# Extract TOTP/HOTP secret keys from Google Authenticator
Extract two-factor authentication (2FA, TFA) secret keys from export QR codes of "Google Authenticator" app
## Usage
1. Export the QR codes from "Google Authenticator" app
2. Read QR codes with QR code reader
3. Save the captured QR codes in a text file. Save each QR code on a new line. (The captured QR codes look like `otpauth-migration://offline?data=...` )
4. Call this script with the file as input:
python extract_otp_secret_keys.py -p example_export.txt
## Requirement
The protobuf package of Google for proto3 is required for running this script. protobuf >= 3.14 is recommended.
pip install protobuf
Known to work with
* Python 3.6.12 and protobuf 3.14.0
* Python 3.8.5 and protobuf 3.14.0
### Optional
For printing QR codes, the qrcode module is required
pip install qrcode[pil]
### Alternative installation method
Alternatively, you can use a python virtual env for the dependencies:
python -m venv venv
. venv/bin/activate
pip install -r requirements-buildenv.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` .
## 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):
protoc --python_out=generated_python google_auth.proto
## References
* Proto3 documentation: https://developers.google.com/protocol-buffers/docs/pythontutorial
* Template code: https://github.com/beemdevelopment/Aegis/pull/406
