sha256

Documentation

Overview

Package sha256 implements the SHA224 and SHA256 hash algorithms as defined in FIPS 180-4.

Index

• Constants
• func New() hash.Hash
• func New224() hash.Hash
• func Sum224(data []byte) [Size224]byte
• func Sum256(data []byte) [Size]byte

Examples

• New
• New (File)
• Sum256

Constants

const BlockSize = 64

The blocksize of SHA256 and SHA224 in bytes.

const Size = 32

The size of a SHA256 checksum in bytes.

const Size224 = 28

The size of a SHA224 checksum in bytes.

Functions

func New

func New() hash.Hash

New returns a new hash.Hash computing the SHA256 checksum. The Hash also implements encoding.BinaryMarshaler and encoding.BinaryUnmarshaler to marshal and unmarshal the internal state of the hash.

Example

package main

import (
	"crypto/sha256"
	"fmt"
)

func main() {
	h := sha256.New()
	h.Write([]byte("hello world\n"))
	fmt.Printf("%x", h.Sum(nil))
}

Output:

a948904f2f0f479b8f8197694b30184b0d2ed1c1cd2a1ec0fb85d299a192a447

Example (File)

package main

import (
	"crypto/sha256"
	"fmt"
	"io"
	"log"
	"os"
)

func main() {
	f, err := os.Open("file.txt")
	if err != nil {
		log.Fatal(err)
	}
	defer f.Close()

	h := sha256.New()
	if _, err := io.Copy(h, f); err != nil {
		log.Fatal(err)
	}

	fmt.Printf("%x", h.Sum(nil))
}

func New224

func New224() hash.Hash

New224 returns a new hash.Hash computing the SHA224 checksum.

func Sum224

func Sum224(data []byte) [Size224]byte

Sum224 returns the SHA224 checksum of the data.

func Sum256

func Sum256(data []byte) [Size]byte

Sum256 returns the SHA256 checksum of the data.

Example

package main

import (
	"crypto/sha256"
	"fmt"
)

func main() {
	sum := sha256.Sum256([]byte("hello world\n"))
	fmt.Printf("%x", sum)
}

Output:

a948904f2f0f479b8f8197694b30184b0d2ed1c1cd2a1ec0fb85d299a192a447