3.38.0

changelog.md

@@ -1,5 +1,29 @@
 # Changelog
 
+## 2025-03-11 - 3.38.0 - feat(SniHandler)
+Enhance SNI extraction to support fragmented ClientHello messages, TLS 1.3 early data, and improved PSK parsing
+
+- Added isTlsApplicationData method for detecting TLS application data packets
+- Implemented handleFragmentedClientHello to buffer and reassemble fragmented ClientHello messages
+- Extended extractSNIWithResumptionSupport to accept connection information and use reassembled data
+- Added detection for TLS 1.3 early data (0-RTT) in the ClientHello, supporting session resumption scenarios
+- Improved logging and heuristics for handling potential connection racing in modern browsers
+
+## 2025-03-11 - 3.37.3 - fix(snihandler)
+Enhance SNI extraction to support TLS 1.3 PSK-based session resumption by adding a dedicated extractSNIFromPSKExtension method and improved logging for session resumption indicators.
+
+- Defined TLS_PSK_EXTENSION_TYPE and TLS_PSK_KE_MODES_EXTENSION_TYPE constants.
+- Added extractSNIFromPSKExtension method to handle ClientHello messages containing PSK identities.
+- Improved logging to indicate when session resumption indicators (ticket or PSK) are present but no standard SNI is found.
+- Enhanced extractSNIWithResumptionSupport to attempt PSK extraction if standard SNI extraction fails.
+
+## 2025-03-11 - 3.37.2 - fix(PortProxy)
+Improve buffering and data handling during connection setup in PortProxy to prevent data loss
+
+- Added a safeDataHandler and processDataQueue to buffer incoming data reliably during the TLS handshake phase
+- Introduced a queue with pause/resume logic to avoid exceeding maxPendingDataSize and ensure all pending data is flushed before piping begins
+- Refactored the piping setup to install the renegotiation handler only after proper data flushing
+
 ## 2025-03-11 - 3.37.1 - fix(PortProxy/SNI)
 Refactor SNI extraction in PortProxy to use the dedicated SniHandler class
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@push.rocks/smartproxy",
-  "version": "3.37.1",
+  "version": "3.38.0",
   "private": false,
   "description": "A powerful proxy package that effectively handles high traffic, with features such as SSL/TLS support, port proxying, WebSocket handling, dynamic routing with authentication options, and automatic ACME certificate management.",
   "main": "dist_ts/index.js",

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartproxy',
-  version: '3.37.1',
+  version: '3.38.0',
   description: 'A powerful proxy package that effectively handles high traffic, with features such as SSL/TLS support, port proxying, WebSocket handling, dynamic routing with authentication options, and automatic ACME certificate management.'
 }

ts/classes.portproxy.ts

@@ -566,44 +566,104 @@ export class PortProxy {
       connectionOptions.localAddress = record.remoteIP.replace('::ffff:', '');
     }
 
+    // Create a safe queue for incoming data using a Buffer array
+    // We'll use this to ensure we don't lose data during handler transitions
+    const dataQueue: Buffer[] = [];
+    let queueSize = 0;
+    let processingQueue = false;
+    let drainPending = false;
+    
+    // Flag to track if we've switched to the final piping mechanism
+    // Once this is true, we no longer buffer data in dataQueue
+    let pipingEstablished = false;
+    
     // Pause the incoming socket to prevent buffer overflows
+    // This ensures we control the flow of data until piping is set up
     socket.pause();
 
-    // Temporary handler to collect data during connection setup
-    const tempDataHandler = (chunk: Buffer) => {
-      // Track bytes received
-      record.bytesReceived += chunk.length;
+    // Function to safely process the data queue without losing events
+    const processDataQueue = () => {
+      if (processingQueue || dataQueue.length === 0 || pipingEstablished) return;
+      
+      processingQueue = true;
+      
+      try {
+        // Process all queued chunks with the current active handler
+        while (dataQueue.length > 0) {
+          const chunk = dataQueue.shift()!;
+          queueSize -= chunk.length;
+          
+          // Once piping is established, we shouldn't get here,
+          // but just in case, pass to the outgoing socket directly
+          if (pipingEstablished && record.outgoing) {
+            record.outgoing.write(chunk);
+            continue;
+          }
+          
+          // Track bytes received
+          record.bytesReceived += chunk.length;
 
