A md5 bruteforce cracker multithreaded in go.

md5cracker.go

package main

import (
"fmt"
"io/ioutil"
"strings"
"sync"
"log"
"time"
"crypto/md5"
)

var alfabeto = []rune {'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','0','1','2','3','4','5','6','7','8','9'}


func compute(prefix int, n int, a string, wgFather *sync.WaitGroup){
    defer wgFather.Done()

    if prefix == n-1 {
        for _, d := range alfabeto {
            password := fmt.Sprintf("%s%c", a, d)

            if searchPassword(password) {
                if len(passwords) == 0{
                    return
                }
            }
        }
    }else {
        for i := range alfabeto{
            wgFather.Add(1)
            go compute(prefix+1, n, fmt.Sprintf("%s%c", a, alfabeto[i]), wgFather)
        }
    }
}

var passwords []string


func main(){

    if loadPasswords() {
        return
    }
    fmt.Println("File with passwords loaded. We're gonna crack", len(passwords),"passwords!")
    start := time.Now()
    cont := 2
    for len(passwords) > 0  {
            fmt.Println("Searching for passwords at length: ", cont)

            var wg sync.WaitGroup
            wg.Add(1)
            go compute(0, cont, "", &wg)
            wg.Wait()
            cont++    
        }

    elapsed := time.Since(start)
    fmt.Println("Password's file cracked in:", elapsed)

}

func searchPassword(pass string) bool{
    hash := fmt.Sprintf("%x", md5.Sum([]byte(pass)))
    for i, value := range passwords{
        if strings.Compare(hash, value) == 0{
            // Password found!
            fmt.Println("Find Password:", pass, " with hash:", hash)
            passwords = append(passwords[:i], passwords[i+1:]...)
            return true
        }
    }
    return false
}

func loadPasswords() bool{
    stream, err := ioutil.ReadFile("file.txt")
    if err != nil{
        log.Fatal(err)
        return true
    }
    readstring := string(stream)

    passwords= strings.Split(readstring, "\n")
    return false
}