Update 1 : Application Development : domainScan

Following up from my post earlier this month regarding building a security application that scans publicly available data (Google) and report on potential information leakage from a hostname.

I created a repo on github if anyone is interested in contributing. First thing any good developer does is to check code in early and often :). The repo is at https://github.com/kudithipudi/security-domainscan

Here’s the sudo code I put together as a framework to build on

[code]

functions
read_file(file)
open file;
for each line
process_line(hostname)

process_line(hostname)
search_google(hostname)
write to log

search_google (hostname)
connect to google api
get results for hostname
return number of results

main
read_file(input)

[/code]

 

Lessons of the trade : Handling CVV numbers

Just for my notes.. Even though the CVV numbers on a credit card, look like numbers :), don’t treat them as integers in your code. Some of the numbers start with a 0.. so 059 might become 59 by the time you try to process it if you capture the CVV field as an integer.

Just treat them like a string.

And obviously you are not storing them anywhere in your application/network :). Or you might end up in the headlines like some of our retailers.

HOW TO : Convert PFX/P12 crypto objects into a java keystore

We needed to add a certificate that is currently in PKCS#12 format currently into a java keystore at work recently. The typical step would be due to create an empty keystore and then import the certificate from the PKCS#12 store using the following command

[code]keytool -importkeystore -srckeystore sourceFile.p12 -srcstoretype PKCS12 -destkeystore destinationFile.jks[/code]

Note: PKCS#12 files can have extensions “.p12” or “.pfx”

The command executed without any issues, but we received the following error when we started the application server using this newly created keystore

[code]java.io.IOException: Error initializing server socket factory SSL context: Cannot recover key [/code]

It didn’t make sense, because we were able to view the certificate in the keystore and were using the right password in the configuration files.

After a lot of searching and head scratching, the team came up with the following solution

  1. Export the public key and private key from the PKCS#12 store using openssl.
  2. Import these keys into the java keystore (default format of JKS)

The commands used were

[code]
openssl pkcs12 -in sourcePKCS12File.p12 -nocerts -out privateKey.pem
openssl pkcs12 -in sourcePKCS12File.p12 -nokeys -out publicCert.pem
openssl pkcs12 -export -out intermittentPKCS12File.p12 -inkey privateKey.pem -in publicCert.pem
keytool -importkeystore -srckeystore intermittantPKCS12File.p12 -srcstoretype PKCS12 -destkeystore finalKeyStore.jks
[/code]

HOW TO : Use curl to check the impact of DNS changes

Ran into an interesting scenario at work today. We had to check the impact of a DNS change on a certain hostname. Normally, you would edit your host file entry to reflect the DNS change and do your testing. Here is another way you can do it using cURL. In this particular example, I am checking the SSL certificate details of the hostname .

[code]curl –insecure –trace-ascii debug.txt https://HOSTNAME:PORT –resolve HOSTNAME:PORT:IP_ADDRESS [/code]

That’s a pretty convoluted command :). Let’s try to break it down

[code]–insecure [/code]

: tells cURL to ignore certificate warnings. This is helpful if you are using self signed certs

[code]–trace-ascii [/code]

: tells cURL to save the SSL connection details (in debug mode) to a file called debug.txt

[code]–resolve [/code]

: tells cURL to use the options mentioned after it to resolve the hostname, rather than using DNS. The format for resolve is <host:port:address>

NOTE: You need to have version 7.21.3 or higher of cURL to use this option

Here’s a real world example. Say, I want to see how the IP address 72.30.38.140 would reacts if www.google.com requests are routed to it

[code]

