Outlook Live browser cookie issues

Posted on October 25, 2010 by arfore

In June of 2010, Valdosta State University transitioned to using Microsoft’s Live@EDU service for our e-mail. This is Microsoft’s competing product line with Google’s Apps for Education service. There were many reasons why we chose the Microsoft service which I won’t get into here, suffice it to say, that was the decision that was made.

While I don’t use the web interface all that much, when I do use it on Safari 5 for the Mac, I have noticed an oddity. After you login to the system and do whatever you plan to do that session, to logout you should click the “Sign Out” link. Seems standard enough, right? Well, not exactly. On Safari on the Mac I have noticed that I get an error when the signout process is attempted. When testing Firefox 3.6.11, I found I wasn’t receiving the error screen and the signout process completed successfully.

After delving more into this it turns out that the problem is third-party cookies. The default settings in Safari are very restrictive. They are also all or none. There is no exception list to the privacy settings for browser cookies in Safari, unlike Firefox. Also, it turns out that if you change the settings in Firefox to match the restrictive settings in Safari you get the same error screen.

In order to find out what site was causing the problem I cleared all the cookies for Safari, then enable the setting to always allow cookies. After comparing the list of cookies that were set, I found one listed for the domain passport.com that did not show up in the cookie list when Safari is set to accept cookies only from sites that I visited.

Further investigation using the Live HTTP Headers add-on in Firefox revealed the following for that domain:

http://loginnet.passport.com/ThirdPartyCookieCheck.srf?ct=1287943985
 
GET /ThirdPartyCookieCheck.srf?ct=1287943985 HTTP/1.1
Host: loginnet.passport.com
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.11) Gecko/20101012 Firefox/3.6.11
Accept: image/png,image/*;q=0.8,*/*;q=0.5
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Referer: http://login.live.com/logout.srf?lc=1033&amp;nossl=1&amp;lc=1033&amp;ru=https://login.microsoftonline.com/login.srf%3Flc%3D1033%26ct%3D1287943985%26rver%3D6.1.6206.0%26id%3D260563%26wa%3Dwsignoutcleanup1.0%26nossl%3D1%26wreply%3Dhttps:%252F%252Foutlook.com%252Fowa%252F%253Frealm%253Dvaldosta.edu&amp;id=12&amp;wa=wsignout1.0
 
HTTP/1.1 302 Found
Connection: close
Date: Sun, 24 Oct 2010 18:13:05 GMT
Server: Microsoft-IIS/6.0
PPServer: PPV: 30 H: BAYIDSLGN1F57 V: 0
Content-Type: text/html; charset=utf-8
Expires: Sun, 24 Oct 2010 18:12:05 GMT
Cache-Control: no-cache
Pragma: no-cache
P3P: CP="DSP CUR OTPi IND OTRi ONL FIN"
Set-Cookie: MSPP3RD=2832116359; domain=.passport.com;path=/;HTTPOnly= ;version=1
Content-Length: 0
Location: http://loginnet.passport.com/ThirdPartyCookieCheck.srf?tpc=2832116359&amp;lc=1033
----------------------------------------------------------
http://loginnet.passport.com/ThirdPartyCookieCheck.srf?tpc=2832116359&amp;lc=1033
 
GET /ThirdPartyCookieCheck.srf?tpc=2832116359&amp;lc=1033 HTTP/1.1
Host: loginnet.passport.com
User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; en-US; rv:1.9.2.11) Gecko/20101012 Firefox/3.6.11
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Referer: http://login.live.com/logout.srf?lc=1033&amp;nossl=1&amp;lc=1033&amp;ru=https://login.microsoftonline.com/login.srf%3Flc%3D1033%26ct%3D1287943985%26rver%3D6.1.6206.0%26id%3D260563%26wa%3Dwsignoutcleanup1.0%26nossl%3D1%26wreply%3Dhttps:%252F%252Foutlook.com%252Fowa%252F%253Frealm%253Dvaldosta.edu&amp;id=12&amp;wa=wsignout1.0
Cookie: MSPP3RD=2832116359
 
HTTP/1.1 200 OK
Cache-Control: no-cache
Connection: close
Date: Sun, 24 Oct 2010 18:13:06 GMT
Pragma: no-cache
Content-Type: image/gif
Expires: Sun, 24 Oct 2010 18:12:06 GMT
Server: Microsoft-IIS/6.0
PPServer: PPV: 30 H: BAYIDSLGN1F50 V: 0
P3P: CP="DSP CUR OTPi IND OTRi ONL FIN"
Content-Encoding: gzip
Vary: Accept-Encoding
Transfer-Encoding: chunked

