Mobile SDK Uniffi Bindings

Maturity Disclaimer

In its current version, Mobile SDK has not yet undergone a formal security audit to desired levels of confidence for suitable use in production systems. This implementation is currently suitable for exploratory work and experimentation only. We welcome feedback on the usability, architecture, and security of this implementation and are committed to a conducting a formal audit with a reputable security firm before the v1.0 release.

Structure of the Project

.               // The Rust crate is at the root
│
├── kotlin      // Contains the Android library project (without the generated
│               // source or dynamic libraries, these are present in the
│               // published package associated with this repo)
│
├── MobileSdkRs // Contains the iOS library, with all the generated source files
│               // and dylibs, as Git is the package manager of Swift
│
├── tests       // Contains cargo tests for Kotlin and Swift for the generated
│               // libraries. These tests act as sanity checks to ensure the
│               // generated libraries will be usable, and are not meant to be
│               // full-fledged functional tests.

Release

Use the release Github Action which is a manually triggered action.

Pre-requisites

For developing Kotlin code, install cargo-ndk.

cargo install cargo-ndk

Ensure you have the following rust build targets installed:

rustup target install \
    armv7-linux-androideabi \
    aarch64-linux-android \
    i686-linux-android \
    x86_64-linux-android

See the cargo-ndk documentation for more information.

Build

Kotlin

cd kotlin
./gradlew buildCargoNdkDebug

If you get this error:

> java.io.FileNotFoundException: .../local.properties (No such file or directory)

run:

touch local.properties

and try the build again.

Swift

cargo swift package -p ios -n MobileSdkRs --release

⚠ If you need to call verify_vcb_qrcode_against_mrz or verify_pdf417_barcode in your iOS app, you must build with the --release flag to avoid runtime errors when executing these methods.

You will need cargo-swift which you can install with cargo install cargo-swift.

Test

In order to run the tests you'll need to install the kotlin compiler and download a copy of JNA

wget https://repo1.maven.org/maven2/net/java/dev/jna/jna/5.14.0/jna-5.14.0.jar
wget https://repo1.maven.org/maven2/org/jetbrains/kotlinx/kotlinx-coroutines-core-jvm/1.6.4/kotlinx-coroutines-core-jvm-1.6.4.jar

JNA will also need to explicitly be on your CLASSPATH. Simply being in a directory doesn't necessarily work. Here is an example of how you might configure this in your .bashrc file

export CLASSPATH="/path/to/jna-5.14.0.jar:/path/to/kotlinx-coroutines-core-jvm-1.6.4.jar:$CLASSPATH"

This lets you just run cargo test as normal.

Alternatively, if you don't like the addition to your environment you can specify it on every invocation of cargo test:

CLASSPATH="/path/to/jna-5.14.0.jar:/path/to/kotlinx-coroutines-core-jvm-1.6.4.jar" cargo test

Local Development

Kotlin

To locally test integration with mobile-sdk-kt, it is preferrable to use a mavenLocal() repository.

To release to mavenLocal() you may use the following command:

cd kotlin/ && VERSION=x.y.z ./gradlew publishDebugPublicationToMavenLocal

Where VERSION is set to a SemVer (Semantic Versioning). Note that it is possible to use a tagged version, e.g. 0.0.33-SNAPSHOT, which may be preferrable to denote that a certain release version is a local release. Other values may be used instead of SNAPSHOT.

When adding the local repository to mobile-sdk-kt, update the version in the build.gradle file:

api("com.spruceid.mobile.sdk.rs:mobilesdkrs:x.y.z-SNAPSHOT")

Swift

To test local intgration with mobile-sdk-swift, update the Package.swift file target to use a local path binary target. For example:

targets: [
    .binaryTarget(name: "RustFramework", path: "./MobileSdkRs/RustFramework.xcframework"),
    .target(
        name: "SpruceIDMobileSdkRs",
        dependencies: [
            .target(name: "RustFramework")
        ],
        path: "./MobileSdkRs/Sources/MobileSdkRs"
    ),
]

NOTE: For production release, it will be important to replace the binary target with an actual release artifact or revision tag, for example:

.binaryTarget(name: "RustFramework", url: "https://github.com/spruceid/mobile-sdk-rs/releases/download/0.0.36/RustFramework.xcframework.zip", checksum: "df587ab46f3604df744a9394c229be40e9a65102429ff1b0379dfeb6ca7fdc3c")

And update the packages property in project.yml file in mobile-sdk-swift to use the local path to mobile-sdk-rs, for example:

packages:
  SpruceIDMobileSdkRs:
    path: "../mobile-sdk-rs"

Finally, run xcodegen in mobile-sdk-swift to generate the xcodeproject file to open in xcode.

Funding

This work is funded in part by the U.S. Department of Homeland Security's Science and Technology Directorate under contract 70RSAT24T00000011 (Open-Source and Privacy-Preserving Digital Credentialing Infrastructure). Through this contract, SpruceID’s open-source libraries will be used to build privacy-preserving digital credential wallets and verifier capabilities to support standards while ensuring safe usage and interoperability across sectors like finance, healthcare, and various cross-border applications. To learn more about this work, read more here .