Configuring KMIP Encryption

Set up encryption using keys from a Key Management Interoperability Protocol (KMIP) host to protect sensitive configuration file properties, system resources, and tables.

DataStax recommends using KMIP key server security policies to limit the number of nodes in the cluster that can remotely manage keys, due to the risks associated with expiring, revoking, and destroying keys.

Use OpsCenter to monitor KMIP server status. See Configuring an alert for KMIP errors.

Adding a KMIP Host

DataStax Enterprise supports using encryption keys from one or more remote Key Management Interoperability Protocol (KMIP) hosts to encrypt or decrypt table data or sensitive properties, or both, in the dse.yaml and cassandra.yaml configuration files.

The location of each configuration file depends on the type of installation:

Configuration File Location
Filename	Package installations	Tarball installations
`cassandra.yaml`	`/etc/dse/cassandra/cassandra.yaml`	`<installation_location>/resources/cassandra/conf/cassandra.yaml`
`dse.yaml`	`/etc/dse/dse.yaml`	`<installation_location>/resources/dse/conf/dse.yaml`

Follow these steps to add a KMIP server information to the list of available hosts.

DataStax recommends limiting the number of nodes that can remotely manage KMIP keys using a security policy on the KMIP host.

Procedure

Perform all steps on every node in the cluster.

Set up KMIP agents and registered DSE with the KMIP service:

Refer to the KMIP key provider documentation for detailed steps.
1. Download and install the KMIP agent.
2. Connect to the KMIP host.
3. Register the DSE node.
4. Locate the SSL key pair generated by the KMIP agent.
Convert the key pair from PEM to a DSE compatible JKS format:
1. Secure the KMIP agent private key files by removing read access for all users. For example, the Vormetric DSM agents creates two files named kmip-key.pem and kmip-<host_name>.pem.
2. Copy both keys to another directory, such as your home directory.
3. Generate a PKCS12 format file from the PEM files:
  openssl pkcs12 -export -out <kmip_keystore>.p12 -inkey <kmip-key.pem> -in <kmip-host_name.pem>
  Where <kmip_keystore>.p12 is the output file name and <kmip-host_name.pem> is part of the key pair created by the KMIP agent.

Due to an OpenSSL issue, you cannot use a PKCS12 truststore that was generated via OpenSSL. For example, a truststore generated via the following command will not work with DSE:

openssl pkcs12 -export -nokeys -out truststore.pfx -in <intermediate.chain.pem>

However, truststores generated via Java’s keytool and then converted to PKCS12 work with DSE. Example:

keytool -importcert -alias <rootca> -file <rootca.pem> -keystore <truststore.jks>

keytool -importcert -alias <intermediate> -file <intermediate.pem> -keystore <truststore.jks>

keytool -importkeystore -srckeystore <truststore.jks> -destkeystore <truststore.pfx> -deststoretype pkcs12

Create a JKS keystore:
```
keytool -importkeystore -destkeystore <kmip_keystore.jks> -srcstoretype PKCS12 -srckeystore <kmip_keystore.p12>
```
Where
- <kmip_keystore.jks> is the keystore file name that is created
- <kmip_keystore.p12> is the PKC12 file generated in the previous step
  
  Enter a password for the keystore at the prompt and fill out the host information.
Install the KMIP root certificate into the JKS truststore:
```
keytool -import -alias <kmipCA> -file <kmip-host_CA.pem> -keystore <kmip_truststore.jks>
```
Enter a password for the truststore at the prompt and fill out the host information.
Move the keystore and truststore to a directory accessible by DSE and change the file to allow the DSE account read/write access.
Delete or secure the files used to create the keystore and truststore.
1. Add the host details to the kmip_hosts section of the dse.yaml:
  kmip_hosts: <kmip_group_name>: hosts: <FQDN>[, <FQDN> , ...] keystore_path: </etc/dse/conf/kmip_keystore.jks> keystore_type: jks keystore_password: <password> truststore_path: </etc/dse/conf/kmip_truststore.jks> truststore_type: jks truststore_password: <password> key_cache_millis: <N> timeout: <N> protocol: <protocol> cipher_suites: <supported_cipher>
  - Required settings:
    
    <kmip_group_name>: User-defined group name that identifies the KMIP host in DSE related commands.
    
    hosts: Comma separated list of Fully-Qualified Domain Names (FQDN) of KMIP hosts. DSE tries the hosts in the order listed.
    
