PKCS#11 hardware security module
DS servers support key management using a PKCS#11 token store. The PKCS#11 standard defines a cryptographic token interface, a platform-independent API for storing keys in an HSM, for example.
DS servers rely on the PKCS#11 interface and Java APIs to use it. DS servers do not support vendor-specific interfaces.
DS servers use an HSM only to hold asymmetric key pairs and, optionally, CA certificates. (Since the CA certificate holds the CA’s public key, which is not secret, Store it in a separate, file-based keystore or PEM file, not in the HSM.) The asymmetric key pairs you can store in the HSM are the server’s TLS keys, and the shared master key for the deployment. DS servers use the shared master key to wrap symmetric (secret) keys. DS servers store secret keys in the data they encrypt. Therefore, DS servers do not use the HSM for secret keys. |
Using a PKCS#11 device for storing DS keys involves:
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Storing the keys on the PKCS#11 device.
How you generate and store keys in your HSM depends on the device. For details, refer to the documentation for your device.
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Creating the DS PKCS11 key manager provider to access the device.
The DS server accesses a PKCS#11 device using a PIN. The PIN can be provided in the server configuration, in a separate file, or as the value of an environment variable or Java system property. The PIN must be stored as a cleartext value, so take care to protect it in production environments.
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Configuring DS components to use the key manager provider.
For example, DS connection handlers and OAuth 2.0 authorization mechanisms requiring mutual TLS can reference the key manager provider in their configurations.
Prepare the HSM
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Install SoftHSM.
For details, refer to the SoftHSM documentation for details.
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Initialize the SoftHSM device:
$ softhsm2-util --init-token --slot 0 --label "My token 1" --pin password --so-pin password The token has been initialized and is reassigned to slot <number>
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The user PIN is the one the DS server needs to access the device.
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The SO PIN is to reinitialize the token.
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The <number> is the slot number to use in the PKCS#11 configuration.
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Prepare a Java PKCS#11 configuration file to generate key pairs and configure DS.
For example, to use the Java
keytool
command with the device, create a PKCS#11 configuration file for the security provider implementation.The file name is
/path/to/hsm.conf
. Replace <number> in the following example with the slot number from the previous step. If you lost track of the slot number, runsofthsm2-util --show-slots
to view it again:name = SoftHSM library = /usr/local/lib/softhsm/libsofthsm2.so slot = <number> attributes(generate, *, *) = { CKA_TOKEN = true } attributes(generate, CKO_CERTIFICATE, *) = { CKA_PRIVATE = false } attributes(generate, CKO_PUBLIC_KEY, *) = { CKA_PRIVATE = false } attributes(*, CKO_SECRET_KEY, *) = { CKA_PRIVATE = false CKA_EXTRACTABLE = false }
Notes regarding the configuration file:
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The format is described in the Java PKCS#11 Reference Guide.
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The
library
must point to the SoftHSMlibsofthsm2.so
library. -
The
slot
must be one obtained when initializing the device. -
You can find configuration recommendations for production deployments in the platform documentation page, HSMs and platform software.
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Verify Java can access the device using your configuration.
The following example shows how you can use the Java
keytool
command to list the SoftHSM keys:$ keytool \ -list \ -keystore NONE \ -storetype PKCS11 \ -storepass password \ -providerClass sun.security.pkcs11.SunPKCS11 \ -providerArg /path/to/hsm.conf Keystore type: PKCS11 Keystore provider: SunPKCS11-SoftHSM Your keystore contains 0 entries
Store keys for securing connections
The following examples use SoftHSM to store the TLS keys for securing network connections (LDAPS, HTTPS, and so on). Adapt them to your HSM.
Generate a TLS key pair for securing connections
This is the server key pair for securing TLS connections. It can be specific to one DS server, and does not need to be shared.
DS presents the certificate to client applications, so get it signed by a CA they trust.
This example is for evaluation only, and uses localhost
as the hostname and a self-signed certificate:
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Generate a TLS key pair.
The following example generates a key pair with the alias
ssl-key-pair
:$ keytool \ -genkeypair \ -alias ssl-key-pair \ -keyalg EC \ -groupname secp521r1 \ -ext "san=dns:localhost" \ -dname "CN=localhost,O=Example Corp,C=FR" \ -keystore NONE \ -storetype PKCS11 \ -storepass password \ -providerClass sun.security.pkcs11.SunPKCS11 \ -providerArg /path/to/hsm.conf
The keystore password is the user PIN.
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Get the public key certificate signed.
The following example self-signs the certificate:
$ keytool \ -selfcert \ -alias ssl-key-pair \ -keystore NONE \ -storetype PKCS11 \ -storepass password \ -providerClass sun.security.pkcs11.SunPKCS11 \ -providerArg /path/to/hsm.conf
Refer to your HSM documentation for details on getting the certificate signed by a CA.
