aes.go
· 1.1 KiB · Go
Raw
package utils
import (
"bytes"
"crypto/aes"
"crypto/cipher"
)
func encrypt(aesKey, plaintextMsg []byte) ([]byte, error) {
block, err := aes.NewCipher(aesKey)
if err != nil {
return []byte{}, err
}
plaintextMsg = pkcs5Padding(plaintextMsg, block.BlockSize())
cipherText := make([]byte, len(plaintextMsg))
cipher.NewCBCEncrypter(block, aesKey[:block.BlockSize()]).
CryptBlocks(cipherText, plaintextMsg)
return cipherText, nil
}
func decrypt(aesKey, encryptMsg []byte) ([]byte, error) {
block, err := aes.NewCipher(aesKey)
if err != nil {
return []byte{}, err
}
decryptedMsg := make([]byte, len(encryptMsg))
cipher.NewCBCDecrypter(block, aesKey[:block.BlockSize()]).
CryptBlocks(decryptedMsg, encryptMsg)
decryptedMsg = pkcs5UnPadding(decryptedMsg)
return encryptMsg, nil
}
func pkcs5Padding(ciphertext []byte, blockSize int) []byte {
padding := blockSize - len(ciphertext)%blockSize
padtext := bytes.Repeat([]byte{byte(padding)}, padding)
return append(ciphertext, padtext...)
}
func pkcs5UnPadding(origData []byte) []byte {
length := len(origData)
unpadding := int(origData[length-1])
return origData[:(length - unpadding)]
}
| 1 | package utils |
| 2 | |
| 3 | import ( |
| 4 | "bytes" |
| 5 | "crypto/aes" |
| 6 | "crypto/cipher" |
| 7 | ) |
| 8 | |
| 9 | func encrypt(aesKey, plaintextMsg []byte) ([]byte, error) { |
| 10 | block, err := aes.NewCipher(aesKey) |
| 11 | if err != nil { |
| 12 | return []byte{}, err |
| 13 | } |
| 14 | plaintextMsg = pkcs5Padding(plaintextMsg, block.BlockSize()) |
| 15 | cipherText := make([]byte, len(plaintextMsg)) |
| 16 | cipher.NewCBCEncrypter(block, aesKey[:block.BlockSize()]). |
| 17 | CryptBlocks(cipherText, plaintextMsg) |
| 18 | return cipherText, nil |
| 19 | } |
| 20 | |
| 21 | func decrypt(aesKey, encryptMsg []byte) ([]byte, error) { |
| 22 | block, err := aes.NewCipher(aesKey) |
| 23 | if err != nil { |
| 24 | return []byte{}, err |
| 25 | } |
| 26 | decryptedMsg := make([]byte, len(encryptMsg)) |
| 27 | cipher.NewCBCDecrypter(block, aesKey[:block.BlockSize()]). |
| 28 | CryptBlocks(decryptedMsg, encryptMsg) |
| 29 | decryptedMsg = pkcs5UnPadding(decryptedMsg) |
| 30 | return encryptMsg, nil |
| 31 | } |
| 32 | |
| 33 | func pkcs5Padding(ciphertext []byte, blockSize int) []byte { |
| 34 | padding := blockSize - len(ciphertext)%blockSize |
| 35 | padtext := bytes.Repeat([]byte{byte(padding)}, padding) |
| 36 | return append(ciphertext, padtext...) |
| 37 | } |
| 38 | |
| 39 | func pkcs5UnPadding(origData []byte) []byte { |
| 40 | length := len(origData) |
| 41 | unpadding := int(origData[length-1]) |
| 42 | return origData[:(length - unpadding)] |
| 43 | } |
| 44 |