UNIX BUILD NOTES ==================== Some notes on how to build Litecoin Core in Unix. (for OpenBSD specific instructions, see [build-openbsd.md](build-openbsd.md)) Note --------------------- Always use absolute paths to configure and compile litecoin and the dependencies, for example, when specifying the path of the dependency: ../dist/configure --enable-cxx --disable-shared --with-pic --prefix=$BDB_PREFIX Here BDB_PREFIX must be an absolute path - it is defined using $(pwd) which ensures the usage of the absolute path. To Build --------------------- ```bash ./autogen.sh ./configure make make install # optional ``` This will build litecoin-qt as well if the dependencies are met. Dependencies --------------------- These dependencies are required: Library | Purpose | Description ------------|------------------|---------------------- libssl | Crypto | Random Number Generation, Elliptic Curve Cryptography libboost | Utility | Library for threading, data structures, etc libevent | Networking | OS independent asynchronous networking Optional dependencies: Library | Purpose | Description ------------|------------------|---------------------- miniupnpc | UPnP Support | Firewall-jumping support libdb4.8 | Berkeley DB | Wallet storage (only needed when wallet enabled) qt | GUI | GUI toolkit (only needed when GUI enabled) protobuf | Payments in GUI | Data interchange format used for payment protocol (only needed when GUI enabled) libqrencode | QR codes in GUI | Optional for generating QR codes (only needed when GUI enabled) univalue | Utility | JSON parsing and encoding (bundled version will be used unless --with-system-univalue passed to configure) libzmq3 | ZMQ notification | Optional, allows generating ZMQ notifications (requires ZMQ version >= 4.x) For the versions used in the release, see [release-process.md](release-process.md) under *Fetch and build inputs*. Memory Requirements -------------------- C++ compilers are memory-hungry. It is recommended to have at least 1.5 GB of memory available when compiling Litecoin Core. On systems with less, gcc can be tuned to conserve memory with additional CXXFLAGS: ./configure CXXFLAGS="--param ggc-min-expand=1 --param ggc-min-heapsize=32768" Dependency Build Instructions: Ubuntu & Debian ---------------------------------------------- Build requirements: sudo apt-get install build-essential libtool autotools-dev automake pkg-config libssl-dev libevent-dev bsdmainutils Options when installing required Boost library files: 1. On at least Ubuntu 14.04+ and Debian 7+ there are generic names for the individual boost development packages, so the following can be used to only install necessary parts of boost: sudo apt-get install libboost-system-dev libboost-filesystem-dev libboost-chrono-dev libboost-program-options-dev libboost-test-dev libboost-thread-dev 2. If that doesn't work, you can install all boost development packages with: sudo apt-get install libboost-all-dev BerkeleyDB is required for the wallet. db4.8 packages are available [here](https://launchpad.net/~bitcoin/+archive/bitcoin). You can add the repository and install using the following commands: sudo apt-get install software-properties-common sudo add-apt-repository ppa:bitcoin/bitcoin sudo apt-get update sudo apt-get install libdb4.8-dev libdb4.8++-dev Ubuntu and Debian have their own libdb-dev and libdb++-dev packages, but these will install BerkeleyDB 5.1 or later, which break binary wallet compatibility with the distributed executables which are based on BerkeleyDB 4.8. If you do not care about wallet compatibility, pass `--with-incompatible-bdb` to configure. See the section "Disable-wallet mode" to build Litecoin Core without wallet. Optional: sudo apt-get install libminiupnpc-dev (see --with-miniupnpc and --enable-upnp-default) ZMQ dependencies: sudo apt-get install libzmq3-dev (provides ZMQ API 4.x) Dependencies for the GUI: Ubuntu & Debian ----------------------------------------- If you want to build Litecoin-Qt, make sure that the required packages for Qt development are installed. Either Qt 5 or Qt 4 are necessary to build the GUI. If both Qt 4 and Qt 5 are installed, Qt 5 will be used. Pass `--with-gui=qt4` to configure to choose Qt4. To build without GUI pass `--without-gui`. To build with Qt 5 (recommended) you need the following: sudo apt-get install libqt5gui5 libqt5core5a libqt5dbus5 qttools5-dev qttools5-dev-tools libprotobuf-dev protobuf-compiler Alternatively, to build with Qt 4 you need the following: sudo apt-get install libqt4-dev libprotobuf-dev protobuf-compiler libqrencode (optional) can be installed with: sudo apt-get install libqrencode-dev Once these are installed, they will be found by configure and a litecoin-qt executable will be built by default. Dependency Build Instructions: Fedora ------------------------------------- Build requirements: sudo dnf install gcc-c++ libtool make autoconf automake openssl-devel libevent-devel boost-devel libdb4-devel libdb4-cxx-devel Optional: sudo dnf install miniupnpc-devel To build with Qt 5 (recommended) you need the following: sudo dnf install qt5-qttools-devel qt5-qtbase-devel protobuf-devel libqrencode (optional) can be installed with: sudo dnf install qrencode-devel Notes ----- The release is built with GCC and then "strip litecoind" to strip the debug symbols, which reduces the executable size by about 90%. miniupnpc --------- [miniupnpc](http://miniupnp.free.fr/) may be used for UPnP port mapping. It can be downloaded from [here]( http://miniupnp.tuxfamily.org/files/). UPnP