From 08ec158d19beb4b973baa6284075be380f39990b Mon Sep 17 00:00:00 2001
From: Craig Raw <craigraw@gmail.com>
Date: Tue, 26 Mar 2024 13:26:32 +0200
Subject: [PATCH] support cookie authentication for tor control port

---
 .../sparrowwallet/sparrow/net/TorUtils.java   | 55 ++++++++++++++++++-
 1 file changed, 52 insertions(+), 3 deletions(-)

diff --git a/src/main/java/com/sparrowwallet/sparrow/net/TorUtils.java b/src/main/java/com/sparrowwallet/sparrow/net/TorUtils.java
index ab1548c4..1df3ec09 100644
--- a/src/main/java/com/sparrowwallet/sparrow/net/TorUtils.java
+++ b/src/main/java/com/sparrowwallet/sparrow/net/TorUtils.java
@@ -1,16 +1,22 @@
 package com.sparrowwallet.sparrow.net;
 
 import com.google.common.net.HostAndPort;
+import com.sparrowwallet.drongo.Utils;
 import com.sparrowwallet.sparrow.AppServices;
 import io.matthewnelson.kmp.tor.controller.common.control.usecase.TorControlSignal;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.io.IOException;
+import java.io.*;
 import java.net.Socket;
+import java.nio.file.Files;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 public class TorUtils {
     private static final Logger log = LoggerFactory.getLogger(TorUtils.class);
+    private static final Pattern TOR_OK = Pattern.compile("^2\\d{2}[ -]OK$");
+    private static final Pattern TOR_AUTH_METHODS = Pattern.compile("^2\\d{2}[ -]AUTH METHODS=(\\S+)\\s?(COOKIEFILE=\"?(.+?)\"?)?$");
 
     public static void changeIdentity(HostAndPort proxy) {
         if(AppServices.isTorRunning()) {
@@ -22,16 +28,59 @@ public class TorUtils {
         } else {
             HostAndPort control = HostAndPort.fromParts(proxy.getHost(), proxy.getPort() + 1);
             try(Socket socket = new Socket(control.getHost(), control.getPort())) {
-                writeNewNym(socket);
+                if(authenticate(socket)) {
+                    writeNewNym(socket);
+                }
+            } catch(TorAuthenticationException e) {
+                log.warn("Error authenticating to Tor at " + control + ", server returned " + e.getMessage());
             } catch(Exception e) {
                 log.warn("Error connecting to " + control + ", no Tor ControlPort configured?");
             }
         }
     }
 
+    private static boolean authenticate(Socket socket) throws IOException, TorAuthenticationException {
+        socket.getOutputStream().write("PROTOCOLINFO\r\n".getBytes());
+        BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+        String line;
+        File cookieFile = null;
+        while((line = reader.readLine()) != null) {
+            Matcher authMatcher = TOR_AUTH_METHODS.matcher(line);
+            if(authMatcher.matches()) {
+                String methods = authMatcher.group(1);
+                if(methods.contains("COOKIE") && !authMatcher.group(3).isEmpty()) {
+                    cookieFile = new File(authMatcher.group(3));
+                }
+            }
+            if(TOR_OK.matcher(line).matches()) {
+                break;
+            }
+        }
+
+        if(cookieFile != null && cookieFile.exists()) {
+            byte[] cookieBytes = Files.readAllBytes(cookieFile.toPath());
+            String authentication = "AUTHENTICATE " + Utils.bytesToHex(cookieBytes) + "\r\n";
+            socket.getOutputStream().write(authentication.getBytes());
+        } else {
+            socket.getOutputStream().write("AUTHENTICATE \"\"\r\n".getBytes());
+        }
+
+        line = reader.readLine();
+        if(TOR_OK.matcher(line).matches()) {
+            return true;
+        } else {
+            throw new TorAuthenticationException(line);
+        }
+    }
+
     private static void writeNewNym(Socket socket) throws IOException {
         log.debug("Sending NEWNYM to " + socket);
-        socket.getOutputStream().write("AUTHENTICATE \"\"\r\n".getBytes());
         socket.getOutputStream().write("SIGNAL NEWNYM\r\n".getBytes());
     }
+
+    private static class TorAuthenticationException extends Exception {
+        public TorAuthenticationException(String message) {
+            super(message);
+        }
+    }
 }