From 68354be45a5510058e57d5781b2a6f06ae7e99d5 Mon Sep 17 00:00:00 2001
From: Bernardo Damele <bernardo.damele@gmail.com>
Date: Thu, 18 Dec 2008 22:49:35 +0000
Subject: [PATCH] Ahead with enhancements on comparison algorithm: implemented
 content-length technique

---
 lib/controller/checks.py     | 17 +++++++++++------
 lib/controller/controller.py |  5 +----
 lib/request/comparison.py    |  6 +++++-
 3 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/lib/controller/checks.py b/lib/controller/checks.py
index 6e2b98d48..597b3a6b3 100644
--- a/lib/controller/checks.py
+++ b/lib/controller/checks.py
@@ -320,15 +320,16 @@ def checkStability():
                 contentLengths.append(int(clHeader.group(1)))
 
         if contentLengths:
-            clSum = 0
+            conf.contentLengths = ( min(contentLengths), max(contentLengths) )
 
-            for cl in contentLengths:
-                clSum += cl
+            warnMsg  = "url is not stable, sqlmap inspected the headers "
+            warnMsg += "and identified that Content-Length can be used "
+            warnMsg += "in the comparison algorithm"
+            logger.warn(warnMsg)
 
-            clAverage = clSum / len(contentLengths)
+            kb.defaultResult = True
 
-        # TODO: go ahead here with the technique to compare True/False
-        # based upon clAverage discard (conf.contentLengths)
+            return True
 
         # Prepare for the comparison algorithm based on page content's
         # stable lines subset
@@ -356,6 +357,10 @@ def checkStability():
 
             return True
 
+    if condition == True:
+        logMsg = "url is stable"
+        logger.info(logMsg)
+
     return condition
 
 
diff --git a/lib/controller/controller.py b/lib/controller/controller.py
index b734b9d66..f53b67ea2 100644
--- a/lib/controller/controller.py
+++ b/lib/controller/controller.py
@@ -175,10 +175,7 @@ def start():
 
         if not kb.injPlace or not kb.injParameter or not kb.injType:
             if not conf.string and not conf.regexp and not conf.eRegexp:
-                if checkStability():
-                    logMsg = "url is stable"
-                    logger.info(logMsg)
-                else:
+                if not checkStability():
                     errMsg  = "url is not stable, try with --string or "
                     errMsg += "--regexp options, refer to the user's manual "
                     errMsg += "paragraph 'Page comparison' for details"
diff --git a/lib/request/comparison.py b/lib/request/comparison.py
index 3c7ad6847..dc60e66c3 100644
--- a/lib/request/comparison.py
+++ b/lib/request/comparison.py
@@ -75,7 +75,11 @@ def comparison(page, headers=None, content=False):
 
     # Comparison algorithm based on Content-Length header value
     elif conf.contentLengths:
-        pass
+        minValue = conf.contentLengths[0] - 10
+        maxValue = conf.contentLengths[1] + 10
+
+        if len(page) >= minValue and len(page) <= maxValue:
+            return True
 
     # Comparison algorithm based on page content's stable lines subset
     elif conf.equalLines: