p2p、分布式，区块链笔记: libp2p基础

通信密钥 noise::{Keypair, X25519Spec}

• X25519/Ed25519类似RSA 算法。
• Noise 用于设计和实现安全通信协议。它允许通信双方在没有预先共享密钥的情况下进行安全的密钥交换，并通过加密和身份验证保护通信内容。libp2p 提供了对 Noise 协议的原生支持，它允许节点之间使用 Noise 协议进行安全的点对点通信。
• 例：use libp2p::{noise::{Keypair, X25519Spec},identity,};, let local_keys = Keypair::<X25519Spec>::new().into_authentic(&identity::Keypair::generate_ed25519());

identity::Keypair

• 在 libp2p 中，identity::Keypair 是一个用于管理加密和身份验证密钥的结构体。它允许你生成和管理加密算法（如椭圆曲线加密）所需的公钥和私钥对，以及进行数字签名和验证等操作。
• 下面是一个简单的示例，展示如何使用 Keypair 生成一个 Ed25519 算法的密钥对，并使用它进行签名和验证：

use libp2p::identity::{Keypair, ed25519};fn main() {// 生成一个 Ed25519 类型的密钥对let keypair = Keypair::generate_ed25519();// 获取公钥和私钥let public_key = keypair.public();let private_key = keypair.secret();// 创建一个消息let message = b"Hello, libp2p!";// 使用私钥对消息进行签名let signature = keypair.sign(message);// 使用公钥验证签名assert!(public_key.verify(message, &signature).is_ok());println!("Message: {:?}", message);println!("Signature: {:?}", signature);
}

transport

• 传输在两个对等方之间提供面向连接的通信 通过有序的数据流（即连接）
• 负责从一个peer到另一个peer的实际数据的传输
• 收听和拨号
• 例如使用let transport = libp2p::development_transport(local_keys).await?;调用libp2p提供的高级API函数development_transport来创建传输。这个函数封装了传输的创建过程，通常会使用一组默认的配置参数和最佳实践，以便快速启动和测试libp2p应用程序。在这种情况下，local_keys是本地密钥，用于加密和身份验证。有关这个API的未来发展可以看这个ISSUE。
• 还可以手动配置和创建传输（transport）。下面的例子使用了TokioTcpConfig作为基础的TCP传输配置，手动指定了协议升级、身份认证和多路复用的配置。这种方式适用于需要精确控制传输行为和配置的场景，允许开发者根据具体需求进行灵活的设置和调整。

    //Creates transport which is a feature of the lib p2p frameworklet transport = TokioTcpConfig::new()//Upgrades version of the transport once connection is established as Version 1 of the multi-stream-select protocol is the version that interacts with the noise protocol//in short handles protocol negotiation.upgrade(upgrade::Version::V1)//Authenticates that channel is secure with the noise XX handshake.authenticate(libp2p::noise::NoiseConfig::xx(auth_keys).into_authenticated())//multiplex transport negotiates multiple sub-streams and/or connections on the authenticated transport.multiplex(mplex::MplexConfig::new())//boxed allows only output and error types to be captured.boxed();

