Edollar

Development resources

Web: edollar.cash
Mail: electronicdollar@gmail.com
GitHub: https://github.com/edollar-project/edollar

Introduction

Edollar is a private, secure, untraceable, decentralised digital currency. You are your bank, you control your funds, and nobody can trace your transfers unless you allow them to do so.

Privacy: Edollar 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, Edollar 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 Edollar. 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 Edollar 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 Edollar'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.

Supporting the project

Edollar development can be supported directly through donations.

BTC: 1Fqq1dmfinPv32tqxD63hTfs7zJ9WHUzuS ETH: 0x94258dABfa3664b640d06A6329c949f532392097 BCC: 1Fqq1dmfinPv32tqxD63hTfs7zJ9WHUzuS XMR: 44spQe3Q3PDXingNyRjRiSCqH3b52cL1J52r6DvfBaLvSiRhEsZe4WiYGRm6LsEq2i221jbLpVvD1Z1 7UWga2oBn1Co6Szq

Core development funding and/or some supporting services are also graciously provided by sponsors: (we will update later)

License

See LICENSE.

Contributing

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

Compiling Edollar 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
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/

Build instructions

Edollar 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 edollar
  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/edollar/build/release/bin" to .profile
Run Edollar with edollard --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
```
Optional: build documentation in doc/html (omit HAVE_DOT=YES if graphviz is not installed):
```
  HAVE_DOT=YES doxygen Doxyfile
```

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 edollar 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 Edollar into the ports tree in the near future, which will aid in managing installations using ports or packages.

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 Edollar.

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. Choose version 4 for db. pkg_add db cmake miniupnpc zeromq.

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 a boost patch, required for OpenBSD
ftp -o boost.patch https://raw.githubusercontent.com/openbsd/ports/bee9e6df517077a7269ff0dfd57995f5c6a10379/devel/boost/patches/patch-boost_test_impl_execution_monitor_ipp
cd boost_1_64_0
patch -p0 < ../boost.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 --with-toolset=clang
./b2 toolset=clang cxxflags="-stdlib=libc++" linkflags="-stdlib=libc++"
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 --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 a library link so cmake is able to find it
doas ln -s /usr/local/lib/libzmq.so.4.1 /usr/local/lib/libzmq.so

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

# Fetch cppzmq source
ftp -o cppzmq-4.2.2.tar.gz https://github.com/zeromq/cppzmq/archive/v4.2.2.tar.gz

# MUST output: (SHA256) cppzmq-4.2.2.tar.gz: OK
echo "3ef50070ac5877c06c6bb25091028465020e181bbfd08f110294ed6bc419737d cppzmq-4.2.2.tar.gz" | sha256 -c
tar xfz cppzmq-4.2.2.tar.gz

# Start building cppzmq
cd cppzmq-4.2.2
mkdir build
cd build
cmake ..
doas make install

Build edollar: 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.

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 edollard

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/edollard

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

To run as a systemd service, copy edollard.service to /etc/systemd/system/ and edollard.conf to /etc/. The example service assumes that the user edollar exists and its home is the data directory specified in the example config.

If you're on Mac, you may need to add the --max-concurrency 1 option to edollar-wallet-cli, and possibly edollard, if you get crashes refreshing.

Debugging

This section contains general instructions for debugging failed installs or problems encountered with Edollar. 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/edollard `pidof edollard`

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 edollard. 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/edollard /path/to/dumpfile

Print the stack trace with bt

To run edollar within gdb:

Type gdb /path/to/edollard

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

Type run to run edollard

Analysing memory corruption

We use the tool valgrind for this.

Run with valgrind /path/to/edollard. 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 ~/edollar/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.

whompy / edollar