Extract TOTP/HOTP secret keys from Google Authenticator

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TODO add src/ TODO rename extract_otp_secret_keys

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

Capture QR codes from camera

1. Open "Google Authenticator" app on the mobile phone

2. Export the QR codes from "Google Authenticator" app

3. Point the QR codes to the camera of your computer

4. Call this script with the file as input:

   python extract_otp_secret_keys.py

With builtin QR decoder from image files

1. Open "Google Authenticator" app on the mobile phone

2. Export the QR codes from "Google Authenticator" app

3. Save the captured QR codes as image files, e.g. example_export.png

4. Transfer the images files to the computer where his script is installed.

5. Call this script with the file as input:

   python extract_otp_secret_keys.py example_export.png

With external QR decoder app from text files

1. Open "Google Authenticator" app on the mobile phone

2. Export the QR codes from "Google Authenticator" app

3. Read QR codes with a QR code reader (e.g. from another phone)

4. 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=...)

5. Transfer the file to the computer where his script is installed.

6. 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] [--camera NUMBER] [--json FILE] [--csv FILE] [--keepass FILE] [--printqr] [--saveqr DIR] [--verbose | --quiet] [infile ...]

Extracts one time password (OTP) secret keys from QR codes, e.g. from Google Authenticator app.
If no infiles are provided, the QR codes are interactively captured from the camera.

positional arguments:
  infile                      a) file or - for stdin with 'otpauth-migration://...' URLs separated by newlines, lines starting with # are ignored;
                              b) 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
  --camera NUMBER, -C NUMBER  camera number of system (default camera: 0)
  --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 -

examples:
python extract_otp_secret_keys.py
python extract_otp_secret_keys.py example_*.txt
python extract_otp_secret_keys.py - < example_export.txt
python extract_otp_secret_keys.py --csv - example_*.png | tail -n+2
python extract_otp_secret_keys.py = < example_export.png

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.

Shared libs installation for reading QR code images

For reading QR code images the zbar library must be installed. If you do not extract directly from images, you do not need to install the zbar shared library.

For a detailed installation documentation of pyzbar.

Windows

The zbar DLLs are included with the Windows Python wheels. On other operating systems, you will need to install the zbar shared library.

Linux (Debian, Ubuntu, ...)

sudo apt-get install libzbar0

Linux (OpenSUSE)

sudo zypper install libzbar0

Linux (Fedora)

sudo dnf install libzbar0

Mac OS X

brew install zbar

Examples

Printing otp secrets form text file

python extract_otp_secret_keys.py example_export.txt

Printing otp secrets from image file

python extract_otp_secret_keys.py example_export.png

Printing otp secrets multiple files

python extract_otp_secret_keys.py example_*.txt
python extract_otp_secret_keys.py example_*.png
python extract_otp_secret_keys.py example_export.*
python extract_otp_secret_keys.py example_*.txt example_*.png

Printing otp secrets from stdin (text)

python extract_otp_secret_keys.py - < example_export.txt

Printing otp secrets from stdin (image)

python extract_otp_secret_keys.py = < example_export.png

Printing otp secrets csv to stdout

python extract_otp_secret_keys.py --csv - example_export.txt

Printing otp secrets csv to stdout without header line

python extract_otp_secret_keys.py --csv - example_*.png | tail -n+2

Reading from stdin and printing to stdout

cat example_*.txt | python extract_otp_secret_keys.py --csv - - | tail -n+2

Features

• Free and open source
• Supports Google Authenticator exports (and compatible apps like Aegis Authenticator)
• Captures the the QR codes directly from the camera using QR code detection (based on OpenCV)
• Supports TOTP and HOTP
• Generates QR codes
• Exports to various formats:
  • CSV
  • JSON
  • Dedicated CSV for KeePass
  • QR code images
• Supports reading from stdin and writing to stdout
• Reads QR codes images: (See OpenCV docu)
  • Portable Network Graphics - *.png
  • WebP - *.webp
  • JPEG files - *.jpeg, *.jpg, *.jpe
  • TIFF files - *.tiff, *.tif
  • Windows bitmaps - *.bmp, *.dib
  • JPEG 2000 files - *.jp2
  • Portable image format - *.pbm, *.pgm, *.ppm *.pxm, *.pnm
  • Sun rasters - *.sr, *.ras
  • OpenEXR Image files - *.exr
  • Radiance HDR - *.hdr, *.pic
  • Raster and Vector geospatial data supported by GDAL
• Errors and warnings are written to stderr
• Many ways to run the script:
  • Native Python
  • pipenv
  • pip
  • venv
  • Docker
  • VSCode devcontainer
  • devbox
• Compatible with major platforms:
  • Linux
  • macOS
  • Windows
• Uses UTF-8 on all platforms
• Supports Python >= 3.7
• All these features are backed by tests ran nightly
• All functionality in one Python script: extract_otp_secret_keys.py (except protobuf generated code in protobuf_generated_python)

