Using Fortanix Self-Defending KMS with IBM DB2

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Introduction

IBM Db2® is a family of hybrid data management products offering a complete suite of AI-empowered capabilities designed to help you manage both structured and unstructured data on-premises as well as in private and public cloud environments. Db2 is built on an intelligent common SQL engine designed for scalability and flexibility.

Why use Fortanix Self-Defending KMS with IBM DB2

Db2® native encryption uses a two-tier approach to data encryption. Data is encrypted with a Data Encryption Key (DEK), which is in turn encrypted with a Master Key (MK). The encrypted DEK is stored with the data while the MK is stored in a keystore external to Db2.

Db2 native encryption ensures that the DEK is never exposed outside of the encrypted database, transaction log, or backup file. There are no interfaces provided to access the DEK in either its clear text or encrypted forms. As the MK is stored in a different location from the encrypted data, the chance of the encrypted DEK being concurrently exposed with the MK used to encrypt it is very unlikely. Since the risk of the DEK being exposed is extremely low, the need to rotate it is negligible. The rotation of the MK, which is used to protect the DEK, can be done efficiently without the need to decrypt and re-encrypt the data.

The Db2 database system supports SSL, which means that a Db2 client application that also supports SSL can connect to a Db2 database by using an SSL socket. CLI, CLP, and .Net Data Provider client applications and applications that use the IBM® Data Server Driver for JDBC and SQLJ (type 4 connections) support SSL.

Prerequisites

  • Fortanix Self-Defending KMS
  • IBM DB2
  • Access to create a certificate for KMIP Server

Adding App in Fortanix Self-Defending KMS

  1. Add an app in the Fortanix Self-Defending KMS in an appropriate group or a new group. For instructions on how to add a group or app please refer to the Self Defending KMS Getting Started Guide. 1.png
                                                           Figure 1: Create New App
  2.  Once you have added the application, note down its App-ID by copying App UUID from the App table view by clicking the icon for “Copy UUID” as shown below. You will need this App-ID for the certificate 2.png
                                                           Figure 2: Copy UUID

If an App / Client needs to authenticate to Fortanix Self-Defending KMS using the only certificate, then the App ID needs to be embedded in the certificate in one of the following ways:

  • Provided as the value of a custom OID in the certificate 1.3.6.1.4.1.49690.1.2.1
  • Standard human-readable UUID encoding: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxx provided as the value of CN.

CN example: c2ba663a-4a09-4c9d-a32f-4608e4d8c20c

Configuration on IBM DB2

Create Folders for Certificates and Config File

  1. Log in to the IBM DB2 machine and log in as the DB user as shown in the following screenshot. 3.png
                                               Figure 3: Login to IBM DB2 as a DB user
  2. Next, create folders so as to bifurcate the certificates and config file.
    1. KMIP (For Config file)
    2. SDKMS_Certs ( For all the certificates)
  3. Create a self-signed certificate and make sure that you should have the App-ID handy as we need to update the Common name for the self-signed certificate.
    1. Change directory to SDKMS_Certs and run the following command.
    openssl req -newkey rsa:2048 -nodes -keyout private.key -x509 -days 365 -out certificate.crt
    4.png
                                                                Figure 4: Create self-signed certificate
    5.png
                                                                Figure 5: Certificate generated
  4. Now go back to the Fortanix Self-Defending KMS UI and change the application’s authentication method to Certificate and paste or upload the certificate that was generated in Step 3 above. 6.png
                                       Figure 6: Upload certificate in Fortanix Self-Defending KMS
  5. Update the certificate in the authentication method.
  6. Make sure you change the configuration to KMIP from default i.e. REST API.
  7. Now import the private key and certificate into the SSL key store, you need to combine the private key and certificate into one.
    Note.png NOTE:
    • The certificate should come first, followed by the private key. Combine them as follows.
    • We give this entry label which will be used in the KMIP configuration file. Make a note of the label.
    • Depending on where you are running this command from, tweak the path of the "sdkms.pem" file. 
      cat certificate.crt private.key > sdkms.pem
      7.png
                                                             Figure 7: Combine cert and private key

Create the SDKMS-KMIP.P12 and Stashed File

gsk8capicmd_64 -keydb -create -db "sdkms-kmip.p12" -pw "sdkms-kmip.pWd" -type pkcs12 -stash

In case you get an error that the gsk8capicmd_64 command is not found; you need to export the libraries for gsk8capicmd_64 from sqllib.

Linux Environments:

export LD_LIBRARY_PATH=$HOME/sqllib/lib64/gskit:$LIBPATH
export PATH=$HOME/sqllib/gskit/bin:$PATH

Re-run the above command to create .p12 and stash file. In the following screenshot sdkms-kmip.p12 and sdkms-kmip.sth file is created.

8.png
                                                       Figure 8: Create .p12 and stash file

Add Client Cert and Key to SSL Keystore

  1. Add client cert and key to the SSL keystore by running the following command: 
    gsk8capicmd_64 -cert -add -db "sdkms-kmip.p12" -stashed -label "sdkms_app_cert" -file "sdkms.pem"
  2. Find the CA certificate from your Fortanix Self-Defending KMS installation and copy it into a file CA.pem. Please note that if your CA certificate has a chain then the complete chain must be copied into this file. You can get the complete chain from your Fortanix Self-Defending KMS browser by going to your Fortanix Self-Defending KMS URL and then view certificates and download the certificate chain.
    Since we are using https://sdkms.fortanix.com,  let us get the CA Certificate from the UI.
  3. In the IBM shell, create the CA.pem file using the following command. 
    touch CA.pem
  4. Perform vi on CA.pem and then paste the certificate information to give the following output. 9.png
                                                     Figure 9: Output of CA.pem

Import CA Certificate into SSL Keystore

Import CA Certificate into the SSL keystore by running the following command:

gsk8capicmd_64 -cert -add -db "sdkms-kmip.p12" -stashed -label "trustedCA" -file CA.pem

List Certificate in the Keystore

List certificate in your keystore to verify everything is fine by running the following command

gsk8capicmd_64 -cert -list -db sdkms-kmip.p12 -stashed

10.png
                                                                   Figure 10: List certificates

Create a KMIP config file in the KMIP folder.

