Automating AMI builds for Amazon EC2

I started to use Amazon EC2 cloud for penetration tests. Besides having short-term (costs money) scalable processing power for various tasks it also enables me to care less if automated IPS response blocks my IP. I can always bring up another instance...

Provisioning new instances is not hard. There's now AWS console to take advantage of. Useful and pretty. What's been bugging me is that the EC2 images are snapshots of system configuration that revert back to known configuration. So if I apt-get my system and/or download some software I have to rebuild the image so I don;t loose the work. Yes I can mount S3 persistent storage drive and "try" to install all my software there; and then just move it between instances as I bring them up. However it may not work for me all the time. I want to have an (semi)-automated way of "fixating" changes I make to core system and staring new instances with updated image.





So here is somewhat automated way of building Amazon EC2 AMIs.


#!/bin/bash


usage(){
echo "ERROR: arguments "
}

EC2_HOST="$1"
EC2_SNAPSHOT="$2"

# Environment
EC2_HOME=/usr/local/ec2
EC2_PRIVATE_KEYF=pk-RKxxxxxxxxxxxxxxxxxxxxxx.pem
EC2_PRIVATE_KEY=$EC2_HOME/pk-RKxxxxxxxxxxxxxxxxxxxxxxx.pem
EC2_CERTF=cert-RKxxxxxxxxxxxxxxxxxxxxxxxxx.pem
EC2_CERT=$EC2_HOME/cert-RKxxxxxxxxxxxxxxxxxxxxxxxxxx.pem
EC2_HOST_DIR="/mnt"
EC2_RSA="$EC2_HOME/id_rsa-dxs-keypair"
EC2_ACCT=2245946456456456
EC2_DEFAULT_ARCH=i386

S3_BUCKET="dxs-yZksjhflsaudhflkajsdf"
EC2_ACCESSKEY="05HAPBln3245jk32j45"
EC2_SECKEY="pdyyyyyyyyyyyyyyyyyyyyyyyyyyy"

if [[ $# -ne 2 ]]
then
usage && exit 1
fi


echo "[*] Going to $EC2_HOME"
cd $EC2_HOME

echo "[*] Copying [PRIV] and [CERT] from $EC2_HOME to $EC2_HOST"
scp -i $EC2_RSA $EC2_CERT $EC2_PRIVATE_KEY root@$EC2_HOST:$EC2_HOST_DIR



echo "[*] Building AMI $EC2_SNAPSHOT to $EC2_HOST_DIR"
ssh -i $EC2_RSA root@$EC2_HOST \
"EC2_HOME=$EC2_HOME $EC2_HOME/bin/ec2-bundle-vol -d $EC2_HOST_DIR -k \
$EC2_HOST_DIR/$EC2_PRIVATE_KEYF \
-c $EC2_HOST_DIR/$EC2_CERTF -u $EC2_ACCT -r $EC2_DEFAULT_ARCH -p $EC2_SNAPSHOT"

echo "[*] Uploading AMI $EC2_SNAPSHOT to S3"
ssh -i $EC2_RSA root@$EC2_HOST "EC2_HOME=$EC2_HOME $EC2_HOME/bin/ec2-upload-bundle \
-b $S3_BUCKET -m $EC2_HOST_DIR/${EC2_SNAPSHOT}.manifest.xml -a $EC2_ACCESSKEY -s \
$EC2_SECKEY"

echo "[*] Checking S3 bucket"
/usr/bin/s3cmd ls s3://$S3_BUCKET

echo "[*] Currently Registered Instances"
$EC2_HOME/bin/ec2-describe-images

echo "[*] Registering Instance ${EC2_SNAPSHOT} "
$EC2_HOME/bin/ec2-register $S3_BUCKET/${EC2_SNAPSHOT}.manifest.xml

echo "[*] Newly Registered Instances"
$EC2_HOME/bin/ec2-describe-images If

You may need to fetch Amazon AMI Tools and creating AMI build environment
on EC2 instance if you don;t have it yet.

