Golang : ROT32768 (rotate by 0x80) UTF-8 strings example



Tags : golang rot32768 caesar-cipher utf8 rune-character-substitution

Previously we learned how to implement ROT13, ROT5 and ROT47 character substitution algorithms in Golang. However, these implementations are meant for rotating ASCII characters. If you try to rotate UTF-8 strings, you will be disappointed because ASCII != UTF8.

The following is the implementation of ROT32768 (rotate by 0x80) that will be able to handle UTF-8 strings with added ROT5 mapping to handle ASCII digits rotation. It will be handle ASCII characters as well and in fact, it would be a better choice to use ROT32768 than ROT13 or ROT47 because the resulting rotation is hard to distinguish by human eyes.

For example: handle alphabets to èáîäìå áìðèáâåôó

Here you go!


 package main

 import (
  "fmt"
  "strings"
  "unicode"
  "unicode/utf8"
 )

 // rot32768 rotates utf8 string
 // rot5map rotates digits
 func rot32768(input string) string {
  var result []string
  rot5map := map[rune]rune{'0': '5', '1': '6', '2': '7', '3': '8', '4': '9', '5': '0', '6': '1', '7': '2', '8': '3', '9': '4'}

  for _,i := range input {
 switch {
 case unicode.IsSpace(i):
 result = append(result, " ")
 case i >= '0' && i <= '9':
 result = append(result, string(rot5map[i]))
 case utf8.ValidRune(i):
 //result = append(result, string(rune(i) ^ 0x80))
 result = append(result, string(rune(i) ^ utf8.RuneSelf))
 }

  }

  return strings.Join(result,"")
 }


 func main() {
  text := "жѳМѭњЂЯёЧВ 一二三 handle alphabets = ขอพฮศโำฐเฦ abc世界你好123 ペツワケザユプルヂザ"
  fmt.Println(text)
  fmt.Println(rot32768(text))

  fmt.Println("Invertible test:")
  fmt.Println(rot32768(rot32768(text)))
 }

Output:

жѳМѭњЂЯёЧВ 一二三 handle alphabets = ขอพฮศโำฐเฦ abc世界你好123 ペツワケザユプルヂザ

ҶӳҜӭӚ҂үӑҧҒ 亀丌争 èáîäìå áìðèáâåôó ½ ຂອພຮຨໂຳຐເ຦ áâã亖痌俠姽678 ずいは〱〶てしにあ〶

Invertible test:

жѳМѭњЂЯёЧВ 一二三 handle alphabets = ขอพฮศโำฐเฦ abc世界你好123 ペツワケザユプルヂザ

Happy coding!

  See also : Golang : Rot13 and Rot5 algorithms example



Tags : golang rot32768 caesar-cipher utf8 rune-character-substitution

By Adam Ng

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