Lethean.io, Private, Community VPN, For Everyone

Copyright (c) 2017-2021, Lethean.io Project
Portions Copyright (c) 2014-2019, The Monero Project
Portions Copyright (c) 2012-2013, The Cryptonote developers

Development Resources

• Web: lethean.io
• GitLab: https://gitlab.com/lethean.io/blockchain/lethean
• Social media: Discord, Twitter, Facebook, LinkedIn, Reddit, Medium, YouTube

Introduction

Lethean is the latest in Blockchain and VPN technology, aimed at unlocking the internet for all to use freely. We offer a suite of privacy tools for users that are fast and easy to use; just download the wallet, obtain some coins, and click "connect" on the VPN node of your choice! Any user can also contribute to the decentralized VPN and earn passive income by becoming an exit node, providing one more choice in our unique open marketplace for users to choose between.

The Lethean software suite comprises many pieces but this repository is for the command-line daemon. Please see our other repositories for the GUI wallet or VPN exit node.

Anonymous payments using the CryptoNote blockchain ensure that users remain anonymous in all senses of the word, both when surfing and when connecting, unlike more traditional VPN services.

Privacy: Lethean uses a cryptographically sound system to allow you to send and receive funds without your transactions being easily revealed on the blockchain (the ledger of transactions that everyone has). This ensures that your purchases, receipts, and all transfers remain absolutely private by default.

Security: Using the power of a distributed peer-to-peer consensus network, every transaction on the network is cryptographically secured. Individual wallets have a 25 word mnemonic seed that is only displayed once, and can be written down to backup the wallet. Wallet files are encrypted with a passphrase to ensure they are useless if stolen.

Untraceability: By taking advantage of ring signatures, a special property of a certain type of cryptography, Lethean is able to ensure that transactions are not only untraceable, but have an optional measure of ambiguity that ensures that transactions cannot easily be tied back to an individual user or computer.

About this Project

This is the core implementation of Lethean. It is open source and completely free to use without restrictions, except for those specified in the license agreement below. There are no restrictions on anyone creating an alternative implementation of Lethean that uses the protocol and network in a compatible manner.

As with many development projects, the repository on Github is considered to be the "staging" area for the latest changes. Before changes are merged into that branch on the main repository, they are tested by individual developers in their own branches, submitted as a pull request, and then subsequently tested by contributors who focus on testing and code reviews. That having been said, the repository should be carefully considered before using it in a production environment, unless there is a patch in the repository for a particular show-stopping issue you are experiencing. It is generally a better idea to use a tagged release for stability.

Anyone is welcome to contribute to Lethean's codebase! If you have a fix or code change, feel free to submit it as a pull request directly to the "master" branch. In cases where the change is relatively small or does not affect other parts of the codebase it may be merged in immediately by any one of the collaborators. On the other hand, if the change is particularly large or complex, it is expected that it will be discussed at length either well in advance of the pull request being submitted, or even directly on the pull request.

License

See LICENSE.

Contributing

If you want to help out, see CONTRIBUTING for a set of guidelines.

Vulnerability Response Process

See Vulnerability Response Process.

Lethean software updates and consensus protocol changes (hard fork schedule)

Lethean uses a fixed-schedule hard fork mechanism to implement new features. This means that users of Lethean (end users and service providers) need to run current versions and update their software on a regular schedule.

The last hard fork was on March 9, 2019. Version 3.1.0 (Congo) or later of the software is required to be compliant with the latest hard fork!

Compiling Lethean from Source

Dependencies

The following table summarizes the tools and libraries required to build. A few of the libraries are also included in this repository (marked as "Vendored"). By default, the build uses the library installed on the system, and ignores the vendored sources. However, if no library is found installed on the system, then the vendored source will be built and used. The vendored sources are also used for statically-linked builds because distribution packages often include only shared library binaries (.so) but not static library archives (.a).