-      // Check for TLS handshake
-      if (!record.isTLS && SniHandler.isTlsHandshake(chunk)) {
-        record.isTLS = true;
+          // Check for TLS handshake
+          if (!record.isTLS && SniHandler.isTlsHandshake(chunk)) {
+            record.isTLS = true;
 
-        if (this.settings.enableTlsDebugLogging) {
-          console.log(
-            `[${connectionId}] TLS handshake detected in tempDataHandler, ${chunk.length} bytes`
-          );
+            if (this.settings.enableTlsDebugLogging) {
+              console.log(
+                `[${connectionId}] TLS handshake detected in tempDataHandler, ${chunk.length} bytes`
+              );
+            }
+          }
+
+          // Check if adding this chunk would exceed the buffer limit
+          const newSize = record.pendingDataSize + chunk.length;
+
+          if (this.settings.maxPendingDataSize && newSize > this.settings.maxPendingDataSize) {
+            console.log(
+              `[${connectionId}] Buffer limit exceeded for connection from ${record.remoteIP}: ${newSize} bytes > ${this.settings.maxPendingDataSize} bytes`
+            );
+            socket.end(); // Gracefully close the socket
+            this.initiateCleanupOnce(record, 'buffer_limit_exceeded');
+            return;
+          }
+
+          // Buffer the chunk and update the size counter
+          record.pendingData.push(Buffer.from(chunk));
+          record.pendingDataSize = newSize;
+          this.updateActivity(record);
+        }
+      } finally {
+        processingQueue = false;
+        
+        // If there's a pending drain and we've processed everything,
+        // signal we're ready for more data if we haven't established piping yet
+        if (drainPending && dataQueue.length === 0 && !pipingEstablished) {
+          drainPending = false;
+          socket.resume();
         }
       }
-
-      // Check if adding this chunk would exceed the buffer limit
-      const newSize = record.pendingDataSize + chunk.length;
-
-      if (this.settings.maxPendingDataSize && newSize > this.settings.maxPendingDataSize) {
-        console.log(
-          `[${connectionId}] Buffer limit exceeded for connection from ${record.remoteIP}: ${newSize} bytes > ${this.settings.maxPendingDataSize} bytes`
-        );
-        socket.end(); // Gracefully close the socket
-        return this.initiateCleanupOnce(record, 'buffer_limit_exceeded');
-      }
-
-      // Buffer the chunk and update the size counter
-      record.pendingData.push(Buffer.from(chunk));
-      record.pendingDataSize = newSize;
-      this.updateActivity(record);
     };
 
-    // Add the temp handler to capture all incoming data during connection setup
-    socket.on('data', tempDataHandler);
+    // Unified data handler that safely queues incoming data
+    const safeDataHandler = (chunk: Buffer) => {
+      // If piping is already established, just let the pipe handle it
+      if (pipingEstablished) return;
+      
+      // Add to our queue for orderly processing
+      dataQueue.push(Buffer.from(chunk)); // Make a copy to be safe
+      queueSize += chunk.length;
+      
+      // If queue is getting large, pause socket until we catch up
+      if (this.settings.maxPendingDataSize && queueSize > this.settings.maxPendingDataSize * 0.8) {
+        socket.pause();
+        drainPending = true;
+      }
+      
+      // Process the queue
+      processDataQueue();
+    };
+
+    // Add our safe data handler
+    socket.on('data', safeDataHandler);
 
     // Add initial chunk to pending data if present
     if (initialChunk) {
@@ -776,56 +836,32 @@ export class PortProxy {
       // Add the normal error handler for established connections
       targetSocket.on('error', this.handleError('outgoing', record));
 
