ssh: Use ed25519 algorithm instead ECDSA

Key generated using ecdsa algorithm is causing issue for podman remote
connection on podman desktop side because the library they consume
doesn't have support for this algorithm. This PR is switching the ecdsa
to ed25519 which is supported by the library consumed in podman desktop.

[0] containers/podman-desktop#8351
[1] mscdex/ssh2#1375

pkg/crc/constants/constants.go

@@ -174,11 +174,11 @@ func EnsureBaseDirectoriesExist() error {
 }
 
 func GetPublicKeyPath() string {
-	return filepath.Join(MachineInstanceDir, DefaultName, "id_ecdsa.pub")
+	return filepath.Join(MachineInstanceDir, DefaultName, "id_ed25519.pub")
 }
 
 func GetPrivateKeyPath() string {
-	return filepath.Join(MachineInstanceDir, DefaultName, "id_ecdsa")
+	return filepath.Join(MachineInstanceDir, DefaultName, "id_ed25519")
 }
 
 func GetHostDockerSocketPath() string {

pkg/crc/ssh/keys.go

@@ -3,8 +3,7 @@ package ssh
 import (
 	"bufio"
 	"bytes"
-	"crypto/ecdsa"
-	"crypto/elliptic"
+	"crypto/ed25519"
 	"crypto/rand"
 	"crypto/x509"
 	"errors"
@@ -14,13 +13,11 @@ import (
 	"strings"
 
 	"github.com/crc-org/crc/v2/pkg/crc/constants"
-	gossh "golang.org/x/crypto/ssh"
 )
 
 var (
 	ErrKeyGeneration     = errors.New("Unable to generate key")
 	ErrPrivateKey        = errors.New("Unable to marshal private key")
-	ErrPublicKey         = errors.New("Unable to convert public key")
 	ErrUnableToWriteFile = errors.New("Unable to write file")
 )
 
@@ -33,7 +30,7 @@ type KeyPair struct {
 // This will return a private & public key encoded as DER.
 func NewKeyPair() (keyPair *KeyPair, err error) {
 
-	priv, err := ecdsa.GenerateKey(elliptic.P521(), rand.Reader)
+	pubSSH, priv, err := ed25519.GenerateKey(rand.Reader)
 	if err != nil {
 		return nil, ErrKeyGeneration
 	}
@@ -42,15 +39,9 @@ func NewKeyPair() (keyPair *KeyPair, err error) {
 	if err != nil {
 		return nil, ErrPrivateKey
 	}
-
-	pubSSH, err := gossh.NewPublicKey(&priv.PublicKey)
-	if err != nil {
-		return nil, ErrPublicKey
-	}
-
 	return &KeyPair{
 		PrivateKey: privDer,
-		PublicKey:  gossh.MarshalAuthorizedKey(pubSSH),
+		PublicKey:  pubSSH,
 	}, nil
 }