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Securing Sun Fire Domains

Building a secure system requires that entry points into the system be limited and restricted, in addition to limiting how authorized users obtain privileges. To effectively secure Sun Fire domains, changes are required to the Solaris OE software running on Sun Fire domains.

To secure Sun Fire domains, perform the following:

  • "Adding Security Software" on page 12

  • "Customizing the Solaris Security Toolkit Driver" on page 19 (optional)

  • "Overriding Solaris Security Toolkit Defaults" on page 21 (optional)

  • "Installing Downloaded Software and Implementing Modifications" on page 21

Adding Security Software

The first stage in hardening Sun Fire domains requires downloading and installing additional software security packages. This section covers the following tasks:

  • "Install Solaris Security Toolkit Software" on page 13

  • "Download Recommended Patch Cluster Software" on page 14

  • "Download FixModes Software" on page 15

  • "Download OpenSSH Software" on page 16

  • "Download the MD5 Software" on page 17

NOTE

Of the software described in this section, the Solaris Security Toolkit, Recommended and Security Patch Cluster, FixModes, and MD5 software are required. On Solaris 9 OE systems, the version of Secure Shell bundled with the OE can be used instead of OpenSSH. Also, on both Solaris 8 OE and Solaris 9 OE systems, a commercial version of Secure Shell can be used. You must install a Secure Shell product on Sun Fire domains.

Install Solaris Security Toolkit Software

The Solaris Security Toolkit software must be downloaded first, then installed on Sun Fire domains. Later, you'll use the Solaris Security Toolkit software to automate installing other security software and implementing the Solaris OE modifications for hardening the domains.

The primary function of the Solaris Security Toolkit software is to automate and simplify building secured Solaris OE systems based on the recommendations contained in this and other security-related Sun BluePrints OnLine articles.

NOTE

The following instructions use filenames that are correct only for version 4.0.1 and newer of the Solaris Security Toolkit software.

To Download Solaris Security Toolkit Software

  1. Download the latest version of the source file from:

  2. http://www.sun.com/security/jass

    NOTE

    If you are using SMS 1.4 software, you must use Solaris Security Toolkit version 4.0.1 or newer.

  3. Extract the source file into a directory on the server by using the uncompress command:

  4. # uncompress SUNWjass-4.0.1.pkg.Z

    Where SUNWjass-4.0.1.pkg.Z is the file name of the most current release.

  5. Install the Solaris Security Toolkit software onto the server by using the pkgadd command:

  6. # pkgadd -d SUNWjass-4.0.1.pkg SUNWjass

    Where SUNWjass-4.0.1.pkg is the file name of the most current release.

Executing this command creates the SUNWjass subdirectory in /opt. This subdirectory contains all Solaris Security Toolkit directories and associated files. The script make-jass-pkg, included in Solaris Security Toolkit software releases since version 0.3, allows administrators to create custom packages using a different installation directory.

Download Recommended Patch Cluster Software

Patches are regularly released by Sun to provide Solaris OE fixes for performance, stability, functionality, and security. It is critical to the security of a system that the most up-to-date patches are installed. Ensure that the latest Solaris OE Recommended and Security Patch Cluster is installed on the Sun Fire domains. This section describes how to download the latest patch cluster.

Downloading the latest patch cluster does not require a SunSolve OnLineSM program support contract.

NOTE

Apply standard best practices to all patch installations. Before installing any patches, evaluate and test them on non-production systems or during scheduled maintenance windows.

To Download Recommended Patch Cluster Software

  1. Download the latest patch from the SunSolve OnLine Web site at:

  2. http://sunsolve.sun.com

  3. Click on the Patches link at the top of the left navigation bar.

  4. Click on Recommended and Security Patches in the Download box.

  5. Select the download option for the appropriate Solaris OE version, either HTTP or FTP, by clicking on the appropriate link.

  6. In our example, we selected Solaris 9 OE using HTTP download.

    The Save As dialog box is displayed in your browser window.

  7. Save the file locally.

  8. Move the file securely to the Sun Fire 12K or 15K domains with the scp command, or ftp if Secure Shell is not available.

  9. If you use the scp command, it should be similar to the following example:

    % scp 9_Recommended.zip sun15-a:/var/tmp
  10. Move the file to the /opt/SUNWjass/Patches directory and uncompress it as follows:

  11. # cd /opt/SUNWjass/Patches
    # mv /var/tmp/9_Recommended.zip .
    # unzip 9_Recommended.zip
    Archive:   9_Recommended.zip
      creating: 9_Recommended/
     inflating: 9_Recommended/CLUSTER_README 
     inflating: 9_Recommended/copyright 
     inflating: 9_Recommended/install_cluster 
    [. . .]

