IBM InfoSphere Guardium Encryption Expert protects data by using a policy-based system. In this article, the software name is described with Encryption Expert. The policies that Encryption Expert uses contain one or more encryption keys and one or more rules for access control. There are two types of policies:
- An online policy is used for encrypting data written to a file system and protecting data with access control. When an online policy is applied to a directory, the policy controls access to files and directories under the directory. The action of applying an online policy to a directory is called Guard FS (File System), the directory is called the Guard Point, and the data read from or written to the file system is called Online Data. Any application that is allowed access by the policy can access the files that are under guard points as long as the application uses system libraries to access the files. Data is automatically encrypted when writing, and decrypted when reading, based on the policy. The encryption is transparent to the application. This means your business critical applications such as SAP, the Oracle Family of Applications, or custom applications will not be effected by IBM InfoSphere Guardium Encryption Expert. In fact, IBM InfoSphere Guardium Encryption Expert is SAP certified. Read more about how IBM InfoSphere Guardium Encryption Expert works with SAP from the Resources section.
- An offline policy is used for protecting database backup images. An offline policy is applied to a machine that is used for backing up and restoring database images. The offline policy controls backup and restore commands, and the encryption and decryption of database backup images. The action of applying an offline policy to a machine is called Guard DB (Database Backup).
Figure 1 shows an overview of the Encryption Expert architecture. It consists of one or more security servers and one or more agents. The security server has configuration information, such as online and offline policies, and audit logs from the agents. The data for the configuration information and audit logs is stored in the DB2 that is bundled with Encryption Expert.
Figure 1. IBM InfoSphere Guardium Encryption Expert architecture overview
An Encryption Expert agent is installed on a machine where data is protected (the host machine). Policies that are kept in the security server are sent to the agent (pushed), or retrieved by the agent (pulled) as necessary. The agent consists of a FS (File System) agent, which guards FS, and a DB (Database Backup) agent, which guards DB. Audit logs, for things such as access violations, are sent to the security server by default.
The security server provides a Web-based interface called the Management
Console, which you can use for tasks such as configuring policies and
browsing audit logs. To use the Management Console, open a Web browser and
go to the following URL:
Figure 2 is a screen shot of the Encryption Expert Management Console dashboard as displayed in a Japanese-language browser.
Figure 2. Encryption Expert Management Console
You can configure the security server over multiple machines to allow for both primary and failover servers. The failover servers are read-only and are populated by replicating with the primary server.
The primary server acts as the Certificate Authority (CA) and publishes X.509 certificates to the security servers and the agents. The X.509 certificates are used for authentication. Secure Socket Layer (SSL) protocol is used for communicating between the security server and each agent, and between the primary server and each failover server.
Configuring for high availability
Two features of Encryption Expert that help you to ensure high availability are the use of failover servers and encryption key caching.
As mentioned in the introduction, you can configure failover servers that can take over in the event of a failure of the primary security server. Using SQL replication technology provided by Encryption Expert, you can synchronize the configuration of failover servers with the configuration of the primary server. With SQL replication, the capture program (asncap) retrieves change records from the database log and stores them to staging tables. The apply program (asnapply) retrieves data from the staging tables every minute and applies the changes to the failover servers. Both programs run on the primary server. Audit logs are not replicated. Each failover server can receive an audit log from the agents and store it independently of other security servers.
Once the failover server is set up, the agent can access it (read-only). Figure 3 shows how the agent chooses a security server to communicate with. Each FS and DB agent has its own configuration file named agent.conf. You can edit the agent.conf files to configure the order in which the security server is chosen. If the agent cannot communicate with the first server, it moves to the next, and so on.
For more information, refer to the "Installing and configuring the Encryption Expert Failover Server" section in "Chapter 3: Installing, removing, and upgrading Encryption Expert" of the IBM InfoSphere Guardium Encryption Expert User's Guide, which is linked to from the Resources section.