[email protected]:~$ curl –insecure –trace-ascii debug.txt https://www.google.com –resolve www.google.com:443:72.30.38.140
The document has moved <A HREF="http://www.google.com/?s=https">here</A>.<P>
<!– ir2.fp.sp2.yahoo.com uncompressed/chunked Mon Nov 12 22:44:41 UTC 2012 –>
[email protected]:~$ more debug.txt
== Info: Added www.google.com:443:72.30.38.140 to DNS cache
== Info: About to connect() to www.google.com port 443 (#0)
== Info: Trying 72.30.38.140… == Info: connected
== Info: Connected to www.google.com (72.30.38.140) port 443 (#0)
== Info: successfully set certificate verify locations:
== Info: CAfile: none
CApath: /etc/ssl/certs
== Info: SSLv3, TLS handshake, Client hello (1):
=> Send SSL data, 223 bytes (0xdf)
0000: ……P.|v..1..kA…….=J.xr.=ft.3.|…Z…..9.8………5…..
0040: …………….3.2…..E.D…../…A………………………
0080: …….W………www.google.com………..4.2……………….
00c0: ………………………….
== Info: SSLv3, TLS handshake, Server hello (2):
<= Recv SSL data, 42 bytes (0x2a)
0000: …&..P.{.I"L….3x..N…9…./<n….A..5.
== Info: SSLv3, TLS handshake, CERT (11):
<= Recv SSL data, 1272 bytes (0x4f8)
0000: ……….0…0..S……….0…*.H……..0N1.0…U….US1.0…
0040: U….Equifax1-0+..U…$Equifax Secure Certificate Authority0…1
0080: 00401230014Z..150703045000Z0..1)0′..U… 2g8aO5wI1bKJ2ZD588UsLvD
00c0: e3gTbg8DU1.0…U….US1.0…U….California1.0…U….Sunnyvale1
0100: .0…U….Yahoo Inc.1.0…U….www.yahoo.com0.."0…*.H……..
0140: …..0……….5.p./……..O…k.C…9E+.J..H.s….Bm.T.E.-..<
0180: ^…m…r.v<\…&Qq..l………. @'(q.m..ZJ.*kt…!.AWU…….M.
01c0: …n…O….0.._…H….4……>.m..K…….Z…:.Df%.lR.!…(!.
0200: .FV.dQ…f.V….P,.J9.c..dM.s>C=….Y..#…47#2…..cP.{….g.rU
0240: .d…P……………..0…0…U………..0…U………….t5.
0280:……U..0:..U…3010/.-.+.)http://crl.geotrust.com/crls/secure
02c0: ca.crl0..[..U…..R0..N..www.yahoo.com..yahoo.com..us.yahoo.com.
0300: .kr.yahoo.com..uk.yahoo.com..ie.yahoo.com..fr.yahoo.com..in.yaho
0340: o.com..ca.yahoo.com..br.yahoo.com..de.yahoo.com..es.yahoo.com..m
0380: x.yahoo.com..it.yahoo.com..sg.yahoo.com..id.yahoo.com..ph.yahoo.
03c0: com..qc.yahoo.com..tw.yahoo.com..hk.yahoo.com..cn.yahoo.com..au.
0400: yahoo.com..ar.yahoo.com..vn.yahoo.com0…U.#..0…H.h.+….G.# .
0440: O3….0…U.%..0…+………+…….0…*.H……………2..0.
0480: S.’.y….GD.Q…=…K+..q..kv…….<h…….ZLE.h$..M2^.C..IT..
04c0: ".5j….Vc7.4……1.Wu.[.a>+………9..{.a:………
== Info: SSLv3, TLS handshake, Server finished (14):
<= Recv SSL data, 4 bytes (0x4)
0000: ….
== Info: SSLv3, TLS handshake, Client key exchange (16):
=> Send SSL data, 262 bytes (0x106)
0000: …….R…..b.,.&.. s.Ob;.E_.EnSw../D…’…..(aB<<……F..]..
0040: o………~…*..r?.C..%..22…J.bu&.x(j|…….>A5..OF.G…C.$.
0080: .9u9n.z…K…..u…..~:W.{Sii.{2..6……..<…..i…8y$y…..6
00c0: …1.(M…fx….#k..r….47..t.q…..A.?.0. .D…..~…G+.,….~
0100: ..=.#y
== Info: SSLv3, TLS change cipher, Client hello (1):
=> Send SSL data, 1 bytes (0x1)
0000: .
== Info: SSLv3, TLS handshake, Finished (20):
=> Send SSL data, 16 bytes (0x10)
0000: ….!9)…6…+.
== Info: SSLv3, TLS change cipher, Client hello (1):
<= Recv SSL data, 1 bytes (0x1)
0000: .
== Info: SSLv3, TLS handshake, Finished (20):
<= Recv SSL data, 16 bytes (0x10)
0000: …..(qN..l.]…
== Info: SSL connection using AES256-SHA
== Info: Server certificate:
== Info: subject: serialNumber=2g8aO5wI1bKJ2ZD588UsLvDe3gTbg8DU; C=US; ST=California; L=Sunnyvale; O=Yahoo Inc.; CN=www.yahoo.com
== Info: start date: 2010-04-01 23:00:14 GMT
== Info: expire date: 2015-07-03 04:50:00 GMT
== Info: subjectAltName does not match www.google.com
=> Send header, 167 bytes (0xa7)
0000: GET / HTTP/1.1
0010: User-Agent: curl/7.21.6 (x86_64-pc-linux-gnu) libcurl/7.21.6 Ope
0050: nSSL/1.0.0e zlib/1.2.3.4 libidn/1.22 librtmp/2.3
0082: Host: www.google.com
0098: Accept: */*
00a5:
<= Recv header, 32 bytes (0x20)
0000: HTTP/1.1 301 Moved Permanently
<= Recv header, 37 bytes (0x25)
0000: Date: Mon, 12 Nov 2012 22:44:41 GMT
<= Recv header, 42 bytes (0x2a)
0000: Location: http://www.google.com/?s=https
<= Recv header, 23 bytes (0x17)
0000: Vary: Accept-Encoding
<= Recv header, 19 bytes (0x13)
0000: Connection: close
<= Recv header, 28 bytes (0x1c)
0000: Transfer-Encoding: chunked
<= Recv header, 40 bytes (0x28)
0000: Content-Type: text/html; charset=utf-8
<= Recv header, 24 bytes (0x18)
0000: Cache-Control: private
<= Recv header, 2 bytes (0x2)
0000:
<= Recv data, 173 bytes (0xad)
0000: 000009d
0009: The document has moved <A HREF="http://www.google.com/?s=https">
0049: here</A>.<P>.<!– ir2.fp.sp2.yahoo.com uncompressed/chunked Mon
0089: Nov 12 22:44:41 UTC 2012 –>.
00a8: 0
00ab:
== Info: Closing connection #0
== Info: SSLv3, TLS alert, Client hello (1):
=> Send SSL data, 2 bytes (0x2)
0000: ..

