ltcd

Table of Contents

1. About
2. Getting Started
   1. Installation
      1. Windows
      2. Linux/BSD/MacOSX/POSIX
   2. Configuration
   3. Controlling and Querying ltcd via ltcctl
   4. Mining
3. Help
   1. Startup
      1. Using bootstrap.dat
   2. Network Configuration
   3. Wallet
4. Contact
   1. Email
5. Developer Resources
   1. Code Contribution Guidelines
   2. JSON-RPC Reference
   3. The ltcsuite Litecoin-related Go Packages
   4. Litecoin functional changes
   5. Diffing ltcd and btcd codebases

1. About

ltcd is a full node litecoin implementation written in Go, licensed under the copyfree ISC License.

This project is currently under active development and is in a Beta state. It is extremely stable and has been in production use since prior December 2018.

It properly downloads, validates, and serves the block chain using the exact rules (including consensus bugs) for block acceptance as Litecoin Core. We have taken great care to avoid ltcd causing a fork to the block chain. It includes a full block validation testing framework which contains all of the 'official' block acceptance tests (and some additional ones) that is run on every pull request to help ensure it properly follows consensus. Also, it passes all of the JSON test data in the Litecoin Core code.

It also properly relays newly mined blocks, maintains a transaction pool, and relays individual transactions that have not yet made it into a block. It ensures all individual transactions admitted to the pool follow the rules required by the block chain and also includes more strict checks which filter transactions based on miner requirements ("standard" transactions).

One key difference between ltcd and Litecoin Core is that ltcd does NOT include wallet functionality and this was a very intentional design decision. See the blog entry here for more details. This means you can't actually make or receive payments directly with ltcd. That functionality is provided by the ltcwallet which is under active development.

Go 1.17 or newer.

2.1 Installation

The first step is to install ltcd. See one of the following sections for details on how to install on the supported operating systems.

2.1.1 Windows Installation

• Install the MSI available at: https://github.com/ltcsuite/ltcd/releases
• Launch ltcd from the Start Menu

2.1.2 Linux/BSD/MacOSX/POSIX Installation

• Install Go according to the installation instructions here: http://go.dev/doc/install

• Ensure Go was installed properly and is a supported version:

$ go version
$ go env GOROOT GOPATH

NOTE: The GOROOT and GOPATH above must not be the same path. It is recommended that GOPATH is set to a directory in your home directory such as ~/goprojects to avoid write permission issues. It is also recommended to add $GOPATH/bin to your PATH at this point.

• Run the following commands to obtain ltcd, all dependencies, and install it:

$ git clone https://github.com/ltcsuite/ltcd
$ cd ltcd
$ GO111MODULE=on go install -v . ./cmd/...

• ltcd (and utilities) will now be installed in $GOPATH/bin. If you did not already add the bin directory to your system path during Go installation, we recommend you do so now.

Updating

• Run the following commands to update ltcd, all dependencies, and install it:

$ cd ltcd
$ git pull
$ GO111MODULE=on go install -v . ./cmd/...

2.2 Configuration

ltcd has a number of configuration options, which can be viewed by running: $ ltcd --help.

2.3 Controlling and Querying ltcd via ltcctl

ltcctl is a command line utility that can be used to both control and query ltcd via RPC. ltcd does not enable its RPC server by default; You must configure at minimum both an RPC username and password or both an RPC limited username and password:

• ltcd.conf configuration file

[Application Options]
rpcuser=myuser
rpcpass=SomeDecentp4ssw0rd
rpclimituser=mylimituser
rpclimitpass=Limitedp4ssw0rd

• ltcctl.conf configuration file

[Application Options]
rpcuser=myuser
rpcpass=SomeDecentp4ssw0rd

OR

[Application Options]
rpclimituser=mylimituser
rpclimitpass=Limitedp4ssw0rd

For a list of available options, run: $ ltcctl --help

2.4 Mining

ltcd supports the getblocktemplate RPC. The limited user cannot access this RPC.

1. Add the payment addresses with the miningaddr option.

[Application Options]
rpcuser=myuser
rpcpass=SomeDecentp4ssw0rd
miningaddr=12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX
miningaddr=1M83ju3EChKYyysmM2FXtLNftbacagd8FR

2. Add ltcd's RPC TLS certificate to system Certificate Authority list.

cgminer uses curl to fetch data from the RPC server. Since curl validates the certificate by default, we must install the ltcd RPC certificate into the default system Certificate Authority list.