Create a PKCS#11 key manager provider
Repeat these steps for each DS server:
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Make the plaintext PIN available to the DS server.
With SoftHSM, this is the user PIN set when initializing the slot where you stored the keys,
softhsm2-util --pin password
.The following example sets the PIN in an environment variable:
$ export SOFTHSM_USER_PIN=password
The value must be accessible every time the DS server starts.
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Create the PKCS#11 key manager provider configuration.
The following example creates a provider for SoftHSM:
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The
pkcs11-provider-name:SunPKCS11
setting uses the Java name for the PKCS#11 provider. -
The
pkcs11-provider-arg:/path/to/hsm.conf
setting holds the absolute path to the Java PKCS#11 configuration file. -
The configuration uses the
SOFTHSM_USER_PIN
environment variable to get the PIN.DS key manager providers also support storing the PIN in the configuration, in a file, or in a Java property.
$ dsconfig \ create-key-manager-provider \ --provider-name SoftHSM \ --type pkcs11 \ --set enabled:true \ --set pkcs11-provider-name:SunPKCS11 \ --set pkcs11-provider-arg:/path/to/hsm.conf \ --set key-store-pin:"&{softhsm.user.pin}" \ --hostname localhost \ --port 4444 \ --bindDN uid=admin \ --bindPassword password \ --usePkcs12TrustStore /path/to/opendj/config/keystore \ --trustStorePassword:file /path/to/opendj/config/keystore.pin \ --no-prompt
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Use the PKCS#11 key manager provider
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Set a connection handler or authorization mechanism to use the PKCS#11 key manager provider.
The following example configures the LDAPS connection handler to use the SoftHSM provider:
$ dsconfig \ set-connection-handler-prop \ --handler-name LDAPS \ --set listen-port:1636 \ --set enabled:true \ --set use-ssl:true \ --set key-manager-provider:SoftHSM \ --hostname localhost \ --port 4444 \ --bindDN uid=admin \ --bindPassword password \ --usePkcs12TrustStore /path/to/opendj/config/keystore \ --trustStorePassword:file /path/to/opendj/config/keystore.pin \ --no-prompt
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Verify the secure connection negotiation works with the HSM configured:
$ ldapsearch \ --hostname localhost \ --port 1636 \ --useSSL \ --baseDN dc=example,dc=com \ "(uid=bjensen)" \ cn User DN : CN=localhost, O=Example Corp, C=FR Issuer : CN=localhost, O=Example Corp, C=FR Validity : <validity-period> Do you trust this server certificate? 1) No 2) Yes, for this session only 3) Yes, also add it to a truststore 4) View certificate details Enter choice: [1]: 2 dn: uid=bjensen,ou=People,dc=example,dc=com cn: Barbara Jensen cn: Babs Jensen
Store the shared master key
- Before you start
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Set up DS servers without the
--start
option, and without any data or setup profiles that create base entries or generate data, as if you were following the instructions in Install DS for custom cases.Do not start the DS server until you have configured it to use the shared master key in your HSM, as described below.
The
setup
command requires a deployment ID and password. It generates a shared master key you will discard.However, if you start DS with any data at all, it protects secret keys for encryption with the generated shared master key, and DS must continue to use that shared master key to decrypt the data.
This procedure is therefore not intended for deployments where you are upgrading servers with encrypted data.
The shared master key is an asymmetric key pair with a self-signed certificate. Only DS uses the shared master key, and only for encrypting and decrypting secret keys. DS does not check the hostname or the validity period of the shared master key, so neither matters. When you store the shared master key in an HSM:
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Generate a shared master key pair in the HSM, using
RSA
as the key algorithm.The following example generates a key pair with the alias
master-key
:$ keytool \ -genkeypair \ -alias master-key \ -keyalg RSA \ -keysize 3072 \ -dname "CN=Master key, O=Example.com" \ -keystore NONE \ -storetype PKCS11 \ -storepass password \ -providerClass sun.security.pkcs11.SunPKCS11 \ -providerArg /path/to/hsm.conf
The keystore password is the user PIN.
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For each DS server, create the PKCS#11 key manager provider to access the HSM, as described in Create a PKCS#11 key manager provider, but without starting the server.
For the
dsconfig create-key-manager-provider
command, replace the connection parameters with--offline
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For each DS server, update the Crypto Manager to reference the PKCS#11 key manager provider.
For example, set the key manager provider to
SoftHSM
using the default alias for the key pair,master-key
:$ dsconfig \ set-crypto-manager-prop \ --set key-manager-provider:SoftHSM \ --offline \ --no-prompt
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For each DS server, apply Setup profiles with the
setup-profile
command, and complete any necessary preliminary configuration. -
Start each DS server.