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src/util/cert.js

@@ -1,6 +1,7 @@
 import fs from 'fs';
 import path from 'path';
 import os from 'os';
+import { X509Certificate } from 'node:crypto';
 import selfsigned from 'selfsigned';
 import env from '../config/env.js';
 
@@ -69,3 +70,18 @@ export async function getOrCreateCert() {
         cert: pems.cert,
     };
 }
+
+/**
+ * Derives pairing metadata (fingerprints and serial number) from the TLS certificate.
+ * @returns {Promise<{ certificateFingerprint: string, certificateSerialNumber: string, serverFingerprint: string }>}
+ */
+export async function getCertMetadata() {
+    const { cert } = await getOrCreateCert();
+    const x509 = new X509Certificate(cert);
+    const sha1 = x509.fingerprint;
+    return {
+        certificateFingerprint: sha1.replace(/:/g, ''),
+        certificateSerialNumber: x509.serialNumber,
+        serverFingerprint: sha1.replace(/:/g, '-'),
+    };
+}