@uppy/companion: fix default getKey for non-standalone too (#3945)

And update docs.

examples/digitalocean-spaces/server.js

@@ -2,6 +2,8 @@ const fs = require('node:fs')
 const path = require('node:path')
 const budo = require('budo')
 const router = require('router')
+const crypto = require('node:crypto')
+
 const companion = require('../../packages/@uppy/companion')
 
 /**
@@ -32,7 +34,7 @@ const { app: companionApp } = companion.app({
     s3: {
       // This is the crucial part; set an endpoint template for the service you want to use.
       endpoint: 'https://{region}.digitaloceanspaces.com',
-      getKey: (req, filename) => `uploads/${filename}`,
+      getKey: (req, filename) => `${crypto.randomUUID()}-${filename}`,
 
       key: process.env.COMPANION_AWS_KEY,
       secret: process.env.COMPANION_AWS_SECRET,

packages/@uppy/companion/src/config/companion.js

@@ -2,6 +2,7 @@ const ms = require('ms')
 const fs = require('node:fs')
 const { isURL } = require('validator')
 const logger = require('../server/logger')
+const { defaultGetKey } = require('../server/helpers/utils')
 
 const defaultOptions = {
   server: {
@@ -13,7 +14,7 @@ const defaultOptions = {
     endpoint: 'https://{service}.{region}.amazonaws.com',
     conditions: [],
     useAccelerateEndpoint: false,
-    getKey: (req, filename) => filename,
+    getKey: defaultGetKey,
     expires: ms('5 minutes') / 1000,
   },
   allowLocalUrls: false,

packages/@uppy/companion/src/server/helpers/utils.js

@@ -164,3 +164,5 @@ module.exports.requestStream = async (req, convertResponseToError) => {
 
   return { stream: resp }
 }
+
+module.exports.defaultGetKey = (req, filename) => `${crypto.randomUUID()}-${filename}`

packages/@uppy/companion/src/standalone/helper.js

@@ -72,7 +72,7 @@ const getConfigFromEnv = () => {
     },
     s3: {
       key: process.env.COMPANION_AWS_KEY,
-      getKey: (req, filename) => `${crypto.randomUUID()}-${filename}`,
+      getKey: utils.defaultGetKey,
       secret: getSecret('COMPANION_AWS_SECRET'),
       bucket: process.env.COMPANION_AWS_BUCKET,
       endpoint: process.env.COMPANION_AWS_ENDPOINT,

website/src/docs/companion.md

@@ -326,7 +326,7 @@ const options = {
     },
   },
   s3: {
-    getKey: (req, filename, metadata) => filename,
+    getKey: (req, filename, metadata) => `${crypto.randomUUID()}-${filename}`,
     key: '***',
     secret: '***',
     bucket: 'bucket-name',
@@ -453,24 +453,26 @@ Get the key name for a file. The key is the file path to which the file will be
 * `filename`, the original name of the uploaded file;
 * `metadata`, user-provided metadata for the file. See the [`@uppy/aws-s3`](https://uppy.io/docs/aws-s3/#metaFields) docs. The `@uppy/aws-s3-multipart` plugin unconditionally sends all metadata fields, so they all are available here.
 
+If your bucket is public, you should include a cryptographically random token in the uploaded name for security (hence the default `crypto.randomUUID()`).
+
 This function should return a string `key`. The `req` parameter can be used to upload to a user-specific folder in your bucket, for example:
 
 ```js
 app.use(authenticationMiddleware)
 app.use(companion.app({
   s3: {
-    getKey: (req, filename, metadata) => `${req.user.id}/${filename}`,
+    getKey: (req, filename, metadata) => `${req.user.id}/${crypto.randomUUID()}-${filename}`,
     /* auth options */
   },
 }))
 ```
 
-The default implementation returns the `filename`, so all files will be uploaded to the root of the bucket as their original file name.
+The default implementation uploads all files to the root of the bucket as their original file name, prefixed with a random UUID.
 
 ```js
 app.use(companion.app({
   s3: {
-    getKey: (req, filename, metadata) => filename,
+    getKey: (req, filename, metadata) => `${crypto.randomUUID()}-${filename}`,
   },
 }))
 ```