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Extract TOTP/HOTP secret keys from Google Authenticator

Extract two-factor authentication (2FA, TFA, OTP) 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.

Installation

git clone https://github.com/scito/extract_otp_secret_keys.git cd extract_otp_secret_keys

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] [--keepass FILE] [--printqr] [--saveqr DIR] [--verbose | --quiet] infile

positional arguments:
  infile                   1) file or - for stdin with "otpauth-migration://..." URLs separated by newlines, lines starting with # are ignored; 2) image file containing a QR code or = for stdin for an image containing a QR code

options:
  -h, --help               show this help message and exit
  --json FILE, -j FILE     export json file or - for stdout
  --csv FILE, -c FILE      export csv file or - for stdout
  --keepass FILE, -k FILE  export totp/hotp csv file(s) for KeePass, - for stdout
  --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, except output set by -

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 3.11.1, protobuf 4.21.12, 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.

Examples

Printing otp secrets form text file

python extract_otp_secret_keys.py example_export.txt

Printing otp secrets from stdin

python extract_otp_secret_keys.py - < example_export.txt

Printing otp secrets from image

python extract_otp_secret_keys.py test/test_googleauth_export.png

Printing otp secrets from stdin (image)

python extract_otp_secret_keys.py = < test/test_googleauth_export.png

Printing otp secrets csv to stdout

python extract_otp_secret_keys.py --csv - example_export.txt

Features

Free and open source
Supports Google Authenticator export
All functionality in one Python script: extract_otp_secret_keys.py (except protobuf generated code in protobuf_generated_python)
Supports TOTP and HOTP
Generates QR codes
Various export formats:
- CSV
- JSON
- Dedicated CSV for KeePass
- QR code images
Supports reading from stdin and writing to stdout by specifying '-'
Errors and warnings are written to stderr
Many ways to run the script:
- Native Python
- pipenv
- venv
- Docker
- VSCode devcontainer
- devbox
- pip

KeePass

KeePass 2.51 (released in May 2022) and newer support the generation of OTPs (TOTP and HOTP).

KeePass can generate the second factor password (2FA) if the OTP secret is stored in TimeOtp-Secret-Base32 string field for TOTP or HmacOtp-Secret-Base32 string field for HOTP. You view or edit them in entry dialog on the 'Advanced' tab page.

KeePass provides menu commands in the main window for generating one-time passwords ('Copy HMAC-Based OTP', 'Show HMAC-Based OTP', 'Copy Time-Based OTP', 'Show Time-Based OTP'). Furthermore, one-time passwords can be generated during auto-type using the {HMACOTP} and {TIMEOTP} placeholders.

In order to simplify the usage of the second factor password generation in KeePass a specific KeePass CSV export is available with option -keepass or -k. This KeePass CSV file can be imported by the "Generic CSV Importer" of KeePass.

If TOTP and HOTP entries have to be exported, then two files with an intermediate suffix .totp or .hotp will be added to the KeePass export filename.

Example:

Only TOTP entries to export and parameter --keepass example_keepass_output.csv
→ example_keepass_output.csv with TOTP entries will be exported
Only HOTP entries to export and parameter --keepass example_keepass_output.csv
→ example_keepass_output.csv with HOTP entries will be exported
If both TOTP and HOTP entries to export and parameter --keepass example_keepass_output.csv
→ example_keepass_output.totp.csv with TOTP entries will be exported
→ example_keepass_output.hotp.csv with HOTP entries will be exported

Import CSV with TOTP entries in KeePass as

Title
User Name
String (TimeOtp-Secret-Base32)
Group (/)

Import CSV with HOTP entries in KeePass as

Title
User Name
String (HmacOtp-Secret-Base32)
String (HmacOtp-Counter)
Group (/)

KeePass can be used as a backup for one time passwords (second factor) from the mobile phone.

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 21.12 (https://github.com/protocolbuffers/protobuf/releases/tag/v21.12).

References

Proto3 documentation: https://developers.google.com/protocol-buffers/docs/pythontutorial
Template code: https://github.com/beemdevelopment/Aegis/pull/406

Glossary

OTP = One-time password
TOTP = Time-based one-time password
HOTP = HMAC-based one-time password (using a counter)
2FA = Second factor authentication
TFA = Two factor authentication
QR code = Quick response code

Alternative installation methods

pip

pip install git+https://github.com/scito/extract_otp_secret_keys
python -m extract_otp_secret_keys

Example

wget https://raw.githubusercontent.com/scito/extract_otp_secret_keys/master/example_export.txt
python -m extract_otp_secret_keys example_export.txt

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

python -m pytest

unittest

There are basic unittests, see test_extract_otp_secret_keys_unittest.py.