fix(tls/sni): Improve logging for TLS session resumption by extracting and logging SNI values from ClientHello messages.

This commit is contained in:
Philipp Kunz 2025-03-12 10:01:54 +00:00
parent 156abbf5b4
commit ab1ec84832
4 changed files with 52 additions and 5 deletions

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@ -1,5 +1,11 @@
# Changelog
## 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.

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@ -3,6 +3,6 @@
*/
export const commitinfo = {
name: '@push.rocks/smartproxy',
version: '3.41.3',
version: '3.41.4',
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.'
}

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@ -945,9 +945,13 @@ export class PortProxy {
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'}, allowSessionTicket: ${this.settings.allowSessionTicket}`
`Has SNI: ${resumptionInfo.hasSNI ? 'Yes' : 'No'}, ` +
`SNI value: ${extractedSNI || 'None'}, ` +
`allowSessionTicket: ${this.settings.allowSessionTicket}`
);
// Block if there's session resumption without SNI
@ -1585,9 +1589,13 @@ export class PortProxy {
if (resumptionInfo.isResumption) {
// Always log resumption attempt for easier debugging
// Try to extract SNI for logging
const extractedSNI = SniHandler.extractSNI(chunk, this.settings.enableTlsDebugLogging);
console.log(
`[${connectionId}] Session resumption detected in initial ClientHello. ` +
`Has SNI: ${resumptionInfo.hasSNI ? 'Yes' : 'No'}, allowSessionTicket: ${this.settings.allowSessionTicket}`
`Has SNI: ${resumptionInfo.hasSNI ? 'Yes' : 'No'}, ` +
`SNI value: ${extractedSNI || 'None'}, ` +
`allowSessionTicket: ${this.settings.allowSessionTicket}`
);
// Block if there's session resumption without SNI
@ -1967,9 +1975,13 @@ export class PortProxy {
if (resumptionInfo.isResumption) {
// Always log resumption attempt for easier debugging
// Try to extract SNI for logging
const extractedSNI = SniHandler.extractSNI(chunk, this.settings.enableTlsDebugLogging);
console.log(
`[${connectionId}] Session resumption detected in SNI handler. ` +
`Has SNI: ${resumptionInfo.hasSNI ? 'Yes' : 'No'}, allowSessionTicket: ${this.settings.allowSessionTicket}`
`Has SNI: ${resumptionInfo.hasSNI ? 'Yes' : 'No'}, ` +
`SNI value: ${extractedSNI || 'None'}, ` +
`allowSessionTicket: ${this.settings.allowSessionTicket}`
);
// Block if there's session resumption without SNI

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@ -413,7 +413,36 @@ export class SniHandler {
// 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');
}