Add external proxy support

src-go/server/go.mod

@@ -1,25 +1,25 @@
 module server
 
-go 1.22.0
+go 1.24.1
 
 toolchain go1.25.6
 
 require (
-	github.com/bogdanfinn/fhttp v0.5.36
-	github.com/bogdanfinn/tls-client v1.8.0
-	github.com/bogdanfinn/utls v1.6.5
+	github.com/bogdanfinn/fhttp v0.6.6
+	github.com/bogdanfinn/tls-client v1.13.1
+	github.com/bogdanfinn/utls v1.7.7-barnius
 )
 
 require (
-	github.com/andybalholm/brotli v1.1.1 // indirect
-	github.com/cloudflare/circl v1.5.0 // indirect
-	github.com/klauspost/compress v1.17.11 // indirect
-	github.com/quic-go/quic-go v0.48.1 // indirect
+	github.com/andybalholm/brotli v1.2.0 // indirect
+	github.com/bdandy/go-errors v1.2.2 // indirect
+	github.com/bdandy/go-socks4 v1.2.3 // indirect
+	github.com/bogdanfinn/quic-go-utls v1.0.7-utls // indirect
+	github.com/klauspost/compress v1.18.2 // indirect
+	github.com/quic-go/qpack v0.6.0 // indirect
 	github.com/tam7t/hpkp v0.0.0-20160821193359-2b70b4024ed5 // indirect
-	golang.org/x/crypto v0.29.0 // indirect
-	golang.org/x/net v0.31.0 // indirect
-	golang.org/x/sys v0.27.0 // indirect
-	golang.org/x/text v0.20.0 // indirect
+	golang.org/x/crypto v0.46.0 // indirect
+	golang.org/x/net v0.48.0 // indirect
+	golang.org/x/sys v0.39.0 // indirect
+	golang.org/x/text v0.32.0 // indirect
 )
-
-replace github.com/ooni/oohttp => github.com/sleeyax/oohttp v0.0.0-20230603105812-6ac0447b1a8e

