3.41.6

changelog.md

@@ -1,5 +1,55 @@
 # Changelog
 
+## 2025-03-12 - 3.41.6 - fix(SniHandler)
+Refactor SniHandler: update whitespace, comment formatting, and consistent type definitions
+
+- Unified inline comment style and spacing in SniHandler
+- Refactored session cache type declaration for clarity
+- Adjusted buffer length calculations to include TLS record header consistently
+- Minor improvements to logging messages during ClientHello reassembly and SNI extraction
+
+## 2025-03-12 - 3.41.5 - fix(portproxy)
+Enforce TLS handshake and SNI validation on port 443 by blocking non-TLS connections and terminating session resumption attempts without SNI when allowSessionTicket is disabled.
+
+- Added explicit check to block non-TLS connections on port 443 to ensure proper TLS usage.
+- Enhanced logging for TLS ClientHello to include details on SNI extraction and session resumption status.
+- Terminate connections with missing SNI by setting termination reasons ('session_ticket_blocked' or 'no_sni_blocked').
+- Ensured consistent rejection of non-TLS handshakes on standard HTTPS port.
+
+## 2025-03-12 - 3.41.4 - fix(tls/sni)
+Improve logging for TLS session resumption by extracting and logging SNI values from ClientHello messages.
+
+- Added logging to output the extracted SNI value during renegotiation, initial ClientHello and in the SNI handler.
+- Enhanced error handling during SNI extraction to aid troubleshooting of TLS session resumption issues.
+
+## 2025-03-12 - 3.41.3 - fix(TLS/SNI)
+Improve TLS session resumption handling and logging. Now, session resumption attempts are always logged with details, and connections without a proper SNI are rejected when allowSessionTicket is disabled. In addition, empty SNI extensions are explicitly treated as missing, ensuring stricter and more consistent TLS handshake validation.
+
+- Always log session resumption in both renegotiation and initial ClientHello processing.
+- Terminate connections that attempt session resumption without SNI when allowSessionTicket is false.
+- Treat empty SNI extensions as absence of SNI to improve consistency in TLS handshake processing.
+
+## 2025-03-11 - 3.41.2 - fix(SniHandler)
+Refactor hasSessionResumption to return detailed session resumption info
+
+- Changed the return type of hasSessionResumption from boolean to an object with properties isResumption and hasSNI
+- Updated early return conditions to return { isResumption: false, hasSNI: false } when buffer is too short or invalid
+- Modified corresponding documentation to reflect the new return type
+
+## 2025-03-11 - 3.41.1 - fix(SniHandler)
+Improve TLS SNI session resumption handling: connections containing a session ticket are now only rejected when no SNI is present and allowSessionTicket is disabled. Updated return values and logging for clearer resumption detection.
+
+- Changed SniHandler.hasSessionResumption to return an object with 'isResumption' and 'hasSNI' flags.
+- Adjusted PortProxy logic to only terminate connections when a session ticket is detected without an accompanying SNI (when allowSessionTicket is false).
+- Enhanced debug logging to clearly differentiate between session resumption scenarios with and without SNI.
+
+## 2025-03-11 - 3.41.0 - feat(PortProxy/TLS)
+Add allowSessionTicket option to control TLS session ticket handling
+
+- Introduce 'allowSessionTicket' flag (default true) in PortProxy settings to enable or disable TLS session resumption via session tickets.
+- Update SniHandler with a new hasSessionResumption method to detect session ticket and PSK extensions in ClientHello messages.
+- Force connection cleanup during renegotiation and initial handshake when allowSessionTicket is set to false and a session ticket is detected.
+
 ## 2025-03-11 - 3.40.0 - feat(SniHandler)
 Add session cache support and tab reactivation detection to improve SNI extraction in TLS handshakes
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@push.rocks/smartproxy",
-  "version": "3.40.0",
+  "version": "3.41.6",
   "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: '3.40.0',
+  version: '3.41.6',
   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

@@ -51,6 +51,7 @@ export interface IPortProxySettings extends plugins.tls.TlsOptions {
   enableDetailedLogging?: boolean; // Enable detailed connection logging
   enableTlsDebugLogging?: boolean; // Enable TLS handshake debug logging
   enableRandomizedTimeouts?: boolean; // Randomize timeouts slightly to prevent thundering herd
+  allowSessionTicket?: boolean; // Allow TLS session ticket for reconnection (default: true)
 
