Copyright (c) 2018-2018 The Knownero Project.
Copyright (c) 2014-2018 The Monero Project.
Portions Copyright (c) 2012-2013 The Cryptonote developers.

• Web: knownero.org
• GitHub: https://github.com/knownero/knownero

Knownero is a private, secure, untraceable, decentralised digital token for knownero.com (Incoming). You are your bank, you control your funds, and nobody can trace your transfers unless you allow them to do so.

Privacy: Knownero 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, Knownero 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.

This is the core implementation of Knownero. 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 Knownero 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 Knownero'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.

See LICENSE.

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

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).

[^] 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/

apt-get install build-essential cmake pkg-config libboost-all-dev libssl-dev libunbound-dev libminiupnpc-dev libunwind8-dev liblzma-dev libldns-dev libexpat1-dev libgtest-dev doxygen graphviz libzmq3-dev

Clone recursively to pull-in needed submodule(s):

$ git clone --recursive https://github.com/knownero/knownero

If you already have a repo cloned, initialize and update:

$ cd knownero && git submodule init && git submodule update

Knownero uses the CMake build system and a top-level Makefile that invokes cmake commands as needed.

• Install the dependencies

• Change to the root of the source code directory and build:

    cd knownero
    make release
  

  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/knownero/build/release/bin" to .profile

• Run Knownero with knownerod --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
  

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/knownerod

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

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

This section contains general instructions for debugging failed installs or problems encountered with Knownero. First ensure you are running the latest version built from the Github repo.

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/knownerod `pidof knownerod` 

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 knownerod. 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/knownerod /path/to/dumpfile

Print the stack trace with bt

• To run knownero within gdb:

Type gdb /path/to/knownerod

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

Type run to run knownerod

We use the tool valgrind for this.

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

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 ~/knownero/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.