How to Generate MD5 Hash from String in Golang?

The MD5 Message-Digest Algorithm is a widely used cryptographic hash function that produces a 128-bit (16-byte) hash value, used to ensure the integrity and consistency of information transmission.

This article will use the crypto/md5 package from the Golang standard library to implement MD5 hash calculation for strings;

Import necessary packages:

import (
	"crypto/md5"
	"encoding/hex"
)

crypto/md5 is the MD5 package in the standard library; while encoding/hex is an encoding utility package that converts byte slices to strings.

Implementation:

func MD5(v string)string{
	d := []byte(v)
	m := md5.New()
	m.Write(d)
	return hex.EncodeToString(m.Sum(nil))
}

md5.New() returns a hash.Hash object; the hash.Hash object defines a Sum interface with the following prototype:

func Sum(data []byte) [Size]byte

Sum() performs checksum calculation on the content stored internally in the hash.Hash object, then appends it to data to form a new byte slice, so data is typically set to nil.

The Write interface of the hash.Hash object only accepts byte slice data type;

Complete code:

package main

import (
	"crypto/md5"
	"encoding/hex"

	"fmt"
)

func MD5(v string)string{
	d := []byte(v)
	m := md5.New()
	m.Write(d)
	return hex.EncodeToString(m.Sum(nil))
}

func main(){
	fmt.Println(MD5("123456"))
}