Dep	Min. Version	Vendored	Debian/Ubuntu Pkg	Arch Pkg	Optional	Purpose
GCC	4.7.3	NO	build-essential	base-devel	NO
CMake	3.0.0	NO	cmake	cmake	NO
pkg-config	any	NO	pkg-config	base-devel	NO
Boost	1.58	NO	libboost-all-dev	boost	NO	C++ libraries
OpenSSL	basically any	NO	libssl-dev	openssl	NO	sha256 sum
libunbound	1.4.16	YES	libunbound-dev	unbound	NO	DNS resolver
libminiupnpc	2.0	YES	libminiupnpc-dev	miniupnpc	YES	NAT punching
libunwind	any	NO	libunwind8-dev	libunwind	YES	Stack traces
liblzma	any	NO	liblzma-dev	xz	YES	For libunwind
ldns	1.6.17	NO	libldns-dev	ldns	YES	SSL toolkit
expat	1.1	NO	libexpat1-dev	expat	YES	XML parsing
GTest	1.5	YES	libgtest-dev^	gtest	YES	Test suite
Doxygen	any	NO	doxygen	doxygen	YES	Documentation
Graphviz	any	NO	graphviz	graphviz	YES	Documentation

[^] On Debian/Ubuntu libgtest-dev only includes sources and headers. You must build the library binary manually. This can be done with the following command sudo apt-get install libgtest-dev && cd /usr/src/gtest && sudo cmake . && sudo make && sudo mv libg* /usr/lib/

Build instructions

Lethean uses the CMake build system and a top-level Makefile that invokes cmake commands as needed.

On Linux and OS X

• Install the dependencies

Ubuntu Dependencies

apt install -y build-essential cmake pkg-config libboost-all-dev libssl-dev libzmq3-dev \
libunbound-dev libsodium-dev libunwind8-dev liblzma-dev libreadline6-dev \
libldns-dev libexpat1-dev doxygen graphviz libpgm-dev qttools5-dev-tools \
libhidapi-dev libusb-1.0-0-dev libprotobuf-dev protobuf-compiler libudev-dev \
ca-certificates git

• Change to the root of the source code directory and build:

    cd lethean
    make
  

  Optional: If your machine has several cores and enough memory, enable parallel build by running make -j<number of threads> instead of make. For this to be worthwhile, the machine should have one core and about 2GB of RAM available per thread.

• The resulting executables can be found in build/release/bin

• Add PATH="$PATH:$HOME/lethean/build/release/bin" to .profile

• Run Lethean with letheand --detach

• Optional: build and run the test suite to verify the binaries:

    make release-test
  

  NOTE: coretests test may take a few hours to complete.

• Optional: to build binaries suitable for debugging:

     make debug
  

• Optional: to build statically-linked binaries:

     make release-static
  

• Optional: build documentation in doc/html (omit HAVE_DOT=YES if graphviz is not installed):

    HAVE_DOT=YES doxygen Doxyfile
  

On the Raspberry Pi 2

Tested on a Raspberry Pi 2 with a clean install of minimal Debian Jessie from https://www.raspberrypi.org/downloads/raspbian/

• apt-get update && apt-get upgrade to install all of the latest software

• Install the dependencies for Lethean except libunwind and libboost-all-dev

• Increase the system swap size:

	sudo /etc/init.d/dphys-swapfile stop  
	sudo nano /etc/dphys-swapfile  
	CONF_SWAPSIZE=1024  
	sudo /etc/init.d/dphys-swapfile start  

• Install the latest version of boost (this may first require invoking apt-get remove --purge libboost* to remove a previous version if you're not using a clean install):

	cd  
	wget https://sourceforge.net/projects/boost/files/boost/1.64.0/boost_1_64_0.tar.bz2  
	tar xvfo boost_1_64_0.tar.bz2  
	cd boost_1_64_0  
	./bootstrap.sh  
	sudo ./b2  

• Wait ~8 hours

	sudo ./bjam install

• Wait ~4 hours

• Change to the root of the source code directory and build:

        cd lethean
        make release

• Wait ~4 hours

• The resulting executables can be found in build/release/bin

• Add PATH="$PATH:$HOME/lethean/build/release/bin" to .profile

• Run Lethean with letheand --detach

• You may wish to reduce the size of the swap file after the build has finished, and delete the boost directory from your home directory

On Windows:

Binaries for Windows are built on Windows using the MinGW toolchain within MSYS2 environment. The MSYS2 environment emulates a POSIX system. The toolchain runs within the environment and cross-compiles binaries that can run outside of the environment as a regular Windows application.

