init f0ckm

src/inc/multipart.mjs

@@ -0,0 +1,86 @@
+/**
+ * Shared Multi-part Form Data Parsing Utilities
+ */
+
+/**
+ * Native multipart form data parser
+ * @param {Buffer} buffer The raw request body buffer
+ * @param {string} boundary The boundary string from the Content-Type header
+ * @returns {Object} Parsed form parts
+ */
+export const parseMultipart = (buffer, boundary) => {
+    const parts = {};
+    const boundaryBuffer = Buffer.from(`--${boundary}`);
+    const segments = [];
+
+    let start = 0;
+    let idx;
+
+    while ((idx = buffer.indexOf(boundaryBuffer, start)) !== -1) {
+        if (start !== 0) {
+            segments.push(buffer.slice(start, idx - 2)); // -2 for \r\n before boundary
+        }
+        start = idx + boundaryBuffer.length + 2; // +2 for \r\n after boundary
+    }
+
+    for (const segment of segments) {
+        const headerEnd = segment.indexOf('\r\n\r\n');
+        if (headerEnd === -1) continue;
+
+        const headers = segment.slice(0, headerEnd).toString();
+        const body = segment.slice(headerEnd + 4);
+
+        const nameMatch = headers.match(/name="([^"]+)"/);
+        const filenameMatch = headers.match(/filename="([^"]+)"/);
+        const contentTypeMatch = headers.match(/Content-Type:\s*([^\r\n]+)/i);
+
+        if (nameMatch) {
+            const name = nameMatch[1];
+            if (filenameMatch) {
+                parts[name] = {
+                    filename: filenameMatch[1],
+                    contentType: contentTypeMatch ? contentTypeMatch[1] : 'application/octet-stream',
+                    data: body
+                };
+            } else {
+                parts[name] = body.toString().trim();
+            }
+        }
+    }
+
+    return parts;
+};
+
+/**
+ * Collects the raw request body buffer
+ * @param {IncomingMessage} req 
+ * @param {number} maxBytes 
+ * @returns {Promise<Buffer>}
+ */
+export const collectBody = (req, maxBytes = 157286400) => { // Default to 150MB (matching maxfilesize)
+    return new Promise((resolve, reject) => {
+        const chunks = [];
+        let received = 0;
+
+        // Fast-path: reject immediately if Content-Length header already exceeds limit
+        const declaredLength = parseInt(req.headers['content-length'] || '0', 10);
+        if (declaredLength > maxBytes) {
+            console.error(`[BODY_TOO_LARGE] Rejection via Content-Length: ${declaredLength} > ${maxBytes}`);
+            req.resume();
+            return reject(Object.assign(new Error('Request body too large'), { code: 'BODY_TOO_LARGE' }));
+        }
+
+        req.on('data', chunk => {
+            received += chunk.length;
+            if (received > maxBytes) {
+                req.destroy();
+                return reject(Object.assign(new Error('Request body too large'), { code: 'BODY_TOO_LARGE' }));
+            }
+            chunks.push(chunk);
+        });
+        req.on('end', () => resolve(Buffer.concat(chunks)));
+        req.on('error', reject);
+
+        if (req.isPaused()) req.resume();
+    });
+};