1 files changed, 52 insertions, 0 deletions
diff --git a/vnext/server/middleware/webfinger.js b/vnext/server/middleware/webfinger.js
new file mode 100644
index 00000000..9800fc01
--- /dev/null
+++ b/vnext/server/middleware/webfinger.js
@@ -0,0 +1,52 @@
+import config from 'config'
+import addrparser from 'address-rfc2822'
+
+import { getUserByName } from '../db/Users'
+
+const baseUrl = config.get('service.baseURL')
+
+/**
+ * WebFinger endpoint
+ * @type {import('express').RequestParamHandler}
+ */
+export const webfinger = async (req, res) => {
+    const resource = req.query.resource
+    if (resource) {
+        const acct = resource.substring(5) // drop "acct:"
+        const addresses = parseAddress(acct)
+        if (addresses && addresses.length == 1) {
+            const address = addresses[0]
+            const ourAddress = new URL(baseUrl)
+            if (address.host() === ourAddress.hostname) {
+                const user = await getUserByName(addresses[0].user())
+                if (user) {
+                    return res.json({
+                        subject: resource,
+                        links: [
+                            {
+                                rel: 'self',
+                                type: 'application/activity+json',
+                                href: `${baseUrl}/u/${user.nick}`
+                            }
+                        ]
+                    })
+                } else {
+                    return res.status(404).send('User not found')
+                }
+            } else {
+                return res.status(404).send('Address not found')
+            }
+        } else {
+            return res.status(400).send('Invalid resource')
+        }
+    }
+    res.status(400).send('Missing `resource` param')
+}
+
+const parseAddress = (address = '') => {
+    try {
+        return addrparser.parse(address, { startAt: 'address' })
+    } catch {
+        return undefined
+    }
+}