Encrypt using AES CBC

encryptAESCBC.go

func encryptKYCData(plainText string) string {
	// refer this - https://chat.openai.com/share/1f7f6ca1-23fb-45c3-9fb1-88c42efb9880
	password := []byte(os.Getenv("ENCRYPTION_KEY"))

	// pad the plaintext if it is not a muliple of aes.BlockSize
	plainTextBytes := []byte(plainText)
	padLength := aes.BlockSize - len(plainTextBytes)%aes.BlockSize
	padding := bytes.Repeat([]byte{byte(padLength)}, padLength)
	plainTextBytes = append(plainTextBytes, padding...)
	cipherText := make([]byte, len(plainTextBytes))

	// create an Initialization Vector of random 16 bytes
	iv := make([]byte, 16)
	_, err := rand.Read(iv)
	if err != nil {
		return ""
	}

	// using sha256 hash to generate an hashed key, then
	// encode it using base64 encoding and take the first 32 bytes
	hash := sha256.New()
	hash.Write([]byte(password))
	hashBytes := hash.Sum(nil)
	key := base64.StdEncoding.EncodeToString(hashBytes)[:32]

	// create a cipher block using this IV and key generated previously
	block, err := aes.NewCipher([]byte(key))
	if err != nil {
		return ""
	}
	cipher := cipher.NewCBCEncrypter(block, iv)
	cipher.CryptBlocks(cipherText, plainTextBytes)
	return hex.EncodeToString(iv) + ":" + hex.EncodeToString(cipherText)
}