Continuing the investigation, I decided to force Firefox to ask me about each cookie that was going to be set. This makes a dialog show up for each cookie attempt giving me the option to deny it, allow it only for the current session, or always allow. After walking through the tortorous process of a complete login/logout session, it turns out that two cookies are being set for the domain passport.com with each of them set to expire at the end of the session. More detail on the cookie can be seen in the screen shot of the cookie detail (provided by the plugin Add N Edit Cookies) shown below:

So, the next step was to fire up my VM and see how all this worked on the Windows side of things. I figured that since we had not been deluged with user requests concerning this that the browsers on the Windows side of the equation were handling it all differently. Firefox on Windows is configured out of the box just like Firefox on Mac OS X. So, as I expected the operation was the same as well. If you allow for third-party cookies, then it works fine, if you don’t then you get the error screen.

The interesting development is the settings for Internet Explorer. Bear in mind that I am using Windows 7 and Internet Explorer 8, but the settings should be fairly similar on Windows XP and between versions 7 and 8. The default setting in IE8 is to all third-party cookies, but (and this is the key) only if they have a compact privacy policy (P3P). This is the setting that makes the big difference.

It turns out that neither Firefox nor Safari support P3P headers by default. In fact there doesn’t appear to be any support for them in Safari at all. Configuring Firefox to support them requires some advanced editing of the main configuration file.

I haven’t found any adverse effects to the workings of Outlook Live when using Safari, but it is rather annoying that this occurs.

References

XDMCP and a tale of a firewall

Posted on October 22, 2010 by arfore

Recently we acquired a new firewall to place in between our datacenter and the rest of our network. This is a fairly standard security procedure used to isolate the servers from the rest of a network that can be loaded with all kinds of nasty spyware, malware and viruses, not to mention really nifty people that want to violate the security of the data.

Security is a two-edged sword for many systems folk. Firewalls are really great security tools, yet they can also get in the way of nice tools that provide access into the servers for remote administration.

Prior to the placement of the new firewall, I often used XDMCP sessions to access my unix servers from the comfort of my office, rather than traipsing to the data center to use the console. While these servers do have iLOM ports, there are some interface issues that make their use less elegant that I would wish.

After the new firewall entered the equation, I found that my normal XDMCP setup using Xephyr on my iMac no longer worked for some reason. It appeared that some of the rulesets were blocking either the particular TCP or UDP traffic necessary for the communication to work. Rather than worry our firewall administrator with troubleshooting the issue, I decided to find another way in via ssh.

It turns out that I could easily tunnel an X11 login session through an ssh session. Given that I have sshd configured to allow for TCP forwarding I was able to use an Xnest session that was initiated after logging in via ssh. Here’s the process I used:

First you need to initiate the ssh session while enabling X11 TCP forwarding. Depending on your particulars this can be done by one of the following commands:

bash-3.2$ ssh -X server.example.com

bash-3.2$ ssh -Y server.example.com

The next command is executed on the server, but the X11 session is actually running under the X11 installation on the local workstation:

Xnest :1 -geometry 1280x1024 -query localhost -terminate

Here’s a breakdown of the command parameters:

:1

determines the X11 screen to be used on the local workstation, screen 0 is the default screen used for X11

-geometry

set the screen resolution to use for the X11 window on the local workstation

-query localhost

determines which host to actually make the connection with

-terminate

closes the XDMCP session once the user logs out

All of this can actually be accomplished with a single step, by chaining the ssh login command with the Xnest command:

ssh -X REMOTESERVERNAME Xnest :1 -geometry 1280x1024 -query localhost -terminate

istatd, rhel5, init.d and me

Posted on October 21, 2010 by arfore

Recently, while configuring two new RHEL5 webserver nodes at VSU, I decided to install the Linux server for the iStat program. The iStat program is an iPhone app that will allow you to receive vital stats on your remote servers. It also gives you a nice interface for both the ping and traceroute network tools.

The installation of the istatd daemon, an open source server for Linux, Solaris and FreeBSD, was quite easy. The configuration file is easily understood and edited for your particular installation needs, allowing you to change the defaults when necessary, for example I did not want to add an additional user, so I configured istatd to use the monitor account I created for use with Nagios.

