chat drin

relay/inc/bootstrap.php

@@ -164,6 +164,23 @@ $db->exec('CREATE TABLE IF NOT EXISTS attachments (
     FOREIGN KEY (recipient_id) REFERENCES tenants(id) ON DELETE CASCADE
 )');
 
+// Chat: separate from `messages` so chat traffic doesnt land in card inboxes.
+// Same decrypt-reencrypt hop as messages: arrives encrypted with senders
+// secret, stored at-rest under the inter-tenant key, returned re-encrypted
+// with the recipients secret.
+$db->exec('CREATE TABLE IF NOT EXISTS chat_messages (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    recipient_id INTEGER NOT NULL,
+    sender_id INTEGER,
+    sender_username TEXT,
+    body TEXT NOT NULL,
+    fetched INTEGER NOT NULL DEFAULT 0,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (recipient_id) REFERENCES tenants(id) ON DELETE CASCADE,
+    FOREIGN KEY (sender_id) REFERENCES tenants(id) ON DELETE SET NULL
+)');
+$db->exec('CREATE INDEX IF NOT EXISTS idx_chat_recipient ON chat_messages(recipient_id, fetched, id)');
+
 $db->exec('CREATE TABLE IF NOT EXISTS sessions (
     id TEXT PRIMARY KEY,
     tenant_id INTEGER NOT NULL,
@@ -181,6 +198,8 @@ $db->exec('CREATE TABLE IF NOT EXISTS rate_limits (
 // Cleanup: 24h ephemeral storage, expired sessions, old rate limits
 $db->exec("DELETE FROM messages WHERE created_at < datetime('now', '-24 hours')");
 $db->exec("DELETE FROM attachments WHERE created_at < datetime('now', '-24 hours')");
+// Chat: 7 days, longer than card sync but still ephemeral
+$db->exec("DELETE FROM chat_messages WHERE created_at < datetime('now', '-7 days')");
 $db->exec("DELETE FROM sessions WHERE expires_at < datetime('now')");
 $db->exec("DELETE FROM rate_limits WHERE attempted_at < datetime('now', '-5 minutes')");
 

relay/inc/routes/chat.php

@@ -0,0 +1,82 @@
+<?php
+// Chat routes (client API only):
+//   POST /api/chat       — send a chat message to {recipient}
+//   GET  /api/chat?since=N — pull all chat messages addressed to me with id > N
+//
+// Same decrypt-reencrypt hop as messages.php: arrives encrypted with the
+// senders client secret, stored at-rest under the inter-tenant key, returned
+// re-encrypted with the recipients client secret. Relay sees plaintext only
+// during the routing hop.
+
+if (!defined('RELAY_BOOTSTRAPPED')) { http_response_code(404); exit; }
+
+// $clientTenant is set by messages.php earlier in the chain via authClient().
+// We re-resolve here to keep this file self-contained.
+$clientTenant = $clientTenant ?? authClient($db);
+
+if ($route === '/api/chat' && $method === 'POST') {
+    if (!$clientTenant) jsonResponse(['error' => 'unauthorized'], 401);
+    $input = json_decode(file_get_contents('php://input'), true) ?: [];
+    $encryptedBody = (string)($input['body'] ?? '');
+    $recipientName = trim((string)($input['recipient'] ?? ''));
+    if ($encryptedBody === '') jsonResponse(['error' => 'body required'], 400);
+    if ($recipientName === '') jsonResponse(['error' => 'recipient required'], 400);
+
+    $recipient = getTenantByUsername($db, $recipientName);
+    if (!$recipient) jsonResponse(['error' => "no such user: $recipientName"], 404);
+
+    if (empty($clientTenant['secret_encrypted'])) {
+        jsonResponse(['error' => 'sender has no client secret set — log into the relay UI and configure one in your account'], 400);
+    }
+    $senderSecret = masterDecrypt($clientTenant['secret_encrypted'], $MASTER_KEY);
+    if (!$senderSecret) jsonResponse(['error' => 'sender secret unavailable'], 500);
+    $interKey = getInterTenantKey($db, $MASTER_KEY);
+    if (!$interKey) jsonResponse(['error' => 'relay super-shared key not set — admin must complete setup'], 500);
+
+    $plain = clientDecrypt($encryptedBody, $senderSecret);
+    if ($plain === '') jsonResponse(['error' => 'body decrypt failed (sender secret mismatch?)'], 400);
+    $stored = clientEncrypt($plain, $interKey);
+
+    $db->prepare('INSERT INTO chat_messages (recipient_id, sender_id, sender_username, body) VALUES (:r, :s, :sn, :b)')
+        ->execute([
+            'r' => $recipient['id'],
+            's' => $clientTenant['id'],
+            'sn' => $clientTenant['username'],
+            'b' => $stored,
+        ]);
+    jsonResponse(['ok' => true, 'id' => (int)$db->lastInsertId()]);
+}
+
+if ($route === '/api/chat' && $method === 'GET') {
+    if (!$clientTenant) jsonResponse(['error' => 'unauthorized'], 401);
+    if (empty($clientTenant['secret_encrypted'])) {
+        jsonResponse(['error' => 'no client secret set — log into the relay UI and configure one in your account'], 400);
+    }
+
+    $since = (int)($_GET['since'] ?? 0);
+    $stmt = $db->prepare('SELECT id, sender_username, body, created_at FROM chat_messages WHERE recipient_id = :r AND id > :s ORDER BY id ASC LIMIT 500');
+    $stmt->execute(['r' => $clientTenant['id'], 's' => $since]);
+    $rows = $stmt->fetchAll();
+
+    $interKey = getInterTenantKey($db, $MASTER_KEY);
+    if (!$interKey) jsonResponse(['error' => 'relay super-shared key not set'], 500);
+    $recipientSecret = masterDecrypt($clientTenant['secret_encrypted'], $MASTER_KEY);
+    if (!$recipientSecret) jsonResponse(['error' => 'recipient secret unavailable'], 500);
+
+    $out = [];
+    $maxId = $since;
+    foreach ($rows as $row) {
+        $plain = clientDecrypt($row['body'] ?? '', $interKey);
+        $row['body'] = clientEncrypt($plain, $recipientSecret);
+        $out[] = $row;
+        if ((int)$row['id'] > $maxId) $maxId = (int)$row['id'];
+    }
+    // Mark fetched so cleanup can prune them sooner if desired. We still
+    // keep them around for the 7-day window so a re-poll with since=0
+    // backfills history if a client wipes its local cache.
+    if ($out) {
+        $db->prepare('UPDATE chat_messages SET fetched = 1 WHERE recipient_id = :r AND id <= :m AND fetched = 0')
+            ->execute(['r' => $clientTenant['id'], 'm' => $maxId]);
+    }
+    jsonResponse(['messages' => $out, 'max_id' => $maxId]);
+}

relay/index.php

@@ -61,6 +61,7 @@ if (str_starts_with($route, '/api/')) {
     require __DIR__ . '/inc/routes/account.php';
     require __DIR__ . '/inc/routes/admin.php';
     require __DIR__ . '/inc/routes/messages.php';
+    require __DIR__ . '/inc/routes/chat.php';
 
     jsonResponse(['error' => 'not found'], 404);
 }