Figure 3. Failover server mechanism
Cache the encryption key on the host
Each encryption key for online data has an option called Cached on Host. If an encryption key is created with this option, the encryption key is stored on the agent disk with password protection. As a result, the agent can work correctly even if the security server has not been running correctly since the agent start-up time. This is described in more detail in the following section.
Protecting online data
Encryption Expert uses symmetric encryption algorithms (3DES, AES128, AES256) for encrypting online data. Figure 4 shows an overview of how this works. An online policy holds one or more encryption keys and rules for access control. You can use the same encryption key or different encryption keys against files and directories under the guard point. Rules for access control are configured as Security Rules. Encryption keys are configured as Key Selection Rules. When you apply an online policy to a directory on a host by using the Management Console, the policy is saved in the security server and is sent to the FS agent on the host.
Figure 4. Protect online data
The FS agent consists of vmd and secfsd processes. A vmd process communicates with the security server. A secfsd process holds online policies, and encrypts and decrypts data with access control. These processes stay on the system as daemons. When a secfsd process starts, all policies related to the host are retrieved from the security server via a vmd process, and the policies are cached in memory. If the process fails to retrieve the policies, it will continue to attempt to retrieve them every 5 seconds. When applying an online policy to a directory, the security server sends the policy to the agent, and the agent caches the policy in memory.
If an application attempts to access a guard point with an encryption key that uses the Cached on Host option, and the attempt is at a time when the agent hasn't cached the encryption key of the guard point in memory because the security server has not been running correctly since the agent start-up time, then the application freezes. In this case, use the command shown in Listing 1 (followed by the predefined password) to get the application to resume working correctly. After that, any applications that access a guard point on the host will work correctly without freezing if the encryption key of the guard point is configured with the Cached on Host option.
Listing 1. Retrieve encryption keys stored on the disk of the host
# vmsec passwd Please enter password: xxxxxxxx OK passwd #
Figure 5 shows an example of Security Rules. In this example, if the db2admin user accesses the guard point, data is encrypted when writing, and data is decrypted when reading. If the root user reads data from the guard point, data is not decrypted, and the action is logged for audit. Other requests for access to the guard point are denied, and the action is logged for audit.
Figure 5. Security Rules example
The User ID condition can be contained in Security Rules. Another setting
related to User ID is called Host Settings. Use Host Settings to
identify which login methods are allowed, which processes are allowed no
matter which login method is used, and so on. For example, if you want to
allow certain users to access guard points only if the users log in via
ssh and telnet, add
|authenticator| in front of
the login processes as shown in Listing 2.
Listing 2. Example of Host Settings that allow user authentication only when logging in via ssh and telnet
|authenticator|/usr/bin/login /usr/bin/su |authenticator|/usr/sbin/sshd /usr/sbin/ftpd /usr/dt/bin/dtlogin /usr/bin/sh
As shown above,
su can also be controlled so
that Encryption Expert will prevent even the root user from accessing
guard points by pretending to be some user.
For more information, refer to the "Configuring host settings" section in "Chapter 6: Configuring hosts" of the IBM InfoSphere Guardium Encryption Expert User's Guide, which is linked to from the Resources section.
Listing 3 shows an example of a User Not Authenticated or FAKED USER error that occurs if you run a program to access a guard point after logging in via a non-authorized login method.
Listing 3. Example of a User Not Authenticated error
EET2604E: [SecFS, 0] [ALARM] Policy[db2admin_online_policy1] User[db2admin,uid=222 (User Not Authenticated)] Process[/usr/bin/ls] Action[read_dir_attr] Res[/home/db2admin/guard/] Effect[DENIED Code (1U,2M)]
Encryption Expert provides a feature to transform data encrypted by one encryption key, or non-encrypted data, into data encrypted by another encryption key. This is called dataxform. An example of when you would use this would be a case where an unencrypted file exists on a directory that you are applying an online policy to. If the policy requires that the file be encrypted, you need to encrypt the file before applying the policy. To do so, use one of the following solutions:
- Use dataxform to transform the data before applying the policy to the directory.
