ed25519-zebra/ed25519jni

JNI

Code that provides a JNI for the library is included. Allows any JNI-using language to interact with specific ed25519-zebra calls and provides a minor analogue for some Rust classes, allowing for things like basic sanity checks of certain values. Tests written in Scala have also been included.

Note that Scala 3 is required to build and test the JNI code.

Build Requirements

• For PEM support, the pem feature must be enabled in both Cargo.toml files (pem = ["der"]).
• For PKCS #8 (DER) support, the pkcs8 feature must be enabled in both Cargo.toml files (pkcs8 = ["dep:pkcs8"]).

Compilation / Library Usage

To build the JNI code, there are several steps. The exact path forward depends on the user's preferred deployment method. No matter what, the following steps must be performed at the beginning.

• Run cargo build in the root directory. This generates the core Rust code.
• Run cargo build in the ed25519jni/rust subdirectory. This generates the Rust glue code libraries (libed25519jni.a and libed25519jni.{so/dylib}).

From here, there are two deployment methods: Direct library usage and JARs.

JAR

It's possible to generate a JAR that can be loaded into a project via SciJava's NativeLoader, along with the Java JNI interface file. There are two extra steps to perform after the mandatory compilation steps.

• Run jni_jar_prereq.sh from the ed25519jni/scripts subdirectory. Use the -d flag if working with debug builds. This script performs some JAR setup steps, and enables the local Scala tests against the JNI code.
• Run sbt clean publishLocal from the ed25519jni/jvm subdirectory. This generates the final ed25519jni.jar file in the {$HOME}/.ivy2/local subdirectory.

Direct library usage

Use a preferred method to load the Rust core and JNI libraries directly as needed. If necessary, include the JNI Java files too.

Note that the code is designed to support only the aforementioned JAR method. Local changes may be required to support other deployment methods.

Testing

Prerequisites

To reiterate, before running any tests, execute the first step from the JAR compilation method section above.

Commands

The precise test command will depend on if you built the code with PKCS8 and/or PEM support. Both are disabled by default. This also means that, without disabling the associated tests or enabling the features, an UnsatisfiedLinkError Java error will occur.

The following examples show how to run tests.

• sbt test - Run all tests. Must compile with PEM and PKCS #8 support.
• sbt "testOnly * -- -l Pkcs8Test" - Run all tests unrelated to PKCS #8.
• sbt "testOnly * -- -l \"PemTest Pkcs8Test\"" - Run all tests unrelated to PEM and PKCS #8.

Capabilities

Among other things, the JNI code can perform the following actions.

• Generate a random 32 byte signing key seed.
• Generate a 32 byte verification key from a signing key seed.
• Sign arbitrary data with a signing key seed.
• Verify a signature for arbitrary data with verification key bytes.
• Generate DER bytes and PEM strings for signing key seeds and verification key bytes, and read back the DER bytes and PEM strings into signing key seeds and verification key bytes.