proof of work

pow.go

package main
import "crypto/sha512"
import "crypto/rand"
import "encoding/hex"
import "strings"
import "strconv"
func HashHex(data string) string {
  d := sha512.Sum512([]byte(data))
  return hex.EncodeToString(d[:])
}
func VerifyWork(diff int, hs, nonce, salt, data string) bool {
  h := HashHex(nonce + ":" + salt + ":" + data)
  if h != hs { return false }
  if !strings.HasPrefix(h, strings.Repeat("0", diff)) {
    return false
  }
  return true
}
func GenWork(diff int, data string) (string, string, string) {
  h := ""
  nr := 0
  done := false
  saltb := make([]byte,8)
  rand.Read(saltb)
  salt := hex.EncodeToString(saltb)
  for !done {
    h = HashHex(strconv.Itoa(nr) + ":" + salt + ":" + data)
    done = VerifyWork(diff, h, strconv.Itoa(nr), salt, data);
    nr++
  }
  return h, strconv.Itoa(nr), salt
}
func main() {
  h, n, s := GenWork(2, "hi")
  println(n + " " + s + " " + h)
}