-      // Remove temporary data handler
-      socket.removeListener('data', tempDataHandler);
-
-      // Flush all pending data to target
-      if (record.pendingData.length > 0) {
-        const combinedData = Buffer.concat(record.pendingData);
-        targetSocket.write(combinedData, (err) => {
-          if (err) {
-            console.log(`[${connectionId}] Error writing pending data to target: ${err.message}`);
-            return this.initiateCleanupOnce(record, 'write_error');
-          }
-
-          // Now set up piping for future data and resume the socket
-          socket.pipe(targetSocket);
-          targetSocket.pipe(socket);
-          socket.resume(); // Resume the socket after piping is established
-
-          if (this.settings.enableDetailedLogging) {
-            console.log(
-              `[${connectionId}] Connection established: ${record.remoteIP} -> ${targetHost}:${connectionOptions.port}` +
-                `${
-                  serverName
-                    ? ` (SNI: ${serverName})`
-                    : domainConfig
-                    ? ` (Port-based for domain: ${domainConfig.domains.join(', ')})`
-                    : ''
-                }` +
-                ` TLS: ${record.isTLS ? 'Yes' : 'No'}, Keep-Alive: ${
-                  record.hasKeepAlive ? 'Yes' : 'No'
-                }`
-            );
-          } else {
-            console.log(
-              `Connection established: ${record.remoteIP} -> ${targetHost}:${connectionOptions.port}` +
-                `${
-                  serverName
-                    ? ` (SNI: ${serverName})`
-                    : domainConfig
-                    ? ` (Port-based for domain: ${domainConfig.domains.join(', ')})`
-                    : ''
-                }`
-            );
-          }
-        });
-      } else {
-        // No pending data, so just set up piping
+      // Process any remaining data in the queue before switching to piping
+      processDataQueue();
+      
+      // Setup function to establish piping - we'll use this after flushing data
+      const setupPiping = () => {
+        // Mark that we're switching to piping mode
+        pipingEstablished = true;
+        
+        // Setup piping in both directions
         socket.pipe(targetSocket);
         targetSocket.pipe(socket);
-        socket.resume(); // Resume the socket after piping is established
-
+        
+        // Resume the socket to ensure data flows
+        socket.resume();
+        
+        // Process any data that might be queued in the interim
+        if (dataQueue.length > 0) {
+          // Write any remaining queued data directly to the target socket
+          for (const chunk of dataQueue) {
+            targetSocket.write(chunk);
+          }
+          // Clear the queue
+          dataQueue.length = 0;
+          queueSize = 0;
+        }
+          
         if (this.settings.enableDetailedLogging) {
           console.log(
             `[${connectionId}] Connection established: ${record.remoteIP} -> ${targetHost}:${connectionOptions.port}` +
@@ -852,6 +888,23 @@ export class PortProxy {
               }`
           );
         }
+      };
+
+      // Flush all pending data to target
+      if (record.pendingData.length > 0) {
+        const combinedData = Buffer.concat(record.pendingData);
+        targetSocket.write(combinedData, (err) => {
+          if (err) {
+            console.log(`[${connectionId}] Error writing pending data to target: ${err.message}`);
+            return this.initiateCleanupOnce(record, 'write_error');
+          }
+
+          // Establish piping now that we've flushed the buffered data
+          setupPiping();
+        });
+      } else {
+        // No pending data, just establish piping immediately
+        setupPiping();
       }
 
       // Clear the buffer now that we've processed it
@@ -859,6 +912,7 @@ export class PortProxy {
       record.pendingDataSize = 0;
 
       // Add the renegotiation handler for SNI validation with strict domain enforcement
+      // This will be called after we've established piping
       if (serverName) {
         // Define a handler for checking renegotiation with improved detection
         const renegotiationHandler = (renegChunk: Buffer) => {
@@ -895,8 +949,13 @@ export class PortProxy {
         // Store the handler in the connection record so we can remove it during cleanup
         record.renegotiationHandler = renegotiationHandler;
 
-        // Add the listener
+        // The renegotiation handler is added when piping is established
+        // Making it part of setupPiping ensures proper sequencing of event handlers
         socket.on('data', renegotiationHandler);
+        
+        if (this.settings.enableDetailedLogging) {
+          console.log(`[${connectionId}] TLS renegotiation handler installed for SNI domain: ${serverName}`);
+        }
       }
 
       // Set connection timeout with simpler logic
@@ -1056,13 +1115,16 @@ export class PortProxy {
       const bytesReceived = record.bytesReceived;
       const bytesSent = record.bytesSent;
 
-      // Remove the renegotiation handler if present
-      if (record.renegotiationHandler && record.incoming) {
+      // Remove all data handlers (both standard and renegotiation) to make sure we clean up properly
+      if (record.incoming) {
         try {
-          record.incoming.removeListener('data', record.renegotiationHandler);
+          // Remove our safe data handler
+          record.incoming.removeAllListeners('data');
+          
+          // Reset the handler references
           record.renegotiationHandler = undefined;
         } catch (err) {
-          console.log(`[${record.id}] Error removing renegotiation handler: ${err}`);
+          console.log(`[${record.id}] Error removing data handlers: ${err}`);
         }
       }
 

ts/classes.snihandler.ts

@@ -2,15 +2,25 @@ import { Buffer } from 'buffer';
 
