Some notes on how to build Safe Core in Unix.
(for OpenBSD specific instructions, see build-openbsd.md)
Always use absolute paths to configure and compile Safe Core 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.
./autogen.sh
./configure
make
make install # optionalThis will build safe-qt as well if the dependencies are met.
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 under Fetch and build inputs.
C++ compilers are memory-hungry. It is recommended to have at least 1 GB of memory available when compiling Safe Core. With 512MB of memory or less compilation will take much longer due to swap thrashing.
Build requirements:
sudo apt-get install build-essential libtool autotools-dev automake pkg-config libssl-dev libevent-dev bsdmainutils
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 libprotobuf-dev protobuf-compiler
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. You can add the repository and install using the following commands:
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 Safe 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)
If you want to build Safe-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 safe-qt executable will be built by default.
The release is built with GCC and then "strip safed" to strip the debug symbols, which reduces the executable size by about 90%.
miniupnpc may be used for UPnP port mapping. It can be downloaded from here. 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
It is recommended to use Berkeley DB 4.8. If you have to build it yourself:
SAFE_ROOT=$(pwd)
# Pick some path to install BDB to, here we create a directory within the safe directory
BDB_PREFIX="${SAFE_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 Safe Core to use our own-built instance of BDB
cd $SAFE_ROOT
./autogen.sh
./configure LDFLAGS="-L${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).
If you need to build Boost yourself:
sudo su
./bootstrap.sh
./bjam install
To help make your Safe 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 ./safedThe 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, Safe Core 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 ./safedthe output should contain: STK/REL/PTL RW- R-- RW-
The STK RW- means that the stack is readable and writeable but not executable.
When the intention is to run only a P2P node without a wallet, Safe Core 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.
A list of additional configure flags can be displayed with:
./configure --help
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.
First install the toolchain:
sudo apt-get install g++-arm-linux-gnueabihf
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 in the depends directory.