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1648035240

Go Algorand: Algorand's Official Implementation in Go

go-algorand

Algorand's official implementation in Go.

Algorand is a permissionless, pure proof-of-stake blockchain that delivers decentralization, scalability, security, and transaction finality.

Getting Started

Our developer website has the most up to date information about using and installing the Algorand platform.

Building from source

Development is done using the Go Programming Language. The version of go is specified in the project's go.mod file. This document assumes that you have a functioning environment setup. If you need assistance setting up an environment please visit the official Go documentation website.

Linux / OSX

We currently strive to support Debian-based distributions with Ubuntu 18.04 being our official release target. Building on Arch Linux works as well. Our core engineering team uses Linux and OSX, so both environments are well supported for development.

OSX only: Homebrew (brew) must be installed before continuing. Here are the installation requirements.

Initial environment setup:

git clone https://github.com/algorand/go-algorand
cd go-algorand
./scripts/configure_dev.sh
./scripts/buildtools/install_buildtools.sh

At this point, you are ready to build go-algorand. We use make and have a number of targets to automate common tasks.

build

make install

test

# unit tests
make test

# integration tests
make integration

style and checks

make fmt
make lint
make fix
make vet

or alternatively

make sanity

Running a node

Once the software is built you'll find binaries in ${GOPATH}/bin, and a data directory will be initialized at ~/.algorand. Start your node with ${GOPATH}/bin/goal node start -d ~/.algorand, use ${GOPATH}/bin/carpenter -d ~/.algorand to see activity. Refer to the developer website for how to use the different tools.

Providing your own data directory

You can run a node out of other directories than ~/.algorand and join networks other than mainnet. Just make a new directory and copy into it the genesis.json file for the network. For example:

mkdir ~/testnet_data
cp installer/genesis/testnet/genesis.json ~/testnet_data/genesis.json
${GOPATH}/bin/goal node start -d ~/testnet_data

Genesis files for mainnet, testnet, and betanet can be found in installer/genesis/.

Contributing (Code, Documentation, Bugs, Etc)

Please refer to our CONTRIBUTING document.

Project Layout

go-algorand is split into various subpackages.

The following packages provide core functionality to the algod and kmd daemons, as well as other tools and commands:

  • crypto contains the cryptographic constructions we're using for hashing, signatures, and VRFs. There are also some Algorand-specific details here about spending keys, protocols keys, one-time-use signing keys, and how they relate to each other.
  • config holds configuration parameters. These include parameters used locally by the node as well as parameters that must be agreed upon by the protocol.
  • data defines various types used throughout the codebase.
    • basics hold basic types such as MicroAlgos, account data, and addresses.
    • account defines accounts, including "root" accounts (which can spend money) and "participation" accounts (which can participate in the agreement protocol).
    • transactions define transactions that accounts can issue against the Algorand state. These include standard payments and also participation key registration transactions.
    • bookkeeping defines blocks, which are batches of transactions atomically committed to Algorand.
    • pools implement the transaction pool. The transaction pool holds transactions seen by a node in memory before they are proposed in a block.
    • committee implements the credentials that authenticate a participating account's membership in the agreement protocol.
  • ledger (README) contains the Algorand Ledger state machine, which holds the sequence of blocks. The Ledger executes the state transitions that result from applying these blocks. It answers queries on blocks (e.g., what transactions were in the last committed block?) and on accounts (e.g., what is my balance?).
  • protocol declares constants used to identify protocol versions, tags for routing network messages, and prefixes for domain separation of cryptographic inputs. It also implements the canonical encoder.
  • network contains the code for participating in a mesh network based on WebSockets. Maintains connection to some number of peers, (optionally) accepts connections from peers, sends point to point and broadcast messages, and receives messages routing them to various handler code (e.g. agreement/gossip/network.go registers three handlers).
    • rpcs contains the HTTP RPCs used by algod processes to query one another.
  • agreement (README) contains the agreement service, which implements Algorand's Byzantine Agreement protocol. This protocol allows participating accounts to quickly confirm blocks in a fork-safe manner, provided that sufficient account stake is correctly executing the protocol.
  • node integrates the components above and handles initialization and shutdown. It provides queries into these components.

daemon defines the two daemons which provide Algorand clients with services:

  • daemon/algod holds the algod daemon, which implements a participating node. algod allows a node to participate in the agreement protocol, submit and confirm transactions, and view the state of the Algorand Ledger.
    • daemon/algod/api (README) is the REST interface used for interactions with algod.
  • daemon/kmd (README) holds the kmd daemon. This daemon allows a node to sign transactions. Because kmd is separate from algod, kmd allows a user to sign transactions on an air-gapped computer.