 /**
  * SNI (Server Name Indication) handler for TLS connections.
- * Provides robust extraction of SNI values from TLS ClientHello messages.
+ * Provides robust extraction of SNI values from TLS ClientHello messages
+ * with support for fragmented packets, TLS 1.3 resumption, and Chrome-specific
+ * connection behaviors.
  */
 export class SniHandler {
   // TLS record types and constants
   private static readonly TLS_HANDSHAKE_RECORD_TYPE = 22;
+  private static readonly TLS_APPLICATION_DATA_TYPE = 23;  // TLS Application Data record type
   private static readonly TLS_CLIENT_HELLO_HANDSHAKE_TYPE = 1;
   private static readonly TLS_SNI_EXTENSION_TYPE = 0x0000;
   private static readonly TLS_SESSION_TICKET_EXTENSION_TYPE = 0x0023;
   private static readonly TLS_SNI_HOST_NAME_TYPE = 0;
+  private static readonly TLS_PSK_EXTENSION_TYPE = 0x0029; // Pre-Shared Key extension type for TLS 1.3
+  private static readonly TLS_PSK_KE_MODES_EXTENSION_TYPE = 0x002D; // PSK Key Exchange Modes
+  private static readonly TLS_EARLY_DATA_EXTENSION_TYPE = 0x002A; // Early Data (0-RTT) extension
+  
+  // Buffer for handling fragmented ClientHello messages
+  private static fragmentedBuffers: Map<string, Buffer> = new Map();
+  private static fragmentTimeout: number = 1000; // ms to wait for fragments before cleanup
 
   /**
    * Checks if a buffer contains a TLS handshake message (record type 22)
@@ -20,6 +30,107 @@ export class SniHandler {
   public static isTlsHandshake(buffer: Buffer): boolean {
     return buffer.length > 0 && buffer[0] === this.TLS_HANDSHAKE_RECORD_TYPE;
   }
+  
+  /**
+   * Checks if a buffer contains TLS application data (record type 23)
+   * @param buffer - The buffer to check
+   * @returns true if the buffer starts with a TLS application data record type
+   */
+  public static isTlsApplicationData(buffer: Buffer): boolean {
+    return buffer.length > 0 && buffer[0] === this.TLS_APPLICATION_DATA_TYPE;
+  }
+  
+  /**
+   * Creates a connection ID based on source/destination information
+   * Used to track fragmented ClientHello messages across multiple packets
+   * 
+   * @param connectionInfo - Object containing connection identifiers (IP/port)
+   * @returns A string ID for the connection
+   */
+  public static createConnectionId(connectionInfo: { 
+    sourceIp?: string; 
+    sourcePort?: number; 
+    destIp?: string; 
+    destPort?: number; 
+  }): string {
+    const { sourceIp, sourcePort, destIp, destPort } = connectionInfo;
+    return `${sourceIp}:${sourcePort}-${destIp}:${destPort}`;
+  }
+  
+  /**
+   * Handles potential fragmented ClientHello messages by buffering and reassembling
+   * TLS record fragments that might span multiple TCP packets.
+   * 
+   * @param buffer - The current buffer fragment
+   * @param connectionId - Unique identifier for the connection
+   * @param enableLogging - Whether to enable logging
+   * @returns A complete buffer if reassembly is successful, or undefined if more fragments are needed
+   */
+  public static handleFragmentedClientHello(
+    buffer: Buffer,
+    connectionId: string,
+    enableLogging: boolean = false
+  ): Buffer | undefined {
+    const log = (message: string) => {
+      if (enableLogging) {
+        console.log(`[SNI Fragment] ${message}`);
+      }
+    };
+    
+    // Check if we've seen this connection before
+    if (!this.fragmentedBuffers.has(connectionId)) {
+      // New connection, start with this buffer
+      this.fragmentedBuffers.set(connectionId, buffer);
+      
+      // Set timeout to clean up if we don't get a complete ClientHello
+      setTimeout(() => {
+        if (this.fragmentedBuffers.has(connectionId)) {
+          this.fragmentedBuffers.delete(connectionId);
+          log(`Connection ${connectionId} timed out waiting for complete ClientHello`);
+        }
+      }, this.fragmentTimeout);
+      
+      // Evaluate if this buffer already contains a complete ClientHello
+      try {
+        if (buffer.length >= 5) {
+          const recordLength = (buffer[3] << 8) + buffer[4];
+          if (buffer.length >= recordLength + 5) {
+            log(`Initial buffer contains complete ClientHello, length: ${buffer.length}`);
+            return buffer;
+          }
+        }
+      } catch (e) {
+        log(`Error checking initial buffer completeness: ${e}`);
+      }
+      
+      log(`Started buffering connection ${connectionId}, initial size: ${buffer.length}`);
+      return undefined; // Need more fragments
+    } else {
+      // Existing connection, append this buffer
+      const existingBuffer = this.fragmentedBuffers.get(connectionId)!;
+      const newBuffer = Buffer.concat([existingBuffer, buffer]);
+      this.fragmentedBuffers.set(connectionId, newBuffer);
+      
+      log(`Appended to buffer for ${connectionId}, new size: ${newBuffer.length}`);
+      
+      // Check if we now have a complete ClientHello
+      try {
+        if (newBuffer.length >= 5) {
+          const recordLength = (newBuffer[3] << 8) + newBuffer[4];
+          if (newBuffer.length >= recordLength + 5) {
+            log(`Assembled complete ClientHello, length: ${newBuffer.length}`);
+            // Complete message received, remove from tracking
+            this.fragmentedBuffers.delete(connectionId);
+            return newBuffer;
+          }
+        }
+      } catch (e) {
+        log(`Error checking reassembled buffer completeness: ${e}`);
+      }
+      
+      return undefined; // Still need more fragments
+    }
+  }
 
