Preface

The encryption algorithm can certainly decrypt .MD5,SHA256,bcrypt Algorithms are irreversible and non decryptable , So it's not an encryption algorithm , for example 2+3 obtain 5, however 5 I don't know if 2+3 obtain , Or maybe 1+4,0+5, So it's irreversible . What is often confused is called encryption algorithm , But the essence is hash algorithm .

One 、MD5 Algorithm It's not safe enough now , It's easy to crack through the rainbow watch

The code is as follows （ Example ）：

func MD5(password string) string {
    
	hash := MD5.New()
	hash.Write([]byte(password))
	res:=hex.EncodeToString(hash.Sum(nil))
	fmt.Println(len(res))
	return res
}
//MD5 Add salt and encrypt   It's safer than not adding salt , But it's not safe enough 
func MD5(password string) string {
    
	const salt = "2021/10/21"// Custom salt 
	hash := MD5.New()
	hash.Write([]byte(password+salt))// Custom combination of password and salt 
	res:=hex.EncodeToString(hash.Sum(nil))
	fmt.Println(len(res))
	return res
}

Two 、SHA256 Algorithm relative MD5 More secure , Of course SHA512 Longer and safer , Greater performance requirements

The code is as follows （ Example ）：

func SHA256(password string) string {
    
	hash := sha256.New()
	hash.Write([]byte(password))
	res:=hex.EncodeToString(hash.Sum(nil))
	fmt.Println(len(res))
	return res
}
// Add salt and encrypt 
func SHA256(password string) string {
    
	const salt = "2021/10/21"// Custom salt 
	hash := sha256.New()
	hash.Write([]byte(password+salt))// Custom combination of password and salt 
	res:=hex.EncodeToString(hash.Sum(nil))
	fmt.Println(len(res))
	return res
}

3、 ... and 、bcrypt Algorithm The cost of cracking is higher , More secure ,bcrypt The algorithm includes random salt addition , It's more convenient

bcrypt Installation package go get golang.org/x/crypto/bcrypt
The code is as follows （ Example ）：

// The password code is Hashi value 
func HashPassword(password string) (string, error) {
    
	start:=time.Now()
	bytes, err := bcrypt.GenerateFromPassword([]byte(password), bcrypt.DefaultCost)//bcrypt.DefaultCost Default value 10, Code once 100ms within , The value can be increased , Increase the time and cost of cracking , For example, set to 14, Code once 1s above 
	time:=time.Since(start)
	log.Printf("Encode Password time:%s",time)
	return string(bytes), err
}
// Verify password , For example, in the actual business, the login password is compared with the hash value stored in the database , To verify equality 
func MatchPasswordHash(password, hash string) bool {
    
	err := bcrypt.CompareHashAndPassword([]byte(hash), []byte(password))
	return err == nil
}