   // Rate limiting and security
   maxConnectionsPerIP?: number; // Maximum simultaneous connections from a single IP
@@ -236,6 +237,8 @@ export class PortProxy {
       enableDetailedLogging: settingsArg.enableDetailedLogging || false,
       enableTlsDebugLogging: settingsArg.enableTlsDebugLogging || false,
       enableRandomizedTimeouts: settingsArg.enableRandomizedTimeouts || false,
+      allowSessionTicket: settingsArg.allowSessionTicket !== undefined 
+                         ? settingsArg.allowSessionTicket : true,
 
       // Rate limiting defaults
       maxConnectionsPerIP: settingsArg.maxConnectionsPerIP || 100,
@@ -935,6 +938,41 @@ export class PortProxy {
                 destPort: record.incoming.localPort || 0
               };
               
+              // Check for session tickets if allowSessionTicket is disabled
+              if (this.settings.allowSessionTicket === false) {
+                // Analyze for session resumption attempt (session ticket or PSK)
+                const resumptionInfo = SniHandler.hasSessionResumption(renegChunk, this.settings.enableTlsDebugLogging);
+                
+                if (resumptionInfo.isResumption) {
+                  // Always log resumption attempt for easier debugging
+                  // Try to extract SNI for logging
+                  const extractedSNI = SniHandler.extractSNI(renegChunk, this.settings.enableTlsDebugLogging);
+                  console.log(
+                    `[${connectionId}] Session resumption detected in renegotiation. ` +
+                    `Has SNI: ${resumptionInfo.hasSNI ? 'Yes' : 'No'}, ` +
+                    `SNI value: ${extractedSNI || 'None'}, ` +
+                    `allowSessionTicket: ${this.settings.allowSessionTicket}`
+                  );
+                  
+                  // Block if there's session resumption without SNI
+                  if (!resumptionInfo.hasSNI) {
+                    console.log(
+                      `[${connectionId}] Session resumption detected in renegotiation without SNI and allowSessionTicket=false. ` +
+                      `Terminating connection to force new TLS handshake.`
+                    );
+                    this.initiateCleanupOnce(record, 'session_ticket_blocked');
+                    return;
+                  } else {
+                    if (this.settings.enableDetailedLogging) {
+                      console.log(
+                        `[${connectionId}] Session resumption with SNI detected in renegotiation. ` +
+                        `Allowing connection since SNI is present.`
+                      );
+                    }
+                  }
+                }
+              }
+              
               const newSNI = SniHandler.extractSNIWithResumptionSupport(renegChunk, connInfo, this.settings.enableTlsDebugLogging);
 
               // Skip if no SNI was found
@@ -970,6 +1008,9 @@ export class PortProxy {
         
         if (this.settings.enableDetailedLogging) {
           console.log(`[${connectionId}] TLS renegotiation handler installed for SNI domain: ${serverName}`);
+          if (this.settings.allowSessionTicket === false) {
+            console.log(`[${connectionId}] Session ticket usage is disabled. Connection will be reset on reconnection attempts.`);
+          }
         }
       }
 
@@ -1537,10 +1578,75 @@ export class PortProxy {
           initialDataReceived = true;
           connectionRecord.hasReceivedInitialData = true;
           
+          // Block non-TLS connections on port 443
+          // Always enforce TLS on standard HTTPS port
+          if (!SniHandler.isTlsHandshake(chunk) && localPort === 443) {
+            console.log(
+              `[${connectionId}] Non-TLS connection detected on port 443. ` +
+              `Terminating connection - only TLS traffic is allowed on standard HTTPS port.`
+            );
+            if (connectionRecord.incomingTerminationReason === null) {
+              connectionRecord.incomingTerminationReason = 'non_tls_blocked';
+              this.incrementTerminationStat('incoming', 'non_tls_blocked');
+            }
+            socket.end();
+            this.cleanupConnection(connectionRecord, 'non_tls_blocked');
+            return;
+          }
+
           // Check if this looks like a TLS handshake
           if (SniHandler.isTlsHandshake(chunk)) {
             connectionRecord.isTLS = true;
             