Preparing the Build Environment

• Download and install the MSYS2 installer, either the 64-bit or the 32-bit package, depending on your system.

• Open the MSYS shell via the MSYS2 Shell shortcut

• Update packages using pacman:

    pacman -Syuu  
  

• Exit the MSYS shell using Alt+F4

• Edit the properties for the MSYS2 Shell shortcut changing "msys2_shell.bat" to "msys2_shell.cmd -mingw64" for 64-bit builds or "msys2_shell.cmd -mingw32" for 32-bit builds

• Restart MSYS shell via modified shortcut and update packages again using pacman:

    pacman -Syuu  
  

• Install dependencies:

  To build for 64-bit Windows:

    pacman -S mingw-w64-x86_64-toolchain make mingw-w64-x86_64-cmake mingw-w64-x86_64-boost
  

  To build for 32-bit Windows:

    pacman -S mingw-w64-i686-toolchain make mingw-w64-i686-cmake mingw-w64-i686-boost
  

• Open the MingW shell via MinGW-w64-Win64 Shell shortcut on 64-bit Windows or MinGW-w64-Win64 Shell shortcut on 32-bit Windows. Note that if you are running 64-bit Windows, you will have both 64-bit and 32-bit MinGW shells.

Building

• If you are on a 64-bit system, run:

    make release-static-win64
  

• If you are on a 32-bit system, run:

    make release-static-win32
  

• The resulting executables can be found in build/release/bin

On FreeBSD:

The project can be built from scratch by following instructions for Linux above. If you are running Lethean in a jail you need to add the flag: allow.sysvipc=1 to your jail configuration, otherwise lmdb will throw the error message: Failed to open lmdb environment: Function not implemented.

We expect to add Lethean into the ports tree in the near future, which will aid in managing installations using ports or packages.

On OpenBSD:

This has been tested on OpenBSD 5.8.

You will need to add a few packages to your system. pkg_add db cmake gcc gcc-libs g++ miniupnpc gtest.

The doxygen and graphviz packages are optional and require the xbase set.

The Boost package has a bug that will prevent librpc.a from building correctly. In order to fix this, you will have to Build boost yourself from scratch. Follow the directions here (under "Building Boost"): https://github.com/bitcoin/bitcoin/blob/master/doc/build-openbsd.md

You will have to add the serialization, date_time, and regex modules to Boost when building as they are needed by Lethean.

To build: env CC=egcc CXX=eg++ CPP=ecpp DEVELOPER_LOCAL_TOOLS=1 BOOST_ROOT=/path/to/the/boost/you/built make release-static-64

On Linux for Android (using docker):

    # Build image (select android64.Dockerfile for aarch64)
    cd utils/build_scripts/ && docker build -f android32.Dockerfile -t lethean-android .
    # Create container
    docker create -it --name lethean-android lethean-android bash
    # Get binaries
    docker cp lethean-android:/opt/android/lethean/build/release/bin .

Building Portable Statically Linked Binaries

By default, in either dynamically or statically linked builds, binaries target the specific host processor on which the build happens and are not portable to other processors. Portable binaries can be built using the following targets:

• make release-static-64 builds binaries on Linux on x86_64 portable across POSIX systems on x86_64 processors
• make release-static-32 builds binaries on Linux on x86_64 or i686 portable across POSIX systems on i686 processors
• make release-static-armv8 builds binaries on Linux portable across POSIX systems on armv8 processors
• make release-static-armv7 builds binaries on Linux portable across POSIX systems on armv7 processors
• make release-static-armv6 builds binaries on Linux portable across POSIX systems on armv6 processors
• make release-static-win64 builds binaries on 64-bit Windows portable across 64-bit Windows systems
• make release-static-win32 builds binaries on 64-bit or 32-bit Windows portable across 32-bit Windows systems

Running letheand

The build places the binary in bin/ sub-directory within the build directory from which cmake was invoked (repository root by default). To run in foreground:

./bin/letheand

To list all available options, run ./bin/letheand --help. Options can be specified either on the command line or in a configuration file passed by the --config-file argument. To specify an option in the configuration file, add a line with the syntax argumentname=value, where argumentname is the name of the argument without the leading dashes, for example log-level=1.

To run in background:

./bin/letheand --log-file letheand.log --detach

Internationalization

See README.i18n.md.