1 files changed, 75 insertions, 0 deletions
diff --git a/server/rate-limiter.js b/server/rate-limiter.js
new file mode 100644
index 0000000..3c269b6
--- /dev/null
+++ b/server/rate-limiter.js
@@ -0,0 +1,75 @@
+const { RateLimiter } = require("limiter");
+const { log } = require("../src/util");
+
+class KumaRateLimiter {
+    /**
+     * @param {object} config Rate limiter configuration object
+     */
+    constructor(config) {
+        this.errorMessage = config.errorMessage;
+        this.rateLimiter = new RateLimiter(config);
+    }
+
+    /**
+     * Callback for pass
+     * @callback passCB
+     * @param {object} err Too many requests
+     */
+
+    /**
+     * Should the request be passed through
+     * @param {passCB} callback Callback function to call with decision
+     * @param {number} num Number of tokens to remove
+     * @returns {Promise<boolean>} Should the request be allowed?
+     */
+    async pass(callback, num = 1) {
+        const remainingRequests = await this.removeTokens(num);
+        log.info("rate-limit", "remaining requests: " + remainingRequests);
+        if (remainingRequests < 0) {
+            if (callback) {
+                callback({
+                    ok: false,
+                    msg: this.errorMessage,
+                });
+            }
+            return false;
+        }
+        return true;
+    }
+
+    /**
+     * Remove a given number of tokens
+     * @param {number} num Number of tokens to remove
+     * @returns {Promise<number>} Number of remaining tokens
+     */
+    async removeTokens(num = 1) {
+        return await this.rateLimiter.removeTokens(num);
+    }
+}
+
+const loginRateLimiter = new KumaRateLimiter({
+    tokensPerInterval: 20,
+    interval: "minute",
+    fireImmediately: true,
+    errorMessage: "Too frequently, try again later."
+});
+
+const apiRateLimiter = new KumaRateLimiter({
+    tokensPerInterval: 60,
+    interval: "minute",
+    fireImmediately: true,
+    errorMessage: "Too frequently, try again later."
+});
+
+const twoFaRateLimiter = new KumaRateLimiter({
+    tokensPerInterval: 30,
+    interval: "minute",
+    fireImmediately: true,
+    errorMessage: "Too frequently, try again later."
+});
+
+module.exports = {
+    loginRateLimiter,
+    apiRateLimiter,
+    twoFaRateLimiter,
+};