Merge pull request #4 from Snawoot/ciphers_options

Ciphers options

README.md

@@ -155,8 +155,14 @@ $ ~/go/bin/dumbproxy -h
     	CA file to authenticate clients with certificates
   -cert string
     	enable TLS and use certificate
+  -ciphers string
+    	colon-separated list of enabled ciphers
+  -disable-http2
+    	disable HTTP2
   -key string
     	key for TLS certificate
+  -list-ciphers
+    	list ciphersuites
   -timeout duration
     	timeout for network operations (default 10s)
   -verbosity int

auth.go

@@ -1,16 +1,16 @@
 package main
 
 import (
-    "os"
+	"bufio"
+	"crypto/subtle"
+	"encoding/base64"
+	"errors"
+	"golang.org/x/crypto/bcrypt"
 	"net/http"
 	"net/url"
-    "errors"
-    "strings"
+	"os"
 	"strconv"
-    "encoding/base64"
-    "crypto/subtle"
-    "golang.org/x/crypto/bcrypt"
-    "bufio"
+	"strings"
 )
 
 const AUTH_REQUIRED_MSG = "Proxy authentication required.\n"
@@ -188,7 +188,6 @@ func (_ NoAuth) Validate(wr http.ResponseWriter, req *http.Request) bool {
 	return true
 }
 
-
 type CertAuth struct{}
 
 func (_ CertAuth) Validate(wr http.ResponseWriter, req *http.Request) bool {

condlog.go

@@ -1,8 +1,8 @@
 package main
 
 import (
-    "log"
 	"fmt"
+	"log"
 )
 
 const (

handler.go

@@ -1,13 +1,13 @@
 package main
 
 import (
-    "net"
+	"context"
 	"fmt"
-    "time"
+	"net"
 	"net/http"
 	"strings"
-    "context"
 	"sync"
+	"time"
 )
 
 type ProxyHandler struct {

logwriter.go

@@ -1,8 +1,8 @@
 package main
 
 import (
-    "io"
 	"errors"
+	"io"
 	"time"
 )
 

main.go

@@ -1,12 +1,13 @@
 package main
 
 import (
-    "log"
-    "os"
-    "fmt"
+	"crypto/tls"
 	"flag"
-    "time"
+	"fmt"
+	"log"
 	"net/http"
+	"os"
+	"time"
 )
 
 func perror(msg string) {
@@ -27,8 +28,16 @@ type CLIArgs struct {
 	verbosity         int
 	timeout           time.Duration
 	cert, key, cafile string
+	list_ciphers      bool
+	ciphers           string
+	disableHTTP2      bool
 }
 
+func list_ciphers() {
+	for _, cipher := range tls.CipherSuites() {
+		fmt.Println(cipher.Name)
+	}
+}
 
 func parse_args() CLIArgs {
 	var args CLIArgs
@@ -40,6 +49,9 @@ func parse_args() CLIArgs {
 	flag.StringVar(&args.cert, "cert", "", "enable TLS and use certificate")
 	flag.StringVar(&args.key, "key", "", "key for TLS certificate")
 	flag.StringVar(&args.cafile, "cafile", "", "CA file to authenticate clients with certificates")
+	flag.BoolVar(&args.list_ciphers, "list-ciphers", false, "list ciphersuites")
+	flag.StringVar(&args.ciphers, "ciphers", "", "colon-separated list of enabled ciphers")
+	flag.BoolVar(&args.disableHTTP2, "disable-http2", false, "disable HTTP2")
 	flag.Parse()
 	return args
 }
@@ -47,6 +59,11 @@ func parse_args() CLIArgs {
 func run() int {
 	args := parse_args()
 
+	if args.list_ciphers {
+		list_ciphers()
+		return 0
+	}
+
 	logWriter := NewLogWriter(os.Stderr)
 	defer logWriter.Close()
 
@@ -73,6 +90,10 @@ func run() int {
 		IdleTimeout:       0,
 	}
 
+	if args.disableHTTP2 {
+		server.TLSNextProto = make(map[string]func(*http.Server, *tls.Conn, http.Handler))
+	}
+
 	mainLogger.Info("Starting proxy server...")
 	if args.cert != "" {
 		cfg, err1 := makeServerTLSConfig(args.cert, args.key, args.cafile)
@@ -80,6 +101,7 @@ func run() int {
 			mainLogger.Critical("TLS config construction failed: %v", err)
 			return 3
 		}
+		cfg.CipherSuites = makeCipherList(args.ciphers)
 		server.TLSConfig = cfg
 		err = server.ListenAndServeTLS("", "")
 	} else {

utils.go

@@ -1,17 +1,19 @@
 package main
 
 import (
-    "context"
-    "net"
-    "sync"
-    "io"
-    "time"
-    "errors"
-    "net/http"
 	"bufio"
+	"context"
 	"crypto/tls"
 	"crypto/x509"
+	"errors"
+	"io"
 	"io/ioutil"
+	"log"
+	"net"
+	"net/http"
+	"strings"
+	"sync"
+	"time"
 )
 
 const COPY_BUF = 128 * 1024
@@ -163,3 +165,27 @@ func makeServerTLSConfig(certfile, keyfile, cafile string) (*tls.Config, error)
 	}
 	return &cfg, nil
 }
+
+func makeCipherList(ciphers string) []uint16 {
+	if ciphers == "" {
+		return nil
+	}
+
+	cipherIDs := make(map[string]uint16)
+	for _, cipher := range tls.CipherSuites() {
+		cipherIDs[cipher.Name] = cipher.ID
+	}
+
+	cipherNameList := strings.Split(ciphers, ":")
+	cipherIDList := make([]uint16, 0, len(cipherNameList))
+
+	for _, name := range cipherNameList {
+		id, ok := cipherIDs[name]
+		if !ok {
+			log.Printf("WARNING: Unknown cipher \"%s\"", name)
+		}
+		cipherIDList = append(cipherIDList, id)
+	}
+
+	return cipherIDList
+}