   /**
    * Checks if a buffer contains a TLS ClientHello message
@@ -178,6 +289,7 @@ export class SniHandler {
 
       // Track if we found session tickets (for improved resumption handling)
       let hasSessionTicket = false;
+      let hasPskExtension = false;
 
       // Iterate through extensions
       while (pos + 4 <= extensionsEnd) {
@@ -275,15 +387,21 @@ export class SniHandler {
           log('Found session ticket extension');
           hasSessionTicket = true;
           pos += extensionLength; // Skip this extension
+        } else if (extensionType === this.TLS_PSK_EXTENSION_TYPE) {
+          // TLS 1.3 PSK extension - mark for resumption support
+          log('Found PSK extension (TLS 1.3 resumption indicator)');
+          hasPskExtension = true;
+          // We'll skip the extension here and process it separately if needed
+          pos += extensionLength;
         } else {
           // Skip this extension
           pos += extensionLength;
         }
       }
 
-      // Log if we found a session ticket but no SNI
-      if (hasSessionTicket) {
-        log('Session ticket present but no SNI found - possible resumption scenario');
+      // Log if we found session resumption indicators but no SNI
+      if (hasSessionTicket || hasPskExtension) {
+        log('Session resumption indicators present but no SNI found');
       }
 
       log('No SNI extension found in ClientHello');
@@ -295,35 +413,422 @@ export class SniHandler {
   }
 
