inklabs/rangedb

package cryptotest
 
import (
    "strings"
)
 
type rotCipher struct{}
 
func NewRot13Cipher() *rotCipher {
    return &rotCipher{}
}
 
func (r rotCipher) Encrypt(_, data string) (string, error) {
    return strings.Map(rot, data), nil
}
 
func (r rotCipher) Decrypt(_, cipherText string) (string, error) {
    return strings.Map(rot, cipherText), nil
}
 
func rot(r rune) rune {
    capital := r >= 'A' && r <= 'Z'
    if !capital && (r < 'a' || r > 'z') {
        return r
    }
 
    r += 13
    if capital && r > 'Z' || !capital && r > 'z' {
        r -= 26
    }
    return r
}