    keystore_path: Location of the keystore created in 2.
    
    keystore_type: jks Keystore format. Must be set to jks.
    
    keystore_password: Password of the keystore file created in 2.
    
    truststore_path: Location of the truststore file created in 2.
    
    truststore_type: jks Truststore format. Must be set to jks.
    
    truststore_password: Password of the truststore file created in 2.
  - Optional settings:
    
    key_cache_millis: <N> where N is the interval at which DSE refreshes the key cache on the node in milliseconds. The default is 300000 (five minutes).
    
    timeout: <N> where N is the socket timeout in milliseconds. The default is 1000.
    
    protocol: <protocol> for communicating between the node and KMIP key server. When not specified, JVM default is used.
    
    cipher_suites: supported_cipher for communicating between the node and KMIP key server. When not specified, JVM default is used.
2. Verify that the node can connect to the KMIP host by listing encryption keys on the remote KMIP server:
  dsetool managekmip list <kmip_group_name>
  dsetool picks up dse.yaml changes without requiring a restart.
  
  If problems connecting to the KMIP server occur, see Troubleshooting KMIP connections.
3. Repeat these steps on all nodes in the cluster.

Encrypting Configuration File Properties

Configure DSE to use a Key Management Interoperability Protocol (KMIP) encryption key to decrypt sensitive configuration properties. Use passwords encrypted with the KMIP key for the following properties:

dse.yaml LDAP values:
```
ldap_options.search_password
ldap_options.truststore_password
```
Restriction: Use plain text for the KMIP keystore or truststore passwords.

cassandra.yaml SSL values:

server_encryption_options.keystore_password
server_encryption_options.truststore_password
client_encryption_options.keystore_password
client_encryption_options.truststore_password

DataStax Enterprise caches encryption keys from the KMIP host and refreshes the cache at the interval set by the key_cache_millis property; the default setting is five minutes.

The location of each configuration file depends on the type of installation:

Configuration File Location
Filename	Package installations	Tarball installations
`cassandra.yaml`	`/etc/dse/cassandra/cassandra.yaml`	`<installation_location>/resources/cassandra/conf/cassandra.yaml`
`dse.yaml`	`/etc/dse/dse.yaml`	`<installation_location>/resources/dse/conf/dse.yaml`

Prerequisites

Complete the steps in Adding a KMIP host.

If any of the defined KMIP groups are not available, DSE startup fails.

Procedure

Back up the configuration files.

Get the URL of the KMIP encryption key:

To create a new key and get the URL:
```
dsetool createsystemkey '<AES/ECB/PKCS5>' <128> -k <kmip_group_name>
```
The example output shows the URL for the host_name in the dse.yaml with ID: 02-1655.
```
kmip://<host_name>/02-1655
```

To use an existing KMIP key, the URL syntax is kmip://<kmip_group_name>/<ID>. To look up the key ID:

dsetool managekmip list <kmip_group_name>

For example, the host_name has the following keys:

Keys on <host_name>:
    ID                                     Name               Cipher         State                Activation Date   Creation Date              Protect Stop Date   Namespace
02-449   82413ef3-4fa6-4d4d-9dc8-71370d731fe4_0        AES/CBC/PKCS5   Deactivated   Mon Apr 25 20:25:47 UTC 2016             n/a                            n/a         n/a
02-540   0eb2277e-0acc-4adb-9241-1dd84dde691c_0                  AES        Active   Tue May 31 12:57:59 UTC 2016             n/a                            n/a`

The URL of the second key in the list is kmip://<host_name>/02-540.

Configure system property encryption settings in the dse.yaml.
1. Enable system property encryption:
  config_encryption_active: true
2. Set the URL of the KMIP key used to decrypt properties:
  config_encryption_key_name: <KMIP_key_URL>
  Where <KMIP_key_URL> format is kmip://kmip_group_name/key-id, for example kmip://<host_name>/02-1655.
For each property, replace plain text passwords with encrypted passwords returned by running the dsetool encryptconfigvalue command:
1. Encrypt the password:
  dsetool encryptconfigvalue
  Using system key system_key Enter value to encrypt: Enter again to confirm: Your encrypted value is: +Vj5oHCR/jqfA+OJE2m8zA==
2. Replace the old value with the new value in the configuration file, for example the SSL truststore password in the cassandra.yaml file:
  truststore_password: +Vj5oHCR/jqfA+OJE2m8zA==
  After the configuration file property encryption is enabled, DSE startup fails if any of the protected properties are not encrypted.
Optional: Set up system resource encryption.
Perform a rolling restart.

