Shamir's Secret Sharing by golang

shamir.go

package main

import (
	"crypto/rand"
	"fmt"
	"reflect"

	"github.com/hashicorp/vault/shamir"
)

// Problem: 
// Company XYZ needs to secure their vault's passcode. 
// They could use something standard, such as AES, but what if the holder of the key is unavailable or dies? 
// What if the key is compromised via a malicious hacker or the holder of the key turns rogue, 
// and uses their power over the vault to their benefit?
// This is where SSS comes in. 
// It can be used to encrypt the vault's passcode and generate a certain number of shares, 
// where a certain number of shares can be allocated to each executive within Company XYZ. 
// Now, only if they pool their shares can they unlock the vault. 
// The threshold can be appropriately set for the number of executives, 
// so the vault is always able to be accessed by the authorized individuals. 
// Should a share or two fall into the wrong hands, 
// they couldn't open the passcode unless the other executives cooperated.
// ref: https://en.wikipedia.org/wiki/Shamir's_Secret_Sharing

func main() {
	data := make([]byte, 32)
	rand.Read(data)

	piece, _ := shamir.Split(data, 5, 3)

	rec0, _ := shamir.Combine([][]byte{piece[0], piece[2], piece[4]})
	fmt.Println("rec0", reflect.DeepEqual(data, rec0)) // true
	rec1, _ := shamir.Combine([][]byte{piece[1], piece[2], piece[3]})
	fmt.Println("rec1", reflect.DeepEqual(data, rec1)) // true
	rec2, _ := shamir.Combine([][]byte{piece[0], piece[1], piece[2]})
	fmt.Println("rec2", reflect.DeepEqual(data, rec2)) // true
	rec3, _ := shamir.Combine([][]byte{piece[2], piece[3], piece[4]})
	fmt.Println("rec3", reflect.DeepEqual(data, rec3)) // true
}