Loki

Copyright (c) 2018 The Loki Project.
Portions Copyright (c) 2014-2018 The Monero Project.
Portions Copyright (c) 2012-2013 The Cryptonote developers.

Development resources

• Web: loki.network
• Telegram: t.me/LokiCommunity
• Mail: team@loki.network
• GitHub: https://github.com/loki-project/loki
• Discord: https://discord.gg/67GXfD6

Vulnerability disclosure

• Check out our Vulnerability Response Process, encourages prompt disclosure of any Vulnerabilities

Information

Loki is a private cryptocurrency based on Monero. Over the course of the coming months, the Loki project aims to offer an incenvised full node layer with a secondary p2p network that offers a private communications layer based on the Tox protocol.

More information on the project can be found on the website and in the whitepaper.

Loki is an open source project, and we encourage contributions from anyone with something to offer. For more information on contributing, please contact team@loki.network

Compiling Loki 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
libzmq	3.0.0	NO	libzmq3-dev	zeromq	NO	ZeroMQ library
libunbound	1.4.16	YES	libunbound-dev	unbound	NO	DNS resolver
libsodium	?	NO	libsodium-dev	?	NO	libsodium
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
libreadline	6.3.0	NO	libreadline6-dev	readline	YES	Input editing
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/

Cloning the repository

Clone recursively to pull-in needed submodule(s):

$ git clone --recursive https://github.com/loki-project/loki

If you already have a repo cloned, initialize and update:

$ cd loki && git submodule init && git submodule update

Build instructions

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

On Linux and OS X

• Install the dependencies

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

    cd loki
    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.

  Note: If cmake can not find zmq.hpp file on OS X, installing zmq.hpp from https://github.com/zeromq/cppzmq to /usr/local/include should fix that error.

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

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

• Run Loki with lokid --detach

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

    make release-test
  

  NOTE: core_tests 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
  

Dependencies need to be built with -fPIC. Static libraries usually aren't, so you may have to build them yourself with -fPIC. Refer to their documentation for how to build them.

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

    HAVE_DOT=YES doxygen Doxyfile
  

On the Raspberry Pi

Tested on a Raspberry Pi Zero with a clean install of minimal Raspbian Stretch (2017-09-07 or later) from https://www.raspberrypi.org/downloads/raspbian/. If you are using Raspian Jessie, please see note in the following section.

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

• Install the dependencies for Loki from the 'Debian' column in the table above.

• 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  

• Clone loki and checkout most recent release version:

        git clone https://github.com/loki-project/loki.git
	cd loki
	git checkout tags/v0.11.0.0

• Build:

        make release

• Wait 4-6 hours

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

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

• Run Loki with lokid --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

Note for Raspbian Jessie users:

If you are using the older Raspbian Jessie image, compiling Loki is a bit more complicated. The version of Boost available in the Debian Jessie repositories is too old to use with Loki, and thus you must compile a newer version yourself. The following explains the extra steps, and has been tested on a Raspberry Pi 2 with a clean install of minimal Raspbian Jessie.

• As before, apt-get update && apt-get upgrade to install all of the latest software, and 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  

• Then, install the dependencies for Loki except libunwind and libboost-all-dev

• 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

• From here, follow the general Raspberry Pi instructions from the "Clone loki and checkout most recent release version" step.

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 mingw-w64-x86_64-openssl mingw-w64-x86_64-zeromq mingw-w64-x86_64-libsodium
  

  To build for 32-bit Windows:

    pacman -S mingw-w64-i686-toolchain make mingw-w64-i686-cmake mingw-w64-i686-boost mingw-w64-i686-openssl mingw-w64-i686-zeromq mingw-w64-i686-libsodium
  

• 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 loki 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.

On OpenBSD:

OpenBSD < 6.2

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 Loki.

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

OpenBSD >= 6.2

You will need to add a few packages to your system. pkg_add cmake miniupnpc zeromq libiconv.

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

Build the Boost library using clang. This guide is derived from: https://github.com/bitcoin/bitcoin/blob/master/doc/build-openbsd.md

We assume you are compiling with a non-root user and you have doas enabled.

Note: do not use the boost package provided by OpenBSD, as we are installing boost to /usr/local.