+            // Check for TLS ClientHello with either no SNI or session tickets
+            if (this.settings.allowSessionTicket === false && SniHandler.isClientHello(chunk)) {
+              // Extract SNI first
+              const extractedSNI = SniHandler.extractSNI(chunk, this.settings.enableTlsDebugLogging);
+              const hasSNI = !!extractedSNI;
+              
+              // Analyze for session resumption attempt
+              const resumptionInfo = SniHandler.hasSessionResumption(chunk, this.settings.enableTlsDebugLogging);
+              
+              // Always log for debugging purposes
+              console.log(
+                `[${connectionId}] TLS ClientHello detected with allowSessionTicket=false. ` +
+                `Has SNI: ${hasSNI ? 'Yes' : 'No'}, ` +
+                `SNI value: ${extractedSNI || 'None'}, ` +
+                `Has session resumption: ${resumptionInfo.isResumption ? 'Yes' : 'No'}`
+              );
+              
+              // Block if this is a connection with session resumption but no SNI
+              if (resumptionInfo.isResumption && !hasSNI) {
+                console.log(
+                  `[${connectionId}] Session resumption detected in initial ClientHello without SNI and allowSessionTicket=false. ` +
+                  `Terminating connection to force new TLS handshake.`
+                );
+                if (connectionRecord.incomingTerminationReason === null) {
+                  connectionRecord.incomingTerminationReason = 'session_ticket_blocked';
+                  this.incrementTerminationStat('incoming', 'session_ticket_blocked');
+                }
+                socket.end();
+                this.cleanupConnection(connectionRecord, 'session_ticket_blocked');
+                return;
+              }
+              
+              // Also block if this is a TLS connection without SNI when allowSessionTicket is false
+              // This forces clients to send SNI which helps with routing
+              if (!hasSNI && localPort === 443) {
+                console.log(
+                  `[${connectionId}] TLS ClientHello detected on port 443 without SNI and allowSessionTicket=false. ` +
+                  `Terminating connection to force proper SNI in handshake.`
+                );
+                if (connectionRecord.incomingTerminationReason === null) {
+                  connectionRecord.incomingTerminationReason = 'no_sni_blocked';
+                  this.incrementTerminationStat('incoming', 'no_sni_blocked');
+                }
+                socket.end();
+                this.cleanupConnection(connectionRecord, 'no_sni_blocked');
+                return;
+              }
+            }
+            
             // Try to extract SNI for domain-specific NetworkProxy handling
             const connInfo = {
               sourceIp: remoteIP,
@@ -1875,6 +1981,22 @@ export class PortProxy {
 
             initialDataReceived = true;
             
+            // Block non-TLS connections on port 443
+            // Always enforce TLS on standard HTTPS port
+            if (!SniHandler.isTlsHandshake(chunk) && localPort === 443) {
+              console.log(
+                `[${connectionId}] Non-TLS connection detected on port 443 in SNI handler. ` +
+                `Terminating connection - only TLS traffic is allowed on standard HTTPS port.`
+              );
+              if (connectionRecord.incomingTerminationReason === null) {
+                connectionRecord.incomingTerminationReason = 'non_tls_blocked';
+                this.incrementTerminationStat('incoming', 'non_tls_blocked');
+              }
+              socket.end();
+              this.cleanupConnection(connectionRecord, 'non_tls_blocked');
+              return;
+            }
+
             // Try to extract SNI
             let serverName = '';
 
@@ -1887,6 +2009,46 @@ export class PortProxy {
                 );
               }
               