#echo "[*] Getting ec2-ami-tools from AMAZON"
wget http://s3.amazonaws.com/ec2-downloads/ec2-ami-tools.zip -o /tmp/ec2-ami-tools.zip

#echo "[*] Getting ec2-ami-tools to $EC2_HOST"
scp -i $EC2_RSA /tmp/ec2-ami-tools.zip root@$EC2_HOST:$EC2_HOST_DIR

#echo "[*] Making $EC2_HOME on $EC2_HOST"
ssh -i $EC2_RSA root@$EC2_HOST "mkdir -p /usr/local/ec2"

Of course, there's no limit to how automated you can make it.

Querying WHOIS Webservice with Powershell

There's an interesting WHOIS Web service at TryNT. If you are scanning a range of addresses trying to determine the owner it's useful to automate.

Apparently TryNT gets banned from certain IP ranges, or simply going too hard at Whois servers, so sometimes the query returns error. But for the most part it works.

Here's how one can query Whois via TryNT webService:



PS C:\Users\dxs\Code\powershell> gc .\Whois-Webservice.ps1
function IpOwner(

[string]$ip="4.2.2.2"
){

BEGIN{
$whois=@{"query"=$ip};
$ErrorActionPreference="SilentlyContinue"
}

PROCESS {

#$uri="http://75.101.151.29/whois-api/v1/?h="+$ip+"&f=0"
$uri="http://www.trynt.com/whois-api/v1/?h="+$ip+"&f=0"
$resp=[xml](New-Object -TypeName System.Net.WebClient).Downloadstring($uri)
$whois.Add("organization",
$($resp.SelectNodes(
"descendant::Trynt/Whois/regrinfo/owner/organization") |
% { $_.InnerXml}) )
$whois.Add("TechEmail",
$($resp.SelectNodes(
"descendant::Trynt/Whois/regrinfo/tech/email") |
% { $_.InnerXml}) )
}

END{
Write-Host $whois.Values
}
}


1..254 | % { sleep(2); IpOwner("124.$_.165.1") }

The run:


PS C:\Users\dxs\Code\powershell> .\Whois-Webservice.ps1
SK Networks co., Ltd 124.1.165.1
WADONG ELEMENTARY SCHOOL 5ypascal@lycos.co.kr 124.2.165.1
Jeonrabukdo Wanju Education Office i3cc11@hanmail.net 124.3.165.1
GE Capital International Services munish.dargan@ge.com 124.4.165.1
KuRO TV noc@cnm.co.kr 124.5.165.1
NETWORK_VISMIN_DSL_IP_POOL aaa81020@globenet.com.ph 124.6.165.1
SIFY INFRASTRUCTURE ipadmin@sifycorp.com 124.7.165.1
Taiwan Fixed Network CO.,LTD. steve_huang@howin.com.tw 124.8.165.1
Taiwan Fixed Network CO.,LTD. steve_huang@howin.com.tw 124.9.165.1
Taiwan Fixed Network CO.,LTD. steve_huang@howin.com.tw 124.10.165.1
Taiwan Fixed Network CO.,LTD. steve_huang@howin.com.tw 124.11.165.1
Taiwan Fixed Network CO.,LTD. steve_huang@howin.com.tw 124.12.165.1
TELEKOM MALAYSIA BERHAD ssc@tmnet.com.my 124.13.165.1
6F Greatwall Bldg., A38 Xueyuan Road Haidian District,Beijing speed0822@sina.com 124.14.165.1
6F Greatwall Bldg., A38 Xueyuan Road Haidian District,Beijing speed0822@sina.com 124.15.165.1
China Science & Technology Network lihong@cstnet.net.cn 124.16.165.1





Syncing NirSoft Repository

Nirsoft has a great collection of tools streamlining some aspects of offensive penetration and system management. If you are stuck without your toolkit, it's possible to automaticaly sync Nirsoft repository to your local cache and go from there. The site posts directory of utils here
Each XML file describes individual utility including direct download link which we can use to cync the depots.

Here's my Powershell script.





