Book Image

Security with Go

By : John Daniel Leon
Book Image

Security with Go

By: John Daniel Leon

Overview of this book

Go is becoming more and more popular as a language for security experts. Its wide use in server and cloud environments, its speed and ease of use, and its evident capabilities for data analysis, have made it a prime choice for developers who need to think about security. Security with Go is the first Golang security book, and it is useful for both blue team and red team applications. With this book, you will learn how to write secure software, monitor your systems, secure your data, attack systems, and extract information. Defensive topics include cryptography, forensics, packet capturing, and building secure web applications. Offensive topics include brute force, port scanning, packet injection, web scraping, social engineering, and post exploitation techniques.
Table of Contents (15 chapters)

Grabbing a banner from a service

After identifying the ports that are open, you can try to read from the connection and see whether the service provides a banner or an initial message.

The following example works like the previous, but instead of just connecting and disconnecting, it will connect and try to read an initial message from the server. If the server provides any data, it is printed, but if the server does not send any data, nothing is printed:

package main

import (
"strconv"
"log"
"net"
"time"
)

var ipToScan = "127.0.0.1"

func main() {
activeThreads := 0
doneChannel := make(chan bool)

for port := 0; port <= 1024 ; port++ {
go grabBanner(ipToScan, port, doneChannel)
activeThreads++
}

// Wait for all threads to finish
for activeThreads > 0 {
<- doneChannel
activeThreads--
...