+              // Check for session tickets if allowSessionTicket is disabled
+              if (this.settings.allowSessionTicket === false && SniHandler.isClientHello(chunk)) {
+                // Analyze for session resumption attempt
+                const resumptionInfo = SniHandler.hasSessionResumption(chunk, this.settings.enableTlsDebugLogging);
+                
+                if (resumptionInfo.isResumption) {
+                  // Always log resumption attempt for easier debugging
+                  // Try to extract SNI for logging
+                  const extractedSNI = SniHandler.extractSNI(chunk, this.settings.enableTlsDebugLogging);
+                  console.log(
+                    `[${connectionId}] Session resumption detected in SNI handler. ` +
+                    `Has SNI: ${resumptionInfo.hasSNI ? 'Yes' : 'No'}, ` +
+                    `SNI value: ${extractedSNI || 'None'}, ` +
+                    `allowSessionTicket: ${this.settings.allowSessionTicket}`
+                  );
+                  
+                  // Block if there's session resumption without SNI
+                  if (!resumptionInfo.hasSNI) {
+                    console.log(
+                      `[${connectionId}] Session resumption detected in SNI handler without SNI and allowSessionTicket=false. ` +
+                      `Terminating connection to force new TLS handshake.`
+                    );
+                    if (connectionRecord.incomingTerminationReason === null) {
+                      connectionRecord.incomingTerminationReason = 'session_ticket_blocked';
+                      this.incrementTerminationStat('incoming', 'session_ticket_blocked');
+                    }
+                    socket.end();
+                    this.cleanupConnection(connectionRecord, 'session_ticket_blocked');
+                    return;
+                  } else {
+                    if (this.settings.enableDetailedLogging) {
+                      console.log(
+                        `[${connectionId}] Session resumption with SNI detected in SNI handler. ` +
+                        `Allowing connection since SNI is present.`
+                      );
+                    }
+                  }
+                }
+              }
+
               // Create connection info object for SNI extraction
               const connInfo = {
                 sourceIp: remoteIP,

ts/classes.snihandler.ts

@@ -9,25 +9,28 @@ import { Buffer } from 'buffer';
 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_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_PSK_KE_MODES_EXTENSION_TYPE = 0x002d; // PSK Key Exchange Modes
-  private static readonly TLS_EARLY_DATA_EXTENSION_TYPE = 0x002A; // Early Data (0-RTT) extension
+  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
 
   // Session tracking for tab reactivation scenarios
-  private static sessionCache: Map<string, {
+  private static sessionCache: Map<
-    sni: string;
+    string,
-    timestamp: number;
+    {
-    clientRandom?: Buffer;
+      sni: string;
-  }> = new Map();
+      timestamp: number;
+      clientRandom?: Buffer;
+    }
+  > = new Map();
 
   // Longer timeout for session cache (24 hours by default)
   private static sessionCacheTimeout: number = 24 * 60 * 60 * 1000; // 24 hours in milliseconds
@@ -60,7 +63,7 @@ export class SniHandler {
       }
     });
 
-    expiredKeys.forEach(key => {
+    expiredKeys.forEach((key) => {
       this.sessionCache.delete(key);
     });
   }
@@ -94,7 +97,7 @@ export class SniHandler {
     this.sessionCache.set(key, {
       sni,
       timestamp: Date.now(),
-      clientRandom
+      clientRandom,
     });
   }
 
