Make SSL cipher suite configurable (#17440)

1 files changed, 191 insertions, 0 deletions

diff --git a/cmd/web_https.go b/cmd/web_https.go
new file mode 100644
index 0000000000..b939dcab8a
--- /dev/null
+++ b/cmd/web_https.go
@@ -0,0 +1,191 @@
+// Copyright 2021 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package cmd
+
+import (
+	"crypto/tls"
+	"net/http"
+	"os"
+	"strings"
+
+	"code.gitea.io/gitea/modules/graceful"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"github.com/klauspost/cpuid/v2"
+)
+
+var tlsVersionStringMap = map[string]uint16{
+	"":        tls.VersionTLS12, // Default to tls.VersionTLS12
+	"tlsv1.0": tls.VersionTLS10,
+	"tlsv1.1": tls.VersionTLS11,
+	"tlsv1.2": tls.VersionTLS12,
+	"tlsv1.3": tls.VersionTLS13,
+}
+
+func toTLSVersion(version string) uint16 {
+	tlsVersion, ok := tlsVersionStringMap[strings.TrimSpace(strings.ToLower(version))]
+	if !ok {
+		log.Warn("Unknown tls version: %s", version)
+		return 0
+	}
+	return tlsVersion
+}
+
+var curveStringMap = map[string]tls.CurveID{
+	"x25519": tls.X25519,
+	"p256":   tls.CurveP256,
+	"p384":   tls.CurveP384,
+	"p521":   tls.CurveP521,
+}
+
+func toCurvePreferences(preferences []string) []tls.CurveID {
+	ids := make([]tls.CurveID, 0, len(preferences))
+	for _, pref := range preferences {
+		id, ok := curveStringMap[strings.TrimSpace(strings.ToLower(pref))]
+		if !ok {
+			log.Warn("Unknown curve: %s", pref)
+		}
+		if id != 0 {
+			ids = append(ids, id)
+		}
+	}
+	return ids
+}
+
+var cipherStringMap = map[string]uint16{
+	"rsa_with_rc4_128_sha":                      tls.TLS_RSA_WITH_RC4_128_SHA,
+	"rsa_with_3des_ede_cbc_sha":                 tls.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
+	"rsa_with_aes_128_cbc_sha":                  tls.TLS_RSA_WITH_AES_128_CBC_SHA,
+	"rsa_with_aes_256_cbc_sha":                  tls.TLS_RSA_WITH_AES_256_CBC_SHA,
+	"rsa_with_aes_128_cbc_sha256":               tls.TLS_RSA_WITH_AES_128_CBC_SHA256,
+	"rsa_with_aes_128_gcm_sha256":               tls.TLS_RSA_WITH_AES_128_GCM_SHA256,
+	"rsa_with_aes_256_gcm_sha384":               tls.TLS_RSA_WITH_AES_256_GCM_SHA384,
+	"ecdhe_ecdsa_with_rc4_128_sha":              tls.TLS_ECDHE_ECDSA_WITH_RC4_128_SHA,
+	"ecdhe_ecdsa_with_aes_128_cbc_sha":          tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
+	"ecdhe_ecdsa_with_aes_256_cbc_sha":          tls.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
+	"ecdhe_rsa_with_rc4_128_sha":                tls.TLS_ECDHE_RSA_WITH_RC4_128_SHA,
+	"ecdhe_rsa_with_3des_ede_cbc_sha":           tls.TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA,
+	"ecdhe_rsa_with_aes_128_cbc_sha":            tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
+	"ecdhe_rsa_with_aes_256_cbc_sha":            tls.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
+	"ecdhe_ecdsa_with_aes_128_cbc_sha256":       tls.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,
+	"ecdhe_rsa_with_aes_128_cbc_sha256":         tls.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
+	"ecdhe_rsa_with_aes_128_gcm_sha256":         tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+	"ecdhe_ecdsa_with_aes_128_gcm_sha256":       tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+	"ecdhe_rsa_with_aes_256_gcm_sha384":         tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+	"ecdhe_ecdsa_with_aes_256_gcm_sha384":       tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+	"ecdhe_rsa_with_chacha20_poly1305_sha256":   tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
+	"ecdhe_ecdsa_with_chacha20_poly1305_sha256": tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
+	"ecdhe_rsa_with_chacha20_poly1305":          tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
+	"ecdhe_ecdsa_with_chacha20_poly1305":        tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,
+	"aes_128_gcm_sha256":                        tls.TLS_AES_128_GCM_SHA256,
+	"aes_256_gcm_sha384":                        tls.TLS_AES_256_GCM_SHA384,
+	"chacha20_poly1305_sha256":                  tls.TLS_CHACHA20_POLY1305_SHA256,
+}
+
+func toTLSCiphers(cipherStrings []string) []uint16 {
+	ciphers := make([]uint16, 0, len(cipherStrings))
+	for _, cipherString := range cipherStrings {
+		cipher, ok := cipherStringMap[strings.TrimSpace(strings.ToLower(cipherString))]
+		if !ok {
+			log.Warn("Unknown cipher: %s", cipherString)
+		}
+		if cipher != 0 {
+			ciphers = append(ciphers, cipher)
+		}
+	}
+
+	return ciphers
+}
+
+// defaultCiphers uses hardware support to check if AES is specifically
+// supported by the CPU.