src-go/server/go.sum

@@ -1,38 +1,46 @@
-github.com/andybalholm/brotli v1.1.1 h1:PR2pgnyFznKEugtsUo0xLdDop5SKXd5Qf5ysW+7XdTA=
-github.com/andybalholm/brotli v1.1.1/go.mod h1:05ib4cKhjx3OQYUY22hTVd34Bc8upXjOLL2rKwwZBoA=
-github.com/bogdanfinn/fhttp v0.5.34 h1:avRD2JNYqj6I6DqjSrI9tl8mP8Nk7T4CCmUsPz7afhg=
-github.com/bogdanfinn/fhttp v0.5.34/go.mod h1:BlcawVfXJ4uhk5yyNGOOY2bwo8UmMi6ccMszP1KGLkU=
-github.com/bogdanfinn/fhttp v0.5.36 h1:t1sO/EkO4K40QD/Ti8f6t80leZIdh2AaeLfN7dMvjH8=
-github.com/bogdanfinn/fhttp v0.5.36/go.mod h1:BlcawVfXJ4uhk5yyNGOOY2bwo8UmMi6ccMszP1KGLkU=
-github.com/bogdanfinn/tls-client v1.8.0 h1:IB44SqKa0XKdx3GYXpRbkqN3+tsBtg9RJYRsl36boOA=
-github.com/bogdanfinn/tls-client v1.8.0/go.mod h1:ehNITC7JBFeh6S7QNWtfD+PBKm0RsqvizAyyij2d/6g=
-github.com/bogdanfinn/utls v1.6.5 h1:rVMQvhyN3zodLxKFWMRLt19INGBCZ/OM2/vBWPNIt1w=
-github.com/bogdanfinn/utls v1.6.5/go.mod h1:czcHxHGsc1q9NjgWSeSinQZzn6MR76zUmGVIGanSXO0=
-github.com/cloudflare/circl v1.5.0 h1:hxIWksrX6XN5a1L2TI/h53AGPhNHoUBo+TD1ms9+pys=
-github.com/cloudflare/circl v1.5.0/go.mod h1:uddAzsPgqdMAYatqJ0lsjX1oECcQLIlRpzZh3pJrofs=
+github.com/andybalholm/brotli v1.2.0 h1:ukwgCxwYrmACq68yiUqwIWnGY0cTPox/M94sVwToPjQ=
+github.com/andybalholm/brotli v1.2.0/go.mod h1:rzTDkvFWvIrjDXZHkuS16NPggd91W3kUSvPlQ1pLaKY=
+github.com/bdandy/go-errors v1.2.2 h1:WdFv/oukjTJCLa79UfkGmwX7ZxONAihKu4V0mLIs11Q=
+github.com/bdandy/go-errors v1.2.2/go.mod h1:NkYHl4Fey9oRRdbB1CoC6e84tuqQHiqrOcZpqFEkBxM=
+github.com/bdandy/go-socks4 v1.2.3 h1:Q6Y2heY1GRjCtHbmlKfnwrKVU/k81LS8mRGLRlmDlic=
+github.com/bdandy/go-socks4 v1.2.3/go.mod h1:98kiVFgpdogR8aIGLWLvjDVZ8XcKPsSI/ypGrO+bqHI=
+github.com/bogdanfinn/fhttp v0.6.6 h1:S0+4w0wPCiUg0NId6dGIJnR2uNV5/eFYIolCYErGruo=
+github.com/bogdanfinn/fhttp v0.6.6/go.mod h1:A+EKDzMx2hb4IUbMx4TlkoHnaJEiLl8r/1Ss1Y+5e5M=
+github.com/bogdanfinn/quic-go-utls v1.0.7-utls h1:opxU/wt2C6FcD3rkGSOwfpQgfGSFx9eAKYQrFwYBzuo=
+github.com/bogdanfinn/quic-go-utls v1.0.7-utls/go.mod h1:bk8QMY2KypO8A6LzHJ7C4+bdB0ksLOd6NZt600wXYe8=
+github.com/bogdanfinn/tls-client v1.13.1 h1:O2sfv8JK8R7nNz+Km675VOIajum4sMqOb/ys/4gXfPQ=
+github.com/bogdanfinn/tls-client v1.13.1/go.mod h1:4ZnckBKYWaQD9wq55cpUr5/2i45cCBAG+2V3fge+yvQ=
+github.com/bogdanfinn/utls v1.7.7-barnius h1:OuJ497cc7F3yKNVHRsYPQdGggmk5x6+V5ZlrCR7fOLU=
+github.com/bogdanfinn/utls v1.7.7-barnius/go.mod h1:aAK1VZQlpKZClF1WEQeq6kyclbkPq4hz6xTbB5xSlmg=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/klauspost/compress v1.17.11 h1:In6xLpyWOi1+C7tXUUWv2ot1QvBjxevKAaI6IXrJmUc=
-github.com/klauspost/compress v1.17.11/go.mod h1:pMDklpSncoRMuLFrf1W9Ss9KT+0rH90U12bZKk7uwG0=
+github.com/klauspost/compress v1.18.2 h1:iiPHWW0YrcFgpBYhsA6D1+fqHssJscY/Tm/y2Uqnapk=