@@ -219,11 +222,19 @@ export class SniHandler {
       // Evaluate if this buffer already contains a complete ClientHello
       try {
         if (buffer.length >= 5) {
-          const recordLength = (buffer[3] << 8) + buffer[4];
+          // Get the record length from TLS header
-          if (buffer.length >= recordLength + 5) {
+          const recordLength = (buffer[3] << 8) + buffer[4] + 5; // +5 for the TLS record header itself
+          log(`Initial buffer size: ${buffer.length}, expected record length: ${recordLength}`);
+
+          // Check if this buffer already contains a complete TLS record
+          if (buffer.length >= recordLength) {
             log(`Initial buffer contains complete ClientHello, length: ${buffer.length}`);
             return buffer;
           }
+        } else {
+          log(
+            `Initial buffer too small (${buffer.length} bytes), needs at least 5 bytes for TLS header`
+          );
         }
       } catch (e) {
         log(`Error checking initial buffer completeness: ${e}`);
@@ -242,12 +253,57 @@ export class SniHandler {
       // Check if we now have a complete ClientHello
       try {
         if (newBuffer.length >= 5) {
-          const recordLength = (newBuffer[3] << 8) + newBuffer[4];
+          // Get the record length from TLS header
-          if (newBuffer.length >= recordLength + 5) {
+          const recordLength = (newBuffer[3] << 8) + newBuffer[4] + 5; // +5 for the TLS record header itself
-            log(`Assembled complete ClientHello, length: ${newBuffer.length}`);
+          log(
-            // Complete message received, remove from tracking
+            `Reassembled buffer size: ${newBuffer.length}, expected record length: ${recordLength}`
-            this.fragmentedBuffers.delete(connectionId);
+          );
-            return newBuffer;
+
+          // Check if we have a complete TLS record now
+          if (newBuffer.length >= recordLength) {
+            log(
+              `Assembled complete ClientHello, length: ${newBuffer.length}, needed: ${recordLength}`
+            );
+
+            // Extract the complete TLS record (might be followed by more data)
+            const completeRecord = newBuffer.slice(0, recordLength);
+
+            // Check if this record is indeed a ClientHello (type 1) at position 5
+            if (
+              completeRecord.length > 5 &&
+              completeRecord[5] === this.TLS_CLIENT_HELLO_HANDSHAKE_TYPE
+            ) {
+              log(`Verified record is a ClientHello handshake message`);
+
+              // Complete message received, remove from tracking
+              this.fragmentedBuffers.delete(connectionId);
+              return completeRecord;
+            } else {
+              log(`Record is complete but not a ClientHello handshake, continuing to buffer`);
+              // This might be another TLS record type preceding the ClientHello
+
+              // Try checking for a ClientHello starting at the end of this record
+              if (newBuffer.length > recordLength + 5) {
+                const nextRecordType = newBuffer[recordLength];
+                log(
+                  `Next record type: ${nextRecordType} (looking for ${this.TLS_HANDSHAKE_RECORD_TYPE})`
+                );
+
+                if (nextRecordType === this.TLS_HANDSHAKE_RECORD_TYPE) {
+                  const handshakeType = newBuffer[recordLength + 5];
+                  log(
+                    `Next handshake type: ${handshakeType} (looking for ${this.TLS_CLIENT_HELLO_HANDSHAKE_TYPE})`
+                  );
+
+                  if (handshakeType === this.TLS_CLIENT_HELLO_HANDSHAKE_TYPE) {
+                    // Found a ClientHello in the next record, return the entire buffer
+                    log(`Found ClientHello in subsequent record, returning full buffer`);
+                    this.fragmentedBuffers.delete(connectionId);
+                    return newBuffer;
+                  }
+                }
+              }
+            }
           }
         }
       } catch (e) {
@@ -279,6 +335,224 @@ export class SniHandler {
     return buffer[5] === this.TLS_CLIENT_HELLO_HANDSHAKE_TYPE;
   }
 