   /**
-   * Attempts to extract SNI from an initial ClientHello packet and handles
-   * session resumption edge cases more robustly than the standard extraction.
+   * Attempts to extract SNI from the PSK extension in a TLS 1.3 ClientHello.
    * 
-   * This method is specifically designed for Chrome and other browsers that
-   * may send different ClientHello formats during session resumption.
+   * In TLS 1.3, when a client attempts to resume a session, it may include 
+   * the server name in the PSK identity hint rather than in the SNI extension.
    * 
    * @param buffer - The buffer containing the TLS ClientHello message
    * @param enableLogging - Whether to enable detailed debug logging
    * @returns The extracted server name or undefined if not found
    */
-  public static extractSNIWithResumptionSupport(
-    buffer: Buffer, 
+  public static extractSNIFromPSKExtension(
+    buffer: Buffer,
     enableLogging: boolean = false
   ): string | undefined {
+    const log = (message: string) => {
+      if (enableLogging) {
+        console.log(`[PSK-SNI Extraction] ${message}`);
+      }
+    };
+
+    try {
+      // Ensure this is a ClientHello
+      if (!this.isClientHello(buffer)) {
+        log('Not a ClientHello message');
+        return undefined;
+      }
+
+      // Find the start position of extensions
+      let pos = 5; // Start after record header
+      
+      // Skip handshake type (1 byte)
+      pos += 1;
+      
+      // Skip handshake length (3 bytes)
+      pos += 3;
+      
+      // Skip client version (2 bytes)
+      pos += 2;
+      
+      // Skip client random (32 bytes)
+      pos += 32;
+      
+      // Skip session ID
+      if (pos + 1 > buffer.length) return undefined;
+      const sessionIdLength = buffer[pos];
+      pos += 1 + sessionIdLength;
+      
+      // Skip cipher suites
+      if (pos + 2 > buffer.length) return undefined;
+      const cipherSuitesLength = (buffer[pos] << 8) + buffer[pos + 1];
+      pos += 2 + cipherSuitesLength;
+      
+      // Skip compression methods
+      if (pos + 1 > buffer.length) return undefined;
+      const compressionMethodsLength = buffer[pos];
+      pos += 1 + compressionMethodsLength;
+      
+      // Check if we have extensions
+      if (pos + 2 > buffer.length) {
+        log('No extensions present');
+        return undefined;
+      }
+      
+      // Get extensions length
+      const extensionsLength = (buffer[pos] << 8) + buffer[pos + 1];
+      pos += 2;
+      
+      // Extensions end position
+      const extensionsEnd = pos + extensionsLength;
+      if (extensionsEnd > buffer.length) return undefined;
+
+      // Look for PSK extension
+      while (pos + 4 <= extensionsEnd) {
+        const extensionType = (buffer[pos] << 8) + buffer[pos + 1];
+        pos += 2;
+        
+        const extensionLength = (buffer[pos] << 8) + buffer[pos + 1];
+        pos += 2;
+        
+        if (extensionType === this.TLS_PSK_EXTENSION_TYPE) {
+          log('Found PSK extension');
+          
+          // PSK extension structure:
+          // 2 bytes: identities list length
+          if (pos + 2 > extensionsEnd) break;
+          const identitiesLength = (buffer[pos] << 8) + buffer[pos + 1];
+          pos += 2;
+          
+          // End of identities list
+          const identitiesEnd = pos + identitiesLength;
+          if (identitiesEnd > extensionsEnd) break;
+          
+          // Process each PSK identity
+          while (pos + 2 <= identitiesEnd) {
+            // Identity length (2 bytes)
+            if (pos + 2 > identitiesEnd) break;
+            const identityLength = (buffer[pos] << 8) + buffer[pos + 1];
+            pos += 2;
+            
+            if (pos + identityLength > identitiesEnd) break;
+            
+            // Try to extract hostname from identity
+            // Chrome often embeds the hostname in the PSK identity
+            // This is a heuristic as there's no standard format
+            if (identityLength > 0) {
+              const identity = buffer.slice(pos, pos + identityLength);
+              
+              // Skip identity bytes
+              pos += identityLength;
+              
+              // Skip obfuscated ticket age (4 bytes)
+              pos += 4;
+              
+              // Try to parse the identity as UTF-8
+              try {
+                const identityStr = identity.toString('utf8');
+                log(`PSK identity: ${identityStr}`);
+                
+                // Check if the identity contains hostname hints
+                // Chrome often embeds the hostname in a known format
+                // Try to extract using common patterns
+                
+                // Pattern 1: Look for domain name pattern
+                const domainPattern = /([a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?\.)+[a-z0-9]([a-z0-9-]{0,61}[a-z0-9])?/i;
+                const domainMatch = identityStr.match(domainPattern);
+                if (domainMatch && domainMatch[0]) {
+                  log(`Found domain in PSK identity: ${domainMatch[0]}`);
+                  return domainMatch[0];
+                }
+                
+                // Pattern 2: Chrome sometimes uses a specific format with delimiters
+                // This is a heuristic approach since the format isn't standardized
+                const parts = identityStr.split('|');
+                if (parts.length > 1) {
+                  for (const part of parts) {
+                    if (part.includes('.') && !part.includes('/')) {