- Move the file to a non-guarded directory before applying the policy to the directory. After applying the policy to the directory, move the file back into the directory. When you move the file back, it will automatically be encrypted based on the policy you applied.
For more information, refer to the "Using dataxform" section in "Chapter 10: Changing encryption keys" of the IBM InfoSphere Guardium Encryption Expert User's Guide, which is linked to from the Resources section.
Encryption Expert provides commands you can use to obtain agent information. For example, to get guard point information, you could enter the command shown in Listing 4.
Listing 4. Example of command to obtain guard point information
# secfsd -status guard GuardPoint Policy Type ConfigState Status Reason ---------- ------ ---- ----------- ------ ------ /home/db2admin/guard1 db2admin_policy1 local guarded guarded N/A /home/db2admin/guard2 db2admin_policy2 local guarded guarded N/A
You can use the secfsd and vmd processes as commands by specifying options.
Table 1. Tested operating systems
|AIX||v5.2 TL 10 (64-bit), v5.3 TL 6 (64-bit), 6.1 TL3, TL4, TL5 (64-bit)|
|HPUX||11iv1 (64-bit PA-RISC), 11iv2 (64-bit PA-RISC and Itanium)|
|Redhat Linux (secfs only)||Redhat 4 x86 (32-bit) - Update 8, Redhat 4 x86 (64-bit) - Update 4 and up, Redhat 5 x86_64 (64-bit) - Update 2 and up|
|SuSE Linux||SuSE Linux Enterprise Server 10 SP2 and SP3 (64-bit running onx86_64), SLES 10 SP1, Xen kernel, is not supported|
|Windows||Windows 2000 SP4 Rollup 1, Windows 2003 Enterprise Server R1 SP2 (32-bit), Windows 2003 Enterprise Server R1 SP2 (64-bit), Windows 2003 Enterprise Server R2 SP2 (32-bit), Windows 2003 Enterprise Server R2 SP2 (64-bit), Windows 2008 DataCenter SP1, SP2 (32-bit), Windows 2008 DataCenter SP1, SP2 (64-bit), Windows 2008 Enterprise SP1, SP2 (32-bit), Windows 2008 Enterprise SP1, SP2 (64-bit), Windows 2008 DataCenter R1 SP1 (64-bit), Windows 2008 DataCenter R2 (64-bit), Windows 2008 Enterprise Server R2 (64 bit), Windows 7 (32-bit, 64-bit), Windows Vista Business SP1 (32-bit), Windows Vista Business SP1 (64-bit), Windows Vista Ultimate SP1, SP2 (32-bit), Windows Vista Ultimate SP1, SP2 (64-bit), Windows XP Pro SP2 (32-bit), Windows XP Pro SP3 (32-bit)|
Table 2. Supported file systems
|Operating system||File systems|
|AIX||JFS, JFS2, NFS, VxFS (without CFS)|
|HPUX||JFS, NFS, VxFS|
|Redhat Linux (secfs only)||EXT3, NFS, VxFS (without CFS)|
|SuSE Linux||EXT3, ReiserFS, NFS|
For more information on these and other Encryption Expert commands, refer to "Chapter 16: Maintaining Encryption Expert" of the IBM InfoSphere Guardium Encryption Expert User's Guide, which is linked to from the Resources section.
Protecting database backup images
Encryption Expert uses a hybrid encryption algorithm for encrypting database backup images. A symmetric key is dynamically created and used for encrypting a database backup image. The symmetric key itself is encrypted by one or more asymmetric keys (public keys). For symmetric encryption algorithms, you can use either AES128 or AES256. For asymmetric encryption algorithms, you can use RSA1024, RSA2048, or RSA4096.
You can import public keys created by other Encryption Expert security servers. By doing so, a database backup image encrypted by one DB agent and managed by one security server, can be restored to another DB agent managed by another security server.
Figure 6 shows an overview of how Encryption Expert provides protection for a database backup image. The figure shows backup agents for both IDS and DB2, but you cannot use both agents on the same machine. An offline policy that contains multiple backup rules and restore rules can be applied to a machine. Backup and restore operations with the DB agent are logged for audit and sent to the security server by default.
Figure 6. Protect database backup image
Integrating with DB2 backup and restore
You can issue the DB2 backup command with an external module as an option. This enables you to use the DB2 agent module with a backup, which enables you to encrypt a database backup image by communicating with the security server. The database backup image contains the DB2 agent module and information required for decrypting it. The DB2 restore command invokes the DB2 agent contained in the database backup image, and the DB2 agent decrypts it by communicating with the security server.
You can also issue the DB2 restore command with an external module as an option. When an external module is specified, it is used instead of the module contained in the database backup image. If the DB2 agent is upgraded after you backup the database and you want to use the upgraded module, specify the module with the DB2 restore command.
Listing 5 contains an example of a DB2 backup command using the DB2 agent module.
Listing 5. DB2 backup command example
% DB2 BACKUP DB dbname compress comprlib /opt/IBM/DB2TOOLS/LUWEncryptionExpert/agent/db2/lib/libeetdb2.so
You can use other options with the above syntax such as
USE TSM to specify use of Tivoli Storage
Listing 6 contains an example of a DB2 restore command using the DB2 agent module.
Listing 6. DB2 restore command example
% DB2 RESTORE DB dbname
Integrating with IDS backup and restore
There are two types of backup in IDS: ontape and onbar. In both cases, you can specify the IDS agent executable module in the $INFORMIXDIR/etc/$ONCONFIG configuration file. The IDS agent executable module needs an attribute file that describes how to handle data. Use the -f option to identify the attribute file. You can use RAW device to encrypt and backup for IDS. The method to encrypt and backup RAW device is same sa normal db space.
Listing 7 shows an example of a configuration file.
Listing 7. IDS configuration file example
BACKUP_FILTER '/opt/IBM/DB2TOOLS/LUWEncryptionExpert/agent/ids/bin/eetidsagt -f /home/info rmix/attr.w' RESTORE_FILTER '/opt/IBM/DB2TOOLS/LUWEncryptionExpert/agent/ids/bin/eetidsagt -f /home/inf ormix/attr.r'
Listing 8 shows an example of a backup attribute file (attr.w).
Listing 8. Example of a IDS agent attribute file for backup
ENV=INFORMIXSERVER, SERVERNUM OPERATION=write
In the example in Listing 8, the attribute file specifies that:
- INFORMIXSERVER and SERVERNUM environment variables are used for evaluating conditions of the policy.
- This is for backup.
Listing 9 shows an example of a restore attribute file (attr.r).
Listing 9. Example of IDS agent attribute file for restore
ENV=INFORMIXSERVER, SERVERNUM OPERATION=read
In the example in Listing 9, the attribute file specifies that:
- INFORMIXSERVER and SERVERNUM environment variables are used for evaluating conditions of the policy.
- This is for restore.
Listings 10 show and 11 show examples of IDS backup commands.
Listing 10. Example of IDS backup command (onbar)
% onbar -b -w
Listing 11. Example of IDS backup command (ontape)
% ontape -v -s -L 0 -t STDIO > /.../backup.000
Listings 12 and 13 show examples of IDS restore commands.
Listing 12. Example of IDS restore command (onbar)
% onmode -ky % onbar -r
Listing 13. Example of IDS restore command (ontape)
% onmode -ky % cat /.../backup.000 | ontape -r -t STDIO -v
For ontape IDS backups, you also have the option of specifying the IDS agent module as a command that receives the output of the backup or restore command. Listings 14 and 15 show examples of the commands with this option.
