Setting up One-time Keys

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One-time keys and certificates allow you to have a large number of individual signing keys and certificates, despite the often limited storage capabilities of HSMs. One-time keys are created on request and are deleted once the signature has been created.

One-time keys use a specific crypto worker called OneTimeCryptoWorker. The crypto worker references a regular crypto token used to generate the short-lived key-pair. Every time a signer requests a crypto instance from the OneTimeCryptoWorker, a new key-pair is generated and a certificate for the public key is obtained from a CA Connector component.

SignServer allows multiple implementations of the CA component. The following describes how to set up one-time keys either using the Self-Signed CA Connector for testing purposes or using the EJBCA Peers CA Connector or the EJBCA WS CA Connector to connect to the EJBCA.

Step 1: Set Up Crypto Worker with Source Crypto Token 

Make sure you have a CryptoWorker with a source PKCS11CryptoToken set up.

The following shows a source crypto worker CryptoTokenP11 sample configuration pkcs11-crypto.properties:

Step 2: Set Up One-time Crypto Worker Referencing the Source Crypto Worker

Next, set up a OneTimeCryptoWorker referencing the source CryptoWorker. You can choose to test the OneTimeCryptoWorker without an actual CA by setting up the Self-signed CA Connector that generates its own self-signed certificate, using the EJBCA Peers CA Connector that uses EJBCA Peer Systems to request certificates from EJBCA, or EJBCA WS CA Connector that connects to EJBCA using Web Services.

Self-Signed CA Connector

The Self-Signed CA Connector generates its own self-signed certificate and is suitable for testing the OneTimeCryptoWorker without requiring a real CA.

To configure the Self-Signed CA Connector and set up a crypto worker referencing the source crypto worker, do the following:

1. Add a new worker using the template onetime-crypto.properties. See OneTimeCryptoWorker properties for details.

   Property	Value
   NAME	Update as appropriate, for example P11 or P12 and possibly slot.
   CACONNECTOR_IMPLEMENTATION	org.signserver.module.onetime.caconnector.SelfSignedCAConnector
   CERTSIGNATUREALGORITHM	SHA256WithRSA

   Example Configuration Sample
   The following shows a sample configuration onetime-crypto.properties for a crypto worker CryptoTokenP11OneTimeSelfSigned:

   Sample Configuration

   WORKERGENID1.TYPE=CRYPTO_WORKER

   WORKERGENID1.IMPLEMENTATION_CLASS=org.signserver.module.onetime.cryptoworker.OneTimeCryptoWorker

   # Name for other workers to reference this worker:

   WORKERGENID1.NAME=CryptoTokenP11OneTimeSelfSigned

   # References a source CryptoToken

   WORKERGENID1.CRYPTOTOKEN=CryptoTokenP11

   # Key generation

   WORKERGENID1.KEYALG=RSA

   WORKERGENID1.KEYSPEC=2048

   # CA Connector: Self-signed demo connector (not using a real CA)

   WORKERGENID1.CACONNECTOR_IMPLEMENTATION=org.signserver.module.onetime.caconnector.SelfSignedCAConnector

    

   # CSR & Certificate Signing

   WORKERGENID1.CERTSIGNATUREALGORITHM=SHA256WithRSA

2. Check that the status of the worker is ACTIVE, either on the SignServer Admin Web Worker Status page, or in the CLI using the command: ./bin/signserver getstatus brief.

EJBCA Peers CA Connector

The EJBCA Peers Connector uses EJBCA Peer Systems to request certificates from an EJBCA instance.

To configure the EJBCA Peers CA Connector and set up a crypto worker referencing the source crypto worker, do the following:

1. Add a new OneTimeCryptoWorker using the template onetime-crypto.properties and make the following changes. See OneTimeCryptoWorker properties for details.