[/code]

SNL hacked

Screenshot of NBC’ hacked website (in particular the Saturday Night Live section). Link to Hacker News discussion http://news.ycombinator.com/item?id=4740312

I found it interesting that the site was not fixed for several hours even after it was reported on major news outlets. Ironical that NBC itself is a major news outlet :).  It would be great if NBC publishes a follow up on how the server(s) were compromised so that the rest of the world can learn from this incident.

p.s : Nice blog post by my one time colleague, Ed Bellis, on how the security industry should be sharing more information so that we can improve the state of security across the board.

Another day.. Another Hack

The net is up in arms about a new release from team Ghostshell of compromise data. Details of the leak can be found at http://www.theregister.co.uk/2012/08/28/team_ghostshell_megahack/ and the source of the data is at http://pastebin.com/BuabHTvr .

I thought I would put my nascent python skills to use and write a simple script to parse through the release and download all the data. Hoping to analyze it later on. It is pretty basic, but does the job of parsing the release and downloading the content. You can get the script at https://github.com/kudithipudi/Misc-Scripts/blob/master/parseHellfire.py

Watch out for an analysis of the content soon :).

HOW TO : Use Python to look for credit card numbers

Simple script in python to look for credit card numbers in a file.

[code]

#Importing modules
import re
import os

# Define variables
inputFile = ‘test.txt’
searchPattern = ‘((\D(6011|5[1-5]\d{2}|4\d{3}|3\d{3})\d{11,12}\D)|(^(6011|5[1-5]\d{2}|4\d{3}|3\d{3})\d{11,12}\D))’

tempinputFile = open(inputFile)
tempLine = tempinputFile.readline()

while tempLine:
print ("LINE: " + tempLine)
foundContent = re.search(searchPattern,tempLine, re.IGNORECASE)
if foundContent:
print("FOUND: " + foundContent.group())
tempLine = tempinputFile.readline()

tempinputFile.close() [/code]

The script started out as a simple check for any 16 digit numbers that had a non numeric character on either end. But I tweaked it a little bit to look for credit card like numbers using the regex from http://www.regular-expressions.info/creditcard.html. Finally I added an option to match credit card like numbers if the numbers start at the beginning of the line (i.e there is no non-numeric number before the credit card number)