    Later, using the Solaris Security Toolkit software, you'll install the patch after downloading all the other security packages.

    NOTE

    If you do not place the Recommended and Security Patches software into the /opt/SUNWjass/Patches directory, a warning message displays when you execute the Solaris Security Toolkit software. Additionally, the install-recommended-patches.fin script is needed for patch installation with the Solaris Security Toolkit.

Download FixModes Software

FixModes is a software package that tightens the default Solaris OE directory and file permissions. Tightening these permissions can significantly improve overall security of Sun Fire domains. More restrictive permissions make it even more difficult for malicious users to gain privileges on a system.

To Download FixModes Software

  1. Download the FixModes pre-compiled binaries from:

  2. http://www.sun.com/security/jass

    The FixModes software is distributed as a precompiled and compressed pkg file formatted for systems based on SPARC® technology. The file name is SUNBEfixm.pkg.Z.

  3. Once downloaded, move the file securely to the Sun Fire 12K or 15K domains with the scp command, or ftp if Secure Shell is not available.

  4. The scp command used should be similar to the following command:

    % scp SUNBEfixm.pkg.Z sun15-a:/var/tmp
  5. Save the file, SUNBEfixm.pkg.Z, in the Solaris Security Toolkit Packages directory in /opt/SUNWjass/Packages with the following commands:

  6. # cd /opt/SUNWjass/Packages
    # mv /var/tmp/SUNBEfixm.pkg.Z .
  7. Uncompress the file.

  8. Later, using the Solaris Security Toolkit software, you'll install the FixModes software after downloading all the other security packages.

Download OpenSSH Software

In any secured environment, the use of encryption in combination with strong authentication is required to protect user-interactive sessions. At a minimum, user interactive sessions must be encrypted.

The tool most commonly used to implement encryption is Secure Shell software, whether a commercial or open source (freeware) version. To implement all the security modifications performed by the Solaris Security Toolkit software and recommended in this article, you must implement a Secure Shell software product.

Information on where to obtain commercial versions of Secure Shell is provided in "Related Resources" on page 29.

NOTE

If a domain is running Solaris 9 OE, we recommend that you use the Sun-provided implementation of Secure Shell bundled with the OE. If using the Solaris version of Secure Shell, omit the OpenSSH installation steps in this section.

The Solaris Security Toolkit software disables all non-encrypted user-interactive services and daemons on the system, in particular daemons such as in.rshd, in.telnetd, and in.ftpd.

NOTE

If you choose to use a Secure Shell product other than OpenSSH, install and configure it before or during the Solaris Security Toolkit software run.

Access to the system can be gained with Secure Shell similarly to what is provided by RSH, Telnet, and FTP.

To Download OpenSSH Software

  1. Obtain the following Sun BluePrints online article and use the instructions in the article for downloading the software.

  2. A Sun BluePrints OnLine article about how to compile and deploy OpenSSH titled "Building and Deploying OpenSSH on the Solaris Operating Environment" is available at:

    http://www.sun.com/blueprints/0701/openSSH.pdf

    Later, using the Solaris Security Toolkit software, you'll install the OpenSSH software after downloading all the other security packages.

    CAUTION

    Do not compile OpenSSH, and do not install compilers on Sun Fire 12K or 15K domains just to compile OpenSSH. Use a separate Solaris OE system—running the same Solaris OE version, architecture, and mode (for example, Solaris 9 OE, sun4u, and 64-bit)—to compile OpenSSH. If you implement the Secure Shell bundled with Solaris 9 OE or a commercial version of Secure Shell, then no compilation is required. Understand, however, that omitting compilers does not provide significant protection against determined attackers because they could use previously compiled tools.

Download the MD5 Software

The MD5 software validates MD5 digital fingerprints on the Sun Fire domains. Validating the integrity of Solaris OE binaries provides a robust mechanism to detect system binaries that are altered or trojaned (hidden inside something that appears safe) by unauthorized users. By modifying system binaries, attackers provide themselves with backdoor access onto a system; they hide their presence and cause systems to operate in unstable manners.

To Download the MD5 Software

  1. Download the MD5 binaries from the following web site:

  2. http://www.sun.com/security/jass

    The MD5 programs are distributed as a compressed pkg file.

  3. Move the file SUNBEmd5.pkg.Z securely to the Sun Fire 12K or 15K domains with the scp command, or ftp if scp is not available.

  4. The scp command used should be similar to the following

    % scp SUNBEmd5.pkg.Z sun15-a:/var/tmp
  5. Copy the file, SUNBEmd5.pkg.Z, to the Solaris Security Toolkit Packages directory in /opt/SUNWjass/Packages.

