improved security

common.php

@@ -153,6 +153,10 @@ function hkdf_session_key_from_token(string $tokenHex, string $info = 'qdb-aes',
 
 // --- Token-Storage (DB-backed via session table) ---
 
+function token_storage_key(string $token): string {
+    return hash('sha256', $token);
+}
+
 function token_add(string $token, int $ttlSeconds = 86400, array $extra = []): void {
     require_once __DIR__ . '/db_init.php';
     [$pdo, $tmpDb, $lockFp] = qdb_open(true);
@@ -161,7 +165,7 @@ function token_add(string $token, int $ttlSeconds = 86400, array $extra = []): v
         "INSERT INTO session (token, userID, role, entityID, createdAt, expiresAt, temp)
          VALUES (:t, :uid, :role, :eid, :ca, :ea, :tmp)"
     )->execute([
-        ':t'    => $token,
+        ':t'    => token_storage_key($token),
         ':uid'  => $extra['userID']   ?? '',
         ':role' => $extra['role']     ?? '',
         ':eid'  => $extra['entityID'] ?? '',
@@ -178,7 +182,7 @@ function token_get_record(string $token): ?array {
     require_once __DIR__ . '/db_init.php';
     [$pdo, $tmpDb, $lockFp] = qdb_open(false);
     $stmt = $pdo->prepare("SELECT * FROM session WHERE token = :t AND expiresAt >= :now");
-    $stmt->execute([':t' => $token, ':now' => time()]);
+    $stmt->execute([':t' => token_storage_key($token), ':now' => time()]);
     $row = $stmt->fetch(PDO::FETCH_ASSOC);
     qdb_discard($tmpDb, $lockFp);
     if (!$row) return null;
@@ -197,7 +201,7 @@ function token_get_record(string $token): ?array {
 function token_revoke(string $token): void {
     require_once __DIR__ . '/db_init.php';
     [$pdo, $tmpDb, $lockFp] = qdb_open(true);
-    $pdo->prepare("DELETE FROM session WHERE token = :t")->execute([':t' => $token]);
+    $pdo->prepare("DELETE FROM session WHERE token = :t")->execute([':t' => token_storage_key($token)]);
     qdb_save($tmpDb, $lockFp);
 }
 

lib/encrypted_payload.php

@@ -1,14 +1,16 @@
 <?php
 /**
  * Application-layer encryption for sensitive mobile API payloads.
- * AES-256-CBC (IV prepended) + HKDF-SHA256 session key from the Bearer token (info: qdb-aes).
+ * AES-256-GCM (IV prepended) + HKDF-SHA256 session key from the Bearer token (info: qdb-aes).
+ * Legacy CBC envelopes are accepted for compatibility with older app builds.
  */
 
 function qdb_sensitive_envelope(string $plainJson, string $tokenHex): array {
     $key = hkdf_session_key_from_token($tokenHex);
     return [
         'encrypted' => true,
-        'payload'   => base64_encode(aes256_cbc_encrypt_bytes($plainJson, $key)),
+        'alg'       => 'A256GCM',
+        'payload'   => base64_encode(qdb_aes256_gcm_encrypt_bytes($plainJson, $key)),
     ];
 }
 
@@ -21,5 +23,38 @@ function qdb_decrypt_sensitive_envelope(array $envelope, string $tokenHex): stri
         throw new InvalidArgumentException('Invalid base64 payload');
     }
     $key = hkdf_session_key_from_token($tokenHex);
-    return aes256_cbc_decrypt_bytes($raw, $key);
+    $alg = isset($envelope['alg']) && is_string($envelope['alg']) ? $envelope['alg'] : 'A256CBC';
+    return match ($alg) {
+        'A256GCM' => qdb_aes256_gcm_decrypt_bytes($raw, $key),
+        'A256CBC' => aes256_cbc_decrypt_bytes($raw, $key),
+        default => throw new InvalidArgumentException('Unsupported encrypted envelope algorithm'),
+    };
+}
+
+function qdb_aes256_gcm_encrypt_bytes(string $plain, string $key): string {
+    $key = str_pad(substr($key, 0, 32), 32, "\0");
+    $iv = random_bytes(12);
+    $tag = '';
+    $cipher = openssl_encrypt($plain, 'aes-256-gcm', $key, OPENSSL_RAW_DATA, $iv, $tag, '');
+    if ($cipher === false || strlen($tag) !== 16) {
+        throw new RuntimeException('openssl_encrypt failed');
+    }
+    return $iv . $cipher . $tag;
+}
+
+function qdb_aes256_gcm_decrypt_bytes(string $data, string $key): string {
+    $ivLen = 12;
+    $tagLen = 16;
+    if (strlen($data) <= $ivLen + $tagLen) {
+        throw new InvalidArgumentException('cipher too short');
+    }
+    $key = str_pad(substr($key, 0, 32), 32, "\0");
+    $iv = substr($data, 0, $ivLen);
+    $tag = substr($data, -$tagLen);
+    $ct = substr($data, $ivLen, -$tagLen);
+    $plain = openssl_decrypt($ct, 'aes-256-gcm', $key, OPENSSL_RAW_DATA, $iv, $tag, '');
+    if ($plain === false) {
+        throw new InvalidArgumentException('openssl_decrypt failed');
+    }
+    return $plain;
 }

tests/Integration/SecurityPathsTest.php

@@ -18,7 +18,7 @@ final class SecurityPathsTest extends QdbTestCase
             'INSERT INTO session (token, userID, role, entityID, createdAt, expiresAt, temp)
              VALUES (:t, :uid, :role, :eid, :ca, :ea, 0)'
         )->execute([
-            ':t'    => $token,
+            ':t'    => token_storage_key($token),
             ':uid'  => $f->adminUserId,
             ':role' => 'admin',
             ':eid'  => 'ent',

tests/Integration/TokenTest.php

@@ -20,6 +20,11 @@ final class TokenTest extends QdbTestCase
         $rec = token_get_record($token);
         $this->assertNotNull($rec);
         $this->assertSame('admin', $rec['role']);
+        [$pdo, $tmpDb, $lockFp] = qdb_open(false);
+        $stored = $pdo->query('SELECT token FROM session LIMIT 1')->fetchColumn();
+        qdb_discard($tmpDb, $lockFp);
+        $this->assertSame(token_storage_key($token), $stored);
+        $this->assertNotSame($token, $stored);
 
         token_revoke($token);
         $this->assertNull(token_get_record($token));

tests/Unit/EncryptedPayloadTest.php

@@ -16,10 +16,24 @@ final class EncryptedPayloadTest extends TestCase
         $json = '{"clientCode":"X","answers":[]}';
         $env = qdb_sensitive_envelope($json, $token);
         $this->assertTrue($env['encrypted']);
+        $this->assertSame('A256GCM', $env['alg']);
         $plain = qdb_decrypt_sensitive_envelope($env, $token);
         $this->assertSame($json, $plain);
     }
 
+    public function testLegacyCbcEnvelopeStillDecrypts(): void
+    {
+        require_once dirname(__DIR__, 2) . '/lib/encrypted_payload.php';
+        $token = bin2hex(random_bytes(32));
+        $json = '{"legacy":true}';
+        $key = hkdf_session_key_from_token($token);
+        $env = [
+            'encrypted' => true,
+            'payload' => base64_encode(aes256_cbc_encrypt_bytes($json, $key)),
+        ];
+        $this->assertSame($json, qdb_decrypt_sensitive_envelope($env, $token));
+    }
+
     public function testWrongTokenFailsDecrypt(): void
     {
         require_once dirname(__DIR__, 2) . '/lib/encrypted_payload.php';