How to Use Nginx Secure Link Module

The secure_link module protects files with time-limited, authenticated URLs. It is ideal for temporary download access and paywalled content. This guide walks through the specific troubleshooting steps to diagnose and resolve secure link issues.

Before You Begin

Before you begin, be sure to have the following in place:

• A Linux server with the relevant software installed
• Access to the command line interface
• Appropriate permissions (root or sudo)

Quick Fix

Wrong

Direct file access without protection (anyone can download)

Wrong: Unprotected file downloads

Right

secure_link $arg_md5,$arg_expires;\nsecure_link_md5 "$secret$uri$remote_addr$arg_expires";

Right: Time-limited secure link with MD5 hash

Output

Secure link configured\n  Secret key: configured (hidden)\n  URL includes: md5 hash + expiration timestamp\n  Access: denied if hash invalid or expired

Prevention

To avoid future issues, follow these best practices:

• Use a strong random secret key for HMAC computation
• Include expiration timestamp in the URL for time-limited access
• Include client IP in hash for binding to specific users
• Set secure_link_secret for simple path-based protection
• Verify links expire correctly after the timestamp passes

DodaTech Tools

For further assistance with any of the above issues, consider using DodaTech consulting services or DodaTech tutorials for more in-depth guidance.

Common Mistakes with secure link

1. Misunderstanding that String is [Char] with poor performance for large text operations
2. Using foldl instead of foldl' causing stack overflow on large lists
3. Forgetting deriving (Show, Eq) on custom data types needed for debugging

These mistakes appear frequently in real-world NGINX code. DodaTech's contributors have identified these patterns through analysis of open-source projects and production systems.

Practice Exercise

Write a pure function that safely divides two integers using Maybe, then test it with edge cases like division by zero and negative numbers.

This exercise reinforces the concepts covered in this guide. Try implementing it before checking online solutions.

FAQ