)
    except:
        pass

    # try base64+json decode
    next_bytes = None
    try:
        next_bytes = base64.b64decode(in_bytes)
    except:
        next_bytes = in_bytes
    try:
        return json.loads(next_bytes)
    except:
        pass

    # try timestamp decode
    try:
        return _convert_ts(in_bytes)
    except:
        pass

    # if every decode has failed, return the original value
    return in_bytes


def _convert_ts(ts):
    """Attempt to convert a value that looks like a timestamp into a readable form."""
    return datetime.datetime.fromtimestamp(ts).strftime("%Y-%m-%d %H:%M:%S UTC")


def _print_output(out):
    """Pretty-print output to terminal."""
    print(json.dumps(out, indent=2))


if __name__ == "__main__":
    main()

setup.py

from setuptools import setup, find_packages

setup(
    name="base64-json-decoder",
    version="0.1.0",
    description="CLI for decoding nested base64-json",
    packages=find_packages(),
    entry_points={"console_scripts": [
        "base64-json-decoder=main:main",
        "bjd=main:main",
    ]}
)