PS C:\Users\dxs\Code\powershell> gc .\SyncNirsoft.ps1


function GetNirSoftUtils(
$padLink=[string]"http://www.nirsoft.net/pad/pad-links.txt"

){

BEGIN{
Write-host "Getting PAD link"
$webclient=(New-Object -Type System.Net.WebClient)
$webclient.DownloadFile($padlink,"$(pwd)\pad-links.txt")
$padidx=$( Get-ChildItem $(pwd) "*.txt" | %{ $_.Name } )
write-host "Gotten: $padidx"

}
PROCESS{
Write-host "Getting PAD XML Links"
foreach ( $padxmllnk in $(Get-Content $padidx )){

# strip http:// for filesystem operation
$padxmllnkfs=$padxmllnk -replace "http://", ""

# basename the file (i.e /path/to/file -> file )
$padxmlfs=(split-path $padxmllnkfs -leaf).split("/")[-1]

# Conform to full path
$padxmlfs="$(pwd)\$padxmlfs"

# Download XML index files
Write-Host "Getting Index $padxmllnk --> $padxmlfs "
#$webclient.DownloadFile($padxmllnk,"$padxmlfs")

# Parsing Index and Getting Depot Download links
$depotids=[XML](Get-Content $padxmlfs )
$depotURL=$($depotids.SelectNodes(
"descendant::Web_Info/Download_URLs/Primary_Download_URL") |
% { $_.Inner
Xml})


# strip http:// for filesystem operation
$depotfs=$depotURL -replace "http://", ""

# basename the file (i.e /path/to/file -> file )
$depotfs=(split-path $depotfs -leaf).split("/")[-1]

# Conform to full path
$depotfs="$(pwd)\$depotfs"
Write-Host "Getting Depot $depotURL --> $depotfs "

$webclient.DownloadFile($depotURL,"$depotfs")

}
}
END{
Write-host "end"
}

}










Runtime example:


PS C:\Users\dxs\Code\powershell> .\SyncNirsoft.ps1
Getting PAD link
Gotten: pad-links.txt
Getting PAD XML Links
Getting Index http://www.nirsoft.net/pad/acm.xml --> C:\Users\dxs\Downloads\Nirsoft-PAD\acm.xml
Getting Depot http://www.nirsoft.net/utils/acm.zip --> C:\Users\dxs\Downloads\Nirsoft-PAD\acm.zip



Dynamic Link Crawler

So in a typical Web assessment one of the things one normally does is crawl all or some portion of a target website. It just makes the "big" picture a bit clearer when looking at how the web app is structured. Conventional crawlers work on href: references, recursively. Recently I looked at the site which I could not crawl. To be more specific, the site allowed me to either crawl a few links and then it would stall me. Other times, it would send my crawler into infinite loop. Either way, I could not accomplish what I came there to do.

It appeared that Web IDS module was timing the link references and If I went too fast it would shut me down for 10 minutes. Additionally, my crawler's User-Agent near useless navigating dynamically generated buttons/links in AJAX pages. I was a bit stuck. I don't mind manually testing the site, and in fact, I prefer going near-manual once I get through the initial crawl. But I really did not want to spend the whole day manually punching in ( let's call them item number, like in shopping cart scenario ) items to get through all the listings.

Well, we are in Web 2.0. As much as I wanted to stick with good-ol' techniques or fall back to lazy manual crawling I wanted to try and automate form submissions and searches. I needed a browser automation, really.

First I wanted to drive the IE via Powershell COM bridge.
It's a nice solution and I will be looking at it in depth some time later. However, I went with Watir framework to test my crawls and move on to more interesting stuff.

In IE (don;t you love when the site is only interested in MS-made browsers... ) the following was accomplished. Suppose there's a search field and a type of search to perform. I was interested in crawling through the people in the catalog.

I also had a driver script, but manually the following can be invoked as:

C:\Users\dxs\Tools\Ruby\bin\ruby.exe .\wsearch.rb LN "Blakkenship"
LN- for LastName field of search.


