HAProxy Config Validator

Validate HAProxy SSL/TLS configuration for security issues

About HAProxy SSL Validation

HAProxy is a widely used load balancer and reverse proxy that handles SSL/TLS termination for many production environments. Misconfiguring HAProxy's SSL settings can expose your infrastructure to protocol downgrade attacks, weak cipher usage, and certificate validation failures. Our HAProxy Config Validator analyzes your configuration directives and flags potential security issues before they reach production.

How to Use

Copy your HAProxy configuration snippet containing the SSL/TLS bind directives.
Paste the configuration into the text area provided.
Click Validate to analyze the configuration for security issues.
Review each flagged issue and follow the suggested fixes to harden your setup.

Use Cases

Pre-Deployment Review: Validate HAProxy SSL configuration before deploying to production environments.
Security Audits: Quickly audit existing HAProxy configurations for compliance with security policies.
Migration Support: Verify SSL settings when upgrading HAProxy versions or migrating between servers.
Learning Tool: Understand HAProxy SSL best practices by seeing real-time validation feedback.

Frequently Asked Questions

The validator checks for weak TLS protocol versions, deprecated cipher suites, missing SSL options like no-sslv3, certificate path issues, and other common HAProxy SSL misconfigurations that could lead to security vulnerabilities.

Minimum requirements include disabling SSLv3 and TLS 1.0/1.1, using strong cipher suites, enabling OCSP stapling, and specifying a modern ssl-min-ver setting. HAProxy 2.0+ supports TLS 1.3 which is strongly recommended.

Yes, you can paste your entire haproxy.cfg file. The validator will extract and analyze all SSL-related bind directives and frontend/backend configurations, providing a comprehensive security report.

No. It analyses the configuration text you paste, statically and locally — nothing is sent to your server and nothing is executed. That is a deliberate limitation: it can find problems in the file, but not runtime issues like certificate files missing on disk, permission errors or a health check failing. For the running behaviour, check the site externally instead.

Because HAProxy defaults to accepting whatever the client offers unless you tell it otherwise, so an unset or too-low floor quietly keeps deprecated protocol support alive. Setting it to TLSv1.2 is the single most effective line in most configurations, and this validator treats a lower value as a high-severity finding for exactly that reason.

The options that disable the same deprecated protocols at the connection level — no-sslv3, no-tlsv10 and no-tlsv11 — so both the floor and the active options agree. Omitting them leaves a gap where a client offering an old version can still be accepted through a path the floor does not cover, which is why the validator reports the absence once per file.

Because static analysis only sees the file. Missing certificate files, unreadable keys, a bind on a port already in use, or a syntax error in a section this validator does not examine all produce startup failures with no corresponding finding here. When the score is clean and the server still will not start, read HAProxy's own error output — it names the exact problem.

As a summary, not a verdict. It subtracts a flat 10 per issue regardless of severity, so one deprecated-protocol floor can score the same as one missing option. Use the score to spot a file that has drifted, then read the list — which gives line numbers and specific fixes — to decide what actually needs changing.

What the Validator Checks

Paste your HAProxy configuration and this page reads it line by line, reporting each problem with its line number, severity and the directive that fixes it. It is static analysis of the text you supply — it never connects to your server or runs your config.

1Flag deprecated protocol floors. An ssl-min-ver set to SSLv3 or TLSv1 accepts clients that should no longer be accommodated, and the finding names the replacement — TLS 1.2 or higher.
2Flag weak cipher components in ssl-default-bind-ciphers — RC4, DES, 3DES, MD5, NULL and export suites — each reported separately with AES-GCM or ChaCha20 suggested instead.
3Check that TLS binds carry a certificate, because a bind with ssl but no crt will not start cleanly and the reason is not obvious from HAProxy's own error. Missing ssl-default-bind-options is reported once for the file as a whole.

The score starts at 100 and loses 10 per issue, and 70 or above passes. That weighting is blunt on purpose: a single deprecated-protocol finding and a single missing-option finding are not equivalent in practice, so read the list rather than leaning on the number. The sibling nginx and Apache validators cover those configurations.

Tips & Best Practices

•Validate HAProxy SSL configuration before applying changes
•Check HAProxy-specific SSL directives and options
•Monitor HAProxy SSL performance after configuration changes
•Use HAProxy stats to monitor SSL connection metrics

Technical Details

Config: HAProxy SSL/TLS configuration validation
Directives: ssl-default-bind-ciphers, ssl-default-bind-options
Features: SNI, OCSP stapling, and SSL termination
Output: HAProxy SSL configuration analysis and recommendations