+github.com/klauspost/compress v1.18.2/go.mod h1:R0h/fSBs8DE4ENlcrlib3PsXS61voFxhIs2DeRhCvJ4=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/quic-go/quic-go v0.48.1 h1:y/8xmfWI9qmGTc+lBr4jKRUWLGSlSigv847ULJ4hYXA=
-github.com/quic-go/quic-go v0.48.1/go.mod h1:yBgs3rWBOADpga7F+jJsb6Ybg1LSYiQvwWlLX+/6HMs=
-github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
-github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/quic-go/qpack v0.6.0 h1:g7W+BMYynC1LbYLSqRt8PBg5Tgwxn214ZZR34VIOjz8=
+github.com/quic-go/qpack v0.6.0/go.mod h1:lUpLKChi8njB4ty2bFLX2x4gzDqXwUpaO1DP9qMDZII=
+github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu7U=
+github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/tam7t/hpkp v0.0.0-20160821193359-2b70b4024ed5 h1:YqAladjX7xpA6BM04leXMWAEjS0mTZ5kUU9KRBriQJc=
 github.com/tam7t/hpkp v0.0.0-20160821193359-2b70b4024ed5/go.mod h1:2JjD2zLQYH5HO74y5+aE3remJQvl6q4Sn6aWA2wD1Ng=
 github.com/xyproto/randomstring v1.0.5 h1:YtlWPoRdgMu3NZtP45drfy1GKoojuR7hmRcnhZqKjWU=
 github.com/xyproto/randomstring v1.0.5/go.mod h1:rgmS5DeNXLivK7YprL0pY+lTuhNQW3iGxZ18UQApw/E=
-golang.org/x/crypto v0.29.0 h1:L5SG1JTTXupVV3n6sUqMTeWbjAyfPwoda2DLX8J8FrQ=
-golang.org/x/crypto v0.29.0/go.mod h1:+F4F4N5hv6v38hfeYwTdx20oUvLLc+QfrE9Ax9HtgRg=
-golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842 h1:vr/HnozRka3pE4EsMEg1lgkXJkTFJCVUX+S/ZT6wYzM=
-golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842/go.mod h1:XtvwrStGgqGPLc4cjQfWqZHG1YFdYs6swckp8vpsjnc=
-golang.org/x/net v0.31.0 h1:68CPQngjLL0r2AlUKiSxtQFKvzRVbnzLwMUn5SzcLHo=
-golang.org/x/net v0.31.0/go.mod h1:P4fl1q7dY2hnZFxEk4pPSkDHF+QqjitcnDjUQyMM+pM=
-golang.org/x/sys v0.27.0 h1:wBqf8DvsY9Y/2P8gAfPDEYNuS30J4lPHJxXSb/nJZ+s=
-golang.org/x/sys v0.27.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/text v0.20.0 h1:gK/Kv2otX8gz+wn7Rmb3vT96ZwuoxnQlY+HlJVj7Qug=
-golang.org/x/text v0.20.0/go.mod h1:D4IsuqiFMhST5bX19pQ9ikHC2GsaKyk/oF+pn3ducp4=
+go.uber.org/mock v0.5.2 h1:LbtPTcP8A5k9WPXj54PPPbjcI4Y6lhyOZXn+VS7wNko=
+go.uber.org/mock v0.5.2/go.mod h1:wLlUxC2vVTPTaE3UD51E0BGOAElKrILxhVSDYQLld5o=
+golang.org/x/crypto v0.46.0 h1:cKRW/pmt1pKAfetfu+RCEvjvZkA9RimPbh7bhFjGVBU=
+golang.org/x/crypto v0.46.0/go.mod h1:Evb/oLKmMraqjZ2iQTwDwvCtJkczlDuTmdJXoZVzqU0=
+golang.org/x/net v0.0.0-20211104170005-ce137452f963/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/net v0.48.0 h1:zyQRTTrjc33Lhh0fBgT/H3oZq9WuvRR5gPC70xpDiQU=
+golang.org/x/net v0.48.0/go.mod h1:+ndRgGjkh8FGtu1w1FGbEC31if4VrNVMuKTgcAAnQRY=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.39.0 h1:CvCKL8MeisomCi6qNZ+wbb0DN9E5AATixKsvNtMoMFk=
+golang.org/x/sys v0.39.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.32.0 h1:ZD01bjUt1FQ9WJ0ClOL5vxgxOI/sVCNgX1YtKwcY0mU=
+golang.org/x/text v0.32.0/go.mod h1:o/rUWzghvpD5TXrTIBuJU77MTaN0ljMWE47kxGJQ7jY=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

