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Native Apple iOS Client to Cisco ASA VPN using Certificate Authentication – Part 1

3rd January 2013 / / 0 Comments

I have been working on this for a while now.  Because of a variety of reasons that I can’t go into here some of my configuration was mandatory.
The Apple iOS (used on iPhone, iPad and iPod Touch) has an in-built VPN client that Cisco assisted with development.  It supports PPTP, L2TP and IPSEC.  Unless you are crazy you would only seriously use IPSEC.  However, it only supports IPSEC using IKEv1 key negotiation.  Unless you have a specific reason really only IKEv2 should be used a it has a number of performance and security benefits.  So that causes a problem with iOS devices.
Using a IKEv1 in conjunction with a group/pre-shared key is well documented and simple to get working.  If you are using Certificates then it gets a whole lot interesting.
One fix is to use the AnyConnect client from the App Store.  This is free to download and can be deployed using the Apple Configurator utility from a Mac OSX device.  This allows SSL VPN as well as IPSEC IKEv2 connections (in version 3.0 of the AnyConnect iOS/Andriod client) and has enterprise grade tools such as logging, diagnotics and a tool similar to the DART utility that the desktop AnyConnect has.
The difficulty with this is that even though you have purchased SSL VPN user licences (AnyConnect Essentials or Premium) Cisco still want some more money in the guise of ‘AnyConnect Mobile’ licence.  These retail at around £500 but still another outlay you did not bargin for.  Also your security policy may mandate the use of the built in client so its time to roll up your sleeves.

So what’s it doing ?

As with most things, being able to see what the iOS device is actually doing would be a good start.  In Apples infinite wisdom any user messages are usually “cannot connect”, “unable to verify server” and not a lot else.
Armed with a Mac you do have a number of tools at your disposal.  Of course if you are reading this it stands a good chance you are doing this is a company and you will need a Mac to deploy Enterprise profiles to iOS devices as lets face it you really, really should lock those babies down.
1) Remember the Mac OSX VPN client is very similar to the iOS VPN client so if its possible to replicate the configuration on the Mac, you may see something more useful to start with.  In my experience you don’t but its worth mentioning.
2) Using Xcode its possible to see the iOS devices system log in realtime (equivalent of the /var/log/messages file)  From this you can see more useful messages from the client.  To do this:

  • Install either Xcode or the Apple Enterprise Configurator from http://www.apple.com/support/iphone/enterprise/  I used Xcode
  • Open Xcode, then select Window > Organiser
  • Connect to iOS device to your Mac using a USB cable
  • You should then be able to select the device then Console Log

3) For a low level view of what’s going on you can use the Mac to create a virtual interface to tunnel the iOS devices network traffic over.  From then you can use TcpDump to take packet captures.
You again need a Mac, USB cable and a utility from the App Store that you an pull the iOS’s UUID device down.  This is important.  I used UDID+ but there are others.   Quite how this will work when Apple remove it from iOS 6 is not well known…… anyhooo…..  Once you have the UDID run the following on the Mac

 $ # First get the current list of interfaces.
 $ ifconfig -l
 lo0 gif0 stf0 en0 en1 p2p0 fw0 ppp0 utun0
 $ # Then run the tool with the UDID of the device.
 $ rvictl -s 74bd53c647548234ddcef0ee3abee616005051ed
Starting device 74bd53c647548234ddcef0ee3abee616005051ed     [SUCCEEDED]
$ # Get the list of interfaces again, and you can see the new virtual
 $ # network interface, rvi0, added by the previous command.
 $ ifconfig -l
 lo0 gif0 stf0 en0 en1 p2p0 fw0 ppp0 utun0 rvi0

Then

$ sudo launchctl load -w /System/Library/LaunchDaemons/com.apple.rpmuxd.plist

Now that you know the name of the RVI, you can point your packet trace tool at it. For example, he’s how you might run tcpdump to take a packet trace from the RVI.

$ sudo tcpdump -i rvi0 -n
tcpdump: WARNING: rvi0: That device doesn't support promiscuous mode
 (BIOCPROMISC: Operation not supported on socket)
 tcpdump: WARNING: rvi0: no IPv4 address assigned
 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
 listening on rvi0, link-type RAW (Raw IP), capture size 65535 bytes

…
When you’re done you can remove the RVI with the following command.

