Compute SHA256 Hashes in Go

Introduction

This lab aims to demonstrate how to compute SHA256 hashes in Go. SHA256 hashes are commonly used to compute short identities for binary or text blobs.

Skills Graph

SHA256 Hashes

Given a string, compute its SHA256 hash.

• The program should import the crypto/sha256 and fmt packages.
• The program should use the sha256.New() function to create a new hash.
• The program should use the Write function to write the bytes of the string to the hash.
• The program should use the Sum function to get the finalized hash result as a byte slice.
• The program should print the original string and the hash result in hexadecimal format.

## Running the program computes the hash and prints it in
## a human-readable hex format.
$ go run sha256-hashes.go
sha256 this string
1af1dfa857bf1d8814fe1af8983c18080019922e557f15a8a...

## You can compute other hashes using a similar pattern to
## the one shown above. For example, to compute
## SHA512 hashes import `crypto/sha512` and use
## `sha512.New()`.

## Note that if you need cryptographically secure hashes,
## you should carefully research
## [hash strength](https://en.wikipedia.org/wiki/Cryptographic_hash_function)!

There is the full code below:

// [_SHA256 hashes_](https://en.wikipedia.org/wiki/SHA-2) are
// frequently used to compute short identities for binary
// or text blobs. For example, TLS/SSL certificates use SHA256
// to compute a certificate's signature. Here's how to compute
// SHA256 hashes in Go.

package main

// Go implements several hash functions in various
// `crypto/*` packages.
import (
	"crypto/sha256"
	"fmt"
)

func main() {
	s := "sha256 this string"

	// Here we start with a new hash.
	h := sha256.New()

	// `Write` expects bytes. If you have a string `s`,
	// use `[]byte(s)` to coerce it to bytes.
	h.Write([]byte(s))

	// This gets the finalized hash result as a byte
	// slice. The argument to `Sum` can be used to append
	// to an existing byte slice: it usually isn't needed.
	bs := h.Sum(nil)

	fmt.Println(s)
	fmt.Printf("%x\n", bs)
}

Summary

This lab demonstrated how to compute SHA256 hashes in Go using the crypto/sha256 package. By following the requirements and completing the TODO section, the program can compute the SHA256 hash of a given string.