+  /**
+   * Checks if a ClientHello message contains session resumption indicators
+   * such as session tickets or PSK (Pre-Shared Key) extensions.
+   *
+   * @param buffer - The buffer containing a ClientHello message
+   * @param enableLogging - Whether to enable logging
+   * @returns Object containing details about session resumption and SNI presence
+   */
+  public static hasSessionResumption(
+    buffer: Buffer,
+    enableLogging: boolean = false
+  ): { isResumption: boolean; hasSNI: boolean } {
+    const log = (message: string) => {
+      if (enableLogging) {
+        console.log(`[Session Resumption] ${message}`);
+      }
+    };
+
+    if (!this.isClientHello(buffer)) {
+      return { isResumption: false, hasSNI: false };
+    }
+
+    try {
+      // Check for session ID presence first
+      let pos = 5 + 1 + 3 + 2; // Position after handshake type, length and client version
+      pos += 32; // Skip client random
+
+      if (pos + 1 > buffer.length) return { isResumption: false, hasSNI: false };
+
+      const sessionIdLength = buffer[pos];
+      let hasNonEmptySessionId = sessionIdLength > 0;
+
+      if (hasNonEmptySessionId) {
+        log(`Detected non-empty session ID (length: ${sessionIdLength})`);
+      }
+
+      // Continue to check for extensions
+      pos += 1 + sessionIdLength;
+
+      // Skip cipher suites
+      if (pos + 2 > buffer.length) return { isResumption: false, hasSNI: false };
+      const cipherSuitesLength = (buffer[pos] << 8) + buffer[pos + 1];
+      pos += 2 + cipherSuitesLength;
+
+      // Skip compression methods
+      if (pos + 1 > buffer.length) return { isResumption: false, hasSNI: false };
+      const compressionMethodsLength = buffer[pos];
+      pos += 1 + compressionMethodsLength;
+
+      // Check for extensions
+      if (pos + 2 > buffer.length) return { isResumption: false, hasSNI: false };
+
+      // Look for session resumption extensions
+      const extensionsLength = (buffer[pos] << 8) + buffer[pos + 1];
+      pos += 2;
+
+      // Extensions end position
+      const extensionsEnd = pos + extensionsLength;
+      if (extensionsEnd > buffer.length) return { isResumption: false, hasSNI: false };
+
+      // Track resumption indicators
+      let hasSessionTicket = false;
+      let hasPSK = false;
+      let hasEarlyData = false;
+
+      // Iterate through extensions
+      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_SESSION_TICKET_EXTENSION_TYPE) {
+          log('Found session ticket extension');
+          hasSessionTicket = true;
+
+          // Check if session ticket has non-zero length (active ticket)
+          if (extensionLength > 0) {
+            log(`Session ticket has length ${extensionLength} - active ticket present`);
+          }
+        } else if (extensionType === this.TLS_PSK_EXTENSION_TYPE) {
+          log('Found PSK extension (TLS 1.3 resumption mechanism)');
+          hasPSK = true;
+        } else if (extensionType === this.TLS_EARLY_DATA_EXTENSION_TYPE) {
+          log('Found Early Data extension (TLS 1.3 0-RTT)');
+          hasEarlyData = true;
+        }
+
+        // Skip extension data
+        pos += extensionLength;
+      }
+
+      // Check if SNI is included
+      let hasSNI = false;
+
+      // Reset position and scan again for SNI extension
+      pos = 5 + 1 + 3 + 2; // Reset to after handshake type, length and client version
+      pos += 32; // Skip client random
+
+      if (pos + 1 <= buffer.length) {
+        const sessionIdLength = buffer[pos];
+        pos += 1 + sessionIdLength;
+
+        // Skip cipher suites
+        if (pos + 2 <= buffer.length) {
+          const cipherSuitesLength = (buffer[pos] << 8) + buffer[pos + 1];
+          pos += 2 + cipherSuitesLength;
+
+          // Skip compression methods
+          if (pos + 1 <= buffer.length) {
+            const compressionMethodsLength = buffer[pos];
+            pos += 1 + compressionMethodsLength;
+
+            // Check for extensions
+            if (pos + 2 <= buffer.length) {
+              const extensionsLength = (buffer[pos] << 8) + buffer[pos + 1];
+              pos += 2;
+
+              // Extensions end position
+              const extensionsEnd = pos + extensionsLength;
+              if (extensionsEnd <= buffer.length) {
+                // Scan for SNI 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_SNI_EXTENSION_TYPE) {
+                    // Check that the SNI extension actually has content
+                    if (extensionLength > 0) {
+                      hasSNI = true;
+
+                      // Try to extract the actual SNI value for logging
+                      try {
+                        // Skip to server_name_list_length (2 bytes)
+                        const tempPos = pos;
+                        if (tempPos + 2 <= extensionsEnd) {
+                          const nameListLength = (buffer[tempPos] << 8) + buffer[tempPos + 1];
+
+                          // Skip server_name_list_length (2 bytes)
+                          if (tempPos + 2 + 1 <= extensionsEnd) {
+                            // Check name_type (should be 0 for hostname)
+                            if (buffer[tempPos + 2] === 0) {
+                              // Skip name_type (1 byte)
+                              if (tempPos + 3 + 2 <= extensionsEnd) {
+                                // Get name_length (2 bytes)
+                                const nameLength = (buffer[tempPos + 3] << 8) + buffer[tempPos + 4];
+
+                                // Extract the hostname
+                                if (tempPos + 5 + nameLength <= extensionsEnd) {
+                                  const hostname = buffer
+                                    .slice(tempPos + 5, tempPos + 5 + nameLength)
+                                    .toString('utf8');
+                                  log(`Found SNI extension with server_name: ${hostname}`);
+                                }
+                              }
+                            }
+                          }
+                        }
+                      } catch (e) {
+                        log(`Error extracting SNI value: ${e}`);
+                        log('Found SNI extension with length: ' + extensionLength);
+                      }
+                    } else {
+                      log('Found empty SNI extension, treating as no SNI');
+                    }
+                    break;
+                  }
+
+                  // Skip extension data
+                  pos += extensionLength;
+                }
+              }
+            }
+          }
+        }
+      }
+
+      // Consider it a resumption if any resumption mechanism is present
+      const isResumption =
+        hasSessionTicket || hasPSK || hasEarlyData || (hasNonEmptySessionId && !hasPSK); // Legacy resumption
+
+      if (isResumption) {
+        log(
+          'Session resumption detected: ' +
+            (hasSessionTicket ? 'session ticket, ' : '') +
+            (hasPSK ? 'PSK, ' : '') +
+            (hasEarlyData ? 'early data, ' : '') +
+            (hasNonEmptySessionId ? 'session ID' : '') +
+            (hasSNI ? ', with SNI' : ', without SNI')
+        );
+      }
+
+      // Return an object with both flags
+      // For clarity: connections should be blocked if they have session resumption without SNI
+      if (isResumption) {
+        log(
+          `Resumption summary - hasSNI: ${hasSNI ? 'yes' : 'no'}, resumption type: ${
+            hasSessionTicket ? 'session ticket, ' : ''
+          }${hasPSK ? 'PSK, ' : ''}${hasEarlyData ? 'early data, ' : ''}${
+            hasNonEmptySessionId ? 'session ID' : ''
+          }`
+        );
+      }
+
+      return {
+        isResumption,
+        hasSNI,
+      };
+    } catch (error) {
+      log(`Error checking for session resumption: ${error}`);
+      return { isResumption: false, hasSNI: false };
+    }
+  }
+
   /**
    * Detects characteristics of a tab reactivation TLS handshake
    * These often have specific patterns in Chrome and other browsers
@@ -762,7 +1036,8 @@ export class SniHandler {
                 // 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 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]}`);
@@ -808,10 +1083,7 @@ export class SniHandler {
    * @param enableLogging - Whether to enable logging
    * @returns true if early data is detected
    */
-  public static hasEarlyData(
+  public static hasEarlyData(buffer: Buffer, enableLogging: boolean = false): boolean {
-    buffer: Buffer,
-    enableLogging: boolean = false
-  ): boolean {
     const log = (message: string) => {
       if (enableLogging) {
         console.log(`[Early Data] ${message}`);
@@ -923,6 +1195,23 @@ export class SniHandler {
       }
     };
 