Code:

require 'watir'
require 'watir/close_all'


browser = Watir::IE.new
form=nil;
criteria=nil;

if ( ARGV.length == 2 )
criteria = ARGV[1]
format = case ARGV[0]
when "KW" then
form="formKeyword"

when "LN" then
form="formLastname"

when "FN" then
form="formFirstname"

else
raise "Invalid Format Arguments: Need KW,LN,FN etc."
end



else
puts "Error in arguments: specify Format (KW,LN,FN,etc.) and Search Criteria"
exit(1)
end

site = "http://site.com/index.cfm?contentID=21&type=1"

browser.goto site
puts "Searching through for: #{form} , criteria: #{criteria}"
browser.text_field(:name, form).set criteria

browser.button(:name, "Search").click
puts "\n\n"
browser.links.each { |l| puts l.href + "--->" + l.text if l.text =~ /#{criteria}/io }

Watir::IE.close_all



Output:

http://url.reference.to.entities?here&it=comes -> Mnemonic Name

I have to admit, instrumenting browsers is slow, and I was not nearly as fast as with the conventional crawler. Then again, the code is crude, no threading, no optimization, just plain "hacked-up" in a hurry. 7 hours later, and 100% under IDS radar, I emulated a human browsing the site. I had a nice database of stuff to work with come morning...


There is also FireWatir for driving Firefox in case it;s needed.

Social Engineering meets Offensive technologies: using USB U3 flash drive with meterpreter payload

I was recently involved in a Social Engineering experiment the goal of which was to obtain access to a PC inside the organization. I am not going to cover the social engineering aspect of the job in this post. I want to concentrate on another, technical, aspect of how close proximity to physical hardware has gotten the data I needed.

I have been reading elsewhere on how Social Engineers leverage client side exploitation which involves either a browser exploitation or email attachments, or
USB devices left with the "secretary". During the engagement I had an opportunity to
corce the receptionist into printing out my "resume" on her machine. So I thought it may be a perfect time to try the "USB" way. To that day I never had messed around with U3 system or created my own custom payload for that specific purpose. This was a perfect opportunity to have fun.

There are several viable approaches and already pre-made USB payload distribution serving the purpose: HackSaw, SwitchBlade, others. Read more Here:
http://dotnetwizard.net/soft-apps/hack-u3-usb-smart-drive-to-become-ultimate-hack-tool/ and here: http://wiki.hak5.org/wiki/USB_Switchblade

I decided to go with customized version of Switchblade. I ripped out what I did not need for the compromise of the targeted computer, created U3CUSTOM image and overlayed the contents of my Walmart-bought $10 U3 SanDisk 1GB Cruzer drive.

The goal was to show up the next morning and attempt to hand the drive with my "resume" to the secretary (very nice and honest woman, btw), and have here print it out. I chose not to rely on Microsoft Word macros because I had some knowledge about the company's policy preventing such elevation. I also knew that the company ran updated Antivirus, and that the solution needed to be stealthy. I was not sure which one though, so I had to be careful to avoid detection of the payload on my USB as best I could. I also had to provision for connection back to her PC.

I needed to know the IP and all other relevant information and only had about 20-30 seconds of "hit-and-run" while she opens up the document and hands me the printed copy.

Prep Steps taken:
1. Remaster U3 image to include Alex Sotirov's http://www.phreedom.org/software/metsvc/. Modify the source and recompile it with MinGW compiler to elevate the chances of AV evasion. Something like this:

C:\metsvc-1.0\metsvc-1.0\src>c:\MinGW\bin\gcc.exe -O4 -o metsvc.exe metsvc.cpp -l ws2_32 -l advapi32

This executable has given me trouble before when I tried several packers: UPX and ASPack, and MPRESS with various degrees of passing the score on VirusTotal. I finally decided not to pack at all and go with heavy optimization at compile time and hexeditor to polish the deal.

I would have loved to use msfpayload for obfuscation but I had no linux box at my disposal, and I did not seem to find this executable in Win32 MSF Framework distribution.

2. UPX-pack other useful executables fetching the history and passwords from her PC (in case my remote session connection fails and I need to login directly to PC).

3. Once inserted into USB slot, U3 will silently run my chain of commands. I had to test for the whole operation to complete within 20 seconds. I have added several more tweaks ( like enabling firewall exceptions for the meterpreter service, via netsh commands) to make extra checks.

