RSA keygen + encrypt + decrypt

rsa_hint.go

package main

import (
	"crypto/rand"
	"crypto/rsa"
	"crypto/x509"
	"encoding/pem"
	"fmt"
	"os"
)

func main() {
	priv, err := rsa.GenerateKey(rand.Reader, 4096)
	if err != nil {
		panic(err)
	}
	pem.Encode(os.Stdout, &pem.Block{
		Type:  "RSA PRIVATE KEY",
		Bytes: x509.MarshalPKCS1PrivateKey(priv),
	})
	fmt.Println()
	pem.Encode(os.Stdout, &pem.Block{
		Type:  "RSA PUBLIC KEY",
		Bytes: x509.MarshalPKCS1PublicKey(&priv.PublicKey),
	})
	fmt.Println()
	messageEnc, err := rsa.EncryptPKCS1v15(rand.Reader, &priv.PublicKey, []byte("Hello! World!"))
	if err != nil {
		panic(err)
	}
	pem.Encode(os.Stdout, &pem.Block{
		Type:  "MESSAGE",
		Bytes: messageEnc,
	})
	fmt.Println()
	messageDec, err := rsa.DecryptPKCS1v15(rand.Reader, priv, messageEnc)
	if err != nil {
		panic(err)
	}
	fmt.Println(string(messageDec))
}