Launcher, app/base, sentry, update service

internal/config/tls/tls.go

@@ -0,0 +1,191 @@
+// Copyright (c) 2021 Proton Technologies AG
+//
+// This file is part of ProtonMail Bridge.
+//
+// ProtonMail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// ProtonMail Bridge is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with ProtonMail Bridge.  If not, see <https://www.gnu.org/licenses/>.
+
+package tls
+
+import (
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/tls"
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"encoding/pem"
+	"fmt"
+	"math/big"
+	"net"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"time"
+
+	"github.com/sirupsen/logrus"
+)
+
+type TLS struct {
+	settingsPath string
+}
+
+func New(settingsPath string) *TLS {
+	return &TLS{
+		settingsPath: settingsPath,
+	}
+}
+
+var tlsTemplate = x509.Certificate{ //nolint[gochecknoglobals]
+	SerialNumber: big.NewInt(-1),
+	Subject: pkix.Name{
+		Country:            []string{"CH"},
+		Organization:       []string{"Proton Technologies AG"},
+		OrganizationalUnit: []string{"ProtonMail"},
+		CommonName:         "127.0.0.1",
+	},
+	KeyUsage:              x509.KeyUsageKeyEncipherment | x509.KeyUsageDigitalSignature | x509.KeyUsageCertSign,
+	ExtKeyUsage:           []x509.ExtKeyUsage{x509.ExtKeyUsageServerAuth, x509.ExtKeyUsageClientAuth},
+	BasicConstraintsValid: true,
+	IsCA:                  true,
+	IPAddresses:           []net.IP{net.ParseIP("127.0.0.1")},
+	NotBefore:             time.Now(),
+	NotAfter:              time.Now().Add(20 * 365 * 24 * time.Hour),
+}
+
+var ErrTLSCertExpireSoon = fmt.Errorf("TLS certificate will expire soon")
+
+// getTLSCertPath returns path to certificate; used for TLS servers (IMAP, SMTP).
+func (t *TLS) getTLSCertPath() string {
+	return filepath.Join(t.settingsPath, "cert.pem")
+}
+
+// getTLSKeyPath returns path to private key; used for TLS servers (IMAP, SMTP).
+func (t *TLS) getTLSKeyPath() string {
+	return filepath.Join(t.settingsPath, "key.pem")
+}
+
+// GenerateConfig generates certs and keys at the given filepaths and returns a TLS Config which holds them.
+// See https://golang.org/src/crypto/tls/generate_cert.go
+func (t *TLS) GenerateConfig() (tlsConfig *tls.Config, err error) {
+	priv, err := rsa.GenerateKey(rand.Reader, 2048)
+	if err != nil {
+		err = fmt.Errorf("failed to generate private key: %s", err)
+		return
+	}
+
+	serialNumberLimit := new(big.Int).Lsh(big.NewInt(1), 128)
+	serialNumber, err := rand.Int(rand.Reader, serialNumberLimit)
+	if err != nil {
+		err = fmt.Errorf("failed to generate serial number: %s", err)
+		return
+	}
+
+	tlsTemplate.SerialNumber = serialNumber
+	derBytes, err := x509.CreateCertificate(rand.Reader, &tlsTemplate, &tlsTemplate, &priv.PublicKey, priv)
+	if err != nil {
+		err = fmt.Errorf("failed to create certificate: %s", err)
+		return
+	}
+
+	certOut, err := os.Create(t.getTLSCertPath())
+	if err != nil {
+		return
+	}
+	defer certOut.Close() //nolint[errcheck]
+	err = pem.Encode(certOut, &pem.Block{Type: "CERTIFICATE", Bytes: derBytes})
+	if err != nil {
+		return
+	}
+
+	keyOut, err := os.OpenFile(t.getTLSKeyPath(), os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		return
+	}
+	defer keyOut.Close() //nolint[errcheck]
+	err = pem.Encode(keyOut, &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(priv)})
+	if err != nil {
+		return
+	}
+
+	return loadTLSConfig(t.getTLSCertPath(), t.getTLSKeyPath())
+}
+
+// GetConfig tries to load TLS config or generate new one which is then returned.
+func (t *TLS) GetConfig() (tlsConfig *tls.Config, err error) {
+	certPath := t.getTLSCertPath()
+	keyPath := t.getTLSKeyPath()
+	tlsConfig, err = loadTLSConfig(certPath, keyPath)
+	if err != nil {
+		logrus.WithError(err).Warn("Cannot load cert, generating a new one")
+		tlsConfig, err = t.GenerateConfig()
+		if err != nil {
+			return
+		}
+
+		if runtime.GOOS == "darwin" {
+			if err := exec.Command( // nolint[gosec]
+				"/usr/bin/security",
+				"execute-with-privileges",
+				"/usr/bin/security",
+				"add-trusted-cert",
+				"-d",
+				"-r", "trustRoot",
+				"-p", "ssl",
+				"-k", "/Library/Keychains/System.keychain",
+				certPath,
+			).Run(); err != nil {
+				logrus.WithError(err).Error("Failed to add cert to system keychain")
+			}
+		}
+	}
+
+	tlsConfig.ServerName = "127.0.0.1"
+	tlsConfig.ClientAuth = tls.VerifyClientCertIfGiven
+
+	caCertPool := x509.NewCertPool()
+	caCertPool.AddCert(tlsConfig.Certificates[0].Leaf)
+	tlsConfig.RootCAs = caCertPool
+	tlsConfig.ClientCAs = caCertPool
+
+	/* This is deprecated:
+	 * SA1019: tlsConfig.BuildNameToCertificate is deprecated:
+	 * NameToCertificate only allows associating a single certificate with a given name.
+	 * Leave that field nil to let the library select the first compatible chain from Certificates.
+	 */
+	tlsConfig.BuildNameToCertificate() // nolint[staticcheck]
+
+	return tlsConfig, err
+}
+
+func loadTLSConfig(certPath, keyPath string) (tlsConfig *tls.Config, err error) {
+	c, err := tls.LoadX509KeyPair(certPath, keyPath)
+	if err != nil {
+		return
+	}
+
+	c.Leaf, err = x509.ParseCertificate(c.Certificate[0])
+	if err != nil {
+		return
+	}
+
+	tlsConfig = &tls.Config{
+		Certificates: []tls.Certificate{c},
+	}
+
+	if time.Now().Add(31 * 24 * time.Hour).After(c.Leaf.NotAfter) {
+		err = ErrTLSCertExpireSoon
+		return
+	}
+	return
+}