6.2 KiB
Extract TOTP/HOTP secret keys from Google Authenticator
Extract two-factor authentication (2FA, TFA) secret keys from export QR codes of "Google Authenticator" app. The secret and otp values can be printed and exported to json or csv. The QR codes can be printed or saved as PNG images.
Usage
-
Open "Google Authenticator" app on the mobile phone
-
Export the QR codes from "Google Authenticator" app
-
Read QR codes with a QR code reader (e.g. from another phone)
-
Save the captured QR codes in the QR code reader to a text file, e.g. example_export.txt. Save each QR code on a new line. (The captured QR codes look like
otpauth-migration://offline?data=...
) -
Transfer the file to the computer where his script is installed.
-
Call this script with the file as input:
python extract_otp_secret_keys.py example_export.txt
Program help: arguments and options
usage: extract_otp_secret_keys.py [-h] [--json FILE] [--csv FILE] [--printqr] [--saveqr DIR] [--verbose] [--quiet] infile positional arguments: infile file or - for stdin (default: -) with "otpauth-migration://..." URLs separated by newlines, lines starting with # are ignored options: -h, --help show this help message and exit --json FILE, -j FILE export to json file --csv FILE, -c FILE export to csv file --printqr, -p print QR code(s) as text to the terminal (requires qrcode module) --saveqr DIR, -s DIR save QR code(s) as images to the given folder (requires qrcode module) --verbose, -v verbose output --quiet, -q no stdout output
Dependencies
pip install -r requirements.txt
Known to work with
- Python 3.10.8, protobuf 4.21.9, qrcode 7.3.1, and pillow 9.2
- Python 3.11.0, protobuf 4.21.9, qrcode 7.3.1, and pillow 9.2
For protobuf versions 3.14.0 or similar or Python 3.6, use the extract_otp_secret_keys version 1.4.0.
Optional
For printing QR codes, the qrcode module is required, otherwise it can be omitted.
pip install qrcode[pil]
Technical background
The export QR code of "Google Authenticator" contains the URL otpauth-migration://offline?data=...
.
The data parameter is a base64 encoded proto3 message (Google Protocol Buffers).
Command for regeneration of Python code from proto3 message definition file (only necessary in case of changes of the proto3 message definition or new protobuf versions):
protoc --python_out=protobuf_generated_python google_auth.proto
The generated protobuf Python code was generated by protoc 21.9 (https://github.com/protocolbuffers/protobuf/releases/tag/v21.9).
References
- Proto3 documentation: https://developers.google.com/protocol-buffers/docs/pythontutorial
- Template code: https://github.com/beemdevelopment/Aegis/pull/406
Alternative installation methods
pipenv
You can you use Pipenv for running extract_otp_secret_keys.
pipenv --rm
pipenv install
pipenv shell
python extract_otp_secret_keys.py example_export.txt
Visual Studio Code Remote - Containers / VSCode devcontainer
You can you use VSCode devcontainer for running extract_otp_secret_keys.
Requirement: Docker
- Start VSCode
- Open extract_otp_secret_keys.code-workspace
- Open VSCode command palette (Ctrl-Shift-P)
- Type command "Remote-Containers: Reopen in Container"
- Open integrated bash terminal in VSCode
- Execute: python extract_otp_secret_keys.py example_export.txt
venv
Alternatively, you can use a python virtual env for the dependencies:
python -m venv venv
. venv/bin/activate
pip install -r requirements-dev.txt
pip install -r requirements.txt
The requirements*.txt files contain all the dependencies (also the optional ones).
To leave the python virtual env just call deactivate
.
devbox
Install devbox, which is a wrapper for nix. Then enter the environment with Python and the packages installed with:
devbox shell
Docker
Install Docker.
Build and run the app within the container:
docker build . -t extract_otp
docker run --rm -v "$(pwd)":/files:ro extract_otp -p example_export.txt
Tests
PyTest
There are basic pytests, see test_extract_otp_secret_keys_pytest.py
.
Run tests:
pytest
or
python -m pytest
unittest
There are basic unittests, see test_extract_otp_secret_keys_unittest.py
.
Run tests:
python -m unittest
VSCode Setup
Setup for running the tests in VSCode.
- Open VSCode command palette (Ctrl-Shift-P)
- Type command "Python: Configure Tests"
- Choose unittest or pytest. (pytest is recommended, both are supported)
- Set ". Root" directory
Maintenance
Upgrade pip Packages
pip install -U -r requirements.txt
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