src-go/server/server.go

@@ -3,10 +3,11 @@ package server
 import (
 	"context"
 	"fmt"
-	fhttp "github.com/bogdanfinn/fhttp"
-	utls "github.com/bogdanfinn/utls"
 	"io"
 	"net"
+
+	fhttp "github.com/bogdanfinn/fhttp"
+	utls "github.com/bogdanfinn/utls"
 )
 
 // ConfigurationHeaderKey is the name of the header field that contains the RoundTripper configuration.

src-go/server/transport.go

@@ -4,10 +4,11 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"strings"
+
 	tls_client "github.com/bogdanfinn/tls-client"
 	"github.com/bogdanfinn/tls-client/profiles"
 	utls "github.com/bogdanfinn/utls"
-	"strings"
 )
 
 type TransportConfig struct {
@@ -38,6 +39,9 @@ type TransportConfig struct {
 
 	// HeaderOrder is the order of headers to be sent in the request.
 	HeaderOrder []string
+
+	// ExternalProxyUrl is an optional upstream proxy (format: `http://user:pass@host:port`).
+	ExternalProxyUrl string
 }
 
 func ParseTransportConfig(data string) (*TransportConfig, error) {
@@ -64,6 +68,10 @@ func NewClient(config *TransportConfig) (tls_client.HttpClient, error) {
 		options = append(options, tls_client.WithTimeoutSeconds(config.HttpTimeout))
 	}
 
+	if config.ExternalProxyUrl != "" {
+		options = append(options, tls_client.WithProxyUrl(config.ExternalProxyUrl))
+	}
+
 	// The order of precedence is:
 	// 1. Custom client hello from intercept proxy
 	// 2. Custom client hello from hex string
@@ -91,6 +99,8 @@ func NewClient(config *TransportConfig) (tls_client.HttpClient, error) {
 			defaultProfile.GetConnectionFlow(),
 			defaultProfile.GetPriorities(),
 			defaultProfile.GetHeaderPriority(),
+			defaultProfile.GetStreamID(),
+			defaultProfile.GetAllowHTTP(),
 		)
 
 		options = append(options, tls_client.WithClientProfile(customClientProfile))

src/main/java/burp/Extension.java

@@ -9,6 +9,7 @@
 import burp.api.montoya.proxy.http.ProxyRequestToBeSentAction;
 import com.google.gson.Gson;
 
+import java.net.URI;
 import java.net.URL;
 import java.nio.charset.StandardCharsets;
 import java.util.Objects;
@@ -60,7 +61,7 @@ public ProxyRequestReceivedAction handleRequestReceived(InterceptedRequest inter
 
     private ProxyRequestToBeSentAction processHttpRequest(InterceptedRequest request) {
         try {
-            var requestURL = new URL(request.url());
+            var requestURL = new URI(request.url()).toURL();
 
             if (requestURL.getHost().equals("awesome-tls-error")) {
                 throw new Error(new String(request.body().getBytes(), StandardCharsets.UTF_8));
@@ -77,7 +78,7 @@ private ProxyRequestToBeSentAction processHttpRequest(InterceptedRequest request
             transportConfig.HeaderOrder = headerOrder;
 
             var goConfigJSON = gson.toJson(transportConfig);
-            var url = new URL("https://" + settings.getSpoofProxyAddress());
+            var url = new URI("https://" + settings.getSpoofProxyAddress()).toURL();
             var httpService = HttpService.httpService(url.getHost(), url.getPort(), Objects.equals(url.getProtocol(), "https"));
             var nextRequest = request.withService(httpService).withAddedHeader(HEADER_KEY, goConfigJSON);
 

src/main/java/burp/Settings.java

@@ -13,13 +13,15 @@ public class Settings {
     private final String hexClientHello = "HexClientHello";
     private final String useInterceptedFingerprint = "UseInterceptedFingerprint";
     private final String httpTimeout = "HttpTimeout";
+    private final String externalProxyUrl = "ExternalProxyUrl";
 
     public static final String DEFAULT_SPOOF_PROXY_ADDRESS = "127.0.0.1:8887";
     public static final String DEFAULT_INTERCEPT_PROXY_ADDRESS = "127.0.0.1:8886";
     public static final String DEFAULT_BURP_PROXY_ADDRESS = "127.0.0.1:8080";
     public static final Integer DEFAULT_HTTP_TIMEOUT = 30;
     public static final String DEFAULT_TLS_FINGERPRINT = "default";
     public static final Boolean USE_INTERCEPTED_FINGERPRINT = false;
+    public static final String DEFAULT_EXTERNAL_PROXY_URL = "";
 
     public Settings(MontoyaApi api) {
         this.storage = api.persistence().preferences();
@@ -120,6 +122,14 @@ public void setHexClientHello(String hexClientHello) {
         this.write(this.hexClientHello, hexClientHello);
     }
 