# Create boost building directory
mkdir ~/boost
cd ~/boost

# Fetch boost source
ftp -o boost_1_64_0.tar.bz2 https://netcologne.dl.sourceforge.net/project/boost/boost/1.64.0/boost_1_64_0.tar.bz2 

# MUST output: (SHA256) boost_1_64_0.tar.bz2: OK
echo "7bcc5caace97baa948931d712ea5f37038dbb1c5d89b43ad4def4ed7cb683332 boost_1_64_0.tar.bz2" | sha256 -c
tar xfj boost_1_64_0.tar.bz2

# Fetch and apply boost patches, required for OpenBSD
ftp -o boost_test_impl_execution_monitor_ipp.patch https://raw.githubusercontent.com/openbsd/ports/bee9e6df517077a7269ff0dfd57995f5c6a10379/devel/boost/patches/patch-boost_test_impl_execution_monitor_ipp
ftp -o boost_config_platform_bsd_hpp.patch https://raw.githubusercontent.com/openbsd/ports/90658284fb786f5a60dd9d6e8d14500c167bdaa0/devel/boost/patches/patch-boost_config_platform_bsd_hpp

# MUST output: (SHA256) boost_config_platform_bsd_hpp.patch: OK
echo "1f5e59d1154f16ee1e0cc169395f30d5e7d22a5bd9f86358f738b0ccaea5e51d boost_config_platform_bsd_hpp.patch" | sha256 -c
# MUST output: (SHA256) boost_test_impl_execution_monitor_ipp.patch: OK
echo "30cec182a1437d40c3e0bd9a866ab5ddc1400a56185b7e671bb3782634ed0206 boost_test_impl_execution_monitor_ipp.patch" | sha256 -c

cd boost_1_64_0
patch -p0 < ../boost_test_impl_execution_monitor_ipp.patch
patch -p0 < ../boost_config_platform_bsd_hpp.patch

# Start building boost
echo 'using clang : : c++ : <cxxflags>"-fvisibility=hidden -fPIC" <linkflags>"" <archiver>"ar" <striper>"strip"  <ranlib>"ranlib" <rc>"" : ;' > user-config.jam
./bootstrap.sh --without-icu --with-libraries=chrono,filesystem,program_options,system,thread,test,date_time,regex,serialization,locale --with-toolset=clang
./b2 toolset=clang cxxflags="-stdlib=libc++" linkflags="-stdlib=libc++" -sICONV_PATH=/usr/local
doas ./b2 -d0 runtime-link=shared threadapi=pthread threading=multi link=static variant=release --layout=tagged --build-type=complete --user-config=user-config.jam -sNO_BZIP2=1 -sICONV_PATH=/usr/local --prefix=/usr/local install

Build cppzmq

Build the cppzmq bindings.

We assume you are compiling with a non-root user and you have doas enabled.

# Create cppzmq building directory
mkdir ~/cppzmq
cd ~/cppzmq

# Fetch cppzmq source
ftp -o cppzmq-4.2.3.tar.gz https://github.com/zeromq/cppzmq/archive/v4.2.3.tar.gz

# MUST output: (SHA256) cppzmq-4.2.3.tar.gz: OK
echo "3e6b57bf49115f4ae893b1ff7848ead7267013087dc7be1ab27636a97144d373 cppzmq-4.2.3.tar.gz" | sha256 -c
tar xfz cppzmq-4.2.3.tar.gz

# Start building cppzmq
cd cppzmq-4.2.3
mkdir build
cd build
cmake ..
doas make install

Build loki: env DEVELOPER_LOCAL_TOOLS=1 BOOST_ROOT=/usr/local make release-static

On Solaris:

The default Solaris linker can't be used, you have to install GNU ld, then run cmake manually with the path to your copy of GNU ld:

    mkdir -p build/release
    cd build/release
    cmake -DCMAKE_LINKER=/path/to/ld -D CMAKE_BUILD_TYPE=Release ../..
    cd ../..

Then you can run make as usual.

On Linux for Android (using docker):

    # Build image (select android64.Dockerfile for aarch64)
    cd utils/build_scripts/ && docker build -f android32.Dockerfile -t loki-android .
    # Create container
    docker create -it --name loki-android loki-android bash
    # Get binaries
    docker cp loki-android:/opt/android/loki/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-linux-x86_64 builds binaries on Linux on x86_64 portable across POSIX systems on x86_64 processors
• make release-static-linux-i686 builds binaries on Linux on x86_64 or i686 portable across POSIX systems on i686 processors
• make release-static-linux-armv8 builds binaries on Linux portable across POSIX systems on armv8 processors
• make release-static-linux-armv7 builds binaries on Linux portable across POSIX systems on armv7 processors
• make release-static-linux-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 lokid

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/lokid

To list all available options, run ./bin/lokid --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/lokid --log-file lokid.log --detach

Internationalization

See README.i18n.md.

