Pwned Passwords API - Go CLI script to test your passwords locally

main.go

package main

import (
	"fmt"
	"os"
	humanize "github.com/dustin/go-humanize"
)

var (
	password string
)

func main() {

	if len(os.Args) != 2 {
		fmt.Printf("Usage: %s '<password>'\n", os.Args[0])
		os.Exit(1)
	}

	password = os.Args[1]

	hash := getSha1(password)
	count := getHashHits(hash)

	if count > 0 {
		fmt.Printf("HIT: %s hit", humanize.Comma(count))
		if count != 1 {
			fmt.Print("s")
		}
		fmt.Println("")
		os.Exit(1)
	} else {
		fmt.Println("MISS")
		os.Exit(0)
	}
}

password.go

package main

import (
	"encoding/hex"
	"log"
	"net/http"
	"crypto/sha1"
	"strings"
	"bufio"
	"strconv"
)

const (
	apiURL = "https://api.pwnedpasswords.com/range/"
)

func getHashHits(hash string) (int64) {

	resp, err := http.Get(apiURL + hash[0:5])

	if err != nil {
		log.Fatalf("Error getting hash")
	}

	defer resp.Body.Close()

	scanner := bufio.NewScanner(resp.Body)

	for scanner.Scan() {
		candidate, count := splitLine(scanner.Text())
		if candidate == hash[5:] {
			countInt, err := strconv.ParseInt(count, 10, 64)
			if err != nil {
				log.Fatalf("Couldn't convert count to int")
			}
			return countInt
		}
	}
	return 0
}

func getSha1(tohash string) (string) {
	data := []byte(tohash)
	h := sha1.New()
	h.Write(data)
	return strings.ToUpper(hex.EncodeToString(h.Sum(nil)));
}

func splitLine(line string) (string, string) {
	x := strings.SplitN(line, ":", 2)
	return x[0], x[1]
}