Switch algorithme for auto-generated TLS certificates from RSA to ECDSA

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changes from version 0.11.1 to master
 
-- Changed default ECDSA curve used by `arangodb create tls ...` from `P521` to `p256`.
+- Changed TLS algorithm for `-ssl.auto-key` from RSA (2048 bits) to ECDSA (`P256` curve).
+- Changed default ECDSA curve used by `arangodb create tls ...` from `P521` to `P256`.
 - Log text showing the address the starter is listening on has been changed from "Listening on ..." to "ArangoDB Starter listening on ...".
 - Solved problem where starter did not properly log a resilientsingle server ("Your resilient single server can now be accessed ...") when leadership challenge was still ongoing.
 

main.go

@@ -579,7 +579,6 @@ func mustPrepareService(generateAutoKeyFile bool) (*service.Service, service.Boo
 		}
 		keyFile, err := service.CreateCertificate(service.CreateCertificateOptions{
 			Hosts:        hosts,
-			RSABits:      2048,
 			Organization: sslAutoOrganization,
 		}, dataDir)
 		if err != nil {

service/certificate.go

@@ -23,121 +23,48 @@
 package service
 
 import (
-	"crypto"
-	"crypto/ecdsa"
-	"crypto/rand"
-	"crypto/rsa"
 	"crypto/tls"
-	"crypto/x509"
 	"crypto/x509/pkix"
-	"encoding/pem"
-	"errors"
-	"fmt"
 	"io/ioutil"
-	"math/big"
-	"net"
 	"strings"
 	"time"
+
+	certificates "github.com/arangodb-helper/go-certificates"
 )
 
 // CreateCertificateOptions configures how to create a certificate.
 type CreateCertificateOptions struct {
 	Hosts        []string // Host names and/or IP addresses
 	ValidFor     time.Duration
-	RSABits      int
 	Organization string
 }
 
 const (
 	defaultValidFor = time.Hour * 24 * 365 // 1year
+	defaultCurve    = "P256"
 )
 
-func publicKey(priv interface{}) interface{} {
-	switch k := priv.(type) {
-	case *rsa.PrivateKey:
-		return &k.PublicKey
-	default:
-		return nil
-	}
-}
-
-func pemBlockForKey(priv interface{}) *pem.Block {
-	switch k := priv.(type) {
-	case *rsa.PrivateKey:
-		return &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(k)}
-	default:
-		return nil
-	}
-}
-
-// Attempt to parse the given private key DER block. OpenSSL 0.9.8 generates
-// PKCS#1 private keys by default, while OpenSSL 1.0.0 generates PKCS#8 keys.
-// OpenSSL ecparam generates SEC1 EC private keys for ECDSA. We try all three.
-func parsePrivateKey(der []byte) (crypto.PrivateKey, error) {
-	if key, err := x509.ParsePKCS1PrivateKey(der); err == nil {
-		return key, nil
-	}
-	if key, err := x509.ParsePKCS8PrivateKey(der); err == nil {
-		switch key := key.(type) {
-		case *rsa.PrivateKey, *ecdsa.PrivateKey:
-			return key, nil
-		default:
-			return nil, maskAny(errors.New("tls: found unknown private key type in PKCS#8 wrapping"))
-		}
-	}
-	if key, err := x509.ParseECPrivateKey(der); err == nil {
-		return key, nil
-	}
-
-	return nil, maskAny(errors.New("tls: failed to parse private key"))
-}
-
 // CreateCertificate creates a self-signed certificate according to the given configuration.
 // The resulting certificate + private key will be written into a single file in the given folder.
 // The path of that single file is returned.
 func CreateCertificate(options CreateCertificateOptions, folder string) (string, error) {
-	priv, err := rsa.GenerateKey(rand.Reader, options.RSABits)
-	if err != nil {
-		return "", maskAny(err)
-	}
-
-	notBefore := time.Now()
 	if options.ValidFor == 0 {
 		options.ValidFor = defaultValidFor
 	}
-	notAfter := notBefore.Add(options.ValidFor)
-
-	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
-	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
-	if err != nil {
-		return "", maskAny(fmt.Errorf("failed to generate serial number: %v", err))
-	}
-
-	template := x509.Certificate{
-		SerialNumber: serialNumber,
-		Subject: pkix.Name{
+	certOpts := certificates.CreateCertificateOptions{
+		Hosts: options.Hosts,
+		Subject: &pkix.Name{
 			Organization: []string{options.Organization},
 		},
-		NotBefore: notBefore,
-		NotAfter:  notAfter,
-
-		KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature,
-		ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth},
-		BasicConstraintsValid: true,
-	}
-
-	for _, h := range options.Hosts {
-		if ip := net.ParseIP(h); ip != nil {
-			template.IPAddresses = append(template.IPAddresses, ip)
-		} else {
-			template.DNSNames = append(template.DNSNames, h)
-		}
+		ValidFrom:  time.Now(),
+		ValidFor:   options.ValidFor,
+		ECDSACurve: defaultCurve,
 	}
 
-	// Create the certificate
-	derBytes, err := x509.CreateCertificate(rand.Reader, &template, &template, publicKey(priv), priv)
+	// Create self-signed certificate
+	cert, priv, err := certificates.CreateCertificate(certOpts, nil)
 	if err != nil {
-		return "", maskAny(fmt.Errorf("Failed to create certificate: %v", err))
+		return "", maskAny(err)
 	}
 
 	// Write the certificate to disk
@@ -146,46 +73,19 @@ func CreateCertificate(options CreateCertificateOptions, folder string) (string,
 		return "", maskAny(err)
 	}
 	defer f.Close()
-	// Public key
-	pem.Encode(f, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
-	// Private key
-	pem.Encode(f, pemBlockForKey(priv))
+	content := strings.TrimSpace(cert) + "\n" + priv
+	if _, err := f.WriteString(content); err != nil {
+		return "", maskAny(err)
+	}
 
 	return f.Name(), nil
 }
 
 // LoadKeyFile loads a SSL keyfile formatted for the arangod server.
 func LoadKeyFile(keyFile string) (tls.Certificate, error) {
-	raw, err := ioutil.ReadFile(keyFile)
+	result, err := certificates.LoadKeyFile(keyFile)
 	if err != nil {
 		return tls.Certificate{}, maskAny(err)
 	}
-
-	result := tls.Certificate{}
-	for {
-		var derBlock *pem.Block
-		derBlock, raw = pem.Decode(raw)
-		if derBlock == nil {
-			break
-		}
-		if derBlock.Type == "CERTIFICATE" {
-			result.Certificate = append(result.Certificate, derBlock.Bytes)
-		} else if derBlock.Type == "PRIVATE KEY" || strings.HasSuffix(derBlock.Type, " PRIVATE KEY") {
-			if result.PrivateKey == nil {
-				result.PrivateKey, err = parsePrivateKey(derBlock.Bytes)
-				if err != nil {
-					return tls.Certificate{}, maskAny(err)
-				}
-			}
-		}
-	}
-
-	if len(result.Certificate) == 0 {
-		return tls.Certificate{}, maskAny(fmt.Errorf("No certificates found in %s", keyFile))
-	}
-	if result.PrivateKey == nil {
-		return tls.Certificate{}, maskAny(fmt.Errorf("No private key found in %s", keyFile))
-	}
-
 	return result, nil
 }