One thing that was missing from istatd was an init script to allow for easily controlling the startup and shutdown of the daemon as well as determining what runlevels the daemon should be active in.

To solve this I wrote an init.d script. These scripts are fairly self-explanatory. I used the script that starts the xinetd service as my base, since I knew that this one checks to ensure that the networking service is active before it starts the service.

The location of both the binary and the configuration file may vary depending on the installation itself. When I built istatd I used the following configure command:

./configure --sysconfdir=/etc

Here’s how to install the script

Copy the file into /etc/init.d/
```
cp istatd /etc/init.d/
```
make a symbolic link to this file in the rc.d directories for each runlevel specified in the script (note: this may differ based on the runlevels you use in the script.)
```
ln -s /etc/init.d/istatd /etc/rc3.d/S99istatd
ln -s /etc/init.d/istatd /etc/rc4.d/S99istatd
ln -s /etc/init.d/istatd /etc/rc3.d/S99istatd
```

Here is the script in it’s entirety, and you can download it as well.

#!/bin/bash
#
# istatd        This starts and stops istatd.
#
# chkconfig: 345 99 01
# description: istatd is a daemon serving statistics to your \
#              iStat iPhone application from Linux, Solaris &amp; FreeBSD. \
#              istatd collects data such as CPU, memory, network and \
#              disk usage and keeps the history. Once connecting from \
#              the iPhone and entering the lock code this data will be \
#              sent to the iPhone and shown in fancy graphs.
#
# processname: /usr/local/bin/istatd
# config: /etc/istat.conf
# pidfile: /var/run/istat/istatd.pid
 
# Source function library.
. /etc/init.d/functions
 
# Get config.
test -f /etc/sysconfig/network &amp;&amp; . /etc/sysconfig/network
test -f /etc/istat.conf
 
# Check that we are root ... so non-root users stop here
[ `id -u` = 0 ] || exit 1
 
# Check that networking is up.
[ "${NETWORKING}" = "yes" ] || exit 0
 
[ -f /usr/local/bin/istatd ] || exit 1
[ -f /etc/istat.conf ] || exit 1
 
RETVAL=0
 
prog="/usr/local/bin/istatd"
 
start(){
    echo -n $"Starting istatd: "
 
    $prog -d --pid=/var/run/istat/istatd.pid
    RETVAL=$?
    echo
    touch /var/lock/subsys/istatd
    return $RETVAL
 
}
 
stop(){
    echo -n $"Stopping istatd: "
    killproc $prog
    RETVAL=$?
    echo
    rm -f /var/lock/subsys/istatd
    return $RETVAL
 
}
 
reload(){
    stop
    start
}
 
restart(){
    stop
    start
}
 
# See how we were called.
case "$1" in
    start)
     start
     ;;
    stop)
     stop
     ;;
    status)
     status $prog
     ;;
    restart)
     restart
     ;;
    reload)
     reload
     ;;
    *)
     echo $"Usage: $0 {start|stop|status|restart|reload}"
     RETVAL=1
esac
 
exit $RETVAL

If you need any assistance creating your own scripts, you might find this link from Novell’s Cool Solutions site: Creating Custom init Scripts.

RHEL5 Password Policy Enforcement

Posted on September 27, 2010 by arfore

Image Credit: Ohio State University

Yesterday in my post on Solaris 10 Password Policy Enforcement, I outlined the steps necessary to implement the password requirements that have been decided upon in my system environment. This post will outline the same process on the RHEL5 systems that I admin. While the policy requirements are the same, the implementation is vastly different.

Desired Policy

To re-cap, here is the policy that is to be applied to normal users:

at least 8 characters in length
no more than 20 characters in length
contain at least on letter
contain at least one number
forced to change at least every 180 days
15 minute lockout after 5 unsuccessful attempts

Implementation Differences with Solaris 10

While there were a couple of pieces of the desired password policy that I was unable to implement on Solaris 10, the ease of which the others were configured wins the game hands down. The PAM module setup on Solaris makes it dead simple to update the policy. All you have to do is to change the various tunable settings. And they are all listed in fairly understandable verbiage, no complex or arcane settings.