$ rvictl -x 74bd53c647548234ddcef0ee3abee616005051ed
Stopping device 74bd53c647548234ddcef0ee3abee616005051ed [SUCCEEDED]

That should get you into a position you can debug the client traffic.  Simply open the captured traffic up in WireShark and you may have a clue…….
In part 2, Ill discuss ASA configuration and what works, what does not and what is an Cisco ASA bug !

My beef with Apple

25th October 2012 / / 0 Comments

I have been thinking about just putting some thoughts down for a while. I’d also like to say I don’t have a favourite vendor or affinity with a manufacturer. I work with Microsoft, Google and other companies stuff all the time. The right tool for the job is my ethos.
Recently I have got a real hump with Apple in general. We have had (in total) in our house:

  • iPod classic
  • 2 x iPod touch
  • iPhone 4
  • iPad 2
  • Unibody MacBook

    • So you can’t say I can’t talk about their stuff as they have certainly taken my money.
    My main problem is how quickly they seem to abandon products and stop releasing upgrades/patches. My old first gen iPod Touch is stuck on iOS 3 something which has known security vulnerabilities and at the time they could of fixed. In the end it helped as I could use the PDF flaw to install Cydia but that’s another story. My iPhone 4 and iPad 2 are more than capable of running Siri but no you need to upgrade. ( Turns out its crap anyway but that’s not the point ). iOS 6 maps are a joke and don’t get me started on there ‘Enterprise’ features such as VPN that I’m currently fighting with.
    Their lock in also annoys me. The only method of playing stuff purchased on iTunes’s is to use a MacBook with iTunes and let that download purchased tunes so you can extract MP3’s from its file system. So iCloud won’t let you access anything of use using a browser. Not even my bloody photos taken with iDevices. Even my MacBook running OSX Lion can’t unless I pay £10 for an iPhoto upgrade. And iTunes is still a spreadsheet smothered in excrement.
    Don’t get me wrong. The industrial design is mostly beautiful and has helped inspire/ kick the industry into making decent products. However they also make some stupid decisions like the new lightning connectors on the new kit. 1000’s of aftermarket devices just going to end up in landfill or lots of £20 adapters being sold……
    I’m astounded that normal folks will pay a lot of their hard earned money to buy their devices. Perhaps they don’t care about some of the things I have said but its very difficult to explain to them that no I can’t get your pictures off easily or no you music can’t be played anywhere else
    Me. Well the iPad and macbook are going soon. The iPhone went a while back so I have nearly purged my life of their stuff. Not good riddance but more ‘go away, get your sh1t together and don’t bother me for a while’

    RSA Authentication Manager–Custom Reports

    30th July 2012 / / 2 Comments

    Working with this product, its evident that the inbuilt reports are not that useful for certain things.   I wanted to find a way of logging users who have used SecurID to authenticate against a number of hosts.

    So time to learn the custom queries section of the product, me thinks.

    The Server is (obviously) SQL based.  The schema is fairly easy to understand, especially if you look at the examples within the help text or provided on the server.

    It is possible to import my SQL scripts by creating a new Custom Query then pasting in the SQL. So…. scripts:

    Todays Unique User Count

    SELECT COUNT(DISTINCT chUserName) 
    FROM SDLogEntry 
    WHERE dtLocalDate = GMTDateNow   
    AND iMessageNum = 1011   
    AND (CHClientName = "host1" OR CHClientName = "host2")

    Remember to change the host1 and host2 entries to your device host names obviously.  If you have more then add more to the last AND

    Message Number 1011 is a ‘Passcode Successful’ – meaning a successful authentication

    Todays Successful Users

    SELECT SDLogEntry.dtLocalDate, SDLogEntry.TLocalTOD, SDLogEntry.chUserName, SDLogEntry.chLogin, SDLogEntry.chClientName, SDLogMessage.chShortMessage
    FROM SDLogEntry, SDLogMessage 
    WHERE SDLogEntry.dtLocalDate = GMTDateNow   
    AND SDLogEntry.iMessageNum = 1011   
    AND SDLogMessage.iMessageNum = SDLogEntry.iMessageNum  
    AND (SDLogEntry.CHClientName = "host1" OR SDLogEntry.CHClientName = "host2")

    Again 1011 is a successful passcode.

