Golang - Generate random SHA1 hash

ramdom_sha1.go

// Source: https://stackoverflow.com/questions/12321133/golang-random-number-generator-how-to-seed-properly

package main

import (
	"crypto/sha1"
	"fmt"
	"math/rand"
	"time"
)

func init() {
	rand.Seed(time.Now().UnixNano())
}

func main() {
	hash := NewSHA1Hash()
	fmt.Println(hash)
}

// NewSHA1Hash generates a new SHA1 hash based on
// a random number of characters.
func NewSHA1Hash(n ...int) string {
	noRandomCharacters := 32

	if len(n) > 0 {
		noRandomCharacters = n[0]
	}

	randString := RandomString(noRandomCharacters)

	hash := sha1.New()
	hash.Write([]byte(randString))
	bs := hash.Sum(nil)

	return fmt.Sprintf("%x", bs)
}

var characterRunes = []rune("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789")

// RandomString generates a random string of n length
func RandomString(n int) string {
	b := make([]rune, n)
	for i := range b {
		b[i] = characterRunes[rand.Intn(len(characterRunes))]
	}
	return string(b)
}