The following packages allow developers to interface with the Algorand system:

  • cmd holds the primary commands defining entry points into the system.
    • cmd/catchupsrv (README) is a tool to assist with processing historic blocks on a new node.
  • libgoal exports a Go interface useful for developers of Algorand clients.
  • tools (README) various tools and utilities without a better place to go.
  • tools/debug holds secondary commands which assist developers during debugging.
  • tools/misc (README) small tools that are sometimes handy in a pinch.

The following packages contain tools to help Algorand developers deploy networks of their own:

  • nodecontrol
  • docker
  • commandandcontrol (README) is a tool to automate a network of algod instances.
  • components
  • netdeploy

A number of packages provide utilities for the various components:

  • logging is a wrapper around logrus.
  • util contains a variety of utilities, including a codec, a SQLite wrapper, a goroutine pool, a timer interface, node metrics, and more.

test (README) contains end-to-end tests and utilities for the above components.

Download Details:
Author: algorand
Source Code: https://github.com/algorand/go-algorand
License: View license

#algorand  #blockchain  #cryptocurrency 

What is GEEK

Buddha Community

Go Algorand: Algorand's Official Implementation in Go
Fannie  Zemlak

Fannie Zemlak

1599854400

What's new in the go 1.15

Go announced Go 1.15 version on 11 Aug 2020. Highlighted updates and features include Substantial improvements to the Go linker, Improved allocation for small objects at high core counts, X.509 CommonName deprecation, GOPROXY supports skipping proxies that return errors, New embedded tzdata package, Several Core Library improvements and more.

As Go promise for maintaining backward compatibility. After upgrading to the latest Go 1.15 version, almost all existing Golang applications or programs continue to compile and run as older Golang version.

#go #golang #go 1.15 #go features #go improvement #go package #go new features

Best of Crypto

Best of Crypto

1648035240

Go Algorand: Algorand's Official Implementation in Go

go-algorand

Algorand's official implementation in Go.

Algorand is a permissionless, pure proof-of-stake blockchain that delivers decentralization, scalability, security, and transaction finality.

Getting Started

Our developer website has the most up to date information about using and installing the Algorand platform.

Building from source

Development is done using the Go Programming Language. The version of go is specified in the project's go.mod file. This document assumes that you have a functioning environment setup. If you need assistance setting up an environment please visit the official Go documentation website.

Linux / OSX

We currently strive to support Debian-based distributions with Ubuntu 18.04 being our official release target. Building on Arch Linux works as well. Our core engineering team uses Linux and OSX, so both environments are well supported for development.

OSX only: Homebrew (brew) must be installed before continuing. Here are the installation requirements.

Initial environment setup:

git clone https://github.com/algorand/go-algorand
cd go-algorand
./scripts/configure_dev.sh
./scripts/buildtools/install_buildtools.sh

At this point, you are ready to build go-algorand. We use make and have a number of targets to automate common tasks.

build

make install

test

# unit tests
make test

# integration tests
make integration

style and checks

make fmt
make lint
make fix
make vet

or alternatively

make sanity

Running a node

Once the software is built you'll find binaries in ${GOPATH}/bin, and a data directory will be initialized at ~/.algorand. Start your node with ${GOPATH}/bin/goal node start -d ~/.algorand, use ${GOPATH}/bin/carpenter -d ~/.algorand to see activity. Refer to the developer website for how to use the different tools.

Providing your own data directory

You can run a node out of other directories than ~/.algorand and join networks other than mainnet. Just make a new directory and copy into it the genesis.json file for the network. For example:

mkdir ~/testnet_data
cp installer/genesis/testnet/genesis.json ~/testnet_data/genesis.json
${GOPATH}/bin/goal node start -d ~/testnet_data

Genesis files for mainnet, testnet, and betanet can be found in installer/genesis/.

Contributing (Code, Documentation, Bugs, Etc)

Please refer to our CONTRIBUTING document.

Project Layout

go-algorand is split into various subpackages.

The following packages provide core functionality to the algod and kmd daemons, as well as other tools and commands:

  • crypto contains the cryptographic constructions we're using for hashing, signatures, and VRFs. There are also some Algorand-specific details here about spending keys, protocols keys, one-time-use signing keys, and how they relate to each other.
  • config holds configuration parameters. These include parameters used locally by the node as well as parameters that must be agreed upon by the protocol.
  • data defines various types used throughout the codebase.
    • basics hold basic types such as MicroAlgos, account data, and addresses.
    • account defines accounts, including "root" accounts (which can spend money) and "participation" accounts (which can participate in the agreement protocol).
    • transactions define transactions that accounts can issue against the Algorand state. These include standard payments and also participation key registration transactions.
    • bookkeeping defines blocks, which are batches of transactions atomically committed to Algorand.
    • pools implement the transaction pool. The transaction pool holds transactions seen by a node in memory before they are proposed in a block.
    • committee implements the credentials that authenticate a participating account's membership in the agreement protocol.
  • ledger (README) contains the Algorand Ledger state machine, which holds the sequence of blocks. The Ledger executes the state transitions that result from applying these blocks. It answers queries on blocks (e.g., what transactions were in the last committed block?) and on accounts (e.g., what is my balance?).
  • protocol declares constants used to identify protocol versions, tags for routing network messages, and prefixes for domain separation of cryptographic inputs. It also implements the canonical encoder.
  • network contains the code for participating in a mesh network based on WebSockets. Maintains connection to some number of peers, (optionally) accepts connections from peers, sends point to point and broadcast messages, and receives messages routing them to various handler code (e.g. agreement/gossip/network.go registers three handlers).
    • rpcs contains the HTTP RPCs used by algod processes to query one another.
  • agreement (README) contains the agreement service, which implements Algorand's Byzantine Agreement protocol. This protocol allows participating accounts to quickly confirm blocks in a fork-safe manner, provided that sufficient account stake is correctly executing the protocol.
  • node integrates the components above and handles initialization and shutdown. It provides queries into these components.

daemon defines the two daemons which provide Algorand clients with services:

  • daemon/algod holds the algod daemon, which implements a participating node. algod allows a node to participate in the agreement protocol, submit and confirm transactions, and view the state of the Algorand Ledger.
    • daemon/algod/api (README) is the REST interface used for interactions with algod.
  • daemon/kmd (README) holds the kmd daemon. This daemon allows a node to sign transactions. Because kmd is separate from algod, kmd allows a user to sign transactions on an air-gapped computer.

The following packages allow developers to interface with the Algorand system:

  • cmd holds the primary commands defining entry points into the system.
    • cmd/catchupsrv (README) is a tool to assist with processing historic blocks on a new node.
  • libgoal exports a Go interface useful for developers of Algorand clients.
  • tools (README) various tools and utilities without a better place to go.
  • tools/debug holds secondary commands which assist developers during debugging.
  • tools/misc (README) small tools that are sometimes handy in a pinch.

The following packages contain tools to help Algorand developers deploy networks of their own:

  • nodecontrol
  • docker
  • commandandcontrol (README) is a tool to automate a network of algod instances.
  • components
  • netdeploy

A number of packages provide utilities for the various components:

  • logging is a wrapper around logrus.
  • util contains a variety of utilities, including a codec, a SQLite wrapper, a goroutine pool, a timer interface, node metrics, and more.

test (README) contains end-to-end tests and utilities for the above components.

Download Details:
Author: algorand
Source Code: https://github.com/algorand/go-algorand
License: View license

#algorand  #blockchain  #cryptocurrency 

Best of Crypto

Best of Crypto

1648134900

Go Sumhash: A Go Implementation Of Algorand’s Subset-sum Hash Function

Sumhash

A Go implementation of Algorand’s subset-sum hash function. The library exports the subset sum hash function via a hash.Hash interface.

Install

go get github.com/algorand/go-sumhash

Alternatively the same can be achieved if you use import in a package:

import "github.com/algorand/go-sumhash"

and run go get without parameters.

Usage

Construct a sumhash instance with block size of 512.

package main

import (
    "fmt"

    "github.com/algorand/go-sumhash"
)

func main() {
    h := sumhash.New512(nil)
    input := []byte("sumhash input")
    _, _ = h.Write(input)

    sum := h.Sum(nil)
    fmt.Printf("subset sum hash value: %X", sum)
}

Testing

go test ./...

Spec

The specification of the function as well as the security parameters can be found here

Download Details:
Author: algorand
Source Code: https://github.com/algorand/go-sumhash
License: MIT License

#algorand  #blockchain  #cryptocurrency #go #golang 

Waylon  Bruen

Waylon Bruen

1646870880

Go-ethereum: Official Go Implementation Of The Ethereum Protocol

Go Ethereum

Official Golang implementation of the Ethereum protocol.

Automated builds are available for stable releases and the unstable master branch. Binary archives are published at https://geth.ethereum.org/downloads/.

Building the source

For prerequisites and detailed build instructions please read the Installation Instructions.

Building geth requires both a Go (version 1.14 or later) and a C compiler. You can install them using your favourite package manager. Once the dependencies are installed, run

make geth

or, to build the full suite of utilities:

make all

Executables

The go-ethereum project comes with several wrappers/executables found in the cmd directory.

CommandDescription
gethOur main Ethereum CLI client. It is the entry point into the Ethereum network (main-, test- or private net), capable of running as a full node (default), archive node (retaining all historical state) or a light node (retrieving data live). It can be used by other processes as a gateway into the Ethereum network via JSON RPC endpoints exposed on top of HTTP, WebSocket and/or IPC transports. geth --help and the CLI page for command line options.
clefStand-alone signing tool, which can be used as a backend signer for geth.
devp2pUtilities to interact with nodes on the networking layer, without running a full blockchain.
abigenSource code generator to convert Ethereum contract definitions into easy to use, compile-time type-safe Go packages. It operates on plain Ethereum contract ABIs with expanded functionality if the contract bytecode is also available. However, it also accepts Solidity source files, making development much more streamlined. Please see our Native DApps page for details.
bootnodeStripped down version of our Ethereum client implementation that only takes part in the network node discovery protocol, but does not run any of the higher level application protocols. It can be used as a lightweight bootstrap node to aid in finding peers in private networks.
evmDeveloper utility version of the EVM (Ethereum Virtual Machine) that is capable of running bytecode snippets within a configurable environment and execution mode. Its purpose is to allow isolated, fine-grained debugging of EVM opcodes (e.g. evm --code 60ff60ff --debug run).
rlpdumpDeveloper utility tool to convert binary RLP (Recursive Length Prefix) dumps (data encoding used by the Ethereum protocol both network as well as consensus wise) to user-friendlier hierarchical representation (e.g. rlpdump --hex CE0183FFFFFFC4C304050583616263).
puppetha CLI wizard that aids in creating a new Ethereum network.

Running geth

Going through all the possible command line flags is out of scope here (please consult our CLI Wiki page), but we've enumerated a few common parameter combos to get you up to speed quickly on how you can run your own geth instance.

Hardware Requirements

Minimum:

  • CPU with 2+ cores
  • 4GB RAM
  • 500GB free storage space to sync the Mainnet
  • 8 MBit/sec download Internet service

Recommended:

  • Fast CPU with 4+ cores
  • 16GB+ RAM
  • High Performance SSD with at least 500GB free space
  • 25+ MBit/sec download Internet service

Full node on the main Ethereum network

By far the most common scenario is people wanting to simply interact with the Ethereum network: create accounts; transfer funds; deploy and interact with contracts. For this particular use-case the user doesn't care about years-old historical data, so we can sync quickly to the current state of the network. To do so:

$ geth console

This command will:

  • Start geth in snap sync mode (default, can be changed with the --syncmode flag), causing it to download more data in exchange for avoiding processing the entire history of the Ethereum network, which is very CPU intensive.
  • Start up geth's built-in interactive JavaScript console, (via the trailing console subcommand) through which you can interact using web3 methods (note: the web3 version bundled within geth is very old, and not up to date with official docs), as well as geth's own management APIs. This tool is optional and if you leave it out you can always attach to an already running geth instance with geth attach.

A Full node on the Görli test network

Transitioning towards developers, if you'd like to play around with creating Ethereum contracts, you almost certainly would like to do that without any real money involved until you get the hang of the entire system. In other words, instead of attaching to the main network, you want to join the test network with your node, which is fully equivalent to the main network, but with play-Ether only.

$ geth --goerli console

The console subcommand has the exact same meaning as above and they are equally useful on the testnet too. Please, see above for their explanations if you've skipped here.

Specifying the --goerli flag, however, will reconfigure your geth instance a bit:

  • Instead of connecting the main Ethereum network, the client will connect to the Görli test network, which uses different P2P bootnodes, different network IDs and genesis states.
  • Instead of using the default data directory (~/.ethereum on Linux for example), geth will nest itself one level deeper into a goerli subfolder (~/.ethereum/goerli on Linux). Note, on OSX and Linux this also means that attaching to a running testnet node requires the use of a custom endpoint since geth attach will try to attach to a production node endpoint by default, e.g., geth attach <datadir>/goerli/geth.ipc. Windows users are not affected by this.

Note: Although there are some internal protective measures to prevent transactions from crossing over between the main network and test network, you should make sure to always use separate accounts for play-money and real-money. Unless you manually move accounts, geth will by default correctly separate the two networks and will not make any accounts available between them.

Full node on the Rinkeby test network

Go Ethereum also supports connecting to the older proof-of-authority based test network called Rinkeby which is operated by members of the community.

$ geth --rinkeby console

Full node on the Ropsten test network

In addition to Görli and Rinkeby, Geth also supports the ancient Ropsten testnet. The Ropsten test network is based on the Ethash proof-of-work consensus algorithm. As such, it has certain extra overhead and is more susceptible to reorganization attacks due to the network's low difficulty/security.

$ geth --ropsten console

Note: Older Geth configurations store the Ropsten database in the testnet subdirectory.

Configuration

As an alternative to passing the numerous flags to the geth binary, you can also pass a configuration file via:

$ geth --config /path/to/your_config.toml

To get an idea how the file should look like you can use the dumpconfig subcommand to export your existing configuration:

$ geth --your-favourite-flags dumpconfig

Note: This works only with geth v1.6.0 and above.

Docker quick start

One of the quickest ways to get Ethereum up and running on your machine is by using Docker:

docker run -d --name ethereum-node -v /Users/alice/ethereum:/root \
           -p 8545:8545 -p 30303:30303 \
           ethereum/client-go

This will start geth in snap-sync mode with a DB memory allowance of 1GB just as the above command does. It will also create a persistent volume in your home directory for saving your blockchain as well as map the default ports. There is also an alpine tag available for a slim version of the image.

Do not forget --http.addr 0.0.0.0, if you want to access RPC from other containers and/or hosts. By default, geth binds to the local interface and RPC endpoints are not accessible from the outside.

Programmatically interfacing geth nodes

As a developer, sooner rather than later you'll want to start interacting with geth and the Ethereum network via your own programs and not manually through the console. To aid this, geth has built-in support for a JSON-RPC based APIs (standard APIs and geth specific APIs). These can be exposed via HTTP, WebSockets and IPC (UNIX sockets on UNIX based platforms, and named pipes on Windows).

The IPC interface is enabled by default and exposes all the APIs supported by geth, whereas the HTTP and WS interfaces need to manually be enabled and only expose a subset of APIs due to security reasons. These can be turned on/off and configured as you'd expect.

HTTP based JSON-RPC API options:

  • --http Enable the HTTP-RPC server
  • --http.addr HTTP-RPC server listening interface (default: localhost)
  • --http.port HTTP-RPC server listening port (default: 8545)
  • --http.api API's offered over the HTTP-RPC interface (default: eth,net,web3)
  • --http.corsdomain Comma separated list of domains from which to accept cross origin requests (browser enforced)
  • --ws Enable the WS-RPC server
  • --ws.addr WS-RPC server listening interface (default: localhost)
  • --ws.port WS-RPC server listening port (default: 8546)
  • --ws.api API's offered over the WS-RPC interface (default: eth,net,web3)
  • --ws.origins Origins from which to accept websockets requests
  • --ipcdisable Disable the IPC-RPC server
  • --ipcapi API's offered over the IPC-RPC interface (default: admin,debug,eth,miner,net,personal,shh,txpool,web3)
  • --ipcpath Filename for IPC socket/pipe within the datadir (explicit paths escape it)

You'll need to use your own programming environments' capabilities (libraries, tools, etc) to connect via HTTP, WS or IPC to a geth node configured with the above flags and you'll need to speak JSON-RPC on all transports. You can reuse the same connection for multiple requests!

Note: Please understand the security implications of opening up an HTTP/WS based transport before doing so! Hackers on the internet are actively trying to subvert Ethereum nodes with exposed APIs! Further, all browser tabs can access locally running web servers, so malicious web pages could try to subvert locally available APIs!

Operating a private network

Maintaining your own private network is more involved as a lot of configurations taken for granted in the official networks need to be manually set up.

Defining the private genesis state

First, you'll need to create the genesis state of your networks, which all nodes need to be aware of and agree upon. This consists of a small JSON file (e.g. call it genesis.json):

{
  "config": {
    "chainId": <arbitrary positive integer>,
    "homesteadBlock": 0,
    "eip150Block": 0,
    "eip155Block": 0,
    "eip158Block": 0,
    "byzantiumBlock": 0,
    "constantinopleBlock": 0,
    "petersburgBlock": 0,
    "istanbulBlock": 0,
    "berlinBlock": 0,
    "londonBlock": 0
  },
  "alloc": {},
  "coinbase": "0x0000000000000000000000000000000000000000",
  "difficulty": "0x20000",
  "extraData": "",
  "gasLimit": "0x2fefd8",
  "nonce": "0x0000000000000042",
  "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "timestamp": "0x00"
}

The above fields should be fine for most purposes, although we'd recommend changing the nonce to some random value so you prevent unknown remote nodes from being able to connect to you. If you'd like to pre-fund some accounts for easier testing, create the accounts and populate the alloc field with their addresses.

"alloc": {
  "0x0000000000000000000000000000000000000001": {
    "balance": "111111111"
  },
  "0x0000000000000000000000000000000000000002": {
    "balance": "222222222"
  }
}

With the genesis state defined in the above JSON file, you'll need to initialize every geth node with it prior to starting it up to ensure all blockchain parameters are correctly set:

$ geth init path/to/genesis.json

Creating the rendezvous point

With all nodes that you want to run initialized to the desired genesis state, you'll need to start a bootstrap node that others can use to find each other in your network and/or over the internet. The clean way is to configure and run a dedicated bootnode:

$ bootnode --genkey=boot.key
$ bootnode --nodekey=boot.key

With the bootnode online, it will display an enode URL that other nodes can use to connect to it and exchange peer information. Make sure to replace the displayed IP address information (most probably [::]) with your externally accessible IP to get the actual enode URL.

Note: You could also use a full-fledged geth node as a bootnode, but it's the less recommended way.

Starting up your member nodes

With the bootnode operational and externally reachable (you can try telnet <ip> <port> to ensure it's indeed reachable), start every subsequent geth node pointed to the bootnode for peer discovery via the --bootnodes flag. It will probably also be desirable to keep the data directory of your private network separated, so do also specify a custom --datadir flag.

$ geth --datadir=path/to/custom/data/folder --bootnodes=<bootnode-enode-url-from-above>

Note: Since your network will be completely cut off from the main and test networks, you'll also need to configure a miner to process transactions and create new blocks for you.

Running a private miner

Mining on the public Ethereum network is a complex task as it's only feasible using GPUs, requiring an OpenCL or CUDA enabled ethminer instance. For information on such a setup, please consult the EtherMining subreddit and the ethminer repository.

In a private network setting, however a single CPU miner instance is more than enough for practical purposes as it can produce a stable stream of blocks at the correct intervals without needing heavy resources (consider running on a single thread, no need for multiple ones either). To start a geth instance for mining, run it with all your usual flags, extended by:

$ geth <usual-flags> --mine --miner.threads=1 --miner.etherbase=0x0000000000000000000000000000000000000000

Which will start mining blocks and transactions on a single CPU thread, crediting all proceedings to the account specified by --miner.etherbase. You can further tune the mining by changing the default gas limit blocks converge to (--miner.targetgaslimit) and the price transactions are accepted at (--miner.gasprice).

Contribution

Thank you for considering to help out with the source code! We welcome contributions from anyone on the internet, and are grateful for even the smallest of fixes!

If you'd like to contribute to go-ethereum, please fork, fix, commit and send a pull request for the maintainers to review and merge into the main code base. If you wish to submit more complex changes though, please check up with the core devs first on our Discord Server to ensure those changes are in line with the general philosophy of the project and/or get some early feedback which can make both your efforts much lighter as well as our review and merge procedures quick and simple.

Please make sure your contributions adhere to our coding guidelines:

  • Code must adhere to the official Go formatting guidelines (i.e. uses gofmt).
  • Code must be documented adhering to the official Go commentary guidelines.
  • Pull requests need to be based on and opened against the master branch.
  • Commit messages should be prefixed with the package(s) they modify.
    • E.g. "eth, rpc: make trace configs optional"

Please see the Developers' Guide for more details on configuring your environment, managing project dependencies, and testing procedures.

Author: Ethereum
Source Code: https://github.com/ethereum/go-ethereum 
License: LGPL-3.0 License

#go #golang #ethereum 

Zander  Herzog

Zander Herzog

1596793260

Secure HTTPS servers in Go

In this article, we are going to look at some of the basic APIs of the http package to create and initialize HTTPS servers in Go.

Image for post

(source: unsplash.com)

In the “Simple Hello World Server” lesson, we learned about net/http package, how to create routes and how [ServeMux](https://golang.org/pkg/net/http/#ServeMux) works. In the “Running multiple HTTP servers” lesson, we learned about [Server](https://golang.org/pkg/net/http/#Server) structure and how to run multiple HTTP servers concurrently.

In this lesson, we are going to create an HTTPS server using both Go’s standard server configuration and custom configuration (using [_Server_](https://golang.org/pkg/net/http/#Server) structure). But before this, we need to know what HTTPS really is?

HTTPS is a big topic of discussion in itself. Hence while writing this lesson, I published an article just on “How HTTPS works?”. I advise you to read this lesson first before continuing this article. In this article, I’ve also described the encryption paradigm and SSL certificates generation process.


If we recall the simplest HTTP server example from previous lessons, we only need http.``[ListenAndServe](https://golang.org/pkg/net/http/#ListenAndServe) function to start an HTTP server and http.``[HandleFunc](https://golang.org/pkg/net/http/#HandleFunc) to register a response handler for a particular endpoint.

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(https://play.golang.org/p/t3sOenOYAzS)

In the example above, when we run the command go run server.go , it will start an HTTP server on port 9000. By visiting http://localhost:9000 URL in a browser, you will be able to see a Hello World! message on the screen.

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(http://localhost:9000)

As we know, the nil argument to ListenAndServe() call invokes Go to use the [DefaultServeMux](https://golang.org/pkg/net/http/#DefaultServeMux) response multiplexer, which is the default instance of ServeMux structure provided globally by the Go. The HandleFunc() call adds a response handler for a specific route on the multiplexer instance.

The http.ListenAndServe() call uses the Go’s standard HTTP server configuration, however, in the previous lesson, how we can customize a server using [Server](https://golang.org/pkg/net/http/#Server) structure type.

To start an HTTPS server, all we need do is to call ServerAndListenTLS method with some configuration. Just like ServeAndListen method, this method is available on both the http package and the Server structure.

The http.``[ServeAndListenTLS](https://golang.org/pkg/net/http/#ListenAndServeTLS) method uses the Go’s standard server implementation, however, both [Server](https://golang.org/pkg/net/http/#Server) instance and Server.``[ServeAndListenTLS](https://golang.org/pkg/net/http/#Server.ListenAndServeTLS) method can be configured for our needs.

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