🧹 Refactor Generate in internal/identity

internal/identity/identity.go

@@ -29,33 +29,17 @@ type Identity struct {
 
 // Generate creates a new self-signed X.509 certificate and ECDSA private key.
 func Generate(shortName string) (*Identity, error) {
-	priv, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	priv, err := newPrivateKey()
 	if err != nil {
-		return nil, fmt.Errorf("failed to generate private key: %w", err)
+		return nil, err
 	}
 
-	notBefore := time.Now()
-	notAfter := notBefore.Add(365 * 24 * time.Hour)
-
-	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
-	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
+	template, err := newCertificateTemplate(shortName)
 	if err != nil {
-		return nil, fmt.Errorf("failed to generate serial number: %w", err)
+		return nil, err
 	}
 
-	template := x509.Certificate{
-		SerialNumber: serialNumber,
-		Subject: pkix.Name{
-			CommonName: shortName,
-		},
-		NotBefore:             notBefore,
-		NotAfter:              notAfter,
-		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
-		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth, x509.ExtKeyUsageClientAuth},
-		BasicConstraintsValid: true,
-	}
-
-	derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &priv.PublicKey, priv)
+	derBytes, err := x509.CreateCertificate(rand.Reader, template, template, &priv.PublicKey, priv)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create certificate: %w", err)
 	}
@@ -167,6 +151,37 @@ func MarshalCertificate(cert *x509.Certificate) []byte {
 	return pem.EncodeToMemory(&pem.Block{Type: "CERTIFICATE", Bytes: cert.Raw})
 }
 
+func newPrivateKey() (*ecdsa.PrivateKey, error) {
+	priv, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		return nil, fmt.Errorf("failed to generate private key: %w", err)
+	}
+	return priv, nil
+}
+
+func newCertificateTemplate(shortName string) (*x509.Certificate, error) {
+	notBefore := time.Now()
+	notAfter := notBefore.Add(365 * 24 * time.Hour)
+
+	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
+	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
+	if err != nil {
+		return nil, fmt.Errorf("failed to generate serial number: %w", err)
+	}
+
+	return &x509.Certificate{
+		SerialNumber: serialNumber,
+		Subject: pkix.Name{
+			CommonName: shortName,
+		},
+		NotBefore:             notBefore,
+		NotAfter:              notAfter,
+		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
+		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth, x509.ExtKeyUsageClientAuth},
+		BasicConstraintsValid: true,
+	}, nil
+}
+
 // UnmarshalCertificate imports a certificate from PEM format.
 func UnmarshalCertificate(data []byte) (*x509.Certificate, error) {
 	block, _ := pem.Decode(data)

internal/identity/identity_test.go

@@ -0,0 +1,29 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package identity
+
+import (
+	"testing"
+)
+
+func TestGenerate(t *testing.T) {
+	shortName := "test-agent"
+	ident, err := Generate(shortName)
+	if err != nil {
+		t.Fatalf("Generate() failed: %v", err)
+	}
+
+	if ident == nil {
+		t.Fatal("Generate() returned nil identity")
+	}
+
+	if ident.Certificate == nil {
+		t.Error("Generate() returned identity with nil certificate")
+	} else if ident.Certificate.Subject.CommonName != shortName {
+		t.Errorf("Generate() certificate common name = %q, want %q", ident.Certificate.Subject.CommonName, shortName)
+	}
+
+	if ident.PrivateKey == nil {
+		t.Error("Generate() returned identity with nil private key")
+	}
+}