On the RHEL5 systems I had to delve into the vagaries of PAM module attributes and ordering. As always, it is important to make backups of any files to protect yourself and allow for disaster recovery. To implement the requirements, I had to edit two files on the system:

/etc/login.defs
/etc/pam.d/system-auth

Implementation Process

It is important during this process to recognize that if you set the PAM requirements incorrectly you can get burned to the point that the root user will be unable to login, forcing you to boot into single-user mode to recover or to boot the system from a live cd and revert the authentication files.

Setting the password expiration requirement and length setting

Before we get into this please note the warning notice from the login.defs file manpage on a RHEL5 system

Much of the functionality that used to be provided by the shadow password suite is now handled by PAM. Thus, /etc/login.defs is no longer used by programs such as: login(1), passwd(1), su(1). Pleaserefer to the corresponding PAM configuration files instead.

It is still important to configure the password length in the login.defs file so that we can account for legacy codebases.

Open /etc/login.defs in your favorite editor
Set the attribute of PASS_MAX_DAYS to be 180
Set the attribute of PAS_MIN_LEN to be 9

Setting the password complexity requirements

Now here is where the going gets real interesting. Before we look at /etc/pam.d/system-auth a strong caution

Backup up the file before you alter it and open a backup terminal session as the root user before continuing. If you put the wrong attributes in place or put the PAM directives in the wrong order you will lock yourself, root user and all, out of the system. At that point you have two options: single user mode recovery from the console or use a live cd to boot the machine and revert to the backup after mounting the filesystem. Oh, and it is wise to give yourself a delay with either GRUB or LILO because without the delay you won’t be able to change the boot option to allow the single user mode recovery option.

So, the file involved in this process is /etc/pam.d/system-auth and before I go into some of the nitty gritty, here’s the configuration I ended up using:

#%PAM-1.0
# This file is auto-generated.
# User changes will be destroyed the next time authconfig is run.
auth        required      pam_env.so
auth        required      pam_tally2.so deny=6 unlock_time=900
auth        sufficient    pam_unix.so nullok try_first_pass nodelay
auth        requisite     pam_succeed_if.so uid &gt;= 500 quiet
auth        required      pam_deny.so
 
account     required      pam_unix.so
account     sufficient    pam_succeed_if.so uid &lt; 500 quiet
account     required      pam_permit.so
account     required      pam_tally2.so per_user
 
password    required      pam_passwdqc.so min=disabled,disabled,12,9,9 max=20 similar=deny enforce=users retry=3
password    sufficient    pam_unix.so md5 shadow nullok try_first_pass use_authtok
password    required      pam_deny.so
 
session     optional      pam_keyinit.so revoke
session     required      pam_limits.so
session     [success=1 default=ignore] pam_succeed_if.so service in crond quiet use_uid
session     required      pam_unix.so

The retries requirement is implemented using the following line

auth        required      pam_tally2.so deny=6 unlock_time=900

The complexity and length requirements are implements using the following line

password    required      pam_passwdqc.so min=disabled,disabled,12,9,9 max=20 similar=deny enforce=users retry=3

The following line is set to ensure that the retries count is maintained even if the counter for the pam_tally2 module is corrupted

account     required      pam_tally2.so per_user

References

Rather than go into the details of each individual attribute and how they interact, here are the resources used to develop this ruleset. They contain an large amount of valuable information.

Solaris 10 Password Policy Enforcement

Posted on September 26, 2010 by arfore

Image Credit: Ohio State University

I was recently handed a baseline policy that was to implemented for all users on the Solaris 10 systems that I support. After a small amount of research I was able to find the various pieces that needed to be altered.

Desired Policy

After discussion between the security officer and the other management level staff, the following policy was decided upon:

Normal User Password Requirements

at least 8 characters in length
no more than 20 characters in length
contain at least on letter
contain at least one number
forced to change at least every 180 days
15 minute lockout after 5 unsuccessful attempts

Most of the restrictions were fairly basic and could be easily accomplished. The only one that I could find no mechanism for control of in Solaris 10 is the automatic unlock of an account after the specified 15 minute lockout. While it is possible to determine when an account has been locked by looking at the timestamp in the syslog, there is no automated method for unlocking the account after a certain amount of time has elapsed. I suppose it would be possible to write a script to check the entries in the shadow file then grep the syslog then do some math on the timestamp, but honestly I am not worried about it.