行为控制 Swarm

• Swarm 包含整个网络的状态。运行一组节点并管理它们之间的连接和行为。整个 libp2p 网络的行为可以通过其进行控制。
• 例子

// https://stackoverflow.com/questions/74126811/rust-libp2p-cannot-find-function-development-transport-in-crate-libp2p
extern crate core;// 显式地声明对 core crate(包含Rust核心标准库)的依赖。use libp2p::{futures::StreamExt,noise::{Keypair, NoiseConfig, X25519Spec},identity,PeerId,tcp::TcpConfig,swarm::{DummyBehaviour,Swarm,SwarmEvent},
};
use std::error::Error;#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {// 生成身份密钥对let local_keys = identity::Keypair::generate_ed25519();// 从公钥生成peeridlet local_peer_id = PeerId::from(local_keys.public());println!("local_peer_id is {:?}",local_peer_id);// 采用“默认”行为let behaviour = DummyBehaviour::default();// 创建 libp2p transport实现peer间的数据let transport  = libp2p::development_transport(local_keys).await?;let mut swarm = {Swarm::new(transport, behaviour, local_peer_id)};swarm.listen_on("/ip4/0.0.0.0/tcp/0".parse()?)?;// 本机中所有的IPV4地址，使用 TCP 协议，端口号为 0 表示让操作系统自动选择一个空闲端口来监听.loop {match swarm.select_next_some().await {SwarmEvent::NewListenAddr { address, .. } => {println!("Listening on local address {:?}", address)}_ => {}}}Ok(())
}

• 运行效果

local_peer_id is PeerId("12D3KooWD4BMTXhmTV46fSbdRv238dRudXcXq9VPSF1PH4N4nWVk")
Listening on local address "/ip4/192.168.0.102/tcp/51516"
Listening on local address "/ip4/127.0.0.1/tcp/51516"

local_peer_id is PeerId("12D3KooWJRoPgqPPC8adBwrFHfx4XtCpCu1BprzBofgVirxoceJB")
Listening on local address "/ip4/192.168.0.102/tcp/51519"
Listening on local address "/ip4/127.0.0.1/tcp/51519"

在 peer 节点之间交换 ping 命令

use libp2p::futures::StreamExt; // 异步流有关
use libp2p::ping::{Ping, PingConfig};// ping 命令相关依赖
use libp2p::swarm::{Swarm, SwarmEvent};
use libp2p::{identity, Multiaddr, PeerId};
use std::error::Error;#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {let new_key = identity::Keypair::generate_ed25519();let new_peer_id = PeerId::from(new_key.public());println!("New Peer ID is: {:?}", new_peer_id);let transport = libp2p::development_transport(new_key).await?;let behaviour = Ping::new(PingConfig::new().with_keep_alive(true));let mut swarm = Swarm::new(transport, behaviour, new_peer_id);swarm.listen_on("/ip4/0.0.0.0/tcp/0".parse()?)?;// 本地节点向远程节点发出连接  从命令行输入的参数取出if let Some(remote_peer) = std::env::args().nth(1) {let remote_peer_multiaddr: Multiaddr = remote_peer.parse()?;swarm.dial(remote_peer_multiaddr)?;// 需要libp2p ，version = "0.46"println!("Dialed remote peer: {:?}", remote_peer); // 打印远程地址}loop {match swarm.select_next_some().await {SwarmEvent::NewListenAddr { address, .. } => {println!("Listening on local Address {:?}", address)}SwarmEvent::Behaviour(event) => println!("Event received from peer is {:?}", event),_ => {}}}
}

• 运行效果

PS C:\Users\kingchuxing\Documents\CODE\P2PRecipeApp> cargo run
New Peer ID is: PeerId("12D3KooWFR97CdrL7jvboqU6MxyWjRzfHsR5V2sgs23yqg4xetnV")
Listening on local Address "/ip4/192.168.0.102/tcp/50997"
Listening on local Address "/ip4/127.0.0.1/tcp/50997"

PS C:\Users\kingchuxing\Documents\CODE\P2PRecipeApp> cargo run /ip4/192.168.0.102/tcp/50997
New Peer ID is: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG")
Dialed remote peer: "/ip4/192.168.0.102/tcp/50997"  //对远程地址进行了拨号
Listening on local Address "/ip4/192.168.0.102/tcp/51014"
Listening on local Address "/ip4/127.0.0.1/tcp/51014"
Event received from peer is Event { peer: PeerId("12D3KooWFR97CdrL7jvboqU6MxyWjRzfHsR5V2sgs23yqg4xetnV"), result: Ok(Pong) }
Event received from peer is Event { peer: PeerId("12D3KooWFR97CdrL7jvboqU6MxyWjRzfHsR5V2sgs23yqg4xetnV"), result: Ok(Ping { rtt: 314.3µs }) } 

