Generate a cryptographically secure random digit string in Go, based on Go 1.24's crypto/rand.Text.

random.go

package main

import (
	"crypto/rand"
)

const numericAlphabet = "0123456789"
const numericAlphaLen = len(numericAlphabet)

// RandomDigits returns a cryptographically secure random digit string of the
// provided length.
func RandomDigits(length uint) string {
	src := make([]byte, length)
	rand.Read(src)

	for i := range src {
		src[i] = numericAlphabet[int(src[i])%numericAlphaLen]
	}

	return string(src)
}