support is compiled in and turned off by default. See the configure options for upnp behavior desired: --without-miniupnpc No UPnP support miniupnp not required --disable-upnp-default (the default) UPnP support turned off by default at runtime --enable-upnp-default UPnP support turned on by default at runtime Berkeley DB ----------- It is recommended to use Berkeley DB 4.8. If you have to build it yourself: ```bash LITECOIN_ROOT=$(pwd) # Pick some path to install BDB to, here we create a directory within the litecoin directory BDB_PREFIX="${LITECOIN_ROOT}/db4" mkdir -p $BDB_PREFIX # Fetch the source and verify that it is not tampered with wget 'http://download.oracle.com/berkeley-db/db-4.8.30.NC.tar.gz' echo '12edc0df75bf9abd7f82f821795bcee50f42cb2e5f76a6a281b85732798364ef db-4.8.30.NC.tar.gz' | sha256sum -c # -> db-4.8.30.NC.tar.gz: OK tar -xzvf db-4.8.30.NC.tar.gz # Build the library and install to our prefix cd db-4.8.30.NC/build_unix/ # Note: Do a static build so that it can be embedded into the executable, instead of having to find a .so at runtime ../dist/configure --enable-cxx --disable-shared --with-pic --prefix=$BDB_PREFIX make install # Configure Litecoin Core to use our own-built instance of BDB cd $LITECOIN_ROOT ./autogen.sh ./configure LDFLAGS="-L${BDB_PREFIX}/lib/" CPPFLAGS="-I${BDB_PREFIX}/include/" # (other args...) ``` **Note**: You only need Berkeley DB if the wallet is enabled (see the section *Disable-Wallet mode* below). Boost ----- If you need to build Boost yourself: sudo su ./bootstrap.sh ./bjam install Security -------- To help make your litecoin installation more secure by making certain attacks impossible to exploit even if a vulnerability is found, binaries are hardened by default. This can be disabled with: Hardening Flags: ./configure --enable-hardening ./configure --disable-hardening Hardening enables the following features: * Position Independent Executable Build position independent code to take advantage of Address Space Layout Randomization offered by some kernels. Attackers who can cause execution of code at an arbitrary memory location are thwarted if they don't know where anything useful is located. The stack and heap are randomly located by default but this allows the code section to be randomly located as well. On an AMD64 processor where a library was not compiled with -fPIC, this will cause an error such as: "relocation R_X86_64_32 against `......' can not be used when making a shared object;" To test that you have built PIE executable, install scanelf, part of paxutils, and use: scanelf -e ./litecoin The output should contain: TYPE ET_DYN * Non-executable Stack If the stack is executable then trivial stack based buffer overflow exploits are possible if vulnerable buffers are found. By default, litecoin should be built with a non-executable stack but if one of the libraries it uses asks for an executable stack or someone makes a mistake and uses a compiler extension which requires an executable stack, it will silently build an executable without the non-executable stack protection. To verify that the stack is non-executable after compiling use: `scanelf -e ./litecoin` the output should contain: STK/REL/PTL RW- R-- RW- The STK RW- means that the stack is readable and writeable but not executable. Disable-wallet mode -------------------- When the intention is to run only a P2P node without a wallet, litecoin may be compiled in disable-wallet mode with: ./configure --disable-wallet In this case there is no dependency on Berkeley DB 4.8. Mining is also possible in disable-wallet mode, but only using the `getblocktemplate` RPC call not `getwork`. Additional Configure Flags -------------------------- A list of additional configure flags can be displayed with: ./configure --help Setup and Build Example: Arch Linux ----------------------------------- This example lists the steps necessary to setup and build a command line only, non-wallet distribution of the latest changes on Arch Linux: pacman -S git base-devel boost libevent python git clone https://github.com/litecoin-project/litecoin.git cd litecoin/ ./autogen.sh ./configure --disable-wallet --without-gui --without-miniupnpc make check Note: Enabling wallet support requires either compiling against a Berkeley DB newer than 4.8 (package `db`) using `--with-incompatible-bdb`, or building and depending on a local version of Berkeley DB 4.8. The readily available Arch Linux packages are currently built using `--with-incompatible-bdb` according to the [PKGBUILD](https://projects.archlinux.org/svntogit/community.git/tree/bitcoin/trunk/PKGBUILD). As mentioned above, when maintaining portability of the wallet between the standard Litecoin Core distributions and independently built node software is desired, Berkeley DB 4.8 must be used. ARM Cross-compilation ------------------- These steps can be performed on, for example, an Ubuntu VM. The depends system will also work on other Linux distributions, however the commands for installing the toolchain will be different. Make sure you install the build requirements mentioned above. Then, install the toolchain and curl: sudo apt-get install g++-arm-linux-gnueabihf curl To build executables for ARM: cd depends make HOST=arm-linux-gnueabihf NO_QT=1 cd .. ./configure --prefix=$PWD/depends/arm-linux-gnueabihf --enable-glibc-back-compat --enable-reduce-exports LDFLAGS=-static-libstdc++ make For further documentation on the depends system see [README.md](../depends/README.md) in the depends directory.