Encrypting system resources

Use a KMIP key to encrypt the system.batchlog and system.paxos tables, hint files and commit logs.

Prerequisites

Complete the steps in Adding a KMIP host.

If any of the defined KMIP groups are not available, DSE startup fails.

Procedure

Locate the dse.yaml configuration file. The location of this file depends on the type of installation:
- Package installations: /etc/dse/dse.yaml
- Tarball installations: <installation_location>/resources/dse/conf/dse.yaml
In the dse.yaml file, configure encryption settings for system tables, the commit log, and the hints files.
```
system_info_encryption:
  enabled: ( true | false )
  cipher_algorithm: <cipher_name>
  secret_key_strength: <length>
  key_provider: KmipKeyProviderFactory
  kmip_host: <kmip_group_name>
  chunk_length_kb: 64
```
- Required properties:
  - enabled: Set to true. On the next startup, system resources are encrypted. If the system tables have existing data, use nodetool upgradesstables to apply encryption.
  - key_provider: Set to KmipKeyProviderFactory.
  - kmip_host: Use the group name from the kmip_hosts section.
- Optional: To ensure that KMIP generates a compatible key, configure the type of encryption key to use:
  - cipher_algorithm: Set the name of a supported JCE cipher algorithm to use. DSE supports the following algorithms:
    
    Supported cipher algorithm names
    
    cipher_algorithm secret_key_strength
    
    AES
    
    128, 192, or 256
    
    DES
    
    56
    
    DESede
    
    112 or 168
    
    Blowfish
    
    32-448
    
    RC2
    
    40-128
  - secret_key_strength: Specify the key length.
  - chunk_length_kb: Configures chuck size for SSTables. The default 64 is used if the option is excluded. When these properties are set, DSE only uses a key that matches; if no matching key exists, start up fails.
Perform a rolling restart.
To encrypt existing data, run nodetool upgradesstables -a system batchlog paxos on all nodes in the cluster.

Supported cipher algorithm names
cipher_algorithm	secret_key_strength
AES	128, 192, or 256
DES	56
DESede	112 or 168
Blowfish	32-448
RC2	40-128

Encrypting table data

Encrypt data stored in a table using a Key Management Interoperability Protocol (KMIP) key.

Starting with DSE 6.8, when Transparent Data Encryption (TDE) is enabled, all header data in indexes are encrypted, including partition keys in SSTable indexes. This feature is designed to protect sensitive data that might be present in the primary key. Consequently, DSE cannot access SSTables that are not decryptable.

When non-decryptable SSTables are present, DSE issues an error message during startup. If the error is ignored because the disk failure policy is specified as either ignore or best_effort, then DSE skips the non-decryptable SSTable and therefore ignores its content on queries without issuing a warning or error.

Prerequisites

Complete the steps in Adding a KMIP host.

If any of the defined KMIP groups are not available, DSE startup fails.

Procedure

Locate the dse.yaml configuration file. The location of this file depends on the type of installation:
- Package installations: /etc/dse/dse.yaml
- Tarball installations: <installation_location>/resources/dse/conf/dse.yaml
To create a new encrypted table using a key from a KMIP server:
- Encryption without compression:
  CREATE TABLE customers ... WITH COMPRESSION = { 'class': 'Encryptor', 'key_provider': 'KmipKeyProviderFactory', 'kmip_host': 'kmip_group_name' ['key_keyspace': 'kmip_keyspace'], 'cipher_algorithm': 'AES/ECB/PKCS5Padding', 'secret_key_strength': 128 };
  - 'key_provider': 'KmipKeyProviderFactory' tells the encryptor to use a KMIP key server to manage its encryption keys. Include the 'key provider' entry only to specify to use a KMIP key server, otherwise omit this entry.
  - 'kmip_host': 'kmip_group_name' specifies the user-defined KMIP key server group name defined in the kmip_hosts section of the dse.yaml file.
  - 'kmip_host': 'kmip_group_name' ['key_keyspace': 'kmip_keyspace'] specify an optional KMIP keyspace. Use keyspaces to allow granular management of keys on a per table or keyspace basis.
- Compression and encryption:
  CREATE TABLE customers ... WITH COMPRESSION = { 'class': 'EncryptingDeflateCompressor', 'key_provider': 'KmipKeyProviderFactory', 'kmip_host': 'kmip_group_name', 'cipher_algorithm': 'AES/ECB/PKCS5Padding', 'secret_key_strength': 128 };
To encrypt a pre-existing table:
1. Change the table compression settings:
  - Encryption without compression:
    
