Generates random n sized hex string

randomstring.go

import (
	crand "crypto/rand"
	"math/big"
)

// Generates random n sized hex string
func RandString(n int) string {
	const alphanum = "0123456789ABCDEF"
	symbols := big.NewInt(int64(len(alphanum)))
	states := big.NewInt(0)
	states.Exp(symbols, big.NewInt(int64(n)), nil)
	r, err := crand.Int(crand.Reader, states)
	if err != nil {
		panic(err)
	}
	var bytes = make([]byte, n)
	r2 := big.NewInt(0)
	symbol := big.NewInt(0)
	for i := range bytes {
		r2.DivMod(r, symbols, symbol)
		r, r2 = r2, r
		bytes[i] = alphanum[symbol.Int64()]
	}
	return string(bytes)
}