UNIX BUILD NOTES ==================== Some notes on how to build Litecoin in Unix. Note --------------------- Always use absolute paths to configure and compile litecoin and the dependencies, for example, when specifying the the path of the dependency: ../dist/configure --enable-cxx --disable-shared --with-pic --prefix=$BDB_PREFIX Here BDB_PREFIX must 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 | SSL Support | Secure communications libboost | Boost | C++ Library 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) For the versions used in the release, see [release-process.md](release-process.md) under *Fetch and build inputs*. System requirements -------------------- C++ compilers are memory-hungry. It is recommended to have at least 1 GB of memory available when compiling Litecoin Core. With 512MB of memory or less compilation will take much longer due to swap thrashing. Dependency Build Instructions: Ubuntu & Debian ---------------------------------------------- Build requirements: sudo apt-get install build-essential libtool autotools-dev autoconf pkg-config libssl-dev for Ubuntu 12.04 and later or Debian 7 and later libboost-all-dev has to be installed: sudo apt-get install libboost-all-dev db4.8 packages are available [here](https://launchpad.net/~bitcoin/+archive/bitcoin). You can add the repository using the following command: sudo add-apt-repository ppa:bitcoin/bitcoin sudo apt-get update Ubuntu 12.04 and later have packages for libdb5.1-dev and libdb5.1++-dev, but using these will break binary wallet compatibility, and is not recommended. for Debian 7 (Wheezy) and later: The oldstable repository contains db4.8 packages. Add the following line to /etc/apt/sources.list, replacing [mirror] with any official debian mirror. deb http://[mirror]/debian/ oldstable main To enable the change run sudo apt-get update for other Debian & Ubuntu (with ppa): sudo apt-get install libdb4.8-dev libdb4.8++-dev Optional: sudo apt-get install libminiupnpc-dev (see --with-miniupnpc and --enable-upnp-default) 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 4 or Qt 5 are necessary to build the GUI. If both Qt 4 and Qt 5 are installed, Qt 4 will be used. Pass `--with-gui=qt5` to configure to choose Qt5. To build without GUI pass `--without-gui`. To build with Qt 4 you need the following: sudo apt-get install libqt4-dev libprotobuf-dev protobuf-compiler For Qt 5 you need the following: sudo apt-get install libqt5gui5 libqt5core5a libqt5dbus5 qttools5-dev qttools5-dev-tools 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. 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 To build: tar -xzvf miniupnpc-1.6.tar.gz cd miniupnpc-1.6 make sudo su make install 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 $BDB_PREFIX # Fetch the source and verify that it is not tampered with wget 'http://download.oracle.com/berkeley-db/db-4.8.30.NC.tar.gz' echo '12edc0df75bf9abd7f82f821795bcee50f42cb2e5f76a6a281b85732798364ef db-4.8.30.NC.tar.gz' | sha256sum -c # -> db-4.8.30.NC.tar.gz: OK tar -xzvf db-4.8.30.NC.tar.gz # Build the library and install to our prefix cd db-4.8.30.NC/build_unix/ # Note: Do a static build so that it can be embedded into the exectuable, instead of having to find a .so at runtime ../dist/configure --enable-cxx --disable-shared --with-pic --prefix=$BDB_PREFIX make install # Configure Litecoin Core to use our own-built instance of BDB cd $LITECOIN_ROOT ./configure (other args...) LDFLAGS="-L${BDB_PREFIX}/lib/" CPPFLAGS="-I${BDB_PREFIX}/include/" ``` **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. An attacker who is able to cause execution of code at an arbitrary memory location is thwarted if he doesn'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`.