/remix

Primary LanguageC++OtherNOASSERTION

Remix

Copyright 2018, The Remix Project
Copyright 2014-2017, The Monero Project
Portions Copyright 2012-2013 The Cryptonote developers

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Remix Development and Community Resources

Introduction

Remix is a private, secure, untraceable, decentralized digital currency based on the Monero codebase. Remix aims to be a fungible and untraceable digital peer-to-peer medium of exchange, actively developed. Remix is the start of a new, distinctive period for CryptoNote cryptocurrencies.

  • Privacy: Remix uses a cryptographically sound system to allow you to send and receive funds without your transactions being easily revealed on the blockchain1. 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 24 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, Remix 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 Remix. It is open source and free to use without restrictions, less those specified in the license agreement referenced below. There are no restrictions on anyone creating an alternative implementation of Remix that uses the protocol and network in a compatible manner.

As with many other existing development projects, the repository on GitLab is considered to be the staging2 area for the latest changes. Before changes are merged into the master repository they are tested by individual developers as well as contributors who focus on thorough testing and code reviews. However, 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.

License

Remix is released under the terms of the Modified BSD License. See LICENSE for more information.

Supporting the project

Remix development can be supported directly through donations. Both Remix and Monero donations can be made in support of future development.

Remix donations:

  • Address: REMXiqQhgfqWtZ1gfxP4iDbXEV4f8cUDFAp2Bz43PztJSJvv2mUqG4Z2YFBMauJV74YCDcJLyqkbCfsC55LNJhQfZxdiE5tGxKq
  • Viewkey: e4a70b5a09330375c11dfcd7ba7e40974ec57a6be85c5da7cfae36d4c50cd44b

Monero donations:

  • Address: 4963h1qpTN8MP7ETNEuaKU9M8zxEXw36ZYpaHaDkRkyXKrxyHXQdzoeDx8jLPmdQfEVCMXzhzTxFo8xC1X5ozGceUbyq1CL
  • Viewkey: c3ed0297af23654d6d29f10b01dbc5a892494c5d0968f62f8a09244d8b87f7f4

Note: you can easily donate Remix to the Remix donation address by using the donate command. Type help in the command-line wallet for details.

There are also several mining pools that kindly donate a portion of their fees

Contributing to Remix

Anyone can contribute to Remix. If you have a fix or code change, it is encouraged to submit it as a pull request. In cases where the change is relatively small or does not impact other parts of the Remix codebase, it may be merged in immediately by any one of the collaborators. If the change is particularly large, significant, or complex, it is expected that the change and its intent will be discussed at length either in advance of the pull request being submitted, or even directly on the pull request prior to final approval.

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

Compiling Remix from source

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).

Dependencies

Dep Min. version Vendored Debian/Ubuntu pkg Arch pkg Required Purpose
GCC 4.7.3 NO build-essential base-devel YES
CMake 3.0.0 NO cmake cmake YES
pkg-config any NO pkg-config base-devel YES
Boost 1.58 NO libboost-all-dev boost YES C++ libraries
OpenSSL basically any NO libssl-dev openssl YES sha256 sum
libzmq 3.0.0 NO libzmq3-dev zeromq YES ZeroMQ library
libunbound 1.4.16 YES libunbound-dev unbound YES DNS resolver
libminiupnpc 2.0 YES libminiupnpc-dev miniupnpc NO NAT punching
libunwind any NO libunwind8-dev libunwind NO Stack traces
liblzma any NO liblzma-dev xz NO For libunwind
libreadline 6.3.0 NO libreadline-dev readline NO Input editing
ldns 1.6.17 NO libldns-dev ldns NO SSL toolkit
expat 1.1 NO libexpat1-dev expat NO XML parsing
GTest 1.5 YES libgtest-dev gtest NO Test suite
Doxygen any NO doxygen doxygen NO Documentation
Graphviz any NO graphviz graphviz NO Documentation

Build instructions

Remix 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 remix
  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/remix/build/release/bin" to .profile

  • Run Remix with remixd --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

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-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 remixd

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/remixd

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

To run as a systemd service, copy remixd.service to /etc/systemd/system/ and remixd.conf to /etc/. The example service assumes that the user remix 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 remix-wallet-cli, and possibly remixd, if you get crashes refreshing.

Using Tor

While Remix isn't made to integrate with Tor, it can be used wrapped with torsocks, if you add --p2p-bind-ip 127.0.0.1 to the remixd command line. You also want to set DNS requests to go over TCP, so they'll be routed through Tor, by setting DNS_PUBLIC=tcp or use a particular DNS server with DNS_PUBLIC=tcp://a.b.c.d (default is 8.8.4.4, which is Google DNS). You may also disable IGD (UPnP port forwarding negotiation), which is pointless with Tor. To allow local connections from the wallet, you might have to add TORSOCKS_ALLOW_INBOUND=1, some OSes need it and some don't. Example:

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

or:

DNS_PUBLIC=tcp TORSOCKS_ALLOW_INBOUND=1 torsocks remixd --p2p-bind-ip 127.0.0.1 --no-igd

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 ./remixd --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

./remix-wallet-cli

Debugging

This section contains general instructions for debugging failed installs or problems encountered with Remix. First ensure you are running the latest version built from the Gitlab 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/remixd `pidof remixd`

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 remixd. 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/remixd /path/to/dumpfile

Print the stack trace with bt

  • To run Remix within gdb:

Type gdb /path/to/remixd

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

Type run to run remixd

Analyzing memory corruption

We use the tool valgrind for this.

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

LMDB

Instructions for debugging suspected blockchain corruption as per @HYC of the Monero Project

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 ~/remix/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.

Open Alias

The Remix wallet client supports OpenAlias Addresses. Instructions for setting up OpenAlias on a domain name.

Create a TXT DNS Record on your domain with using the following syntax

oa1:remix recipient_address=<YOUR WALLET ADDRESS>;

You can then send funds to the domain name in place of the wallet address.

transfer 2 alias.domain.com 100

Please refer to OpenAlias.org for full implementation and security recommendations

1. Decentralized, digital ledger of transactions ↩
2. Staging is an environment for final testing immediately prior to deploying to production ↩