Corda Open Source Edition 4.12 release notes

Corda Open Source Edition 4.12.2 release notes

Corda Open Source Edition 4.12.2 is a patch release of Corda Community Edition focused on resolving issues.

Upgrade recommendation

As a developer or node operator, you should upgrade to the latest released version of Corda as soon as possible. The latest Corda Open Source release notes are on this page, and for the latest upgrade guide, refer to Corda Open Source Edition 4.11 to 4.12 upgrade guide.

The steps from this guide only work for direct upgrades from Corda 4.11 to 4.12. If you have any nodes on versions 4.10 or below, you must upgrade them to 4.11 first. To do that, consult the relevant release upgrade documentation.

Documentation Updates

The following section describes the updated requirements for running Corda 4.12 nodes. It clarifies and enhances the previous documentation. The current patch release documentation has been updated to reflect the following:

• Legacy contracts directory: The legacy contracts directory is no longer required when running 4.12 nodes, provided all nodes on the network are version 4.12 nodes.

• Purpose of legacy contracts directory: The legacy contracts directory is now only needed for enabling 4.12 nodes to build transactions that include legacy contracts. This is only applicable in a mixed network of 4.12 nodes and pre-4.12 nodes.

• Legacy JARs directory: You may need to include a legacy-jars directory when running the node. See point 3 below for further details.

Corda 4.12 nodes

1. If your network includes a mix of 4.12 nodes and pre-4.12 nodes, each 4.12 node must have a legacy-contracts directory containing pre-4.12 contract CorDapps. This allows 4.12 nodes to build transactions that include pre-4.12 contracts, enabling interoperability with pre-4.12 nodes. In this scenario, you may also need a legacy-jars directory - see point 3 below.

2. If your network consists solely of upgraded 4.12 nodes, there is no need for the legacy-contracts directory. The 4.12 nodes will create transactions without legacy contracts, which is fine as there are no pre-4.12 nodes in the network. In this scenario, since the ledger already contains pre-4.12 transactions, you may still need a legacy-jars directory - see point 3 below.

3. Pre-4.12 transactions are verified in an external verifier process when encountered. This process does not, by default, include all third-party libraries that shipped with Corda 4.11 and earlier, nor does it have the drivers directory on the classpath. If your contracts in the ledger attachments depend on such third-party libraries or any contents from the drivers directory in Corda 4.11 or earlier, you can place the necessary JAR files in a directory called legacy-jars within the node directory. Any JARs in this directory will be added to the classpath of the external verifier. The TVU will assist you in identifying and verifying the resolution of such issues.

Fixed issues

• There is no need for the external verifier to use the legacy-contracts folder anymore. The external verifier verifies pre-4.12 transactions and now solely uses the database to retrieve the contract attachments.
• An open telemetry span has been added around the send to multiple parties and receive from multiple parties operations.
• Previously, the transaction builder would log any failed verification attempts when trying to add missing dependencies. Now, these failed attempts are no longer logged if they occur while determining the missing dependencies.
• This release contains AMQP serialisation performance improvements.
• It is now possible to create two nodes whose X.500 names have the same Organisation (O) field value but different Organisation Unit (OU) values when using the driver DSL for testing.
• There is no longer a memory leak when creating a series of mock networks for testing purposes.
• The transaction builder no longer attaches legacy attachments to a transaction if the minimum platform version is 140 (i.e., 4.12).
• A new legacy-jars directory has been introduced to improve backward compatibility with earlier versions of Corda. See the description above and the upgrade guide for details.
• Contract JAR signing key rotation of R3-provided CorDapps is included in this patch release.

Third party components upgrade

The following table lists the dependency version changes between 4.12.1 and 4.12.2 Open Source Editions:

Corda Open Source Edition 4.12.1 release notes

Corda Open Source Edition 4.12.1 is a patch release of Corda Community Edition focused on resolving issues.

Upgrade recommendation

As a developer or node operator, you should upgrade to the latest released version of Corda as soon as possible. The latest Corda Open Source release notes are on this page, and for the latest upgrade guide, refer to Corda Open Source Edition 4.11 to 4.12 upgrade guide.

The steps from this guide only work for direct upgrades from Corda 4.11 to 4.12. If you have any nodes on versions 4.10 or below, you must upgrade them to 4.11 first. To do that, consult the relevant release upgrade documentation.

Fixed issues

• ReceiveFinalityFlow was returning a transaction that was missing the notary signature. This has now been fixed. The returned transaction now includes the notary signature.
• ReceiveTransactionFlow was checking that the network parameters on the transaction existed before ResolveTransactionFlow was executed. This could cause a problem in certain scenarios; for example, when sending a top-level transaction to a new node in a migrated network, as the old network parameters would not exist on this new node. This has now been fixed.
• When resolving a party, in some code paths, wellKnownPartyFromAnonymous did not consider notaries from network parameters when trying to resolve an X.500 name. This scenario could occur when introducing a new node to a newly-migrated network as the new node would not have the old notary in its network map. This has now been fixed. Notaries from network parameters are now considered in the check.

Corda Open Source Edition 4.12 release notes

The Corda Open Source Edition 4.12 release introduces upgrades to the Java and Kotlin versions, along with associated upgrade support. Apart from the features supporting the Java and Kotlin upgrade, no other major new features have been introduced. In this release, Java has been upgraded to Java 17 from Java 8 and Kotlin has been upgraded to Kotlin 1.9.20 from 1.2.71.

When a CorDapp(s) and a node are successfully upgraded to 4.12, you are able to seamlessly interoperate 4.12 and 4.11 (or earlier) nodes on the same network, including the existing transactions on the ledger.