• 后续两个peer之间会不断的ping和pang

Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Pong) }
Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Ping { rtt: 250.7µs }) }
Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Pong) }
Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Ping { rtt: 319.7µs }) }
Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Pong) }
Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Ping { rtt: 479.6µs }) }
Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Pong) }
Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Ping { rtt: 217.8µs }) }
Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Pong) }
Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Ping { rtt: 266.7µs }) }
Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Pong) }
Event received from peer is Event { peer: PeerId("12D3KooWMGLjRBpysfHqjYWcYPf89bDNWH4S9Ao8RXj5tBehksCG"), result: Ok(Ping { rtt: 1.0212ms }) }

mdns发现peer

• 在计算机网络中，mDNS (Multicast DNS) 是一种用于在局域网内部广播和发现服务的协议。它允许设备在没有集中式DNS服务器的情况下相互发现和通信，特别是在没有预先配置的情况下。

use libp2p::{futures::StreamExt, identity,mdns::{Mdns, MdnsConfig, MdnsEvent},swarm::{Swarm, SwarmEvent},PeerId,
};
use std::error::Error;#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {let new_key = identity::Keypair::generate_ed25519();let new_peer_id = PeerId::from(new_key.public());println!("New Peer ID is: {:?}", new_peer_id);let transport = libp2p::development_transport(new_key).await?; // 使用密钥对创建传输let behaviour = Mdns::new(MdnsConfig::default()).await?; // 创建网络行为let mut swarm = Swarm::new(transport, behaviour, new_peer_id); // 创建Swarmswarm.listen_on("/ip4/0.0.0.0/tcp/0".parse()?)?;loop {match swarm.select_next_some().await {SwarmEvent::NewListenAddr { address, .. } => {println!("Listening on local Address {:?}", address)}SwarmEvent::Behaviour(MdnsEvent::Discovered(peers)) => {for (peer, addr) in peers {println!("discovered {} {}", peer, addr);}}SwarmEvent::Behaviour(MdnsEvent::Expired(expired)) => {for (peer, addr) in expired {println!("expired {} {}", peer, addr);}}_ => {}}}
}

• 运行效果

PS C:\Users\kingchuxing\Documents\CODE\P2PRecipeApp> cargo run
New Peer ID is: PeerId("12D3KooWMU94yU8ZAFnPdRwLyQ9FuR47sVQfMG9VJUiiykCvmYdt")
Listening on local Address "/ip4/192.168.0.102/tcp/51361"
Listening on local Address "/ip4/127.0.0.1/tcp/51361"
discovered 12D3KooWNMofXEV4fp5NCEBF3m7km3keRnAuScrhoKqvc5Jiacy9 /ip4/192.168.0.102/tcp/51360
discovered 12D3KooWNMofXEV4fp5NCEBF3m7km3keRnAuScrhoKqvc5Jiacy9 /ip4/127.0.0.1/tcp/51360

PS C:\Users\kingchuxing\Documents\CODE\P2PRecipeApp> cargo runFinished `dev` profile [unoptimized + debuginfo] target(s) in 0.28sRunning `target\debug\P2PRecipeApp.exe`
New Peer ID is: PeerId("12D3KooWNMofXEV4fp5NCEBF3m7km3keRnAuScrhoKqvc5Jiacy9")
Listening on local Address "/ip4/192.168.0.102/tcp/51360"
Listening on local Address "/ip4/127.0.0.1/tcp/51360"
discovered 12D3KooWMU94yU8ZAFnPdRwLyQ9FuR47sVQfMG9VJUiiykCvmYdt /ip4/192.168.0.102/tcp/51361
discovered 12D3KooWMU94yU8ZAFnPdRwLyQ9FuR47sVQfMG9VJUiiykCvmYdt /ip4/127.0.0.1/tcp/51361

CG

• Swarm部分相关代码来自教程使用 Async Rust 构建简单的 P2P 节点【完结】