+    public String getExternalProxyUrl() {
+        return this.read(this.externalProxyUrl, DEFAULT_EXTERNAL_PROXY_URL);
+    }
+
+    public void setExternalProxyUrl(String externalProxyUrl) {
+        this.write(this.externalProxyUrl, externalProxyUrl);
+    }
+
     public String[] getFingerprints() {
         return ServerLibrary.INSTANCE.GetFingerprints().split("\n");
     }
@@ -132,6 +142,7 @@ public TransportConfig toTransportConfig() {
         transportConfig.UseInterceptedFingerprint = this.getUseInterceptedFingerprint();
         transportConfig.BurpAddr = this.getBurpProxyAddress();
         transportConfig.InterceptProxyAddr = this.getInterceptProxyAddress();
+        transportConfig.ExternalProxyUrl = this.getExternalProxyUrl();
         return transportConfig;
     }
 }

src/main/java/burp/SettingsTab.form

@@ -17,7 +17,7 @@
         <properties/>
         <border type="none"/>
         <children>
-          <grid id="65d0" binding="panelSettings" layout-manager="GridLayoutManager" row-count="10" column-count="1" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
+          <grid id="65d0" binding="panelSettings" layout-manager="GridLayoutManager" row-count="12" column-count="1" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
             <margin top="0" left="0" bottom="0" right="0"/>
             <constraints>
               <tabbedpane title="settings"/>
@@ -79,10 +79,29 @@
                   <toolTipText value="The maximum amount of time a dial will wait for a connect to complete."/>
                 </properties>
               </component>
+              <component id="e1a2b" class="javax.swing.JLabel" binding="labelExternalProxyUrl">
+                <constraints>
+                  <grid row="8" column="0" row-span="1" col-span="1" vsize-policy="0" hsize-policy="0" anchor="8" fill="0" indent="0" use-parent-layout="false"/>
+                </constraints>
+                <properties>
+                  <text value="External proxy URL:"/>
+                  <toolTipText value=""/>
+                </properties>
+              </component>
+              <component id="f3c4d" class="javax.swing.JTextField" binding="textFieldExternalProxyUrl">
+                <constraints>
+                  <grid row="9" column="0" row-span="1" col-span="1" vsize-policy="0" hsize-policy="6" anchor="8" fill="1" indent="0" use-parent-layout="false">
+                    <preferred-size width="150" height="-1"/>
+                  </grid>
+                </constraints>
+                <properties>
+                  <toolTipText value="Upstream proxy (e.g. socks5://127.0.0.1:1080 or http://127.0.0.1:8080)"/>
+                </properties>
+              </component>
               <grid id="4bfb5" layout-manager="GridLayoutManager" row-count="1" column-count="1" same-size-horizontally="false" same-size-vertically="false" hgap="-1" vgap="-1">
                 <margin top="0" left="0" bottom="0" right="0"/>
                 <constraints>
-                  <grid row="9" column="0" row-span="1" col-span="1" vsize-policy="3" hsize-policy="3" anchor="0" fill="3" indent="0" use-parent-layout="false"/>
+                  <grid row="11" column="0" row-span="1" col-span="1" vsize-policy="3" hsize-policy="3" anchor="0" fill="3" indent="0" use-parent-layout="false"/>
                 </constraints>
                 <properties/>
                 <border type="none"/>
@@ -111,7 +130,7 @@
               </component>
               <component id="da183" class="javax.swing.JButton" binding="buttonSave">
                 <constraints>
-                  <grid row="8" column="0" row-span="1" col-span="1" vsize-policy="0" hsize-policy="3" anchor="8" fill="0" indent="0" use-parent-layout="false"/>
+                  <grid row="10" column="0" row-span="1" col-span="1" vsize-policy="0" hsize-policy="3" anchor="8" fill="0" indent="0" use-parent-layout="false"/>
                 </constraints>
                 <properties>
                   <text value="Save all settings"/>