Revision of golang aes cbc encrypt & decrypt

1 file changed, 43 insertions

aes.go(檔案已創建)

		@@ -0,0 +1,43 @@
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	+	}