small go script to ask a imap server to delete all its emails - part of the first module for the OSWE course

imap-clean.go

package main

import (
	"bufio"
	"fmt"
	"log"
	"net"
	"regexp"
	"strconv"
	"strings"
)

var messageHeader = "m "

func check(err error) {
	if err != nil {
		log.Fatal(err)
	}
}

func main() {
	service := "192.168.167.106:143"
	tcpAddress, err := net.ResolveTCPAddr("tcp4", service)
	check(err)

	conn, err := net.DialTCP("tcp", nil, tcpAddress)
	check(err)
	defer conn.Close()

	reader := bufio.NewReader(conn)

	readOne := func() string {
		received, err := reader.ReadString('\n')
		check(err)
		text := string(received)
		fmt.Print(text)
		return text
	}

	read := func() string {
		result := ""
		for {
			text := readOne()
			result += text
			if strings.HasPrefix(text, messageHeader) {
				break
			}
		}

		return result
	}

	write := func(text string) {
		fmt.Println(messageHeader + text)
		_, err = conn.Write([]byte(messageHeader + text + "\r\n"))
		check(err)
	}

	readOne() // just getting the connect ok message

	write("login [email protected] 123456")

	read()

	write("select inbox")

	response := read()
	extracted := regexp.MustCompile(`(\d*) EXISTS`).FindStringSubmatch(response)
	emails, err := strconv.Atoi(extracted[1])
	check(err)

	for i := 1; i <= emails; i++ {
		write(fmt.Sprintf("store %d +flags \\deleted", i))
		read()
	}

	if emails > 0 {
		write("expunge")
		read()
	}

	write("logout")
	read()
}