Implementation

The implementation process involves editing two files that are key to the functionality of user login security. As always when altering system files it is a good idea to make backups of the originals in case things go wrong. The files involved are:

/etc/default/login
/etc/default/passwd

Setting the account lockout (aka Three Strikes)

Generally the default on a Solaris 10 system is to set the account lockout to three password retries before an account is locked. We decided to relax this a little and allow for five retries.

Open /etc/default/login in your favorite editor
Search for the line reading RETRIES=3
Change the line to read RETRIES=5

Configuring the complexity rules

The password complexity ruleset for Solaris 10 is fairly understandable. The rules are defined in /etc/default/passwd and the values to be tweaked are:

MINDIFF
MINALPHA
MINNONALPHA
MINUPPER
MINLOWER
MAXREPEATS
MINSPECIAL
MINDIGIT
WHITESPACE

The desired policy decided upon was to require at least one number and one letter. There was some discussion about special characters, but it was decided to not require any special characters for normal user accounts. Given these requirements the following process is used to implement the complexity ruleset:

Open the file /etc/default/passwd in your favorite editor
Set the password complexity tunables to look as follows

MINDIFF=3
MINALPHA=1
#MINNONALPHA=1
#MINUPPER=1
#MINLOWER=1
MAXREPEATS=0
#MINSPECIAL=0
MINDIGIT=1
WHITESPACE=YES

Setting the password expiration and length rules

Configuring account lockouts and password complexity is a great start, however it is not the complete picture. While reasonable complexity rules will allow users to set passwords that they can readily remember, and a flexible lockout value will give some room for fumble fingers, if users are not required to change their passwords every so often then the security of the system can suffer as well.

You also should consider password length. A shorter password, regardless of complexity, is going to be easier to crack from an algorithmic standpoint. This is simply due to the mathematical requirements. The problem is that user’s tend to not like long passwords. As you increase the password length, you increase the likelihood the passwords will use dictionary words (we can account for that as well).

The agreed upon setting for normal users on our systems was 180 days. Unfortunately Solaris 10 uses a setting measured in weeks and not days. What this means is that the setting will have to be slightly longer. The password length was decided to be at least 8 characters and no longer than 20 characters. Also, Solaris 10 has no setting to enable a maximum password length.

Open /etc/default/passwd in your favorite editor
Set the value for MAXWEEKS to be the value of number of days divided by 7, rounding up
Set the value for PASSLENGTH to be the value of the minimum number of characters

Important Notes and Considerations

Password Length

The default algorithm used for passwords under Solaris 10 is crypt_unix. This algorithm is not considered sufficiently secure, even by Oracle. You should investigate using a different algorithm such as MD5 or Blowfish instead. The default will not allow for passwords that are longer than 8 characters. You can set the password to be longer, but all characters after the eighth position will be discarded during the authentication check process.

Retroactive Usage

Changes to the password expiration policy is not immediately retroactive. For the expiration requirements to take effect on existing accounts you will need to initiate a manual password change for the shadow file entry to be updated.

Dictionary Words

When Solaris 10 was introduced one of the changes made to PAM was the ability to use a comma-delimited list of dictionary files to avoid usage of common words during password selection. This can be configured with the DICTIONLIST variable in the /etc/default/passwd file.

Applying lockout to the root user

While this is not the default, you can apply the lockout rule to the root user account by editing the /etc/user_attr file and changing the lock_after_retries value for this user to yes. Be warned this is not recommended since a locked account can only be unlocked by the root user. If your root level account becomes locked then you will need to have an account that allows sudo access or you will end up going to some extreme lengths to re-enable access to the system.

References

Of course, none of this information is really unique. Here is the list of resources I used to put all of this together:

For more commentary on password length, complexity, etc., see a few of these sites:

arfore dot com

welcome to the foremind

Category Archives: work

Outlook Live browser cookie issues

References

XDMCP and a tale of a firewall

istatd, rhel5, init.d and me

RHEL5 Password Policy Enforcement

Desired Policy

Implementation Differences with Solaris 10

Implementation Process

Setting the password expiration requirement and length setting

Setting the password complexity requirements

References

Solaris 10 Password Policy Enforcement

Desired Policy

Normal User Password Requirements

Implementation

Setting the account lockout (aka Three Strikes)

Configuring the complexity rules

Setting the password expiration and length rules

Important Notes and Considerations

Password Length

Retroactive Usage

Dictionary Words

Applying lockout to the root user

References