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crypt.go
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crypt.go
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package main
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"encoding/base64"
"errors"
"io"
)
func encryptHash(key []byte, message string) (encmess string, err error) {
plainText := []byte(message)
block, err := aes.NewCipher(key)
if err != nil {
return
}
//IV needs to be unique, but doesn't have to be secure.
//It's common to put it at the beginning of the ciphertext.
cipherText := make([]byte, aes.BlockSize+len(plainText))
iv := cipherText[:aes.BlockSize]
if _, err = io.ReadFull(rand.Reader, iv); err != nil {
return
}
stream := cipher.NewCFBEncrypter(block, iv)
stream.XORKeyStream(cipherText[aes.BlockSize:], plainText)
//returns to base64 encoded string
encmess = base64.URLEncoding.EncodeToString(cipherText)
return
}
func decryptHash(key []byte, securemess string) (decodedmess string, err error) {
cipherText, err := base64.URLEncoding.DecodeString(securemess)
if err != nil {
return
}
block, err := aes.NewCipher(key)
if err != nil {
return
}
if len(cipherText) < aes.BlockSize {
err = errors.New("Ciphertext block size is too short")
return
}
//IV needs to be unique, but doesn't have to be secure.
//It's common to put it at the beginning of the ciphertext.
iv := cipherText[:aes.BlockSize]
cipherText = cipherText[aes.BlockSize:]
stream := cipher.NewCFBDecrypter(block, iv)
// XORKeyStream can work in-place if the two arguments are the same.
stream.XORKeyStream(cipherText, cipherText)
decodedmess = string(cipherText)
return
}