Using Tor

While Loki isn't made to integrate with Tor, it can be used wrapped with torsocks, by setting the following configuration parameters and environment variables:

• --p2p-bind-ip 127.0.0.1 on the command line or p2p-bind-ip=127.0.0.1 in lokid.conf to disable listening for connections on external interfaces.
• --no-igd on the command line or no-igd=1 in lokid.conf to disable IGD (UPnP port forwarding negotiation), which is pointless with Tor.
• DNS_PUBLIC=tcp or DNS_PUBLIC=tcp://x.x.x.x where x.x.x.x is the IP of the desired DNS server, for DNS requests to go over TCP, so that they are routed through Tor. When IP is not specified, lokid uses the default list of servers defined in src/common/dns_utils.cpp.
• TORSOCKS_ALLOW_INBOUND=1 to tell torsocks to allow lokid to bind to interfaces to accept connections from the wallet. On some Linux systems, torsocks allows binding to localhost by default, so setting this variable is only necessary to allow binding to local LAN/VPN interfaces to allow wallets to connect from remote hosts. On other systems, it may be needed for local wallets as well.
• Do NOT pass --detach when running through torsocks with systemd, (see utils/systemd/lokid.service for details).

Example command line to start lokid through Tor:

DNS_PUBLIC=tcp torsocks lokid --p2p-bind-ip 127.0.0.1 --no-igd

Using Tor on Tails

TAILS ships with a very restrictive set of firewall rules. Therefore, you need to add a rule to allow this connection too, in addition to telling torsocks to allow inbound connections. Full example:

sudo iptables -I OUTPUT 2 -p tcp -d 127.0.0.1 -m tcp --dport 18081 -j ACCEPT
DNS_PUBLIC=tcp torsocks ./lokid --p2p-bind-ip 127.0.0.1 --no-igd --rpc-bind-ip 127.0.0.1 \
    --data-dir /home/amnesia/Persistent/your/directory/to/the/blockchain

Debugging

This section contains general instructions for debugging failed installs or problems encountered with Loki. First ensure you are running the latest version built from the Github repo.

Obtaining stack traces and core dumps on Unix systems

We generally use the tool gdb (GNU debugger) to provide stack trace functionality, and ulimit to provide core dumps in builds which crash or segfault.

• To use gdb in order to obtain a stack trace for a build that has stalled:

Run the build.

Once it stalls, enter the following command:

gdb /path/to/lokid `pidof lokid` 

Type thread apply all bt within gdb in order to obtain the stack trace

• If however the core dumps or segfaults:

Enter ulimit -c unlimited on the command line to enable unlimited filesizes for core dumps

Enter echo core | sudo tee /proc/sys/kernel/core_pattern to stop cores from being hijacked by other tools

Run the build.

When it terminates with an output along the lines of "Segmentation fault (core dumped)", there should be a core dump file in the same directory as lokid. It may be named just core, or core.xxxx with numbers appended.

You can now analyse this core dump with gdb as follows:

gdb /path/to/lokid /path/to/dumpfile

Print the stack trace with bt

• To run loki within gdb:

Type gdb /path/to/lokid

Pass command-line options with --args followed by the relevant arguments

Type run to run lokid

Analysing memory corruption

We use the tool valgrind for this.

Run with valgrind /path/to/lokid. It will be slow.

LMDB

Instructions for debugging suspected blockchain corruption as per @HYC

There is an mdb_stat command in the LMDB source that can print statistics about the database but it's not routinely built. This can be built with the following command:

cd ~/loki/external/db_drivers/liblmdb && make

The output of mdb_stat -ea <path to blockchain dir> will indicate inconsistencies in the blocks, block_heights and block_info table.

The output of mdb_dump -s blocks <path to blockchain dir> and mdb_dump -s block_info <path to blockchain dir> is useful for indicating whether blocks and block_info contain the same keys.

These records are dumped as hex data, where the first line is the key and the second line is the data.