From e64cc86fc4c9a28893733f4cfb6cee0e865055db Mon Sep 17 00:00:00 2001
From: Miroslav Stampar <miroslav.stampar@gmail.com>
Date: Mon, 25 Mar 2019 11:42:16 +0100
Subject: [PATCH] Patch related to the #3524

---
 lib/controller/checks.py | 59 ++++++++++++++++++++++++----------------
 lib/core/enums.py        |  1 +
 lib/core/settings.py     |  2 +-
 3 files changed, 37 insertions(+), 25 deletions(-)

diff --git a/lib/controller/checks.py b/lib/controller/checks.py
index 3f299bfdb..2ba006e19 100644
--- a/lib/controller/checks.py
+++ b/lib/controller/checks.py
@@ -1507,44 +1507,55 @@ def checkNullConnection():
     if conf.data:
         return False
 
-    infoMsg = "testing NULL connection to the target URL"
-    logger.info(infoMsg)
+    _ = hashDBRetrieve(HASHDB_KEYS.CHECK_NULL_CONNECTION_RESULT, True)
+    if _ is not None:
+        kb.nullConnection = _
 
-    pushValue(kb.pageCompress)
-    kb.pageCompress = False
+        if _:
+            dbgMsg = "resuming NULL connection method '%s'" % _
+            logger.debug(dbgMsg)
 
-    try:
-        page, headers, _ = Request.getPage(method=HTTPMETHOD.HEAD, raise404=False)
+    else:
+        infoMsg = "testing NULL connection to the target URL"
+        logger.info(infoMsg)
 
-        if not page and HTTP_HEADER.CONTENT_LENGTH in (headers or {}):
-            kb.nullConnection = NULLCONNECTION.HEAD
+        pushValue(kb.pageCompress)
+        kb.pageCompress = False
 
-            infoMsg = "NULL connection is supported with HEAD method ('Content-Length')"
-            logger.info(infoMsg)
-        else:
-            page, headers, _ = Request.getPage(auxHeaders={HTTP_HEADER.RANGE: "bytes=-1"})
+        try:
+            page, headers, _ = Request.getPage(method=HTTPMETHOD.HEAD, raise404=False)
 
-            if page and len(page) == 1 and HTTP_HEADER.CONTENT_RANGE in (headers or {}):
-                kb.nullConnection = NULLCONNECTION.RANGE
+            if not page and HTTP_HEADER.CONTENT_LENGTH in (headers or {}):
+                kb.nullConnection = NULLCONNECTION.HEAD
 
-                infoMsg = "NULL connection is supported with GET method ('Range')"
+                infoMsg = "NULL connection is supported with HEAD method ('Content-Length')"
                 logger.info(infoMsg)
             else:
-                _, headers, _ = Request.getPage(skipRead=True)
+                page, headers, _ = Request.getPage(auxHeaders={HTTP_HEADER.RANGE: "bytes=-1"})
 
-                if HTTP_HEADER.CONTENT_LENGTH in (headers or {}):
-                    kb.nullConnection = NULLCONNECTION.SKIP_READ
+                if page and len(page) == 1 and HTTP_HEADER.CONTENT_RANGE in (headers or {}):
+                    kb.nullConnection = NULLCONNECTION.RANGE
 
-                    infoMsg = "NULL connection is supported with 'skip-read' method"
+                    infoMsg = "NULL connection is supported with GET method ('Range')"
                     logger.info(infoMsg)
+                else:
+                    _, headers, _ = Request.getPage(skipRead=True)
 
-    except SqlmapConnectionException:
-        pass
+                    if HTTP_HEADER.CONTENT_LENGTH in (headers or {}):
+                        kb.nullConnection = NULLCONNECTION.SKIP_READ
 
-    finally:
-        kb.pageCompress = popValue()
+                        infoMsg = "NULL connection is supported with 'skip-read' method"
+                        logger.info(infoMsg)
 
-    return kb.nullConnection is not None
+        except SqlmapConnectionException:
+            pass
+
+        finally:
+            kb.pageCompress = popValue()
+            kb.nullConnection = False if kb.nullConnection is None else kb.nullConnection
+            hashDBWrite(HASHDB_KEYS.CHECK_NULL_CONNECTION_RESULT, kb.nullConnection, True)
+
+    return kb.nullConnection in getPublicTypeMembers(NULLCONNECTION, True)
 
 def checkConnection(suppressOutput=False):
     threadData = getCurrentThreadData()
diff --git a/lib/core/enums.py b/lib/core/enums.py
index a050e8b01..18510404c 100644
--- a/lib/core/enums.py
+++ b/lib/core/enums.py
@@ -231,6 +231,7 @@ class HASHDB_KEYS:
     DBMS = "DBMS"
     DBMS_FORK = "DBMS_FORK"
     CHECK_WAF_RESULT = "CHECK_WAF_RESULT"
+    CHECK_NULL_CONNECTION_RESULT = "CHECK_NULL_CONNECTION_RESULT"
     CONF_TMP_PATH = "CONF_TMP_PATH"
     KB_ABS_FILE_PATHS = "KB_ABS_FILE_PATHS"
     KB_BRUTE_COLUMNS = "KB_BRUTE_COLUMNS"
diff --git a/lib/core/settings.py b/lib/core/settings.py
index be5ccca1a..0b0d990ee 100644
--- a/lib/core/settings.py
+++ b/lib/core/settings.py
@@ -19,7 +19,7 @@ from lib.core.enums import DBMS_DIRECTORY_NAME
 from lib.core.enums import OS
 
 # sqlmap version (<major>.<minor>.<month>.<monthly commit>)
-VERSION = "1.3.3.46"
+VERSION = "1.3.3.47"
 TYPE = "dev" if VERSION.count('.') > 2 and VERSION.split('.')[-1] != '0' else "stable"
 TYPE_COLORS = {"dev": 33, "stable": 90, "pip": 34}
 VERSION_STRING = "sqlmap/%s#%s" % ('.'.join(VERSION.split('.')[:-1]) if VERSION.count('.') > 2 and VERSION.split('.')[-1] == '0' else VERSION, TYPE)