Added pin numbers for library meetups.

app/index.js

@@ -19,6 +19,66 @@ $(document).ready(function () {
       window.open( url, target );
     }
   });
+
+  $('.unlock-pin').click(async function() {
+    const btn = $(this);
+    const pinDisplay = btn.siblings('.pin-display');
+    const ciphertext = btn.data('ciphertext');
+    const iv = btn.data('iv');
+    const salt = btn.data('salt');
+    const tag = btn.data('tag');
+
+    const password = prompt("Enter the members password to unlock the PIN:");
+    if (!password) return;
+
+    try {
+      const decrypted = await decryptPin(ciphertext, iv, salt, tag, password);
+      pinDisplay.val(decrypted);
+      btn.text('Copy').removeClass('unlock-pin').attr('action', 'copy').attr('value', decrypted);
+      // Re-bind the click event for the new copy action (or use delegation)
+      btn.off('click').click(function() {
+        navigator.clipboard.writeText($(this).attr('value'));
+        alert('PIN copied to clipboard!');
+      });
+    } catch (e) {
+      alert(e.message);
+    }
+  });
+
+  async function decryptPin(ciphertextBase64, ivBase64, saltBase64, tagBase64, password) {
+    const encoder = new TextEncoder();
+    const passwordKey = await crypto.subtle.importKey(
+      "raw", encoder.encode(password), "PBKDF2", false, ["deriveKey"]
+    );
+    const salt = Uint8Array.from(atob(saltBase64), c => c.charCodeAt(0));
+    const iv = Uint8Array.from(atob(ivBase64), c => c.charCodeAt(0));
+    const tag = Uint8Array.from(atob(tagBase64), c => c.charCodeAt(0));
+    const ciphertext = Uint8Array.from(atob(ciphertextBase64), c => c.charCodeAt(0));
+    
+    const data = new Uint8Array(ciphertext.length + tag.length);
+    data.set(ciphertext);
+    data.set(tag, ciphertext.length);
+
+    const key = await crypto.subtle.deriveKey(
+      { name: "PBKDF2", salt, iterations: 100000, hash: "SHA-256" },
+      passwordKey,
+      { name: "AES-GCM", length: 256 },
+      false,
+      ["decrypt"]
+    );
+
+    try {
+      const decrypted = await crypto.subtle.decrypt(
+        { name: "AES-GCM", iv, tagLength: 128 },
+        key,
+        data
+      );
+      return new TextDecoder().decode(decrypted);
+    } catch (e) {
+      throw new Error("Decryption failed. Probably wrong password.");
+    }
+  }
+
   var isPhone = /Mobi|Android|iPhone|iPod/i.test(navigator.userAgent) || window.innerWidth <= 768;
   if (isPhone) {
     $("body").addClass("phone");