diff --git a/zh/09.6.md b/zh/09.6.md
index b4a69fc9..7503dbdf 100644
--- a/zh/09.6.md
+++ b/zh/09.6.md
@@ -6,38 +6,38 @@
 
 ```Go
 
-	package main
+package main
 
-	import (
-		"encoding/base64"
-		"fmt"
-	)
+import (
+	"encoding/base64"
+	"fmt"
+)
 
-	func base64Encode(src []byte) []byte {
-		return []byte(base64.StdEncoding.EncodeToString(src))
+func base64Encode(src []byte) []byte {
+	return []byte(base64.StdEncoding.EncodeToString(src))
+}
+
+func base64Decode(src []byte) ([]byte, error) {
+	return base64.StdEncoding.DecodeString(string(src))
+}
+
+func main() {
+	// encode
+	hello := "你好，世界！ hello world"
+	debyte := base64Encode([]byte(hello))
+	fmt.Println(debyte)
+	// decode
+	enbyte, err := base64Decode(debyte)
+	if err != nil {
+		fmt.Println(err.Error())
 	}
 
-	func base64Decode(src []byte) ([]byte, error) {
-		return base64.StdEncoding.DecodeString(string(src))
+	if hello != string(enbyte) {
+		fmt.Println("hello is not equal to enbyte")
 	}
 
-	func main() {
-		// encode
-		hello := "你好，世界！ hello world"
-		debyte := base64Encode([]byte(hello))
-		fmt.Println(debyte)
-		// decode
-		enbyte, err := base64Decode(debyte)
-		if err != nil {
-			fmt.Println(err.Error())
-		}
-
-		if hello != string(enbyte) {
-			fmt.Println("hello is not equal to enbyte")
-		}
-
-		fmt.Println(string(enbyte))
-	}
+	fmt.Println(string(enbyte))
+}
 
 ```
 ## 高级加解密
@@ -50,70 +50,70 @@ Go语言的`crypto`里面支持对称加密的高级加解密包有：
 因为这两种算法使用方法类似，所以在此，我们仅用aes包为例来讲解它们的使用，请看下面的例子
 ```Go
 
-	package main
+package main
 
-	import (
-		"crypto/aes"
-		"crypto/cipher"
-		"fmt"
-		"os"
-	)
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"fmt"
+	"os"
+)
 
-	var commonIV = []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f}
+var commonIV = []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f}
 
-	func main() {
-		//需要去加密的字符串
-		plaintext := []byte("My name is Astaxie")
-		//如果传入加密串的话，plaint就是传入的字符串
-		if len(os.Args) > 1 {
-			plaintext = []byte(os.Args[1])
-		}
-
-		//aes的加密字符串
-		key_text := "astaxie12798akljzmknm.ahkjkljl;k"
-		if len(os.Args) > 2 {
-			key_text = os.Args[2]
-		}
-
-		fmt.Println(len(key_text))
-
-		// 创建加密算法aes
-		c, err := aes.NewCipher([]byte(key_text))
-		if err != nil {
-			fmt.Printf("Error: NewCipher(%d bytes) = %s", len(key_text), err)
-			os.Exit(-1)
-		}
-
-		//加密字符串
-		cfb := cipher.NewCFBEncrypter(c, commonIV)
-		ciphertext := make([]byte, len(plaintext))
-		cfb.XORKeyStream(ciphertext, plaintext)
-		fmt.Printf("%s=>%x\n", plaintext, ciphertext)
-
-		// 解密字符串
-		cfbdec := cipher.NewCFBDecrypter(c, commonIV)
-		plaintextCopy := make([]byte, len(plaintext))
-		cfbdec.XORKeyStream(plaintextCopy, ciphertext)
-		fmt.Printf("%x=>%s\n", ciphertext, plaintextCopy)
+func main() {
+	//需要去加密的字符串
+	plaintext := []byte("My name is Astaxie")
+	//如果传入加密串的话，plaint就是传入的字符串
+	if len(os.Args) > 1 {
+		plaintext = []byte(os.Args[1])
 	}
 
+	//aes的加密字符串
+	key_text := "astaxie12798akljzmknm.ahkjkljl;k"
+	if len(os.Args) > 2 {
+		key_text = os.Args[2]
+	}
+
+	fmt.Println(len(key_text))
+
+	// 创建加密算法aes
+	c, err := aes.NewCipher([]byte(key_text))
+	if err != nil {
+		fmt.Printf("Error: NewCipher(%d bytes) = %s", len(key_text), err)
+		os.Exit(-1)
+	}
+
+	//加密字符串
+	cfb := cipher.NewCFBEncrypter(c, commonIV)
+	ciphertext := make([]byte, len(plaintext))
+	cfb.XORKeyStream(ciphertext, plaintext)
+	fmt.Printf("%s=>%x\n", plaintext, ciphertext)
+
+	// 解密字符串
+	cfbdec := cipher.NewCFBDecrypter(c, commonIV)
+	plaintextCopy := make([]byte, len(plaintext))
+	cfbdec.XORKeyStream(plaintextCopy, ciphertext)
+	fmt.Printf("%x=>%s\n", ciphertext, plaintextCopy)
+}
+
 ```
 上面通过调用函数`aes.NewCipher`(参数key必须是16、24或者32位的[]byte，分别对应AES-128, AES-192或AES-256算法),返回了一个`cipher.Block`接口，这个接口实现了三个功能：
 
 ```Go
 
-	type Block interface {
-		// BlockSize returns the cipher's block size.
-		BlockSize() int
+type Block interface {
+	// BlockSize returns the cipher's block size.
+	BlockSize() int
 
-		// Encrypt encrypts the first block in src into dst.
-		// Dst and src may point at the same memory.
-		Encrypt(dst, src []byte)
+	// Encrypt encrypts the first block in src into dst.
+	// Dst and src may point at the same memory.
+	Encrypt(dst, src []byte)
 
-		// Decrypt decrypts the first block in src into dst.
-		// Dst and src may point at the same memory.
-		Decrypt(dst, src []byte)
-	}
+	// Decrypt decrypts the first block in src into dst.
+	// Dst and src may point at the same memory.
+	Decrypt(dst, src []byte)
+}
 ```
 这三个函数实现了加解密操作，详细的操作请看上面的例子。