Vernam.go

package main

import (
	"os"
	"sync"
)

var alphabet [32]string

func ini() {
	for index := 0; index < 32; index++ {
		num := 'a' + rune(index)
		if 122 < num {
			num = 'A' + rune(num-122-1)
		}
		alphabet[index] = string(num)
	}
	// for index := 0; index < 32; index++ {
	// 	print(alphabet[index])
	// }
}

func toNum(str rune) int {
	return int(str - 'a')
}

type Key struct{ content int }

func (key *Key) nextKey() {
	r := key.content + 1
	switch {
	case 32 <= r:
		key.content = r - 32
	default:
		key.content = r
	}
}

func xor(char int, key int) int {
	return char ^ key
}

func decrypt(text string, indexKey int) string {
	key := Key{indexKey}

	var result string
	for _, r := range text {
		index := xor(toNum(r), key.content)
		result += alphabet[index]
		key.nextKey()
	}
	println(result, ":", key.content)
	return result
}

// go run Vernam.go eaonj
func main() {
	var wg sync.WaitGroup
	varnamText := os.Args[1]
	ini()

	for index := 0; index < 32; index++ {
		wg.Add(1)
		go func(index int) {
			decrypt(varnamText, index)
			wg.Done()
		}(index)
	}
	wg.Wait()

}