4. I remove the drive with information saved in the logs and go from there...

Show time

Everything went better than I expected from the AV evasion perspective. No popups or error messages. I even got Wireless Key hash via WIFIKE from NirSoft. The logs showed that the meterpreter service did start up and I did eventually find a way to verify that :)


So I was happy because I now have more or less another methodology I can use to help others realize the risks of Social Engineering meeting Exploitation technology.

Discovering Metasploit API: Structure of installation

I was playing with MSF user cache and overwrote it, accidentally :)

1. To avoid my inevitable sloppiness in the future I am going to try and offload scripts to a more "static" location ( like ~/Code/metasploit) and try and invoke MSF APIs from there. This will allow me to develop and debug scripts outside of ~/.msf or /modules/. I can always move the m there eventually.

For that I have to add the following at the beginning of the script:

$:.unshift("/Users/dimas/framework-3.2/lib")

This line essentially allows me to prepend MSF library path to the search order for useful MSF classes and modules.

2. To better understand how MSF is laid out I also wanted to create a little helper for myself showing what's where. MSF class Msf::Config allows to create such a reference.
I will use calls similar to the following:

Msf::Config.get_config_root

For detailed information see Metasploit API here.

I am also going to use MSF's Rex library to nicely format the table of locations. Like so:

rt=Rex::Ui::Text::Table.new({
     "Header" => "Structure of the installation",
     "HeaderIndent" => 3,
     "Columns" => ["Setting Name", "Location"],
     "Indent" => 1

                        })

Here's what I came up with:

#!/usr/bin/env ruby
#
$:.unshift("/Users/dimas/framework-3.2/lib")

#
require 'rex/ui'
require 'msf/base'

rt=Rex::Ui::Text::Table.new({
   "Header" => "Structure of the installation",
   "HeaderIndent" => 3,
   "Columns" => ["Setting Name", "Location"],
   "Indent" => 1

                        })
rt.add_hr()
copts={
        "Config Root" => Msf::Config.get_config_root,
        "Install Root" => Msf::Config.install_root,
        "Config Directory" => Msf::Config.config_directory,
        "Config File" => Msf::Config.config_file,
        "Data Directory" => Msf::Config.data_directory,
        "Module Directory" => Msf::Config.module_directory,
        "Plugin Directory" => Msf::Config.plugin_directory,
        "Script Directory" => Msf::Config.script_directory,
        "Session Directory" => Msf::Config.session_log_directory,
        "User Module Directory" => Msf::Config.user_module_directory,
        "User Script Directory" => Msf::Config.user_script_directory,
        "Log Directory" => Msf::Config.log_directory
}

copts.each { |k,v| rt.add_row([k,v]) }
rt.add_hr()
rt.print

And I now have a nice reference:

   Structure of the installation
   =============================

 Setting Name           Location
 ------------           --------

 Plugin Directory       /Users/dimas/framework-3.2/plugins
 Script Directory       /Users/dimas/framework-3.2/scripts
 User Module Directory  /Users/dimas/.msf3/modules
 Config Directory       /Users/dimas/.msf3
 Config Root            /Users/dimas/.msf3
 Data Directory         /Users/dimas/framework-3.2/data
 Log Directory          /Users/dimas/.msf3/logs
 User Script Directory  /Users/dimas/.msf3/scripts
 Session Directory      /Users/dimas/.msf3/logs/sessions
 Module Directory       /Users/dimas/framework-3.2/modules
 Install Root           /Users/dimas/framework-3.2
 Config File            /Users/dimas/.msf3/config

Discovering Metasploit API : Utility functions

I often write scripts and programs to help me in my automation and testing projects. Many times I find it easier to do a one- or two- liner or write a short program than to search for a command line tool or GUI interface to accomplish my tasks. There are so many great specialized tools out there but I just don't do a good job of keeping track of their releases and functionality. However, I am very much fond of the scriptable frameworks because they give you best of the both worlds: flexibility and familiarity/repeatability.

