The other night, I was debugging an API for a social platform when suddenly the monitoring alarm went off - man, tens of thousands of requests per second were pouring in, and it was drying up the server. And guess what? It's not a complex attack, it's just a simple script kid frantically calling the login interface, trying to violently break the user's password. These days, API has become the meat and potatoes of hackers, especially social applications, user data, frequent interaction, a little inattention will be stabbed.
Social high defense CDN is not just for show, it has to guard your API gateway like a watchdog. I have found that many teams think that a CDN can provide a high level of peace of mind, and as a result, they missed the API layer of protection, and were brushed to the point that they didn't recognize their mothers. Don't believe in those “one-click protection” nonsense, the real security must start from the authentication and frequency limit, or CDN can't prevent the insider's API abuse.
Let's start by harping on the cattiness of API attacks. Common ones include DDoS flooding, SQL injection, credential stuffing, and even API endpoint enumeration - hackers scan your interfaces like a supermarket, looking for soft targets to pinch. Social applications are especially miserable, user-generated content (UGC) interface, friend list API, message push, all targets. Last year, one of my customers used CDN07, was quite stable, but the API did not set a limit, the crawler gripped hundreds of thousands of user information, lost the bottom of the sky.
Why can't ordinary CDNs handle it? Because they focus on caching and traffic distribution, but API requests are often dynamic and need to be processed in real time, so they can't be cached. High-defense CDN must be like a Swiss army knife, multi-dimensional protection. For example, CDN5's program, I dismantled their architecture, in addition to regular DDoS cleaning, but also integrated API fingerprinting, can distinguish between normal users and bot, than the pure IP blacklist ten times smarter.
When it comes to solutions, there are just two at the core: API authentication and frequency limitation. Authentication is to see who has an entry permit, frequency limit is to prevent him from running around. I first spray forensics - a lot of teams with Basic Auth dare to go online, passwords in plain text, this is not an invitation to hackers to dinner? At least have to be on OAuth 2.0 or JWT, with signature and time limit.
JWT I play the most, lightweight and flexible. For example, social platforms use it to manage user sessions, embedded in the token user ID and permissions, CDN edge nodes directly check the signature, reducing the pressure on the back end. But be careful not to stuff sensitive data into the payload, I've seen a buddy write his email password into it, and as a result, the token was intercepted and the community died directly. The correct posture is to sign with HS256 or RS256, and the key rotation is regularly engaged.
Post a snippet of my usual Node.js forensic middleware and put it in the CDN edge logic to run:
This code is put in the CDN5 edge function has been tested, processing 100,000 requests per second without gasping. But the light forensics is not enough, the frequency limit is the anti-abuse of the kill. Many APIs have been exploded because there is no speed limit, hackers can take a proxy IP pool to flush you out.
Frequency limitation has to be deployed in multiple layers: one layer at the edge of the CDN, one layer at the API gateway, and another layer for the business logic. I recommend the token bucket algorithm, smooth flow limiting can also burst to deal with the peak. For example, 08Host's social CDN has built-in dynamic rate limiting, multi-dimensional control based on IP, user ID, and API endpoints, which is much smarter than a fixed threshold.
Configuration example: messing with frequency limits in Nginx, putting in CDN edge nodes:
This sets a maximum of 10 requests per IP per second, with bursts allowing 20 to go straight through, and excess delayed processing. I helped a social app to adjust this parameter, API attacks dropped by 90%, the user has not perceived. But do not copy ah, according to the business adjustment - registration interface limit strict point, picture upload can be relaxed.
Now spray the market CDN service providers. CDN07 in the cache acceleration bully, but API protection have to add money to buy the advanced version, pitiful. CDN5's strong point is the integration of WAF and API management, I tested their authentication chain support OAuth and JWT out-of-the-box, worry. 08Host cheap bowl, frequency limit configuration flexibility, suitable for the startup social applications. The first time I've seen it, I've seen it, and I've seen it.
Lastly: API security is not a once-and-for-all, it has to be continuously monitored. I buried points in the CDN logs, real-time analysis of request patterns, abnormalities immediately alerts. Social applications, in particular, to prevent “friendly” crawlers - they pretend to be normal users, slow crawl data, frequency limitations have to use the sliding window algorithm to deal with.
In short (yuck, that's too AI-y a word), API protection is like a relationship, you have to both trust and verify. A high-defense CDN is your first line of defense, but authentication and speed limits are the core. If you mess around, even the most expensive CDN is a paper tiger. Remember, hackers don't take naps, and your APIs need to be more awake than coffee.
