generator share links; secure send copy message

plugins/tools/frontend/views/SecureSendCreate.vue

@@ -94,8 +94,30 @@
       </p>
       <div class="link-row">
         <input ref="linkInput" class="form-control mono" :value="link" readonly @focus="selectAll" />
-        <button class="btn btn-primary" @click="copyLink">{{ copied ? 'Copied' : 'Copy' }}</button>
+        <button class="btn btn-primary" @click="copyLink">{{ copied ? 'Copied' : 'Copy link' }}</button>
+        <!--
+          Copies a whole sentence, not the bare URL. Pasted into an EMPTY chat
+          box there is nothing selected for the link to attach itself to - which
+          is the failure this button exists to prevent. See copyMessage().
+        -->
+        <button class="btn btn-secondary" @click="copyMessage">
+          {{ messagecopied ? 'Copied' : 'Copy message' }}
+        </button>
       </div>
+
+      <!--
+        The warning that matters, stated where the mistake gets made. The hint
+        below is about the key being unrecoverable, which is a different point
+        and does not stop anybody pasting the password itself.
+      -->
+      <div class="alert-send">
+        <strong>Send the link, not the secret.</strong>
+        If the password is already typed in a chat box, delete it before pasting
+        this. Pasting a link over selected text turns that text into the link's
+        caption, and the secret then travels in the message itself - the link
+        beside it protects nothing.
+      </div>
+
       <p class="control-hint">
         This is the only time the link is shown - it is not stored anywhere you can
         look it up, and the key in it exists nowhere else.
@@ -142,6 +164,7 @@ const busy = ref(false)
 const error = ref('')
 const link = ref('')
 const copied = ref(false)
+const messagecopied = ref(false)
 const linkInput = ref(null)
 
 // Only nag once there is something to nag about: an empty box is not a mistake.
@@ -222,6 +245,35 @@ async function copyLink() {
   }
 }
 
+/**
+ * The link with a sentence around it.
+ *
+ * A bare URL invites being pasted onto text that is already in the chat box,
+ * and a chat client turns the selection into the link's caption - so the secret
+ * travels as the visible message and the link protects nothing. It has happened
+ * in production: six LAPS passwords sent as the caption of a link whose whole
+ * job was to keep them out of the chat.
+ *
+ * A sentence has nowhere to attach itself. Pasted into an empty box it is a
+ * message; pasted over a selection it replaces it rather than decorating it.
+ * Plain text on purpose - a rich-text flavour is what would let a secret ride
+ * along as markup.
+ */
+async function copyMessage() {
+  const opens = views.value === 1
+    ? 'It opens once and then destroys itself'
+    : `It opens ${views.value} times and then destroys itself`
+  const message =
+    `Secure link - ${opens}, and expires ${expiryLabel.value}: ${link.value}`
+  try {
+    await navigator.clipboard.writeText(message)
+    messagecopied.value = true
+    setTimeout(() => { messagecopied.value = false }, 2000)
+  } catch (err) {
+    selectAll()
+  }
+}
+
 function selectAll() {
   linkInput.value?.select()
 }
@@ -245,6 +297,17 @@ function reset() {
 .counter.over { color: var(--warning); font-weight: 600; }
 .control-note { color: var(--warning); font-size: 0.875rem; margin: 8px 0; }
 .control-hint { color: var(--text-light); font-size: 0.8125rem; margin: 8px 0 12px; }
+/* Loud enough to be read before the paste, quiet enough not to look like an
+   error on a page where nothing went wrong. */
+.alert-send {
+  border-left: 3px solid var(--warning);
+  background: var(--bg-card-solid);
+  padding: 0.6rem 0.9rem;
+  margin: 0.75rem 0;
+  font-size: 0.875rem;
+  line-height: 1.5;
+}
+.alert-send strong { display: block; margin-bottom: 2px; }
 .link-row { display: flex; gap: 8px; align-items: center; margin: 0.5rem 0; }
 .link-row .form-control { flex: 1; }
 .mono { font-family: 'SF Mono', 'Monaco', 'Consolas', monospace; font-size: 0.875rem; }