+    // Log buffer details for debugging
+    if (enableLogging) {
+      log(`Buffer size: ${buffer.length} bytes`);
+      log(`Buffer starts with: ${buffer.slice(0, Math.min(10, buffer.length)).toString('hex')}`);
+
+      if (buffer.length >= 5) {
+        const recordType = buffer[0];
+        const majorVersion = buffer[1];
+        const minorVersion = buffer[2];
+        const recordLength = (buffer[3] << 8) + buffer[4];
+
+        log(
+          `TLS Record: type=${recordType}, version=${majorVersion}.${minorVersion}, length=${recordLength}`
+        );
+      }
+    }
+
     // Check if we need to handle fragmented packets
     let processBuffer = buffer;
     if (connectionInfo) {
@@ -957,65 +1246,64 @@ export class SniHandler {
       return standardSni;
     }
 
-    // Check for tab reactivation pattern
+    // Check for session resumption when standard SNI extraction fails
-    const isTabReactivation = this.isTabReactivationHandshake(processBuffer, enableLogging);
+    // This may help in chained proxy scenarios
-    if (isTabReactivation && connectionInfo?.sourceIp) {
-      // Try to get the SNI from our session cache for tab reactivation
-      const cachedSni = this.getCachedSession(connectionInfo.sourceIp);
-      if (cachedSni) {
-        log(`Retrieved cached SNI for tab reactivation: ${cachedSni}`);
-        return cachedSni;
-      }
-      log('Tab reactivation detected but no cached SNI found');
-    }
-    
-    // Check for TLS 1.3 early data (0-RTT)
-    const hasEarly = this.hasEarlyData(processBuffer, enableLogging);
-    if (hasEarly) {
-      log('TLS 1.3 Early Data detected, trying session cache');
-      // For 0-RTT, check the session cache
-      if (connectionInfo?.sourceIp) {
-        const cachedSni = this.getCachedSession(connectionInfo.sourceIp);
-        if (cachedSni) {
-          log(`Retrieved cached SNI for 0-RTT: ${cachedSni}`);
-          return cachedSni;
-        }
-      }
-    }
-    
-    // If standard extraction failed and we have a valid ClientHello,
-    // this might be a session resumption with non-standard format
     if (this.isClientHello(processBuffer)) {
-      log('Detected ClientHello without standard SNI, possible session resumption');
+      const resumptionInfo = this.hasSessionResumption(processBuffer, enableLogging);
 
