Generate Ed25519 key pair in PEM format

gen_ed25519_key_pair.go

package main

import (
	"crypto/ed25519"
	"crypto/rand"
	"crypto/x509"
	"encoding/pem"
	"fmt"
	"os"
)

func main() {
	// Generate ED25519 key pair
	publicKey, privateKey, err := ed25519.GenerateKey(rand.Reader)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error generating ED25519 key pair: %v\n", err)
		os.Exit(1)
	}

	// Convert private key to PKCS8 form
	privateKeyBytes, err := x509.MarshalPKCS8PrivateKey(privateKey)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error marshaling private key: %v\n", err)
		os.Exit(1)
	}

	// Create PEM block for private key
	privateKeyPEM := &pem.Block{
		Type:  "PRIVATE KEY",
		Bytes: privateKeyBytes,
	}

	// Convert public key to PKIX form
	publicKeyBytes, err := x509.MarshalPKIXPublicKey(publicKey)
	if err != nil {
		fmt.Fprintf(os.Stderr, "Error marshaling public key: %v\n", err)
		os.Exit(1)
	}

	// Create PEM block for public key
	publicKeyPEM := &pem.Block{
		Type:  "PUBLIC KEY",
		Bytes: publicKeyBytes,
	}

	os.WriteFile("public_key.pem", pem.EncodeToMemory(publicKeyPEM), 0644)
	os.WriteFile("private_key.pem", pem.EncodeToMemory(privateKeyPEM), 0644)

	// Print both keys
	fmt.Println("ED25519 Private Key (PEM format):")
	fmt.Println(string(pem.EncodeToMemory(privateKeyPEM)))

	fmt.Println("ED25519 Public Key (PEM format):")
	fmt.Println(string(pem.EncodeToMemory(publicKeyPEM)))
}