Listing 14. Example of IDS backup command (ontape) specifying the IDS agent module
% ontape -v -s -L 0 -t STDIO | /opt/IBM/DB2TOOLS/LUWEncryptionExpert/agent/ids/bin/eetidsagt -f /home/informix/attr.w > /.../backup.000
Listing 15. Example of IDS restore command (ontape) specifying the IDS agent module
% cat /.../backup.000 | /opt/IBM/DB2TOOLS/LUWEncryptionExpert/agent/ids/bin/eetidsagt -f /home/informix/attr.r | ontape -r -t STDIO -v
Table 3. Tested database version
|DB2||v8.1.2 FixPack 15, v9.1 FixPack 8, v9.5 FixPack 5, v9.7 FixPack 1|
|IDS||IDS 10.00 FC10 (64-bit), IDS 11.10 FC3 (64-bit), IDS 11.50 FC6 (64-bit)|
For more information about IDS backup and restore, refer to "Chapter 12: Backing up and restoring IDS databases" of the IBM InfoSphere Guardium Encryption Expert User's Guide, which is linked to from the Resources section.
Configuring the audit log
Use the Management Console to configure parameters for the audit log. Each host and each agent (FS agent, DB2 agent, and IDS agent) has its own configuration. For example, you can specify if the log is sent to the security server, how many logs are sent at once, and the minimum and maximum number of seconds the agent should wait before sending the logs.
If an attempt is made to send a log when all security servers are not working correctly, the log is stored in a temporary file on the agent. Retry attempts are made after the minimum time interval specified for sending logs. This does not affect the application's ability to access the guard points.
For more information about configuring the audit log, refer to "Chapter 15: Setting Preferences" of the IBM InfoSphere Guardium Encryption Expert User's Guide, which is linked to from the Resources section.
Maintaining X.509 certificates
Each X.509 certificate published by the primary server has an expiration date. The expiration period of X.509 certificates for the CA and the primary server is 10 years. The expiration period for other certificates is 4 years.
The following list shows the directories that X.509 certificates are in. The CA's certificates are created on the primary server. The CA's certificates are copied to the failover servers and the agents when creating and registering their certificates.
- Security server (primary and failover)
- FS agent
- DB2 agent
- IDS agent
Listing 16 shows an example of the command you can use to view an X.509 certificate. An example of why you might want to do this would be to verify the expiration date of a certificate.
Listing 16. Command syntax for browsing X.509 certificate
openssl x509 -in filename -noout -text
In the command, filename is the X.509 certificate file name under the directory as shown in the list above.
Listing 17 shows an example of the information that is returned from the command for viewing an X.509 certificate.
Listing 17. X.509 certificate example
Certificate: Data: Version: 3 (0x2) Serial Number: 0c:82:d5:ad:e7:f2:b0:fd:d7:22:14:e2:9f Signature Algorithm: sha1WithRSAEncryption Issuer: CN=EET CA (S) on srv1.yamato.ibm.com, OU=I, O=IBM, L=Yamato, ST=Kanagawa, C=JP // Issuer: Certificate Authority (CA) Validity Not Before: Dec 14 06:52:41 2008 GMT Not After : Dec 14 06:52:41 2012 GMT // Expiration date Subject: OU=This agent certificate was automatically generated, CN=EET FS_VMD Agent on host1.yamato.ibm.com // Subject: primary server, failover server, or agent .....
To verify the expiration date of each Encryption Expert component, check the X.509 certificate files shown in Table 4. The table shows the certificate file name and expiration period for each Encryption Expert component.
Table 4. X.509 certificate information
|Encryption Expert component (Subject)||X.509 Certificate File (one of them)||Expiration Period|
|Primary server||donkey_server_hostname-cert.pem||10 years|
|Failover server||donkey_server_hostname-cert.pem||4 years|
Listing 18 shows the command to renew the CA's X.509 certificates. Issue the command on the primary server.
Listing 18. Command to renew the CA's X.509 certificates
When you renew the CA's X.509 certificates, other X.509 certificates are invalidated. Therefore you also need to renew the X.509 certificates for the primary server, the failover servers, and the agents.
Listing 19 shows the two commands you can use to renew the primary server's X.509 certificates.
Listing 19. Commands to renew the primary server's X.509 certificates (use one or the other)
# /opt/IBM/DB2TOOLS/LUWEncryptionExpert/server/bin/re_gen_cert # /opt/IBM/DB2TOOLS/LUWEncryptionExpert/server/bin/re_sign_cert
re_gen_cert command recreates the key. The
re_sign_cert command reuses the key.
