Merge pull request #27679 from overleaf/msm-aws-sdk-upgrade

Upgrade `aws-sdk` to v3

GitOrigin-RevId: 4989ae920d8b7fd9e79623947b7c40bcc2e56d92

libraries/object-persistor/src/S3Md5Middleware.js

@@ -0,0 +1,49 @@
+const Crypto = require('node:crypto')
+
+/**
+ * Creates an S3 client that uses MD5 checksums for DeleteObjects operations
+ * https://github.com/aws/aws-sdk-js-v3/blob/main/supplemental-docs/MD5_FALLBACK.md
+ */
+const md5Middleware = (next, context) => async args => {
+  if (context.commandName !== 'DeleteObjectsCommand') {
+    return next(args)
+  }
+
+  const headers = args.request.headers
+
+  // Remove any checksum headers added by default middleware
+  // This ensures our Content-MD5 is the primary integrity check
+  Object.keys(headers).forEach(header => {
+    const lowerHeader = header.toLowerCase()
+    if (
+      lowerHeader.startsWith('x-amz-checksum-') ||
+      lowerHeader.startsWith('x-amz-sdk-checksum-')
+    ) {
+      delete headers[header]
+    }
+  })
+
+  if (args.request.body) {
+    const bodyContent = Buffer.from(args.request.body)
+    headers['Content-MD5'] = Crypto.createHash('md5')
+      .update(bodyContent)
+      .digest('base64')
+  }
+
+  return await next(args)
+}
+
+function addMd5Middleware(client) {
+  // Add the middleware relative to the flexible checksums middleware
+  // This ensures it runs after default checksums might be added, but before signing
+  client.middlewareStack.add(md5Middleware, {
+    step: 'build',
+    toMiddleware: 'flexibleChecksumsMiddleware',
+    name: 'addMD5ChecksumForDeleteObjects',
+    tags: ['MD5_FALLBACK'],
+  })
+}
+
+module.exports = {
+  addMd5Middleware,
+}