Support CA certificates in CI (#2136)

* Support CA setting in generate-keys

* Set DNS names correctly

* Use generate-config -server not sed

internal/test/config.go

@@ -20,6 +20,7 @@ import (
 	"crypto/x509"
 	"encoding/base64"
 	"encoding/pem"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"math/big"
@@ -158,11 +159,10 @@ func NewMatrixKey(matrixKeyPath string) (err error) {
 
 const certificateDuration = time.Hour * 24 * 365 * 10
 
-// NewTLSKey generates a new RSA TLS key and certificate and writes it to a file.
-func NewTLSKey(tlsKeyPath, tlsCertPath string) error {
+func generateTLSTemplate(dnsNames []string) (*rsa.PrivateKey, *x509.Certificate, error) {
 	priv, err := rsa.GenerateKey(rand.Reader, 4096)
 	if err != nil {
-		return err
+		return nil, nil, err
 	}
 
 	notBefore := time.Now()
@@ -170,7 +170,7 @@ func NewTLSKey(tlsKeyPath, tlsCertPath string) error {
 	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
 	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
 	if err != nil {
-		return err
+		return nil, nil, err
 	}
 
 	template := x509.Certificate{
@@ -180,20 +180,21 @@ func NewTLSKey(tlsKeyPath, tlsCertPath string) error {
 		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
 		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
 		BasicConstraintsValid: true,
+		DNSNames:              dnsNames,
 	}
-	derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, &priv.PublicKey, priv)
-	if err != nil {
-		return err
-	}
+	return priv, &template, nil
+}
+
+func writeCertificate(tlsCertPath string, derBytes []byte) error {
 	certOut, err := os.Create(tlsCertPath)
 	if err != nil {
 		return err
 	}
 	defer certOut.Close() // nolint: errcheck
-	if err = pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes}); err != nil {
-		return err
-	}
+	return pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
+}
 
+func writePrivateKey(tlsKeyPath string, priv *rsa.PrivateKey) error {
 	keyOut, err := os.OpenFile(tlsKeyPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
 	if err != nil {
 		return err
@@ -205,3 +206,73 @@ func NewTLSKey(tlsKeyPath, tlsCertPath string) error {
 	})
 	return err
 }
+
+// NewTLSKey generates a new RSA TLS key and certificate and writes it to a file.
+func NewTLSKey(tlsKeyPath, tlsCertPath string) error {
+	priv, template, err := generateTLSTemplate(nil)
+	if err != nil {
+		return err
+	}
+
+	// Self-signed certificate: template == parent
+	derBytes, err := x509.CreateCertificate(rand.Reader, template, template, &priv.PublicKey, priv)
+	if err != nil {
+		return err
+	}
+
+	if err = writeCertificate(tlsCertPath, derBytes); err != nil {
+		return err
+	}
+	return writePrivateKey(tlsKeyPath, priv)
+}
+
+func NewTLSKeyWithAuthority(serverName, tlsKeyPath, tlsCertPath, authorityKeyPath, authorityCertPath string) error {
+	priv, template, err := generateTLSTemplate([]string{serverName})
+	if err != nil {
+		return err
+	}
+
+	// load the authority key
+	dat, err := ioutil.ReadFile(authorityKeyPath)
+	if err != nil {
+		return err
+	}
+	block, _ := pem.Decode([]byte(dat))
+	if block == nil || block.Type != "RSA PRIVATE KEY" {
+		return errors.New("authority .key is not a valid pem encoded rsa private key")
+	}
+	authorityPriv, err := x509.ParsePKCS1PrivateKey(block.Bytes)
+	if err != nil {
+		return err
+	}
+
+	// load the authority certificate
+	dat, err = ioutil.ReadFile(authorityCertPath)
+	if err != nil {
+		return err
+	}
+	block, _ = pem.Decode([]byte(dat))
+	if block == nil || block.Type != "CERTIFICATE" {
+		return errors.New("authority .crt is not a valid pem encoded x509 cert")
+	}
+	var caCerts []*x509.Certificate
+	caCerts, err = x509.ParseCertificates(block.Bytes)
+	if err != nil {
+		return err
+	}
+	if len(caCerts) != 1 {
+		return errors.New("authority .crt contains none or more than one cert")
+	}
+	authorityCert := caCerts[0]
+
+	// Sign the new certificate using the authority's key/cert
+	derBytes, err := x509.CreateCertificate(rand.Reader, template, authorityCert, &priv.PublicKey, authorityPriv)
+	if err != nil {
+		return err
+	}
+
+	if err = writeCertificate(tlsCertPath, derBytes); err != nil {
+		return err
+	}
+	return writePrivateKey(tlsKeyPath, priv)
+}