05/18 Enhanced codes and functionalities 4

app/static/js/sharing.js

@@ -151,6 +151,38 @@ const SharingCrypto = (() => {
     return JSON.parse(new TextDecoder().decode(plaintext));
   }
 
+  /**
+   * Encrypt a display name string with the ECDH shared key.
+   * Uses the same AES-256-GCM primitive as encryptForShare but operates on
+   * a plain string rather than a JSON-serialised object.
+   */
+  async function encryptName(sharedKey, name) {
+    const iv = window.crypto.getRandomValues(new Uint8Array(12));
+    const plaintext = new TextEncoder().encode(name);
+    const ciphertext = await subtle.encrypt({ name: 'AES-GCM', iv }, sharedKey, plaintext);
+    return {
+      enc_name: bytesToBase64(new Uint8Array(ciphertext)),
+      iv_name: bytesToBase64(iv),
+    };
+  }
+
+  /**
+   * Decrypt an encrypted display name.
+   * Returns null on failure (e.g. legacy share with no enc_name).
+   */
+  async function decryptName(sharedKey, enc_name, iv_name) {
+    try {
+      const plaintext = await subtle.decrypt(
+        { name: 'AES-GCM', iv: base64ToBytes(iv_name) },
+        sharedKey,
+        base64ToBytes(enc_name),
+      );
+      return new TextDecoder().decode(plaintext);
+    } catch {
+      return null;
+    }
+  }
+
   // ── Public API ────────────────────────────────────────────────────────────
 
   return {
@@ -162,6 +194,8 @@ const SharingCrypto = (() => {
     deriveSharedKey,
     encryptForShare,
     decryptShare,
+    encryptName,
+    decryptName,
   };
 })();
 

app/static/js/vault.js

@@ -1413,7 +1413,15 @@ const Vault = (() => {
         ${
           !s.accepted
             ? `<button class="btn-primary btn-sm" data-accept="${s.id}">Accept</button>`
-            : `<button class="btn-secondary btn-sm" data-view-share="${s.id}" data-owner-key="${escHtml(s.owner_public_key || "")}" data-enc="${escHtml(s.enc_data)}" data-iv="${escHtml(s.iv)}" data-name="${escHtml(s.item_name)}" data-type="${escHtml(s.item_type || "")}">View</button>`
+            : `<button class="btn-secondary btn-sm"
+                data-view-share="${s.id}"
+                data-owner-key="${escHtml(s.owner_public_key || "")}"
+                data-enc="${escHtml(s.enc_data)}"
+                data-iv="${escHtml(s.iv)}"
+                data-enc-name="${escHtml(s.enc_name || "")}"
+                data-iv-name="${escHtml(s.iv_name || "")}"
+                data-name="${escHtml(s.item_name)}"
+                data-type="${escHtml(s.item_type || "")}">View</button>`
         }
       </li>`,
       )
@@ -1452,7 +1460,18 @@ const Vault = (() => {
             btn.dataset.enc,
             btn.dataset.iv,
           );
-          showSharedItemDetails(btn.dataset.name, btn.dataset.type, plain);
+          // Decrypt the item name if an encrypted version is available.
+          // Falls back to the non-sensitive label for legacy shares.
+          let displayName = btn.dataset.name;
+          if (btn.dataset.encName && btn.dataset.ivName) {
+            const decrypted = await SharingCrypto.decryptName(
+              sharedKey,
+              btn.dataset.encName,
+              btn.dataset.ivName,
+            );
+            if (decrypted) displayName = decrypted;
+          }
+          showSharedItemDetails(displayName, btn.dataset.type, plain);
         } catch (err) {
           showToast("Could not decrypt: " + err.message, "error");
         }
@@ -1564,6 +1583,14 @@ const Vault = (() => {
         item.plain,
       );
 
+      // Encrypt the display name with the same ECDH shared key so the server
+      // never sees the plaintext name. item_name is set to item_type as a
+      // non-sensitive fallback label for legacy-compat (server requires the field).
+      const { enc_name, iv_name } = await SharingCrypto.encryptName(
+        sharedKey,
+        item.name,
+      );
+
       const res = await apiFetch("/api/sharing", {
         method: "POST",
         body: JSON.stringify({
@@ -1571,8 +1598,10 @@ const Vault = (() => {
           recipient_email: recipientEmail,
           enc_data,
           iv,
-          item_name: item.name,
+          item_name: item.item_type,  // non-sensitive label; real name is in enc_name
           item_type: item.item_type,
+          enc_name,
+          iv_name,
         }),
       });
       if (!res) return;
@@ -4016,4 +4045,4 @@ const Vault = (() => {
   }
 })();
 
-document.addEventListener("DOMContentLoaded", Vault.init);
+document.addEventListener("DOMContentLoaded", Vault.init);