  6. Uncompress the file.

  7. After the MD5 software is saved to the /opt/SUNWjass/Packages directory, the execution of the Solaris Security Toolkit installs the software.

    After the MD5 binaries are installed, you can use them to verify the integrity of executables on the system through the Solaris Fingerprint Database. More information on the Solaris Fingerprint Database is available in the Sun BluePrints OnLine article titled "The Solaris TM Fingerprint Database - A Security Tool for Solaris Software and Files."

  8. (Optional) Download and install Solaris Fingerprint Database Companion and Solaris Fingerprint Database Sidekick software from the SunSolve Online web site at:

  9. http://sunsolve.sun.com

    We strongly recommend that you install these optional tools and use them with the MD5 software. These tools simplify the process of validating system binaries against the database of MD5 checksums. Use these tools frequently to validate the integrity of the Solaris OE binaries and files on the cluster nodes.

    These tools are described in the "The Solaris TM Fingerprint Database - A Security Tool for Solaris Software and Files" article.

Customizing the Solaris Security Toolkit Driver

If you determine that your system requires some of the services and daemons disabled by the Solaris Security Toolkit, or you want to enable any of the inactive scripts available in the Solaris Security Toolkit, do so before executing the Solaris Security Toolkit.

As described earlier in this article, the SMS 1.4 software provides capabilities for securing the MAN network, which are as follows:

  • Disable ARP on the I1 MAN network.

  • Disable all I1 MAN IP traffic for one or more domains.

Disabling all I1 IP traffic to domains can only be done on the SC. Refer to the BluePrint OnLine article titled "Securing Sun Fire 12K and 15K System Controllers" for details on how this is done.

Disabling ARP on the MAN network can only be done for an entire chassis. It is not possible to make this change only for certain domains. It must be done on all domains having IP connectivity to the I1 network.

CAUTION

When disabling ARP on a SunFire 12K or 15K system, it is critical that the necessary configuration changes be made to all domains and both SCs at the same time. Making the changes only on certain domains or SCs causes the system to malfunction.

Using the Solaris Security Toolkit to disable ARP on the domains requires modifications to the default files distributed with the Solaris Security Toolkit.

NOTE

We recommend that the SCs be secured first, particularly when implementing static ARP between the SCs and domains. If the SCs are not secured and validated, do not proceed with implementing static ARP. Complete the hardening process of the SCs first.

To Disable Dynamic ARP on the I1 MAN Network

  1. To add the necessary features or customize the hardening required for your system, edit a copy of the sunfire_15k_domain-hardening.driver file..

  2. # cd /opt/SUNWjass/Drivers
    # vi sunfire_15k_domain-hardening.driver

    CAUTION

    To preserve your changes for future updates and prevent the Solaris Security Toolkit from overriding your changes, modify only a copy of the driver. Keep the original Solaris Security Toolkit driver as a master.

  3. If ARP is being disabled on the I1 MAN network, uncomment s15k-static-arp.fin from the driver by removing the # symbol in front of the script.

  4. After you edit the line, it should appear as follows in the JASS_SCRIPTS definition:

     s15k-static-arp.fin
  5. Review the IP Address for the I1 MAN interface and matching MAC address of the SC in the sms_domain_arp file.

  6. This file is in the /opt/SUNWjass/Files/etc directory. The Solaris Security Toolkit uses the following initial values in this file:

    192.168.103.1      08:00:20:63:49:1e
    1. If your site configuration for the MAN network uses a different IP Address for the I1 MAN interface of the SC, replace the 192.168.103.1 value with the IP address of the I1 MAN interface used in your environment.

    2. If your site configuration requires a different MAC address than the initial 08:00:20:63:49:1e value, replace it with the MAC address that matches the IP Address for the I1 MAN interface on all domains and both SCs.

    All the domains must use the same /etc/sms_domain_arp file.

    CAUTION

    The IP address of the main SC in this file must match the IP address chosen as the IP Address of the SC on the I1 MAN network. Any mismatches cause MAN network failures. These failures can adversely affect the reliability, availability, serviceability, and security of the platform.

  7. Reboot the domains to implement the modified settings.

  8. You must reboot the domains for these settings to take effect.

Overriding Solaris Security Toolkit Defaults

If there are some services that must remain enabled, and the Solaris Security Toolkit automatically disables them, you can override the defaults before executing the driver.

To Override Defaults

  1. To prevent the Solaris Security Toolkit from disabling a service, comment out the call to the appropriate finish script in the driver.