So I have started playing with Metasploit API to better understand the framework and see what else I could be doing with it. I wanted to educate myself on the "framework" part. Besides, the quality of code is amazing - I am actually referencing Metasploit Framework for Ruby programming.

I started by reading the Developer's Guide and going through Rex API first.

Here are some things I will use going forward.

- Can discover Byte-order of the Host/target:

Rex::Arch.endian("ppc") => 1
Rex::Arch.endian("x86") => 0

- Can Pack and Re-pack data based on the byte-order

>> Rex::Arch.pack_addr(ARCH_X86,0x7889)
=> "\211x\000\000"
>> Rex::Arch.pack_addr(ARCH_MIPS,0x7889)
=> "\000\000x\211"

- Can programmatically take advantage of Inline assembly:

>> Rex::Assembly::Nasm.assemble("Mov ebp, 0x1")
=> "\275\001\000\000\000"

... and disassembly

>> Rex::Assembly::Nasm.disassemble("\275\001\000\000\000")
=> "00000000 BD01000000 mov ebp,0x1\n"

- Can determine OS cross-platform:

>> Rex::Compat.is_macosx
=> true

- Can open browser on target system ( also cross-platform. This example is what Windows likes)

Rex::Compat.open_browser(url='http://metasploit.com/')

Also, conversion and transformation facilities are very handy.
- Convert To ASCII encoding

>> Rex::Encoder::NDR::byte(0x5e)
=> "^"

- XOR encode/decode

Rex::Encoder::Xor::EncoderKlass = Rex::Encoding::Xor::Dword
enc=Rex::Encoder::Xor.new
enc.encode("AAA",'')

- or -

enc.encode("AAA",'BADCHARS-GO-HERE')
=> "\340\267y"

Now, this is nice and very useful - Obfuscating Javascript:

@opts={"Strings"=>nil, "Symbols"=>{"Namespaces"=>[], "Variables"=>['a'], "Classes"=>[], "Methods"=>['fun1']}}

js="var a=5; function fun1{ return false; }; //Comment"

Rex::Exploitation::ObfuscateJS.new(js, @opts).obfuscate
=> "vgMzBoAwuwunIaYjqXMaeHaGBWr gMzBoAwuwunIaYjqXMaeHaGBW=5;
function jibbyKShzFDQ{ return fgMzBoAwuwunIaYjqXMaeHaGBWlse; }; "

- Epoch to Human Time Conversion and back

>> Rex::ExtTime.sec_to_s(6444444)
=> "74 days 14 hours 7 mins 24 secs "

>> Rex::ExtTime.str_to_sec("5 days 4 hours 3 minutes")
=> 446580

- Equivalent of "which" on *nix platforms

>> Rex::FileUtils.find_full_path("apropos")
=> "/usr/bin/apropos"

- MIME encodings and attachments. I always miss this one - cannot seem to remember the format and have to go back to my old scripts to reference.

msg=Rex::MIME::Message.new
msg.add_part("hello",'text/plain',"8bit",nil)
msg.add_part_inline_attachment("this is inline", "inline_name")
msg.to_s
=> "\r\n\r\n--_Part_525_148040077_1316503564\r\nContent-Type: text/plain\r\nContent-Transfer-Encoding: 8bit\r\n\r\nhello\r\n--_Part_525_148040077_1316503564\r\nContent-Type: application/octet-stream; name=\"inline_name\"\r\nContent-Transfer-Encoding: base64\r\nContent-Disposition: inline; filename=\"inline_name\"\r\n\r\ndGhpcyBpcyBpbmxpbmU=\r\n\r\n--_Part_525_148040077_1316503564--\r\n"

- Ad-hoc Ruby block execution

Rex::Script.execute("puts 'hello'")

- Abundant Networking functionality

Rex::Socket.addr_atoi("1.2.3.4")
=> 16909060

Rex::Socket.addr_ntoa("\001\002\003\004")
=> "1.2.3.4"

>> Rex::Socket.bit2netmask(18)
=> "255.255.192.0"

...Invaluable:

>> Rex::Socket.cidr_crack("192.168.3.0/25")
=> ["192.168.3.0", "192.168.3.127"]