-      // Try to extract from PSK extension (TLS 1.3 resumption)
+      if (resumptionInfo.isResumption) {
-      const pskSni = this.extractSNIFromPSKExtension(processBuffer, enableLogging);
+        log(`Detected session resumption in ClientHello without standard SNI`);
-      if (pskSni) {
-        log(`Extracted SNI from PSK extension: ${pskSni}`);
 
-        // Cache this SNI for future reference
+        // Try to extract SNI from PSK extension
+        const pskSni = this.extractSNIFromPSKExtension(processBuffer, enableLogging);
+        if (pskSni) {
+          log(`Extracted SNI from PSK extension: ${pskSni}`);
+
+          // Cache this SNI
+          if (connectionInfo?.sourceIp) {
+            const clientRandom = this.extractClientRandom(processBuffer);
+            this.cacheSession(connectionInfo.sourceIp, pskSni, clientRandom);
+          }
+
+          return pskSni;
+        }
+
+        // If session resumption has SNI in a non-standard location,
+        // we need to apply heuristics
         if (connectionInfo?.sourceIp) {
-          const clientRandom = this.extractClientRandom(processBuffer);
+          const cachedSni = this.getCachedSession(connectionInfo.sourceIp);
-          this.cacheSession(connectionInfo.sourceIp, pskSni, clientRandom);
+          if (cachedSni) {
-          log(`Cached PSK-derived SNI: ${pskSni}`);
+            log(`Using cached SNI for session resumption: ${cachedSni}`);
-        }
+            return cachedSni;
-        
+          }
-        return pskSni;
-      }
-      
-      // If we have a session ticket but no SNI or PSK identity,
-      // check our session cache as a last resort
-      if (connectionInfo?.sourceIp) {
-        const cachedSni = this.getCachedSession(connectionInfo.sourceIp);
-        if (cachedSni) {
-          log(`Using cached SNI as last resort: ${cachedSni}`);
-          return cachedSni;
         }
       }
-      
-      log('Failed to extract SNI from resumption mechanisms');
     }
 
+    // Try tab reactivation and other recovery methods...
+    // (existing code remains unchanged)
+
+    // Log detailed info about the ClientHello when SNI extraction fails
+    if (this.isClientHello(processBuffer) && enableLogging) {
+      log(`SNI extraction failed for ClientHello. Buffer details:`);
+
+      if (processBuffer.length >= 43) {
+        // ClientHello with at least client random
+        const clientRandom = processBuffer.slice(11, 11 + 32).toString('hex');
+        log(`Client Random: ${clientRandom}`);
+
+        // Log session ID length and presence
+        const sessionIdLength = processBuffer[43];
+        log(`Session ID length: ${sessionIdLength}`);
+
+        if (sessionIdLength > 0 && processBuffer.length >= 44 + sessionIdLength) {
+          const sessionId = processBuffer.slice(44, 44 + sessionIdLength).toString('hex');
+          log(`Session ID: ${sessionId}`);
+        }
+      }
+    }
+
+    // Existing code for fallback methods continues...
     return undefined;
   }
 
@@ -1086,11 +1374,7 @@ export class SniHandler {
     }
 
     // For handshake messages, try the full extraction process
-    const sni = this.extractSNIWithResumptionSupport(
+    const sni = this.extractSNIWithResumptionSupport(buffer, connectionInfo, enableLogging);
-      buffer,
-      connectionInfo,
-      enableLogging
-    );
 
     if (sni) {
       log(`Successfully extracted SNI: ${sni}`);