Go SHA-3 Hash Code Example (Online Runner)

Go SHA-3 hashing examples for SHA3-224/256/384/512 with runnable snippets and file hashing.

Online calculator: use the site SHA-3 text tool.

Note: This snippet requires locally installed dependencies and will not run in the online runner. Run it locally with: go mod init sha3-demo && go get golang.org/x/crypto/sha3 && go run sha3_basic.go

Calculation method

Use golang.org/x/crypto/sha3 and select the desired output size (224/256/384/512).

Implementation notes

Package: golang.org/x/crypto/sha3.
Implementation: file hashing streams bytes to avoid loading large files into memory.
Notes: SHA-3 is unkeyed; for keyed integrity use HMAC-SHA3.

Text hashing example

package main

import (
	"encoding/hex"
	"fmt"

	"golang.org/x/crypto/sha3"
)

func sha3Text(text string) string {
	sum := sha3.Sum256([]byte(text))
	return hex.EncodeToString(sum[:])
}

func main() {
	fmt.Println(sha3Text("hello world"))
}

File hashing example

package main

import (
	"encoding/hex"
	"fmt"
	"io"
	"os"

	"golang.org/x/crypto/sha3"
)

func sha3File(path string) (string, error) {
	file, err := os.Open(path)
	if err != nil {
		return "", err
	}
	defer file.Close()

	hash := sha3.New512()
	if _, err := io.Copy(hash, file); err != nil {
		return "", err
	}
	return hex.EncodeToString(hash.Sum(nil)), nil
}

func main() {
	file, err := os.CreateTemp("", "sha3-example-*.bin")
	if err != nil {
		panic(err)
	}
	defer os.Remove(file.Name())
	if _, err := file.Write([]byte("example payload\n")); err != nil {
		panic(err)
	}
	if err := file.Close(); err != nil {
		panic(err)
	}

	value, err := sha3File(file.Name())
	if err != nil {
		panic(err)
	}
	fmt.Println(value)
}

Complete script (implementation + tests)

package main

import (
	"encoding/hex"
	"errors"
	"fmt"
	"io"
	"os"

	"golang.org/x/crypto/sha3"
)

type Variant string

const (
	SHA3_224 Variant = "sha3-224"
	SHA3_256 Variant = "sha3-256"
	SHA3_384 Variant = "sha3-384"
	SHA3_512 Variant = "sha3-512"
)

func sha3Hex(data []byte, variant Variant) (string, error) {
	switch variant {
	case SHA3_224:
		sum := sha3.Sum224(data)
		return hex.EncodeToString(sum[:]), nil
	case SHA3_256:
		sum := sha3.Sum256(data)
		return hex.EncodeToString(sum[:]), nil
	case SHA3_384:
		sum := sha3.Sum384(data)
		return hex.EncodeToString(sum[:]), nil
	case SHA3_512:
		sum := sha3.Sum512(data)
		return hex.EncodeToString(sum[:]), nil
	default:
		return "", errors.New("unsupported SHA-3 variant")
	}
}

func sha3Text(text string, variant Variant) (string, error) {
	return sha3Hex([]byte(text), variant)
}

func sha3File(path string, variant Variant) (string, error) {
	file, err := os.Open(path)
	if err != nil {
		return "", err
	}
	defer file.Close()

	var hash io.Writer
	var sumFunc func() []byte

	switch variant {
	case SHA3_224:
		h := sha3.New224()
		hash = h
		sumFunc = func() []byte { return h.Sum(nil) }
	case SHA3_256:
		h := sha3.New256()
		hash = h
		sumFunc = func() []byte { return h.Sum(nil) }
	case SHA3_384:
		h := sha3.New384()
		hash = h
		sumFunc = func() []byte { return h.Sum(nil) }
	case SHA3_512:
		h := sha3.New512()
		hash = h
		sumFunc = func() []byte { return h.Sum(nil) }
	default:
		return "", errors.New("unsupported SHA-3 variant")
	}

	if _, err := io.Copy(hash, file); err != nil {
		return "", err
	}
	return hex.EncodeToString(sumFunc()), nil
}

func main() {
	digest, err := sha3Text("hello", SHA3_256)
	if err != nil {
		panic(err)
	}
	fmt.Println("sha3-256(hello)=", digest)

	file, err := os.CreateTemp("", "sha3-example-*.bin")
	if err != nil {
		panic(err)
	}
	defer os.Remove(file.Name())
	if _, err := file.Write([]byte("example payload\n")); err != nil {
		panic(err)
	}
	if err := file.Close(); err != nil {
		panic(err)
	}

	fileHash, err := sha3File(file.Name(), SHA3_512)
	if err != nil {
		panic(err)
	}
	fmt.Println("sha3-512(file)=", fileHash)
}