+//
+// If AES is supported AES ciphers will be preferred over ChaCha based ciphers
+// (This code is directly inspired by the certmagic code.)
+func defaultCiphers() []uint16 {
+	if cpuid.CPU.Supports(cpuid.AESNI) {
+		return defaultCiphersAESfirst
+	}
+	return defaultCiphersChaChaFirst
+}
+
+var (
+	defaultCiphersAES = []uint16{
+		tls.TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
+		tls.TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
+		tls.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
+		tls.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
+	}
+
+	defaultCiphersChaCha = []uint16{
+		tls.TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305,
+		tls.TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305,
+	}
+
+	defaultCiphersAESfirst    = append(defaultCiphersAES, defaultCiphersChaCha...)
+	defaultCiphersChaChaFirst = append(defaultCiphersChaCha, defaultCiphersAES...)
+)
+
+// runHTTPs listens on the provided network address and then calls
+// Serve to handle requests on incoming TLS connections.
+//
+// Filenames containing a certificate and matching private key for the server must
+// be provided. If the certificate is signed by a certificate authority, the
+// certFile should be the concatenation of the server's certificate followed by the
+// CA's certificate.
+func runHTTPS(network, listenAddr, name, certFile, keyFile string, m http.Handler) error {
+	tlsConfig := &tls.Config{}
+	if tlsConfig.NextProtos == nil {
+		tlsConfig.NextProtos = []string{"h2", "http/1.1"}
+	}
+
+	if version := toTLSVersion(setting.SSLMinimumVersion); version != 0 {
+		tlsConfig.MinVersion = version
+	}
+	if version := toTLSVersion(setting.SSLMaximumVersion); version != 0 {
+		tlsConfig.MaxVersion = version
+	}
+
+	// Set curve preferences
+	tlsConfig.CurvePreferences = []tls.CurveID{
+		tls.X25519,
+		tls.CurveP256,
+	}
+	if curves := toCurvePreferences(setting.SSLCurvePreferences); len(curves) > 0 {
+		tlsConfig.CurvePreferences = curves
+	}
+
+	// Set cipher suites
+	tlsConfig.CipherSuites = defaultCiphers()
+	if ciphers := toTLSCiphers(setting.SSLCipherSuites); len(ciphers) > 0 {
+		tlsConfig.CipherSuites = ciphers
+	}
+
+	tlsConfig.Certificates = make([]tls.Certificate, 1)
+
+	certPEMBlock, err := os.ReadFile(certFile)
+	if err != nil {
+		log.Error("Failed to load https cert file %s for %s:%s: %v", certFile, network, listenAddr, err)
+		return err
+	}
+
+	keyPEMBlock, err := os.ReadFile(keyFile)
+	if err != nil {
+		log.Error("Failed to load https key file %s for %s:%s: %v", keyFile, network, listenAddr, err)
+		return err
+	}
+
+	tlsConfig.Certificates[0], err = tls.X509KeyPair(certPEMBlock, keyPEMBlock)
+	if err != nil {
+		log.Error("Failed to create certificate from cert file %s and key file %s for %s:%s: %v", certFile, keyFile, network, listenAddr, err)
+		return err
+	}
+
+	return graceful.HTTPListenAndServeTLSConfig(network, listenAddr, name, tlsConfig, m)
+}
+
+func runHTTPSWithTLSConfig(network, listenAddr, name string, tlsConfig *tls.Config, m http.Handler) error {
+	return graceful.HTTPListenAndServeTLSConfig(network, listenAddr, name, tlsConfig, m)
+}