crypto/x509: fix names in certificate generation.

I had a brain fart in af84b15fbae2 and messed up the names in
generated certificates.

R=rsc, bradfitz
CC=golang-dev
https://golang.org/cl/5315046

src/pkg/crypto/x509/x509.go

@@ -928,11 +928,11 @@ func CreateCertificate(rand io.Reader, template, parent *Certificate, pub *rsa.P
 		return
 	}
 
-	asn1Issuer, err := asn1.Marshal(parent.Issuer.ToRDNSequence())
+	asn1Issuer, err := asn1.Marshal(parent.Subject.ToRDNSequence())
 	if err != nil {
 		return
 	}
-	asn1Subject, err := asn1.Marshal(parent.Subject.ToRDNSequence())
+	asn1Subject, err := asn1.Marshal(template.Subject.ToRDNSequence())
 	if err != nil {
 		return
 	}

src/pkg/crypto/x509/x509_test.go

@@ -243,10 +243,11 @@ func TestCreateSelfSignedCertificate(t *testing.T) {
 		return
 	}
 
+	commonName := "test.example.com"
 	template := Certificate{
 		SerialNumber: big.NewInt(1),
 		Subject: pkix.Name{
-			CommonName:   "test.example.com",
+			CommonName:   commonName,
 			Organization: []string{"Acme Co"},
 		},
 		NotBefore: time.SecondsToUTC(1000),
@@ -283,6 +284,14 @@ func TestCreateSelfSignedCertificate(t *testing.T) {
 		t.Errorf("Failed to parse name constraints: %#v", cert.PermittedDNSDomains)
 	}
 
+	if cert.Subject.CommonName != commonName {
+		t.Errorf("Subject wasn't correctly copied from the template. Got %s, want %s", cert.Subject.CommonName, commonName)
+	}
+
+	if cert.Issuer.CommonName != commonName {
+		t.Errorf("Issuer wasn't correctly copied from the template. Got %s, want %s", cert.Issuer.CommonName, commonName)
+	}
+
 	err = cert.CheckSignatureFrom(cert)
 	if err != nil {
 		t.Errorf("Signature verification failed: %s", err)