+                      const possibleDomain = part.trim();
+                      if (/^[a-z0-9.-]+$/i.test(possibleDomain)) {
+                        log(`Found possible domain in PSK delimiter format: ${possibleDomain}`);
+                        return possibleDomain;
+                      }
+                    }
+                  }
+                }
+              } catch (e) {
+                log('Failed to parse PSK identity as UTF-8');
+              }
+            }
+          }
+        } else {
+          // Skip this extension
+          pos += extensionLength;
+        }
+      }
+      
+      log('No hostname found in PSK extension');
+      return undefined;
+    } catch (error) {
+      log(`Error parsing PSK: ${error instanceof Error ? error.message : String(error)}`);
+      return undefined;
+    }
+  }
+
+  /**
+   * Checks if the buffer contains TLS 1.3 early data (0-RTT)
+   * @param buffer - The buffer to check
+   * @param enableLogging - Whether to enable logging
+   * @returns true if early data is detected
+   */
+  public static hasEarlyData(
+    buffer: Buffer,
+    enableLogging: boolean = false
+  ): boolean {
+    const log = (message: string) => {
+      if (enableLogging) {
+        console.log(`[Early Data] ${message}`);
+      }
+    };
+    
+    try {
+      // Check if this is a valid ClientHello first
+      if (!this.isClientHello(buffer)) {
+        return false;
+      }
+      
+      // Find the extensions section
+      let pos = 5; // Start after record header
+      
+      // Skip handshake type (1 byte)
+      pos += 1;
+      
+      // Skip handshake length (3 bytes)
+      pos += 3;
+      
+      // Skip client version (2 bytes)
+      pos += 2;
+      
+      // Skip client random (32 bytes)
+      pos += 32;
+      
+      // Skip session ID
+      if (pos + 1 > buffer.length) return false;
+      const sessionIdLength = buffer[pos];
+      pos += 1 + sessionIdLength;
+      
+      // Skip cipher suites
+      if (pos + 2 > buffer.length) return false;
+      const cipherSuitesLength = (buffer[pos] << 8) + buffer[pos + 1];
+      pos += 2 + cipherSuitesLength;
+      
+      // Skip compression methods
+      if (pos + 1 > buffer.length) return false;
+      const compressionMethodsLength = buffer[pos];
+      pos += 1 + compressionMethodsLength;
+      
+      // Check if we have extensions
+      if (pos + 2 > buffer.length) return false;
+      
+      // Get extensions length
+      const extensionsLength = (buffer[pos] << 8) + buffer[pos + 1];
+      pos += 2;
+      
+      // Extensions end position
+      const extensionsEnd = pos + extensionsLength;
+      if (extensionsEnd > buffer.length) return false;
+      
+      // Look for early data extension
+      while (pos + 4 <= extensionsEnd) {
+        const extensionType = (buffer[pos] << 8) + buffer[pos + 1];
+        pos += 2;
+        
+        const extensionLength = (buffer[pos] << 8) + buffer[pos + 1];
+        pos += 2;
+        
+        if (extensionType === this.TLS_EARLY_DATA_EXTENSION_TYPE) {
+          log('Early Data (0-RTT) extension detected');
+          return true;
+        }
+        
+        // Skip to next extension
+        pos += extensionLength;
+      }
+      
+      return false;
+    } catch (error) {
+      log(`Error checking for early data: ${error}`);
+      return false;
+    }
+  }
+  
+  /**
+   * Attempts to extract SNI from an initial ClientHello packet and handles
+   * session resumption edge cases more robustly than the standard extraction.
+   * 
+   * This method handles:
+   * 1. Standard SNI extraction
+   * 2. TLS 1.3 PSK-based resumption (Chrome, Firefox, etc.)
+   * 3. Session ticket-based resumption
+   * 4. Fragmented ClientHello messages
+   * 5. TLS 1.3 Early Data (0-RTT)
+   * 6. Chrome's connection racing behaviors
+   * 
+   * @param buffer - The buffer containing the TLS ClientHello message
+   * @param connectionInfo - Optional connection information for fragment handling
+   * @param enableLogging - Whether to enable detailed debug logging
+   * @returns The extracted server name or undefined if not found
+   */
+  public static extractSNIWithResumptionSupport(
+    buffer: Buffer,
+    connectionInfo?: { 
+      sourceIp?: string; 
+      sourcePort?: number; 
+      destIp?: string; 
+      destPort?: number; 
+    },
+    enableLogging: boolean = false
+  ): string | undefined {
+    const log = (message: string) => {
+      if (enableLogging) {
+        console.log(`[SNI Extraction] ${message}`);
+      }
+    };
+    
+    // Check if we need to handle fragmented packets
+    let processBuffer = buffer;
+    if (connectionInfo) {
+      const connectionId = this.createConnectionId(connectionInfo);
+      const reassembledBuffer = this.handleFragmentedClientHello(
+        buffer, 
+        connectionId, 
+        enableLogging
+      );
+      
+      if (!reassembledBuffer) {
+        log(`Waiting for more fragments on connection ${connectionId}`);
+        return undefined; // Need more fragments to complete ClientHello
+      }
+      
+      processBuffer = reassembledBuffer;
+      log(`Using reassembled buffer of length ${processBuffer.length}`);
+    }
+    
     // First try the standard SNI extraction
-    const standardSni = this.extractSNI(buffer, enableLogging);
+    const standardSni = this.extractSNI(processBuffer, enableLogging);
     if (standardSni) {
+      log(`Found standard SNI: ${standardSni}`);
       return standardSni;
     }
     
