edkey allows you to marshal/write ED25519 private keys in the OpenSSH private key format
package main import ( "crypto/rand" "encoding/pem" "io/ioutil" "github.com/mikesmitty/edkey" "golang.org/x/crypto/ed25519" "golang.org/x/crypto/ssh" ) func main() { // Generate a new private/public keypair for OpenSSH pubKey, privKey, _ := ed25519.GenerateKey(rand.Reader) publicKey, _ := ssh.NewPublicKey(pubKey) pemKey := &pem.Block{ Type: "OPENSSH PRIVATE KEY", Bytes: edkey.MarshalED25519PrivateKey(privKey), } privateKey := pem.EncodeToMemory(pemKey) authorizedKey := ssh.MarshalAuthorizedKey(publicKey) _ = ioutil.WriteFile("id_ed25519", privateKey, 0600) _ = ioutil.WriteFile("id_ed25519.pub", authorizedKey, 0644) }