How the SSL/TLS Checker Works

Our SSL Checker initiates a TLS handshake with the target server, pulling the complete certificate chain. It verifies the cryptographic signature against trusted Root Certificate Authorities (CAs). Beyond mere validity, it negotiates with the server to map out supported TLS protocols (from the deprecated SSLv3 to the modern TLS 1.3) and analyzes the server's accepted cipher suites, flagging weak algorithms like RC4, DES, or those vulnerable to known attacks.

Common TLS Misconfigurations

Even with a valid certificate, misconfigured TLS settings can lead to data interception.Mixed Content occurs when an HTTPS page loads scripts or images over insecure HTTP, bypassing encryption.Supporting Weak Ciphers allows attackers positioned on the network to perform downgrade attacks or decrypt captured traffic.Missing Certificate Revocation checking (OCSP Must-Staple) means browsers might trust a stolen certificate that the CA has already revoked.

SSL Checker vs HTTP Headers

While both secure web communications, they operate at different layers. The SSL Checker analyzes the transport layer (Layer 4/6), ensuring the pipe between the client and server is encrypted and mathematically secure. HTTP Headers (like HSTS or CSP) operate at the application layer (Layer 7), instructing the browser on how to safely interact with the received data, such as forcing HTTPS or restricting script execution.