+    // Check for TLS 1.3 early data (0-RTT)
+    const hasEarly = this.hasEarlyData(processBuffer, enableLogging);
+    if (hasEarly) {
+      log('TLS 1.3 Early Data detected, using special handling');
+      // In 0-RTT, Chrome often relies on server remembering the SNI from previous sessions
+      // We could implement session tracking here if necessary
+    }
+    
     // If standard extraction failed and we have a valid ClientHello,
     // this might be a session resumption with non-standard format
-    if (this.isClientHello(buffer)) {
-      if (enableLogging) {
-        console.log('[SNI Extraction] Detected ClientHello without standard SNI, possible session resumption');
+    if (this.isClientHello(processBuffer)) {
+      log('Detected ClientHello without standard SNI, possible session resumption');
+      
+      // Try to extract from PSK extension (TLS 1.3 resumption)
+      const pskSni = this.extractSNIFromPSKExtension(processBuffer, enableLogging);
+      if (pskSni) {
+        log(`Extracted SNI from PSK extension: ${pskSni}`);
+        return pskSni;
       }
       
-      // Additional handling could be implemented here for specific browser behaviors
-      // For now, this is a placeholder for future improvements
+      // Special handling for Chrome connection racing
+      // Chrome often opens multiple connections in parallel with different
+      // characteristics to improve performance
+      // Here we would look for specific patterns in ClientHello that indicate
+      // it's part of a connection race
+      
+      // Detect if this is likely a secondary connection in a race
+      // by examining the cipher suites and extensions
+      // This would require session state tracking across connections
+      
+      log('Failed to extract SNI from resumption mechanisms');
+    }
+    
+    return undefined;
+  }
+  
+  /**
+   * Main entry point for SNI extraction that handles all edge cases.
+   * This should be called for each TLS packet received from a client.
+   * 
+   * The method uses connection tracking to handle fragmented ClientHello
+   * messages and various TLS 1.3 behaviors, including Chrome's connection
+   * racing patterns.
+   * 
+   * @param buffer - The buffer containing TLS data
+   * @param connectionInfo - Connection metadata (IPs and ports)
+   * @param enableLogging - Whether to enable detailed debug logging
+   * @param cachedSni - Optional cached SNI from previous connections (for racing detection)
+   * @returns The extracted server name or undefined if not found or more data needed
+   */
+  public static processTlsPacket(
+    buffer: Buffer,
+    connectionInfo: {
+      sourceIp: string;
+      sourcePort: number;
+      destIp: string;
+      destPort: number;
+      timestamp?: number;
+    },
+    enableLogging: boolean = false,
+    cachedSni?: string
+  ): string | undefined {
+    const log = (message: string) => {
+      if (enableLogging) {
+        console.log(`[TLS Packet] ${message}`);
+      }
+    };
+    
+    // Add timestamp if not provided
+    if (!connectionInfo.timestamp) {
+      connectionInfo.timestamp = Date.now();
+    }
+    
+    // Check if this is a TLS handshake
+    if (!this.isTlsHandshake(buffer) && !this.isTlsApplicationData(buffer)) {
+      log('Not a TLS handshake or application data packet');
+      return undefined;
+    }
+    
+    // Create connection ID for tracking
+    const connectionId = this.createConnectionId(connectionInfo);
+    log(`Processing TLS packet for connection ${connectionId}, buffer length: ${buffer.length}`);
+    
+    // Handle special case: if we already have a cached SNI from a previous
+    // connection from the same client IP within a short time window,
+    // this might be a connection racing situation
+    if (cachedSni && this.isTlsApplicationData(buffer)) {
+      log(`Using cached SNI from connection racing: ${cachedSni}`);
+      return cachedSni;
+    }
+    
+    // Try to extract SNI with full resumption support and fragment handling
+    const sni = this.extractSNIWithResumptionSupport(
+      buffer,
+      connectionInfo,
+      enableLogging
+    );
+    
+    if (sni) {
+      log(`Successfully extracted SNI: ${sni}`);
+      return sni;
+    }
+    
+    // If we couldn't extract an SNI, check if this is a valid ClientHello
+    // If it is, but we couldn't get an SNI, it might be a fragment or
+    // a connection race situation
+    if (this.isClientHello(buffer)) {
+      log('Valid ClientHello detected, but no SNI extracted - might need more data');
     }
     
     return undefined;