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);
}
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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 framework
    let 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();
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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peerid
    let 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(())
}
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• 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"
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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"
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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),
            _ => {}
        }
    }
}
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• 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"
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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 }) } 
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• 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 }) }
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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Swarm
    swarm.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);
                }
            }

            _ => {}
        }
    }
}
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• 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
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PS C:\Users\kingchuxing\Documents\CODE\P2PRecipeApp> cargo run
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.28s
     Running `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
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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】