Supporting new Java and Kotlin versions is a major feature, as we must also handle legacy contracts from existing backchains. The upgraded Java and Kotlin versions also have implications for CorDapp developers. Simply replacing the Corda JAR without introducing other changes is not possible.

Upgrade recommendation

As a developer or node operator, you should upgrade to the latest released version of Corda as soon as possible. The latest Corda Open Source release notes are on this page, and for the latest upgrade guide, refer to Corda Open Source Edition 4.11 to 4.12 upgrade guide.

The steps from this guide only work for direct upgrades from Corda 4.11 to 4.12. If you have any nodes on versions 4.10 and below, you must upgrade them to 4.11 first. To do that, consult the relevant release upgrade documentation.

Platform version change

Corda 4.12 uses platform version 140.

For more information about platform versions, see Versioning.

New features, enhancements and restrictions

Java and Kotlin upgrade

Corda 4.12 requires Java 17 and Kotlin 1.9.20. This means that you must recompile any legacy CorDapps written for 4.11 or earlier to work with Java 17 and Kotlin 1.9.20 to be compatible with Corda 4.12. These upgrades enhance the supportability and security of Corda.

Java 17 compatible releases of Corda SDKs

The base Corda package includes several SDKs and libraries. These SDKs and libraries are compatible with Java 17 and Kotlin 1.9.20:

Support for signature constraints only

Only CorDapps using signature constraints are supported in Corda 4.12; hash constraints are not supported. Using signature constraints has been recommended in previous releases of Corda as it eases the CorDapp upgrade process. If you have any 4.11 CorDapps using hash constraints, you must migrate them to signature constraints on 4.11 before upgrading to 4.12.

Corda 4.11 and 4.12 CorDapps must be signed by the same set of keys

Once you have recompiled your 4.12 CorDapps for Java 17 and Kotlin 1.9.20, you must sign them using the same set of keys used by the 4.11 CorDapp.

Explicit contract upgrade is not supported

Explicit contract upgrade is not supported in Corda 4.12.

toLedgerTransaction.verify does not work for legacy transactions

You must review your CorDapps and check for any making the following calls:

• SignedTransaction.toLedgerTransaction().verify()
• WireTransaction.toLedgerTransaction().verify()
• TransactionBuilder.toLedgerTransaction().verify()

CorDapps that make the above calls will not work for legacy transactions. To make those CorDapps compatible, change them to SignedTransaction.verify().

Corda node explorer not supported on Java 17

The node explorer has not been converted to use Java 17 and is not provided in the release packs. If you wish to use a node explorer, the only current option is to use a 4.11 node explorer and use it to connect to a 4.12 node.

Samples Kotlin and Java support

The following two public repositories provide various CorDapp samples (branch: release/4.12):

• Samples Kotlin repository
• Samples Java repository

Most samples have been converted over to Java 17, Kotlin 1.9.20, and Gradle 7.6.4.

The samples have been written to work with Corda Open Source. To convert a sample to work with Corda Enterprise, then at a minimum you need to point to a repository where your enterprise artifacts are installed. Also, the artifact group name for ENT (com.r3) must be different from OS (net.corda). For example, switch net.corda:corda-node-driver:4.12 (Corda OS) to com.r3.corda:corda-node-driver:4.12 (Corda ENT).

The following dependencies have been used in samples and can be switched from Corda OS to Corda Enterprise:

• corda
• corda-confidential-identities
• corda-core-test-utils
• corda-finance-workflows
• corda-jackson
• corda-node
• corda-node-api
• corda-node-driver
• corda-rpc
• corda-shell
• corda-test-utils
• corda-testserver-impl

The samples listed below have been converted to and tested with Java 17 and Kotlin 1.9.20:

Kotlin and Java CorDapp templates

The following Kotlin and Java CorDapp templates have been converted to Java 17, Kotlin 1.9.20, and Gradle 7.6.4. They have been written to work with Corda Open Source Edition (branch: release/4.12):

• Kotlin CorDapp template
• Java CorDapp template

CorDapp using internal APIs or reflective access

If your CorDapp is using internal APIs or reflective access, then you may need to explicitly open the module on the command line. You can do this by adding one or more –add-opens options when starting Corda.

Fixed issues

Thread.contextClassLoader set for resumed flow on node startup

Previously, if a flow was resuming on node startup, the thread context class loader was not set, potentially causing ClassNotFound issues for CorDapp classes. This has been fixed now.

Known issues

Extra stack trace output when logging level is TRACE

If you start the node with log level set to trace via the command line option --logging-level=TRACE, then you will see some Unable to format stack trace outputs from Log4j caused by a bug in Artemis. These can be ignored and have no effect on node operation. They can be removed via a custom log4j.xml where trace output from the org.apache.activemq.artemis.core.paging.cursor.impl.PageCursorProviderImpl logger is removed.

Startup warnings from Log4j

At node startup with the default Log4j, the following message appears: main WARN The use of package scanning to locate plugins is deprecated and will be removed in a future release. This is a warning only and can be safely ignored. We are currently investigating alternatives.

Intermittent warning from Bouncy Castle when running deployNodes

When running the Gradle task deployNodes, you may occasionally see the following warning message:

exception in disposal thread: org/bouncycastle/util/dispose/DisposalDaemon$3

This is a warning message from the LTS version of Bouncy Castle we are currently using. There is no user impact and it is related to disposing of references with native code. This will be fixed in a future patch release.

Third party component upgrades

The following table lists the dependency version changes between 4.11 and 4.12 Open Source Editions: