ハッシュ値の文字列長（Hex, Base64） https://play.golang.org/p/LQAUgxzAaIh

hash_strings.go

package main

import (
	"crypto/md5"
	"crypto/sha1"
	"crypto/sha256"
	"crypto/sha512"
	"encoding/base64"
	"encoding/hex"
	"fmt"
	"hash"

	"github.com/google/uuid"
	"golang.org/x/crypto/sha3"
)

func main() {
	printHash("MD5", md5.New())
	printHash("SHA-1", sha1.New())
	printHash("SHA-224", sha256.New224())
	printHash("SHA-256", sha256.New())
	printHash("SHA-384", sha512.New384())
	printHash("SHA-512", sha512.New())
	printHash("SHA-512/224", sha512.New512_224())
	printHash("SHA-512/256", sha512.New512_256())
	printHash("SHA3-224", sha3.New224())
	printHash("SHA3-256", sha3.New256())
	printHash("SHA3-384", sha3.New384())
	printHash("SHA3-512", sha3.New512())

	uuidStr := uuid.Must(uuid.NewRandom()).String()
	fmt.Printf("%21s (%3d): %s\n", "UUIDv4", len(uuidStr), uuidStr)
}

func printHash(name string, f hash.Hash) {
	printHashBytes(name, f.Sum(nil))
}

func printHashBytes(name string, data []byte) {
	hexStr := hex.EncodeToString(data)
	fmt.Printf("%16s (hex, %3d): %s\n", name, len(hexStr), hexStr)
	b64Str := base64.RawURLEncoding.EncodeToString(data)
	fmt.Printf("%16s (b64, %3d): %s\n", name, len(b64Str), b64Str)
}