#!/usr/bin/env python

"""
Copyright (c) 2006-2021 sqlmap developers (http://sqlmap.org/)
See the file 'LICENSE' for copying permission
"""

from lib.core.common import Backend
from lib.core.common import Format
from lib.core.convert import getUnicode
from lib.core.data import conf
from lib.core.data import kb
from lib.core.data import logger
from lib.core.enums import DBMS
from lib.core.enums import OS
from lib.core.session import setDbms
from lib.core.settings import MSSQL_ALIASES
from lib.request import inject
from plugins.generic.fingerprint import Fingerprint as GenericFingerprint

class Fingerprint(GenericFingerprint):
    def __init__(self):
        GenericFingerprint.__init__(self, DBMS.MSSQL)

    def getFingerprint(self):
        value = ""
        wsOsFp = Format.getOs("web server", kb.headersFp)

        if wsOsFp:
            value += "%s\n" % wsOsFp

        if kb.data.banner:
            dbmsOsFp = Format.getOs("back-end DBMS", kb.bannerFp)

            if dbmsOsFp:
                value += "%s\n" % dbmsOsFp

        value += "back-end DBMS: "
        actVer = Format.getDbms()

        if not conf.extensiveFp:
            value += actVer
            return value

        blank = " " * 15
        value += "active fingerprint: %s" % actVer

        if kb.bannerFp:
            release = kb.bannerFp.get("dbmsRelease")
            version = kb.bannerFp.get("dbmsVersion")
            servicepack = kb.bannerFp.get("dbmsServicePack")

            if release and version and servicepack:
                banVer = "%s %s " % (DBMS.MSSQL, release)
                banVer += "Service Pack %s " % servicepack
                banVer += "version %s" % version

                value += "\n%sbanner parsing fingerprint: %s" % (blank, banVer)

        htmlErrorFp = Format.getErrorParsedDBMSes()

        if htmlErrorFp:
            value += "\n%shtml error message fingerprint: %s" % (blank, htmlErrorFp)

        return value

    def checkDbms(self):
        if not conf.extensiveFp and Backend.isDbmsWithin(MSSQL_ALIASES):
            setDbms("%s %s" % (DBMS.MSSQL, Backend.getVersion()))

            self.getBanner()

            Backend.setOs(OS.WINDOWS)

            return True

        infoMsg = "testing %s" % DBMS.MSSQL
        logger.info(infoMsg)

        # NOTE: SELECT LEN(@@VERSION)=LEN(@@VERSION) FROM DUAL does not
        # work connecting directly to the Microsoft SQL Server database
        if conf.direct:
            result = True
        else:
            result = inject.checkBooleanExpression("UNICODE(SQUARE(NULL)) IS NULL")

        if result:
            infoMsg = "confirming %s" % DBMS.MSSQL
            logger.info(infoMsg)

            for version, check in (
                ("2019", "CHARINDEX('15.0.',@@VERSION)>0"),
                ("Azure", "@@VERSION LIKE '%Azure%'"),
                ("2017", "TRIM(NULL) IS NULL"),
                ("2016", "ISJSON(NULL) IS NULL"),
                ("2014", "CHARINDEX('12.0.',@@VERSION)>0"),
                ("2012", "CONCAT(NULL,NULL)=CONCAT(NULL,NULL)"),
                ("2008", "SYSDATETIME()=SYSDATETIME()"),
                ("2005", "XACT_STATE()=XACT_STATE()"),
                ("2000", "HOST_NAME()=HOST_NAME()"),
            ):
                result = inject.checkBooleanExpression(check)

                if result:
                    Backend.setVersion(version)
                    break

            if Backend.getVersion():
                setDbms("%s %s" % (DBMS.MSSQL, Backend.getVersion()))
            else:
                setDbms(DBMS.MSSQL)

            self.getBanner()

            Backend.setOs(OS.WINDOWS)

            return True
        else:
            warnMsg = "the back-end DBMS is not %s" % DBMS.MSSQL
            logger.warn(warnMsg)

            return False

    def checkDbmsOs(self, detailed=False):
        if Backend.getOs() and Backend.getOsVersion() and Backend.getOsServicePack():
            return

        if not Backend.getOs():
            Backend.setOs(OS.WINDOWS)

        if not detailed:
            return

        infoMsg = "fingerprinting the back-end DBMS operating system "
        infoMsg += "version and service pack"
        logger.info(infoMsg)

        infoMsg = "the back-end DBMS operating system is %s" % Backend.getOs()

        self.createSupportTbl(self.fileTblName, self.tblField, "varchar(1000)")
        inject.goStacked("INSERT INTO %s(%s) VALUES (%s)" % (self.fileTblName, self.tblField, "@@VERSION"))

        # Reference: https://en.wikipedia.org/wiki/Comparison_of_Microsoft_Windows_versions
        # https://en.wikipedia.org/wiki/Windows_NT#Releases
        versions = {
            "NT": ("4.0", (6, 5, 4, 3, 2, 1)),
            "2000": ("5.0", (4, 3, 2, 1)),
            "XP": ("5.1", (3, 2, 1)),
            "2003": ("5.2", (2, 1)),
            "Vista or 2008": ("6.0", (2, 1)),
            "7 or 2008 R2": ("6.1", (1, 0)),
            "8 or 2012": ("6.2", (0,)),
            "8.1 or 2012 R2": ("6.3", (0,)),
            "10 or 2016 or 2019": ("10.0", (0,))
        }

        # Get back-end DBMS underlying operating system version
        for version, data in versions.items():
            query = "EXISTS(SELECT %s FROM %s WHERE %s " % (self.tblField, self.fileTblName, self.tblField)
            query += "LIKE '%Windows NT " + data[0] + "%')"
            result = inject.checkBooleanExpression(query)

            if result:
                Backend.setOsVersion(version)
                infoMsg += " %s" % Backend.getOsVersion()
                break

        if not Backend.getOsVersion():
            Backend.setOsVersion("2003")
            Backend.setOsServicePack(2)

            warnMsg = "unable to fingerprint the underlying operating "
            warnMsg += "system version, assuming it is Windows "
            warnMsg += "%s Service Pack %d" % (Backend.getOsVersion(), Backend.getOsServicePack())
            logger.warn(warnMsg)

            self.cleanup(onlyFileTbl=True)

            return

        # Get back-end DBMS underlying operating system service pack
        sps = versions[Backend.getOsVersion()][1]
        for sp in sps:
            query = "EXISTS(SELECT %s FROM %s WHERE %s " % (self.tblField, self.fileTblName, self.tblField)
            query += "LIKE '%Service Pack " + getUnicode(sp) + "%')"
            result = inject.checkBooleanExpression(query)

            if result:
                Backend.setOsServicePack(sp)
                break

        if not Backend.getOsServicePack():
            debugMsg = "assuming the operating system has no service pack"
            logger.debug(debugMsg)

            Backend.setOsServicePack(0)

        if Backend.getOsVersion():
            infoMsg += " Service Pack %d" % Backend.getOsServicePack()

        logger.info(infoMsg)

        self.cleanup(onlyFileTbl=True)
