Etherum methods collision finder

col.go

package main

import (
	"encoding/hex"
	"fmt"
	"log"
	"os"

	"github.com/ethereum/go-ethereum/crypto/sha3"
)

var target = "dc6dd152" // playerRollDice(uint256)
var postfix = `(uint256)`

func main() {
	var c = 0
	for i := 5; i <= 7; i++ {
		for combination := range generateCombinations("0123456789abcdefghijklmnopqrstuvwxyz", i) {
			c++
			if combination[0] == '0' || combination[0] == '1' || combination[0] == '2' || combination[0] == '3' || combination[0] == '4' || combination[0] == '5' || combination[0] == '6' || combination[0] == '7' || combination[0] == '8' || combination[0] == '9' {
				continue
			}
			if getHash(combination) == target {
				log.Println("Found:", string(combination)+postfix)
				os.Exit(0)
			}
			if c%1000000 == 0 {
				log.Println(c)
			}
		}
		log.Println("Finished n", i)
	}

	fmt.Println("Done!")
}

func getHash(src string) string {
	hash := sha3.NewKeccak256()
	var buf []byte
	hash.Write([]byte(src + postfix))
	buf = hash.Sum(buf)
	return hex.EncodeToString(buf)[:8]
}

func generateCombinations(alphabet string, length int) <-chan string {
	c := make(chan string)

	go func(c chan string) {
		defer close(c)

		addLetter(c, "", alphabet, length)
	}(c)

	return c
}

func addLetter(c chan string, combo string, alphabet string, length int) {
	if length <= 0 {
		return
	}
	var newCombo string
	for _, ch := range alphabet {
		newCombo = combo + string(ch)
		c <- newCombo
		addLetter(c, newCombo, alphabet, length-1)
	}
}