Listing 20 shows the two commands you can use to renew the failover server's X.509 certificates.
Listing 20. Commands to renew the failover server's X.509 certificates (use one or the other)
# /opt/IBM/DB2TOOLS/LUWEncryptionExpert/server/bin/re_gen_failover_cert # /opt/IBM/DB2TOOLS/LUWEncryptionExpert/server/bin/re_sign_failover_cert
re_gen_failover_cert command recreates the
re_sign_failover_cert reuses the key.
To renew the agent's X.509 certificates, do the following:
- From the agent machine, issue the following commands to delete the
appropriate agent's X.509 certificates.
To delete the FS agent's X.509 certificate:
# /opt/IBM/DB2TOOLS/LUWEncryptionExpert/agent/vmd/bin/register_host clean
To delete a DB2 agent's certificates:
# /opt/IBM/DB2TOOLS/LUWEncryptionExpert/agent/db2/bin/register_host clean
To delete an IDS agent's certificates:
# /opt/IBM/DB2TOOLS/LUWEncryptionExpert/agent/ids/bin/register_host clean
- Select the host in the Management Console. Clear the Registration Allowed check boxes, and click Apply. As a result, Certificate Fingerprint becomes empty.
- From the Management Console, check the Registration Allowed check boxes .
- From the agent machine, issue the following commands to register the
appropriate agent's X.509 certificates.
To register the FS agent's certificates:
To register a DB2 agent's certificates:
To register an IDS agent's certificates:
- Select the host again in the Management Console. Check the Communication Enabled check boxes, and click Apply.
- If the failover servers are set up, enroll the access points again in
the agent.conf files on the following directories of the host:
- FS agent
- DB2 agent
- IDS agent
- FS agent
For more information refer to the "Configuring an agent to use Security Servers" section of "Chapter 6: Configuring hosts" in the IBM InfoSphere Guardium Encryption Expert User's Guide, which is linked to from the Resources section.
IBM InfoSphere Guardium Encryption Expert protects data with a policy that contains one or more encryption keys and one or more rules for access control. The policies are centrally managed by the security server and are sent to the agents that protect data as necessary. Audit logs for events such as access violations can also be managed by the security server. To ensure high availability requirements, you can set up multiple security servers.
The FS agent provides a feature to encrypt and decrypt data written to or read from file systems. Any application that the policy allows access to can access the files that are under guard points as long as the application uses system libraries to access the files. Data is automatically encrypted when writing, and decrypted when reading, based on the policy. The encryption is transparent to the application, and you do not need to make any changes to the application itself. If the Cached on Host option is enabled with an encryption key, the encryption key is stored on the disk of the FS agent machine with password protection. As a result, the FS agent can work correctly even if all security servers have not been running correctly since the FS agent start-up time. The FS agent process retrieves all related online policies at start-up time and caches them in memory. So after that, the FS agent works correctly even if all security servers become unavailable regardless of whether the Cached on Host option is enabled or not.
The DB agent provides a feature to encrypt and decrypt DB2 and IDS database backup images with controlling backup and restore commands. The DB agent communicates with the security server for the policy every time a backup or a restore command is issued with the DB agent.
SSL protocol is used for communicating between the security server and each agent, and between the primary server and each failover server. X.509 certificates are used for authentication. The X.509 certificates have expiration dates so you should be sure to renew them before they expire.
- Refer to the IBM InfoSphere Guardium Encryption Expert for Linux, UNIX, and Windows User's Guide for more details on using this tool.
- Refer to the IBM InfoSphere Guardium Encryption Expert product web site for system requirements such as supported platforms and supported databases.
- Use the Information Management area on developerWorks as a resource for advancing your skills on DB2, Informix, and many other products in the IBM Information Management portfolio.
- Read how IBM InfoSphere Guardium Encryption Expert works with SAP.
- Find news and links at the Integrated Data Management developerWorks Space.
- Keep up with the latest topics by following the Integrated Data Management expert blog.