Generate SSH private key (Ed25519)

sshKeygen.go

package main

import (
	"crypto/ed25519"
	"crypto/rand"
	"crypto/x509"
	"encoding/pem"

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

func generateSSHPrivateKey() (sshPriv ssh.Signer, err error) {
	_, priv, err := ed25519.GenerateKey(rand.Reader)
	if err != nil {
		return sshPriv, err
	}

	bytes, err := x509.MarshalPKCS8PrivateKey(priv) // Convert a generated ed25519 key into a PEM block so that the ssh library can ingest it, bit round about tbh
	if err != nil {
		return sshPriv, err
	}

	privatePem := pem.EncodeToMemory(
		&pem.Block{
			Type:  "PRIVATE KEY",
			Bytes: bytes,
		},
	)

	sshPriv, err = ssh.ParsePrivateKey(privatePem)
	if err != nil {
		return sshPriv, err
	}

	return sshPriv, nil

}