   Property	Value
   NAME	Update as appropriate, for example, P11 or P12, and possibly slot.
   CACONNECTOR_IMPLEMENTATION	Enable the following by removing the comments for the EjbcaWSCAConnector properties: CACONNECTOR_IMPLEMENTATION=org.signserver.module.onetime.caconnector.EjbcaPeersCAConnector CANAME ENDENTITYPROFILE CERTIFICATEPROFILE USERNAME_PATTERN SUBJECTDN_PATTERN SUBJECTALTNAME_PATTERN CERTIFICATESTARTTIME CERTIFICATEENDTIME
   CERTSIGNATUREALGORITHM	SHA256WithRSA

   Example Configuration

   The following shows a sample configuration onetime-crypto.properties for a crypto worker CryptoTokenP11OneTimeEjbcaPeers:

   WORKERGENID1.TYPE=CRYPTO_WORKER

    

   WORKERGENID1.IMPLEMENTATION_CLASS=org.signserver.module.onetime.cryptoworker.OneTimeCryptoWorker

    

   # Name for other workers to reference this worker:

   WORKERGENID1.NAME=CryptoTokenP11OneTimeEjbcaPeers

    

   # References a source CryptoToken

   WORKERGENID1.CRYPTOTOKEN=CryptoTokenP11

    

   # Key generation

   WORKERGENID1.KEYALG=RSA

   WORKERGENID1.KEYSPEC=2048

    

   # CA Connector: EjbcaPeers (using EJBCA through Peer Connections)

   WORKERGENID1.CACONNECTOR_IMPLEMENTATION=org.signserver.module.onetime.caconnector.EjbcaPeersCAConnector

    

   WORKERGENID1.ENDENTITYPROFILE=EMPTY

   WORKERGENID1.CERTIFICATEPROFILE=ENDUSER

   WORKERGENID1.USERNAME_PATTERN=onetime-${transactionId}

   WORKERGENID1.SUBJECTDN_PATTERN=CN=User ${username},UID=${transactionId},O=SignServer Testing,C=SE

    

   # CSR & Certificate Signing

   WORKERGENID1.CERTSIGNATUREALGORITHM=SHA256WithRSA
2. Setup an EJBCA Peer connection as described in Peer Systems and also ensure to enable the Process incoming requests option for the Peer Connector in EJBCA (EJBCA Admin Web>Peer Systems), see EJBCA documentation on Adding an Outgoing Peer Connection.
3. Check that the status of the worker is ACTIVE, either on the SignServer Admin Web Worker Status page, or in the CLI using the command: ./bin/signserver getstatus brief.

EJBCA WS CA Connector

The EJBCA WS CA Connector connects to EJBCA using Web Services.

To configure the EJBCA WS CA Connector and set up a crypto worker referencing the source crypto worker, do the following:

1. Add a new worker using the template onetime-crypto.properties and make the following changes. See OneTimeCryptoWorker properties for details.

   Property	Value
   NAME	Update as appropriate, for example, P11 or P12, and possibly slot.
   CACONNECTOR_IMPLEMENTATION	Enable the following by removing the comments for the EjbcaWSCAConnector properties: CACONNECTOR_IMPLEMENTATION=org.signserver.module.onetime.caconnector.EjbcaWSCAConnector TRUSTSTORETYPE TRUSTSTOREPATH or TRUSTSTOREVALUE (depending on TRUSTSTORETYPE) TRUSTSTOREPASSWORD TLSCLIENTKEY EJBCAWSURL CANAME ENDENTITYPROFILE CERTIFICATEPROFILE USERNAME_PATTERN SUBJECTDN_PATTERN SUBJECTALTNAME_PATTERN CERTIFICATESTARTTIME CERTIFICATEENDTIME
   CERTSIGNATUREALGORITHM	SHA256WithRSA

   Example Configuration Sample
   

   The following shows a sample configuration onetime-crypto.properties for a crypto worker CryptoTokenP11OneTimeEjbcaWS:

