Go gitcoin

gistfile1.go

package main

import (
        "github.com/jgrahamc/go-openssl/sha1"
        //"crypto/sha1"
        "fmt"
        "io/ioutil"
        "log"
        "os"
        "strconv"
        "time"
        //"sync"
        "encoding/hex"
)

//func gitMoney(difficulty string,in []byte, w *sync.WaitGroup) {
func gitMoney(difficulty string,in []byte, w chan bool) {
        hashes := 0
        now := time.Now()
        start_second := now.Truncate(time.Second)
        i := 0
        debug := true
        for {
                //text := fmt.Sprintf("tree %s \n parent %s \n author CTF user <me@example.com> %s +0000 \n committer CTF user <me@example.com> %s +0000 \n Give me a Gitcoin\n $d", "tree", "parent", "time", counter)

                //dumb
                t := strconv.Itoa(i)
                counter := []byte(t)

                h := sha1.New()
                body := append(in, counter...)
                fmt.Fprintf(h, "commit %d\x00", len(body))
                h.Write(body)
                sum := h.Sum(nil)
                //cs := fmt.Sprintf("%x\n", h.Sum(nil))
                cs := hex.EncodeToString(sum[:])
                if cs < difficulty {
                        fmt.Printf("%s%s",in,t)
                        fmt.Fprintln(os.Stderr, cs)
                        break
                }
                hashes++
                now := time.Now()
                end_second := now.Truncate(time.Second)
                if debug == true {
                        if end_second.After(start_second) {
                                fmt.Fprintln(os.Stderr, "hashes per second:", hashes)
                                start_second = end_second
                                hashes = 0
                        }
                }
                i++
        }
        w <- true

}

func main() {

        in, err := ioutil.ReadAll(os.Stdin)
        if err != nil {
                log.Println(err, string(in))
        }
        difficulty := os.Args[1]
        fmt.Fprintln(os.Stderr, "Called with difficulty:", difficulty)
        quit :=make(chan bool)
//      var wg sync.WaitGroup
//      wg.Add(1)
        go gitMoney(difficulty, in, quit)
        for {
                select {
                case <- quit:
                        return
                }
        }
//      wg.Wait()
}

proof:
(lib)root@awesomevm:/projects/level1# echo "testing" | go run dumb.go
038d718da6a1ebbc6a7780a96ed75a70cc2ad6e2
(lib)root@awesomevm:/projects/level1# echo "testing" | git hash-object --stdin
038d718da6a1ebbc6a7780a96ed75a70cc2ad6e2

now with crappy performing solver

Line 30 should be "commit %d\x00", right?