11.png
                                                             Figure 11: Create a KMIP Config file

Note.png NOTE:

  •  Update the path of SSL_KEYDB and SSL_KEYDB_STASH based on your setup.
  •  SSL_KMIP_CLIENT_CERTIFICATE_LABEL must match the label you used when you created the key store.
  • Set value of MASTER_SERVER_HOST to point to your Fortanix Self-Defending KMS cluster.

Configure a DB2 Instance to Use a Keystore

  1. To configure a Db2 instance to use a keystore for native encryption, you need to set two database manager configuration parameters: keystore_type  and keystore_location.
  2. For a centralized keystore, where the key manager product uses the Key Management Interoperability Protocol (KMIP), set keystore_type to "KMIP", and set keystore_location to the absolute path and file name of the centralized keystore configuration file.
  3. To do this run the following command: 
    db2 update dbm cfg using keystore_location /mnt/blumeta0/home/db2inst1/KMIP/kmip.cfg keystore_type kmip
    12.png
                                                         Figure 12: Set keystone type and location
  4. To get the keystore changes to take effect. We need to restart the DB2 again.
    The command to stop the DB2:
    db2stop
  5. The command to start the DB2:
    db2start
    13.png
                                                         Figure 13: Stop and start the DB2
  6.  Verify that the dbm cfg is set correctly by running the following command. Look at value of Keystore type and keystore location.
    db2 get dbm cfg
    14.png
                                                         Figure 14: Verify database manager configuration

Create an Encrypted Database

  1. Create an encrypted database using the following command:
    db2 create db mydb1 encrypt
    15.png
                                            Figure 15: Create encrypted database
  2. Once you create the database you can find the Master key created in Fortanix Self-Defending KMS as shown below.
    16.png
                                                               Figure 16: Master key created
  3. You can find the Activity logs in the Application tab as below.
    17.png
                                                               Figure 17: Activity logs

In Case you are getting any error in your environment. Then you need to troubleshoot the certificate and network-related issue so that we can communicate to the Fortanix Self-Defending KMS.

Rotating Master Keys in Fortanix Self-Defending KMS with IBM DB2

Rotating your encryption keys is part of a complete security policy. And as with passwords, how often is a controversial topic. This article is intended to give you information to make an informed decision about how and when to rotate your encryption keys. The focus is the keys that protect your data at rest and do not discuss SSL certificates.

IBM Db2 native encryption uses a 2-tier approach to data encryption where the data is encrypted with a Data Encryption Key (DEK) and the DEK itself is encrypted with a Master Key (MK). The encrypted DEK is stored with the data while the MK is stored in a keystore external to Db2.

As the master key is stored outside of the database manager, the requirement and frequency to rotate the master key depend on the type of keystore in use and the protections provided by the keystore. A local keystore file is protected by a password and operating system file permissions, however, it is owned by the Db2 Instance Owner, which is often a shared service account. In such an environment policy to rotate the master key on a regular basis would be natural. On the other extreme, master keys protected by Hardware Security Modules (HSM) require much less rotation if at all. Master keys protected by an HSM never leave the secure confines of the hardware device and strong controls exist to prevent the key from being extracted. Master keys accessed from a KMIP server fall somewhere in the middle. Strong controls exist within the KMIP server to authorize who has access to the master keys and audit their usage. However, these servers are often deployed as software running on a traditional operating system and servers and are only as secure as the environment in which they are deployed. On the other hand, there are secure HSMs offering KMIP interfaces. A key rotation schedule would be suggested by the security hardening of the KMIP server and the environment in which it is deployed.

Db2 provides routine SYSPROC.ADMIN_ROTATE_MASTER_KEY() to rotate the database master key to a new value. This operation decrypts the database DEK and re-encrypts it with the new master key.

The 2-tier approach ensures that the key used to encrypt the data, the DEK, is never exposed outside of the encrypted database, transaction log, or backup and no interfaces exist within Db2 to access the DEK. Since the MK is stored in a different location from the encrypted data, this makes concurrent exposure of the encrypted data and the MK much less likely again reducing risk. Finally, since the DEK is not exposed, there is little reason to rotate it, and rotation of the MK used to protect the DEK, can be done efficiently without the need to decrypt and re-encrypt the data itself.

Steps for Rotating Keys in DB2

  1. List your DB directory.
    18.1.png
                                                               Figure 18: List DB directory
  2. Connect the DB to the same database.
    19.2.png
                                                         Figure 19: Connect DB
  3. Check the encryption info from the below command.
    20.png
                                                                  Figure 20: Check encryption info
  4. Now rotate the master key from DB2
    21.1.png
                                                         Figure 21: Rotate master key
  5. Once the key is rotated, check on Fortanix Self-Defending KMS end if the Master Key is rotated.
    22.1.png
                                                        Figure 22: Check in Fortanix Self-Defending KMS
    You will find a new key created in Fortanix-Self Defending KMS.