SSL/TLS Handshake Debugger

Debug and analyze the SSL/TLS handshake process for a domain

Domain

Port

Handshake Analysis

About TLS Handshake Debugger

Step-by-step debugger for TLS handshake process. Shows each message exchange between client and server with timing, cipher selection, and error details.

How to Use

1Enter the domain name and optional port number (default 443).
2Click "Debug Handshake" to start the step-by-step analysis.
3Review each handshake step showing success/failure status and details.

Use Cases

•Debug connection failures and identify where the handshake breaks
•Understand TLS negotiation details and cipher selection
•Troubleshoot timeout issues during TLS connection establishment

Frequently Asked Questions

A TLS handshake involves the client and server exchanging messages to agree on protocol versions, cipher suites, and authentication certificates. This includes ClientHello, ServerHello, certificate exchange, key exchange, and finished messages.

Each step shows OK or Failed status. OK means that handshake phase succeeded. Failed indicates where the connection broke. Look for the first failed step to identify the root cause of connection issues.

Common errors include certificate validation failures, unsupported protocol versions, cipher suite mismatches, and timeout errors due to firewall or network issues blocking TLS traffic.

Tips & Best Practices

•Use handshake debugging to diagnose TLS connection failures
•Analyze handshake messages to identify specific failure points
•Test with different client configurations to reproduce issues
•Check server logs for additional handshake diagnostic information

Technical Details

Debug: TLS handshake message sequence and content analysis
Messages: ClientHello, ServerHello, Certificate, Finished analysis
Errors: Handshake failure identification and cause analysis
Output: Handshake debug log with error details