    This uses a select from multiple tables to get the actual description of the message number to make the report more readable.

    Todays Failures

    SELECT SDLogEntry.dtLocalDate, SDLogEntry.TLocalTOD, SDLogEntry.chUserName, SDLogEntry.chLogin, SDLogEntry.chClientName, SDLogMessage.chShortMessage
    FROM SDLogEntry, SDLogMessage 
    WHERE SDLogEntry.dtLocalDate = GMTDateNow   
    AND SDLogEntry.iMessageNum <> 1011   
    AND SDLogMessage.iMessageNum = SDLogEntry.iMessageNum  
    AND (SDLogEntry.CHClientName = "host1" OR SDLogEntry.CHClientName = "host2")

    This uses the same format as success but with a ‘not’ 1011.  The report can be useful to troubleshoot users having problems or who are dim 🙂

    Using Arguments to Select Dates

    All of the above are for a single day, which is which is specified by the ‘GMTDateNow’ value.  This can be changed to use Argument Selectors which you can build in the same screen as the SQL entry.  Thus an example of ‘Successful Users’ would be:

    SELECT SDLogEntry.dtLocalDate, SDLogEntry.TLocalTOD, SDLogEntry.chUserName, SDLogEntry.chLogin, SDLogEntry.chClientName, SDLogMessage.chShortMessage
    FROM SDLogEntry, SDLogMessage 
    WHERE SDLogEntry.dtLocalDate > ARG01 AND SDLogEntry.dtLocalDate < ARG02
    AND SDLogEntry.iMessageNum = 1011   
    AND SDLogMessage.iMessageNum = SDLogEntry.iMessageNum  
    AND (SDLogEntry.CHClientName = "host1" OR SDLogEntry.CHClientName = "host2")

    Where ARG01 = Start Date and ARG02 = End Date

    These can be applied to any of the reports.

    Other Information

    One thing I found is that the custom queries are stored locally on the machine that create the reports so to share them to others you have to use a fileshare, USB disk or similar method.

    Also the HTML format reports aren’t to bad so its worth a look at using this output method.

    iPhone-less

    25th June 2012 / / 0 Comments

    Yay. I’m finally free of my iPhone 4 as of a couple of days ago. They may be fairly decent portable computers but IMHO are second rate phones. Also once you are outside of the standard apps most of the others are pretty crummy
    I’m now the proud owner of a Nokia Lumia 900 running Windows Phone 7. If you want to see something really well thought out with beautiful hardware then check one out. The integration the OS has with Twitter and Facebook is really good and sets a standard iOS really needs to catch up to
    Plus im not an iSheep (well apart from the iPad, Mac and old iPod Touch) but im working on that!

    Orange + iphone4 + 3G = pile of shit

    17th February 2011 / / 2 Comments

    I have been a loyal (?) customer of Oranges for over 15 years but am at the end of my tether with their network
    I have an iPhone 4 and yes I know it’s a crap phone but why is there 3g network so bad. I am working in a ‘new’ town so would expect decent coverage but no. 3G lies like a cheap watch and is slower than manually setting GPRS, calls continually drop even when the phones showing 3 bars. The place I’m working for even uses Orange as a supplier for 3G and I’m not sure how they put it with the shoddyness.
    I have the same issue at home but made even worse by continually swapping between Orange/T Mobile. Supposedly the result of their ‘everything everywhere’ initiative that feels like ‘nothing nowhere’
    Take my advice. Leave or avoid Orange at all costs!!!!!

    Windows 7– Offline files and SMB shares

    25th September 2010 / / 0 Comments

    Why is it so difficult for this to work out of the box ?
    I’m currently using a hacked WD MyWorld NAS device that runs BusyBox, Optware and the latest release of Samba.   You would think offline files would be easy to get working.
    Wrong.  See http://blog.rainiernetworks.com/2008/06/25/vista-synchronization-errors/ and http://justanothersysadmin.wordpress.com/2008/03/30/vista-offline-files-and-smb-opportunistic-locks/
    Why oh why Microsoft not make the offline files function out of the box.  I guess it works fine against a Microsoft server but in the spirit of greater interoperability fix it please !

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