IP validation

>> Rex::Socket.dotted_ip?("1.2.3.4")
=> true
>> Rex::Socket.dotted_ip?("1.2.3.4.")
=> false

DNS Resolution

>> Rex::Socket.resolv_to_dotted("www.google.com")
=> "208.67.216.231"

sockaddr Structs

>> Rex::Socket.to_sockaddr("208.67.216.231","80")
=> "\020\002\000P\320C\330\347\000\000\000\000\000\000\000\000"

Again, Invaluable - Walking IP ranges

> rw=Rex::Socket::RangeWalker.new("192.168.1.1-192.168.2.2")
=> #
>> rw.next_ip
=> "192.168.1.1"
>> rw.next_ip
=> "192.168.1.2"
>> rw.next_ip
=> "192.168.1.3"

Subnet Walking

sw=Rex::Socket::SubnetWalker.new("192.168.1.0","20")
=> #
>> sw.netmask
=> "208.69.36.132"
>> sw.next_ip
=> "192.168.1.0"

Back to Text Conversion:

>> Rex::Text::compress("dfgdf dfgdfg ddddd")
=> "dfgdf dfgdfg ddddd"

Base-64 in/out:

>> Rex::Text::encode_base64("hello world",":::")
=> "aGVsbG8gd29ybGQ=:::"
>> Rex::Text::decode_base64("aGVsbG8gd29ybGQ=")
=> "hello world"

Gzip:

>> Rex::Text::gzip("hello world")
=> "\037\213\b\000\251\342\001J\002\003\313H\315\311\311W(\317/\312I\001\000\205\021J\r\v\000\000\000"

Awesome:

>> Rex::Text::hex_to_raw('\x20\x2e\x2f')
=> " ./"

>> Rex::Text::hexify("Metasploit rocks!Metasploit rocks!Metasploit rocks!")
=> "\\x4d\\x65\\x74\\x61\\x73\\x70\\x6c\\x6f\\x69\\x74\\x20\\x72\\x6f\\x63\\x6b\n\\x73\\x21\\x4d\\x65\\x74\\x61\\x73\\x70\\x6c\\x6f\\x69\\x74\\x20\\x72\\x6f\n\\x63\\x6b\\x73\\x21\\x4d\\x65\\x74\\x61\\x73\\x70\\x6c\\x6f\\x69\\x74\\x20\n\\x72\\x6f\\x63\\x6b\\x73\\x21\n"

>> Rex::Text::html_encode("http://www.google.com?ggg&4=4")
=> "&#x68&#x74&#x74&#x70&#x3a&
#x2f&#x2f&#x77&#x77&#x77&#x2e&
#x67&#x6f&#x6f&#x67&#x6c&#x65&
#x2e&#x63&#x6f&#x6d&#x3f&#x67&
#x67&#x67&#x26&#x34&#x3d&#x34"

Useful:

>> Rex::Text::md5("hello world!+")
=> "7eae149fd806efc3f80c44223205daeb"
>> Rex::Text::md5_raw("hello world!+")
=> "~\256\024\237\330\006\357\303\370\fD\"2\005\332\353"

>> Rex::Text::rand_base(20,'',"A")
=> "AAAAAAAAAAAAAAAAAAAA"

>> Rex::Text::rand_hostname
=> "rycc.bcn8y.n.f.moyn0oq9.org"

For fuzzing:

> Rex::Text::rand_text(40,'-')
=> "\025\263\022v\340o\3334\253EV.5\335KM[\204s(\362\371V\223\341\343Y\232\025P*\260\225l\e\223\317\342\314\275"

For network dumps:

>> Rex::Text::to_hex_dump("hello World\n")
=> "68 65 6c 6c 6f 20 57 6f 72 6c 64 0a hello World.\n\n"

>> Rex::Text::to_unescape("")
=> "%u673c%u6767%u413e"

>> Rex::Text::to_unicode("hello")
=> "h\000e\000l\000l\000o\000"

This is a nice framework to build testing and automated security and QA solutions around. I will revisit MSF Core API in the next post.