    ALTER TABLE customers ... WITH COMPRESSION = { 'class': 'Encryptor', 'key_provider': 'KmipKeyProviderFactory', 'kmip_host': 'kmip_group_name' ['key_keyspace': 'kmip_keyspace'], 'cipher_algorithm': 'AES/ECB/PKCS5Padding', 'secret_key_strength': 128 };
    
    'key_provider': 'KmipKeyProviderFactory' tells the encryptor to use a KMIP key server to manage its encryption keys. Include the 'key provider' entry only to specify to use a KMIP key server, otherwise omit this entry.
    
    'kmip_host': 'kmip_group_name' specifies the user-defined KMIP key server group name defined in the kmip_hosts section of the dse.yaml file.
    
    ['key_keyspace': 'kmip_keyspace'] specify an optional KMIP keyspace. Use keyspaces to allow granular management of keys on a per table or keyspace basis.
  - Compression and encryption:
    
    ALTER TABLE customers ... WITH COMPRESSION = { 'class': 'EncryptingDeflateCompressor', 'key_provider': 'KmipKeyProviderFactory', 'kmip_host': 'kmip_group_name', 'cipher_algorithm': 'AES/ECB/PKCS5Padding', 'secret_key_strength': 128 };
2. Encrypt existing data on all nodes in the cluster:
```
nodetool upgradesstables -a [keyspace_name [table_name[ tablename]...]
```

Expiring an encryption key

Security policies generally limit the amount of time an encryption key is in use. This section describes how to expire a key without re-encrypting the existing data. After a key expires, it is no longer used to encrypt new data, but it is still used to decrypt existing data.

To change the key used for both encryption and decryption, see Rekeying tables using a new key.

Procedure

Locate the dse.yaml configuration file. The location of this file depends on the type of installation:
- Package installations: /etc/dse/dse.yaml
- Tarball installations: <installation_location>/resources/dse/conf/dse.yaml

Get a list of the available keys and states from the KMIP server:

dsetool managekmip list kmip_group_name

In this example result, a host named vormetricgroup has two keys:

Keys on vormetricgroup:
    ID                                     Name               Cipher         State                Activation Date   Creation Date              Protect Stop Date   Keyspace
02-449   82413ef3-4fa6-4d4d-9dc8-71370d731fe4_0        AES/CBC/PKCS5   Deactivated   Mon Apr 25 20:25:47 UTC 2016             n/a                            n/a         n/a
02-540   0eb2277e-0acc-4adb-9241-1dd84dde691c_0                  AES        Active   Tue May 31 12:57:59 UTC 2016             n/a                            n/a

DSE supports one or more KMIP hosts. Each KMIP host is defined under a user-defined kmip_group_name in the kmip_hosts section of the dse.yaml.

Expire the key:

Immediately expire the key:

dsetool managekmip expirekey kmip\_group\_name key\_id

Schedule an expiration date:

dsetool managekmip expirekey kmip\_group\_name key\_id datetime

After the key expires, the database gets a new key for encryption the next time it refreshes the key cache (key_cache_millis); the default setting is five minutes. Expired keys are still available to decrypt data.

Optional: Force a refresh of the DSE key cache by performing a rolling restart.

Rekeying tables using a new key

Change the encryption key that is used for both encrypting new data and decrypting the existing data. Use these steps to secure the data after an event that potentially compromised an encryption key, such as a change in security administration staff. Before destroying the old key, revoke the compromised KMIP key, wait for the database key cache refresh, and then re-encrypt existing SSTables with the new key.

The database caches the encryption keys and refreshes the cache at an interval set by the key_cache_millis (default setting is 5 minutes). To get a new key, either wait for the key cache refresh interval or perform a rolling restart.

The dsetool managekmip commands proxies KMIP commands to the corresponding host. The commands affect encryption keys as follows:

expirekey: Database stops using the key for encryption at the specified time and continues to use the expired key to decrypt existing data. Data re-keying is not required.

Use this command to satisfy security policies that require periodic switching of the encryption key.
revoke: Permanently disables the key on the KMIP server. Database can no longer use the key for encryption, but continues to use the key for decryption of existing data. Re-encrypt existing data before completely removing the key from the KMIP server.

