SpoofDPI/util/util.go

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package util
import (
"net"
"log"
"strings"
"github.com/babolivier/go-doh-client"
)
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func WriteAndRead(conn net.Conn, message []byte) ([]byte, error){
_, err := conn.Write(message)
if err != nil {
log.Fatal("Error writing to client:", err)
return nil, err
}
// defer conn.(*net.TCPConn).CloseWrite()
buf, err := ReadMessage(conn)
if err != nil {
log.Fatal("failed:", err)
return nil, err
}
return buf, nil
}
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func ReadMessage(conn net.Conn)([]byte, error) {
buf := make([]byte, 0, 4096) // big buffer
tmp := make([]byte, 1024) // using small tmo buffer for demonstrating
for {
n, err := conn.Read(tmp)
if err != nil {
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return nil, err
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}
buf = append(buf, tmp[:n]...)
if n < 1024 {
break
}
}
return buf, nil
}
func ExtractDomain(message *[]byte) (string) {
i := 0
for ; i < len(*message); i++ {
if (*message)[i] == '\n' {
i++
break;
}
}
for ; i < len(*message); i++ {
if (*message)[i] == ' ' {
i++
break;
}
}
j := i
for ; j < len(*message); j++ {
if (*message)[j] == '\n' {
break;
}
}
domain := strings.Split(string((*message)[i:j]), ":")[0]
return strings.TrimSpace(domain)
}
func DnsLookupOverHttps(dns string, domain string)(string, error) {
// Perform a A lookup on example.com
resolver := doh.Resolver{
Host: dns, // Change this with your favourite DoH-compliant resolver.
Class: doh.IN,
}
log.Println(domain)
a, _, err := resolver.LookupA(domain)
if err != nil {
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log.Println("Error looking up dns. ", err)
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return "", err
}
ip := a[0].IP4
return ip, nil
}
func ExtractMethod(message *[]byte) (string) {
i := 0
for ; i < len(*message); i++ {
if (*message)[i] == ' ' {
break;
}
}
method := strings.TrimSpace(string((*message)[:i]))
log.Println(method)
return strings.ToUpper(method)
}