   Sample CryptoTokenP11OneTimeEjbcaWS Configuration

   WORKERGENID1.TYPE=CRYPTO_WORKER

    

   WORKERGENID1.IMPLEMENTATION_CLASS=org.signserver.module.onetime.cryptoworker.OneTimeCryptoWorker

    

   # Name for other workers to reference this worker:

   WORKERGENID1.NAME=CryptoTokenP11OneTimeEjbcaWS

    

   # References a source CryptoToken

   WORKERGENID1.CRYPTOTOKEN=CryptoTokenP11

    

   # Key generation

   WORKERGENID1.KEYALG=RSA

   WORKERGENID1.KEYSPEC=2048

    

   # CA Connector: EjbcaWS (using EJBCA through Web Services)

   WORKERGENID1.CACONNECTOR_IMPLEMENTATION=org.signserver.module.onetime.caconnector.EjbcaWSCAConnector

   WORKERGENID1.TRUSTSTORETYPE=JKS

    

   # To trust the TLS certificate of the CA the trust store properties must be configured and contain the issuer (i.e. CA) certificate that issued the TLS server certificate used when connecting to the CA

   WORKERGENID1.TRUSTSTOREPATH=/opt/jboss-eap-6.4-ca/standalone/configuration/keystore/truststore.jks

   WORKERGENID1.TRUSTSTOREPASSWORD=changeit

    

   WORKERGENID1.TLSCLIENTKEY=tls_key

   WORKERGENID1.EJBCAWSURL=https://localhost:9443/ejbca

   WORKERGENID1.ENDENTITYPROFILE=EMPTY

   WORKERGENID1.CERTIFICATEPROFILE=ENDUSER

   WORKERGENID1.USERNAME_PATTERN=onetime-${transactionId}

   WORKERGENID1.SUBJECTDN_PATTERN=CN=User ${username},UID=${transactionId},O=SignServer Testing,C=SE

    

   # CSR & Certificate Signing

   WORKERGENID1.CERTSIGNATUREALGORITHM=SHA256WithRSA

2. To trust the TLS certificate of the CA, the truststore properties must be configured and contain the issuer (i.e. CA) certificate that issued the TLS server certificate used when connecting to the CA. In some cases you can just point out the path to the truststore.jks from the application server where EJBCA is running.

3. Create a TLS client key (tls_key).
4. Generate a Certificate Signing Request (CSR) for the TLS key created in the step above, get the certificate for the CSR, and install the certificate for the key in the token.
5. Provide Administrator access for the TLS Client certificate under the EJBCA CA Administration section, to enable the TLS client to access the CA resource (Web Service).

6. Check that the status of the worker is ACTIVE, either on the SignServer Admin Web Worker Status page, or in the CLI using the command: ./bin/signserver getstatus brief.

Step 3: Set Up Signer with One-time Key

Configure a signer (for example the XAdESSigner) to use the following properties of your newly created CryptoWorker.

Since the user credentials are used in the certificate issuance, the signer needs to use a username or username/password authorizer, see OneTimeCryptoWorker.

Example Configuration Sample

The following shows a sample configuration xadessigner.properties for a CryptoTokenP11OneTimeEjbcaWS:

Step 4: Test and Verify Signing with One-time Keys

You can now test to sign using SignClient or test the performance using the stresstest tool.

Test Signing with SignClient

To test signing using the SignServer CLI SignClient, run the following:

Note that a new certificate with a new key is used every time.

Signature Verification

• To verify the CMS Signature through OpenSSL, run the following:

  openssl cms -verify -in output.p7s -inform DER -content input.txt -CAfile cacert.pem > /dev/null

• To verify the code signature with jarsigner, run the following:

  jarsigner -verify -strict HelloJar_Signed.jar -certs

Performance Test using Stresstest Tool

To run a performance test using the stresstest tool, run the following:

For more information on using the stresstest tool, see Stresstest CLI.