Ubuntu

1. Copy rpc.cert to /usr/share/ca-certificates: # cp /home/user/.ltcd/rpc.cert /usr/share/ca-certificates/ltcd.crt
2. Add ltcd.crt to /etc/ca-certificates.conf: # echo ltcd.crt >> /etc/ca-certificates.conf
3. Update the CA certificate list: # update-ca-certificates

3. Set your mining software url to use https.

$ cgminer -o https://127.0.0.1:9334 -u rpcuser -p rpcpassword

3. Help

3.1 Startup

Typically ltcd will run and start downloading the block chain with no extra configuration necessary, however, there is an optional method to use a bootstrap.dat file that may speed up the initial block chain download process.

3.1.1 bootstrap.dat

• Using bootstrap.dat

3.1.2 Network Configuration

• What Ports Are Used by Default?
• How To Listen on Specific Interfaces
• How To Configure RPC Server to Listen on Specific Interfaces
• Configuring ltcd with Tor

3.1 Wallet

ltcd was intentionally developed without an integrated wallet for security reasons. Please see ltcwallet for more information.

4. Contact

4.1 Email

• losh11@litecoin.net - maintainers email.

5. Developer Resources

• Code Contribution Guidelines

• JSON-RPC Reference
  • RPC Examples

• The ltcsuite Litecoin-related Go Packages:
  • btcrpcclient - Implements a robust and easy to use Websocket-enabled Litecoin JSON-RPC client
  • btcjson - Provides an extensive API for the underlying JSON-RPC command and return values
  • wire - Implements the Litecoin wire protocol
  • peer - Provides a common base for creating and managing Litecoin network peers.
  • blockchain - Implements Litecoin block handling and chain selection rules
  • blockchain/fullblocktests - Provides a set of block tests for testing the consensus validation rules
  • txscript - Implements the Litecoin transaction scripting language
  • btcec - Implements support for the elliptic curve cryptographic functions needed for the Litecoin scripts
  • database - Provides a database interface for the Litecoin block chain
  • mempool - Package mempool provides a policy-enforced pool of unmined litecoin transactions.
  • ltcutil - Provides Litecoin-specific convenience functions and types
  • chainhash - Provides a generic hash type and associated functions that allows the specific hash algorithm to be abstracted.
  • connmgr - Package connmgr implements a generic Litecoin network connection manager.

• Litecoin functional changes:
  • btcd's litecoin mode often has untested, and unknown errors due to injection implementation. ltcd removed custom parameter injection, and replaces litecoin network constants as default, with several tests.
  • wire/blockheader.go - declare PowHash method (for scrypt) used instead of BlockHash
  • blockchain/difficulty.go - blocksPerRetarget change for Zeitgeist2 attack
  • blockchain/validate.go - use PowHash (for scrypt) used instead of BlockHash
  • mempool/policy.go - adjust minDustFee (litecoin v0.21 rate)
  • mining/cpuminer/cpu_miner.go - use PowHash (for scrypt) used instead of BlockHash
  • wire/protocol.go - ProtocolVersion uses 70016; MainNet magic number is different; TestNet4 is used instead of TestNet3; Remove Bitcoin softfork service flags & replace with NODE_NETWORK_LIMITED and NODE_MWEB flags.
  • example_test.go - litecoin address used instead of bitcoin address
  • wire/msgtx.go - litecoin MWEB txs are fully deserialsised and consumed.
  • wire/msgblock.go - litecoin MWEB blocks are fully parsed
  • ltcutil/address.go - fix address decoding, ltc1 and L prefixes decoded correctly
  • ltcutil/amount.go - use Math.round() for rounding amounts - fixing float64 overflows
  • rpcserver.go - signed message header is "Litecoin Signed Message:\n".

• Diffing ltcd and btcd codebases
  • ltcd and the ltcsuite group of projects are a fork of btcd and btcsuite. A lot of the changes involve simple renaming of 'btc' to 'ltc'.
    If you wish to diff the two projects (ltcd/btcd) without being swamped, the following grep commands will revert the naming changes when run in the ltcd directory. (There are a few exceptions to these rules, so this kind of change should only be used as an aid to diffing). find -name '.go' -exec sed -i 's/ltcd/btcd/g' {} + find -name '.go' -exec sed -i 's/ltcsuite/btcsuite/g' {} + find -name '*.go' -exec sed -i 's/ltcutil/btcutil/g' {} +