Initial code commit

internal/ssh/keygen.go

@@ -0,0 +1,86 @@
+package ssh
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+)
+
+type KeyPair struct {
+	PrivateKey []byte
+	PublicKey  []byte
+	Passphrase string
+}
+
+func GenerateKeyPair(passphrase string) (*KeyPair, error) {
+	if passphrase == "" {
+		var err error
+		passphrase, err = GenerateSecurePassphrase(32)
+		if err != nil {
+			return nil, fmt.Errorf("failed to generate passphrase: %w", err)
+		}
+	}
+
+	// Create temporary directory for key generation
+	tmpDir, err := os.MkdirTemp("", "sslh-lab-keygen-*")
+	if err != nil {
+		return nil, fmt.Errorf("failed to create temp directory: %w", err)
+	}
+	defer os.RemoveAll(tmpDir)
+
+	tmpKeyPath := filepath.Join(tmpDir, "id_ed25519")
+
+	// Use ssh-keygen to generate OpenSSH format key with passphrase
+	cmd := exec.Command("ssh-keygen", "-t", "ed25519", "-f", tmpKeyPath, "-N", passphrase, "-C", "sslh-lab-generated")
+	cmd.Stderr = os.Stderr
+	if err := cmd.Run(); err != nil {
+		return nil, fmt.Errorf("failed to generate SSH key with ssh-keygen: %w", err)
+	}
+
+	// Read the generated private key
+	privateKeyBytes, err := os.ReadFile(tmpKeyPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read generated private key: %w", err)
+	}
+
+	// Read the generated public key
+	publicKeyBytes, err := os.ReadFile(tmpKeyPath + ".pub")
+	if err != nil {
+		return nil, fmt.Errorf("failed to read generated public key: %w", err)
+	}
+
+	return &KeyPair{
+		PrivateKey: privateKeyBytes,
+		PublicKey:  publicKeyBytes,
+		Passphrase: passphrase,
+	}, nil
+}
+
+func SaveKeyPair(keyPair *KeyPair, outputDir string) (string, string, error) {
+	if err := os.MkdirAll(outputDir, 0700); err != nil {
+		return "", "", fmt.Errorf("failed to create output directory: %w", err)
+	}
+
+	privateKeyPath := filepath.Join(outputDir, "id_ed25519")
+	publicKeyPath := filepath.Join(outputDir, "id_ed25519.pub")
+
+	if err := os.WriteFile(privateKeyPath, keyPair.PrivateKey, 0600); err != nil {
+		return "", "", fmt.Errorf("failed to write private key: %w", err)
+	}
+
+	if err := os.WriteFile(publicKeyPath, keyPair.PublicKey, 0644); err != nil {
+		return "", "", fmt.Errorf("failed to write public key: %w", err)
+	}
+
+	return privateKeyPath, publicKeyPath, nil
+}
+
+func LoadPublicKey(publicKeyPath string) (string, error) {
+	publicKeyBytes, err := os.ReadFile(publicKeyPath)
+	if err != nil {
+		return "", fmt.Errorf("failed to read public key file: %w", err)
+	}
+
+	return string(publicKeyBytes), nil
+}