Use this command as the first step when replacing a compromised key.
destroy: Completely removes the key from the KMIP server. Database can no longer use the key for encryption or decryption. Existing data that has not been re-encrypted becomes inaccessible.

Use this command only after revoking a key and re-encrypting existing data.

Procedure

Back up SSTables.

Revoke the compromised key using the dsetool managekmip revoke:

Get the ID of the KMIP encryption key you want to revoke from the KMIP server:

dsetool managekmip list <kmip_groupname>

The following is an example of a KMIP server that has two keys, active and deactivated.

ID                                     Name          Cipher         State                Activation Date   Creation Date              Protect Stop Date   Keyspace
02-449   82413ef3-4fa6-4d4d-9dc8-71370d731fe4_0   AES/CBC/PKCS5   Deactivated   Mon Apr 25 20:25:47 UTC 2016             n/a                            n/a         n/a
02-540   0eb2277e-0acc-4adb-9241-1dd84dde691c_0             AES        Active   Tue May 31 12:57:59 UTC 2016             n/a                            n/a         n/a

DSE supports one or more KMIP hosts. Each KMIP host is defined under a user-defined <kmip_group_name> in the kmip_hosts section of the dse.yaml configuration file.

The location of the dse.yaml file depends on the type of installation:

Package installations: /etc/dse/dse.yaml
Tarball installations: <installation_location>/resources/dse/conf/dse.yaml

Revoke the key you want to replace using the ID:

dsetool managekmip expirekey <kmip_groupname> <key_id>

Revoking permanently deactivates the key on the KMIP server. When the key cache refreshes, a new key for encryption or decryption is automatically created. Revoked keys are used to decrypt existing data. DO NOT destroy the revoked key until after re-encrypting the existing data.

Verify that the key State is Deactivated.

dsetool managekmip list kmip_groupname

The following is an example of a KMIP server that has two keys:

ID                                     Name               Cipher         State                Activation Date   Creation Date              Protect Stop Date   Keyspace
02-449   82413ef3-4fa6-4d4d-9dc8-71370d731fe4_0        AES/CBC/PKCS5   Deactivated   Mon Apr 25 20:25:47 UTC 2016             n/a                            n/a         n/a
02-540   0eb2277e-0acc-4adb-9241-1dd84dde691c_0                  AES   Deactivated   Tue May 31 12:57:59 UTC 2016             n/a   Thu Jul 27 17:16:38 UTC 2017

Refresh the database key cache using one of the following methods:
- Wait the amount of time specified in the key_cache_millis setting before continuing to the next step.
- Perform a rolling restart.
KMIP keys are cached on the DSE node. DSE refreshes the cache and a new key is automatically generated by the KMIP server after key_cache_millis lapses; the default setting is 5 minutes.
Optional: Get a list of the affected tables to re-encrypt using the new key using the DESC keyspace command:

For example to find all tables in the cycling keyspace that use the KMIP group:
```
DESC KEYSPACE cycling
```
Use nodetool upgradesstables to rewrite the encrypted SSTables using the new key. Run the following command on every node in the cluster:
- Target only specific tables:
  nodetool upgradesstables --include-all-sstables keyspace_name table_name [table_name …]
- Target specific keyspace:
  nodetool upgradesstables --include-all-sstables keyspace_name
- All keyspaces and tables:
  nodetool upgradesstables --include-all-sstables
Optional: Remove the encryption key so that it is no longer available for decryption:
```
dsetool managekmip destroy <key_id>
```
The backed up SSTables are only accessible using the old key. Ensure that the data is accessible before removing the key.

Troubleshooting KMIP Connections

The following error message may occur if the DataStax Enterprise SSL certificate is self-signed or from a CA that has not been added to the certificate chain on the KMIP server.

WARN 14:46:42,928 Unable to connect to KMIP host: 10.120.15.100:9005
com.cryptsoft.kmip.TTLVReadException: Error reading TTLV ResponseMessage. Got end-of-stream after reading 0 byte(s). Read bytes: (0) []

Ensure that trust between DSE and KMIP host has been properly configured, see Creating local SSL certificate and keystore files.

Configuring KMIP Encryption

Adding a KMIP Host

Procedure

Encrypting Configuration File Properties

Prerequisites

Procedure

Encrypting system resources

Prerequisites

Procedure

Encrypting table data

Prerequisites

Procedure

Expiring an encryption key

Procedure

Rekeying tables using a new key

Procedure

Troubleshooting KMIP Connections

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