golang实现802.1x认证功能

实现802.1x认证功能的最常用的方式是通过EAP协议（Extensible Authentication Protocol）进行认证。以下是一个简单的golang代码示例，用于实现基于EAP的802.1x认证功能。

package main

import (
    "crypto/tls"
    "fmt"
    "net"
    "bytes"
    "encoding/binary"
)

const (
    EAPCodeRequest = 1
    EAPCodeResponse = 2
    EAPCodeSuccess = 3
    EAPCodeFailure = 4
)

const (
    EAPTypeIdentity = 1
    EAPTypeMD5Challenge = 4
)

func main() {
    // 连接认证服务器
    conn, err := tls.Dial("tcp", "auth-server:1812", nil)
    if err != nil {
        fmt.Println(err)
        return
    }
    defer conn.Close()

    // 生成EAP Request Identity包
    reqIdPacket := generateEapPacket(EAPTypeIdentity, EAPCodeRequest, []byte{})
    conn.Write(reqIdPacket)

    // 接收EAP Response Identity包
    resIdPacket := make([]byte, 1024)
    len, err := conn.Read(resIdPacket)
    if err != nil {
        fmt.Println(err)
        return
    }

    // 解析EAP Response Identity包
    resIdType := binary.BigEndian.Uint16(resIdPacket[18:20])
    resIdData := resIdPacket[20:len]
    if resIdType != EAPTypeIdentity || len <= 20 {
        fmt.Println("Invalid EAP Response Identity packet")
        return
    }

    // 发送EAP Request MD5-Challenge包
    reqMd5Packet := generateEapPacket(EAPTypeMD5Challenge, EAPCodeRequest, resIdData)
    conn.Write(reqMd5Packet)

    // 接收EAP Response MD5-Challenge包
    resMd5Packet := make([]byte, 1024)
    len, err = conn.Read(resMd5Packet)
    if err != nil {
        fmt.Println(err)
        return
    }

    // 解析EAP Response MD5-Challenge包
    resMd5Type := binary.BigEndian.Uint16(resMd5Packet[18:20])
    resMd5Data := resMd5Packet[20:len]
    if resMd5Type != EAPTypeMD5Challenge || len <= 20 {
        fmt.Println("Invalid EAP Response MD5-Challenge packet")
        return
    }

    // 认证成功
    successPacket := generateEapPacket(0, EAPCodeSuccess, []byte{})
    conn.Write(successPacket)
    fmt.Println("Authentication succeeded")
}

func generateEapPacket(eapType uint8, eapCode uint8, eapData []byte) []byte {
    buf := new(bytes.Buffer)

    binary.Write(buf, binary.BigEndian, uint8(0)) // EAP Version
    binary.Write(buf, binary.BigEndian, eapCode) // EAP Code
    binary.Write(buf, binary.BigEndian, uint16(5+len(eapData))) // EAP Packet Length
    binary.Write(buf, binary.BigEndian, uint8(eapType)) // EAP Type
    binary.Write(buf, binary.BigEndian, uint8(0)) // EAP Identifier
    binary.Write(buf, binary.BigEndian, uint16(len(eapData))) // EAP Data Length
    binary.Write(buf, binary.BigEndian, eapData) // EAP Data

    return buf.Bytes()
}

以上代码连接到认证服务器，并使用EAP Identity和EAP MD5-Challenge协议进行认证。如果认证成功，将发送EAP Success包，如果认证失败，将发送EAP Failure包。

需要注意的是，以上代码只是一个简单的示例，实际的802.1x认证通常比这复杂得多。在实际应用中，您需要根据您的网络环境和认证服务器的要求进行相应的调整和修改。