  2. For example, if your environment requires Network File System (NFS)-based services, you can leave them enabled. Comment out the disable-nfs-server.fin and disable-rpc.fin scripts by appending a # sign before them in the copy of the sunfire_15k_domain-hardening.driver script.

    For more information about editing and creating driver scripts, refer to the Solaris Security Toolkit documentation.

Installing Downloaded Software and Implementing Modifications

The Solaris Security Toolkit version 4.0.1 and newer provides a driver (sunfire_15k_domain-secure.driver) for automating the installation of security software and Solaris OE modifications. The driver performs the following tasks:

  • Installs and executes the FixModes software to tighten file system permission

  • Installs the MD5 software

  • Installs the Recommended and Security Patch Cluster software

  • Implements over 100 Solaris OE security modifications

NOTE

The actions performed by each of the scripts is described in the Solaris Security Toolkit documentation. The hardening described is performed in standalone mode, not JumpStart mode, because the Sun Fire domains were built using an interactive Solaris OE installation. For details on the differences between standalone mode and JumpStart mode, refer to the Solaris Security Toolkit documentation.

During the installation and modifications implemented in this section, all non-encrypted access mechanisms to Sun Fire domains—such as Telnet, RSH, and FTP—are disabled. The hardening steps do not disable domain console access from Sun Fire 12K or 15K SCs.

To Install Downloaded Software and Implement Changes

  1. Execute the sunfire_15k_domain-secure.driver script as follows:

  2. # cd /opt/SUNWjass
    # ./jass-execute -d sunfire_15k_domain-secure.driver
    ./jass-execute: NOTICE: Executing driver, 
    sunfire_15k_domain-secure.driver
    
    ============================================================
    sunfire_15k_domain-secure.driver: Driver started.
    ============================================================
    [...]

To View the Contents of the Driver File

  1. To view the contents of the driver file and obtain information about the Solaris OE modifications, refer to the Solaris Security Toolkit documentation available either in the /opt/SUNWjass/Documentation directory or through the web at:

  2. http://www.sun.com/security/jass

To Undo a Solaris Security Toolkit Run

Each Solaris Security Toolkit run creates a run directory in /var/opt/SUNWjass/run. The names of these directories are based on the date and time the run is initiated. In addition to displaying the output to the console, the Solaris Security Toolkit software creates a log file in the /var/opt/SUNWjass/run directory.

CAUTION

Do not modify the contents of the /var/opt/SUNWjass/run directories under any circumstances. Modifying the files can corrupt the contents and cause unexpected errors when you use Solaris Security Toolkit software features such as undo.

The files stored in the /var/opt/SUNWjass/run directory track modifications performed on the system and enable the jass-execute undo feature.

  1. To undo a run or series of runs, use the jass-execute -u command.

  2. For example, on a system where seven separate Solaris Security Toolkit runs are performed, you could undo them by using the following command and options:

    # pwd
    /opt/SUNWjass
    # ./jass-execute -u
    Please select a JASS run to restore through:
    1. December 10, 2003 at 19:45:15 (//var/opt/SUNWjass/run/20031210194515)
    2. December 10, 2003 at 19:25:22 (//var/opt/SUNWjass/run/20031210192522)
    3. December 10, 2003 at 19:07:32 (//var/opt/SUNWjass/run/20031210190732)
    4. December 10, 2003 at 19:04:36 (//var/opt/SUNWjass/run/20031210190436)
    5. December 10, 2003 at 18:30:35 (//var/opt/SUNWjass/run/20031210183035)
    6. December 10, 2003 at 18:29:48 (//var/opt/SUNWjass/run/20031210182948)
    7. December 10, 2003 at 18:27:44 (//var/opt/SUNWjass/run/20031210182744)
    8. Restore from all of them
    Choice ('q' to exit)? 8
    ./jass-execute: NOTICE: Restoring to previous run 
    //var/opt/SUNWjass/run/20031210194515
    
    ===============================================================
    undo.driver: Driver started.
    ===============================================================
    [...]

    NOTE

    By default, the Solaris Security Toolkit overwrites any files backed up during earlier runs being undone. In some cases, this action overwrites changes made to files since the run was performed. If you have concerns about overwriting changes, use the -n (no force) option to prevent modified files from being overwritten. Refer to the Solaris Security Toolkit documentation for more details about this option.

    Refer to the Solaris Security Toolkit documentation for details on the capabilities and options available in the jass-execute command.

    NOTE

    Software installations and actions performed by other software are not undone by the Solaris Security Toolkit undo feature. For example, the installation of OpenSSH, FixModes, and MD5 is not undone. In addition, the modifications performed by FixModes are not automatically undone.

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