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 --mypy_out=protobuf_generated_python

The generated protobuf Python code was generated by protoc 21.12 (https://github.com/protocolbuffers/protobuf/releases/tag/v21.12).

https://github.com/nipunn1313/mypy-protobuf

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

For development

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

# pip install -e git+https://github.com/scito/extract_otp_secret_keys@$(git ls-remote  git@github.com:scito/extract_otp_secret_keys@support_img_read.git | head -1 | awk '{print $1;}')#egg=extract_otp_secret_keys
pip3.11 install -e git+https://github.com/scito/extract_otp_secret_keys.git@$(git ls-remote git@github.com:scito/extract_otp_secret_keys.git | grep support_img_read | head -1 | awk '{print $1;}')#egg=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

local pip

pip install -e .

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

1. Start VSCode
2. Open extract_otp_secret_keys.code-workspace
3. Open VSCode command palette (Ctrl-Shift-P)
4. Type command "Remote-Containers: Reopen in Container"
5. Open integrated bash terminal in VSCode
6. 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_secret_keys --pull
docker run --rm -v "$(pwd)":/files:ro extract_otp_secret_keys example_export.txt
docker run --rm -v "$(pwd)":/files:ro extract_otp_secret_keys example_export.png

docker run --rm -v "$(pwd)":/files:ro -i extract_otp_secret_keys = < example_export.png docker run --rm -v "$(pwd)":/files:ro -i --device="/dev/video0:/dev/video0" --env="DISPLAY" -v /tmp/.X11-unix:/tmp/.X11-unix:ro extract_otp_secret_keys docker run --pull always --rm -v "$(pwd)":/files:ro -i --device="/dev/video0:/dev/video0" --env="DISPLAY" -v /tmp/.X11-unix:/tmp/.X11-unix:ro scit0/extract_otp_secret_keys docker run --entrypoint /bin/bash -it --rm -v "$(pwd)":/files:ro extract_otp_secret_keys docker run --pull always --rm -v "$(pwd)":/files:ro -i scit0/extract_otp_secret_keys

docker login -uscit0 docker build . -t extract_otp_secret_keys_no_qr_reader -f Dockerfile_no_qr_reader --pull docker build . -t extract_otp_secret_keys_no_qr_reader -f Dockerfile_no_qr_reader --pull --build-arg RUN_TESTS=false docker run --entrypoint /extract/run_pytest.sh --rm -v "$(pwd)":/files:ro scit0/extract_otp_secret_keys_no_qr_reader test_extract_otp_secret_keys_pytest.py -k "not qreader" --relaxed docker run --rm -v "$(pwd)":/files:ro extract_otp_secret_keys_no_qr_reader example_export.txt docker run --rm -v "$(pwd)":/files:ro -i extract_otp_secret_keys_no_qr_reader - < example_export.txt docker build . -t extract_otp_secret_keys_no_qr_reader -f Dockerfile_no_qr_reader --pull && docker run --entrypoint /extract/run_pytest.sh --rm -v "$(pwd)":/files:ro extract_otp_secret_keys_no_qr_reader test_extract_otp_secret_keys_pytest.py -k "not qreader" -vvv --relaxed -s

docker pull scit0/extract_otp_secret_keys docker pull scit0/extract_otp_secret_keys_no_qr_reader

docker pull ghcr.io/scito/extract_otp_secret_keys docker pull ghcr.io/scito/extract_otp_secret_keys_no_qr_reader

Tests

PyTest

There are basic pytests, see test_extract_otp_secret_keys_pytest.py.

Run tests:

pytest

or

python -m pytest

Hints

Your tests can run against an installed version after executing pip install .

Your tests can run against the local copy with an editable install after executing pip install --editable .

If you don’t use an editable install and are relying on the fact that Python by default puts the current directory in sys.path to import your package, you can execute python -m pytest to execute the tests against the local copy directly, without using pip.

https://docs.pytest.org/en/7.1.x/explanation/pythonpath.html#pytest-vs-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.

1. Open VSCode command palette (Ctrl-Shift-P)
2. Type command "Python: Configure Tests"
3. Choose unittest or pytest. (pytest is recommended, both are supported)
4. Set ". Root" directory

Development

Build

pip install -e .
python src/extract_otp_secret_keys.py

pip wheel .
# --isolated
# --prefer-binary

python3.11 -m build --wheel
# =
pip wheel --no-deps .

Upgrade pip Packages

pip install -U -r requirements.txt

Related projects

• ZBar is an open source software suite for reading bar codes from various sources, including webcams.
• Aegis Authenticator is a free, secure and open source 2FA app for Android.
• Android OTP Extractor can extract your tokens from popular Android OTP apps and export them in a standard format or just display them as QR codes for easy importing. [Requires a rooted Android phone.]
• Python QReader
• pyzbar

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