'''
baseAttackPlugin.py

Copyright 2006 Andres Riancho

This file is part of w3af, w3af.sourceforge.net .

w3af is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation version 2 of the License.

w3af is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with w3af; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

'''

from core.controllers.w3afException import w3afException
from core.controllers.basePlugin.basePlugin import basePlugin
import core.controllers.outputManager as om
import core.data.request.httpPostDataRequest as httpPostDataRequest
import copy

class baseAttackPlugin(basePlugin):
	'''
	This is the base class for attack plugins, all attack plugins should inherit from it 
	and implement the following methods :
		1. fastExploit(...)
		2. exploit(...)
		3. canExploit(...)
		
	@author: Andres Riancho ( andres.riancho@gmail.com )
	'''

	def __init__(self):
		basePlugin.__init__( self )
		self._urlOpener = None
		self._footer = None
		self._header = None

	def fastExploit(self, url ):
		'''
		'''
		raise w3afException('Plugin is not implementing required method fastExploit' )

	def exploit(self, url ):
		'''
		Exploits a vulnerability found by an audit plugin.
		@return: True when the exploit finishes.
		'''
		raise w3afException('Plugin is not implementing required method exploit' )

	def canExploit(self):
		'''
		Determines if audit plugins found exploitable vulns.
		@return: True if we can exploit a vuln stored in the kb.
		'''
		raise w3afException('Plugin is not implementing required method canExploit' )

	def getType(self):
		'''
		Returns the type of exploit, SHELL, PROXY, etc.
		'''
		raise w3afException('Plugin is not implementing required method getType' )
		
	def _defineCut( self, body, expectedResult, exact=True ):
		'''
		Defines the section where the result of an attack will be.
		For example, when doing a local File Include attack, the included file could
		be in the middle of some HTML text, so a regex is created to cut the important
		part out of a simple html.
		
		@return: True if the cut could be defined
		'''
		if body.count( expectedResult ):
			headerEnd = body.find( expectedResult )
			if exact:
				footerStart = headerEnd + len( expectedResult )
				if footerStart == len( body ):
					footerStart = -1
			else:
				footerStart = body.find( '<', headerEnd )
			self._header = body[:headerEnd]
			
			if footerStart == -1:
				self._footer = 'EOBody'
			else:
				self._footer = body[footerStart:len(body)]
			
			return True
		else:
			return False
	
	def _cut( self, body ):
		'''
		After defining a cut, I can cut parts of an HTML and return the important
		sections.
		'''
		if self._footer != 'EOBody':
			if body.rfind(self._footer) == -1:
				raise w3afException('An error ocurred. The command result footer wasnt found.')
			else:
				result = body[ len(self._header) : body.rfind(self._footer) ]
				return result
		else:
				result = body[ len(self._header) : ]
				return result
	
	def GET2POST( self, vuln ):
		'''
		This method changes a vulnerability mutant, so all the data that was sent in the query string,
		is now sent in the postData; of course, the HTTP method is also changed from GET to POST.
		'''
		vulnCopy = copy.deepcopy( vuln )
		mutant = vulnCopy.getMutant()
		if mutant.getMethod() == 'POST':
			# No need to work !
			return vulnCopy
			
		else:
			pdr = httpPostDataRequest.httpPostDataRequest()
			pdr.setURL( mutant.getURL() )
			pdr.setDc( mutant.getDc() )
			pdr.setHeaders( mutant.getHeaders() )
			pdr.setCookie( mutant.getCookie() )
			mutant.setFuzzableReq( pdr )
			return vulnCopy
			
	def getRootProbability( self ):
		'''
		@return: This method returns the probability of getting a root shell using this attack plugin.
		This is used by the "exploit *" function to order the plugins and first try to exploit the more critical ones.
		This method should return 0 for an exploit that will never return a root shell, and 1 for an exploit that WILL ALWAYS
		return a root shell.
		'''
		raise w3afException( 'Plugin is not implementing required method getRootProbability' )