Add Java 9+ module support (JPMS) for jlink compatibility

.github/workflows/java-module-test.yml

@@ -0,0 +1,249 @@
+name: Java 9+ Module Support
+
+on:
+  push:
+    branches: [ 'master', 'main', 'release/**' ]
+  pull_request:
+    branches: [ '*' ]
+
+jobs:
+  # Test Java 9+ module support (JPMS)
+  # Verifies that module-info.java is properly compiled and the resulting
+  # JAR can be used with jlink to create custom Java runtimes.
+  module-test:
+    strategy:
+      matrix:
+        os: [ 'ubuntu-latest' ]
+        jdk_version: [ '11', '17', '21' ]
+    runs-on: ${{ matrix.os }}
+    name: Module Test (JDK ${{ matrix.jdk_version }})
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Cache JUnit dependencies
+        uses: actions/cache@v4
+        id: cache-junit
+        with:
+          path: junit
+          key: junit-jars-v1
+
+      - name: Download junit-4.13.2.jar
+        if: steps.cache-junit.outputs.cache-hit != 'true'
+        run: wget --directory-prefix=$GITHUB_WORKSPACE/junit https://repo1.maven.org/maven2/junit/junit/4.13.2/junit-4.13.2.jar
+
+      - name: Download hamcrest-all-1.3.jar
+        if: steps.cache-junit.outputs.cache-hit != 'true'
+        run: wget --directory-prefix=$GITHUB_WORKSPACE/junit https://repo1.maven.org/maven2/org/hamcrest/hamcrest-all/1.3/hamcrest-all-1.3.jar
+
+      - name: Build native wolfSSL
+        uses: wolfSSL/actions-build-autotools-project@v1
+        with:
+          repository: wolfSSL/wolfssl
+          ref: master
+          path: wolfssl
+          configure: --enable-jni
+          check: false
+          install: true
+
+      - name: Setup Java
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'zulu'
+          java-version: ${{ matrix.jdk_version }}
+
+      - name: Set JUNIT_HOME
+        run: |
+          echo "JUNIT_HOME=$GITHUB_WORKSPACE/junit" >> "$GITHUB_ENV"
+
+      - name: Set LD_LIBRARY_PATH
+        run: |
+          echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$GITHUB_WORKSPACE/build-dir/lib" >> "$GITHUB_ENV"
+
+      - name: Copy makefile
+        run: cp makefile.linux makefile
+
+      - name: Build JNI library
+        run: PREFIX=$GITHUB_WORKSPACE/build-dir make
+
+      - name: Build JAR with module support (ant)
+        run: ant build-jce-release
+
+      - name: Verify module-info.class exists in JAR
+        run: |
+          echo "Checking for module-info.class in wolfcrypt-jni.jar..."
+          if jar tf lib/wolfcrypt-jni.jar | grep -q "module-info.class"; then
+            echo "SUCCESS: module-info.class found in JAR"
+          else
+            echo "FAILURE: module-info.class not found in JAR"
+            echo "JAR contents:"
+            jar tf lib/wolfcrypt-jni.jar | head -20
+            exit 1
+          fi
+
+      - name: Verify module descriptor with jar --describe-module
+        run: |
+          echo "Describing module in wolfcrypt-jni.jar..."
+          jar --describe-module --file=lib/wolfcrypt-jni.jar
+          echo ""
+          echo "Verifying module name is 'com.wolfssl.wolfcrypt'..."
+          MODULE_NAME=$(jar --describe-module --file=lib/wolfcrypt-jni.jar 2>&1 | head -1 | cut -d' ' -f1)
+          if [ "$MODULE_NAME" = "com.wolfssl.wolfcrypt" ]; then
+            echo "SUCCESS: Module name is correct: $MODULE_NAME"
+          else
+            echo "FAILURE: Expected module name 'com.wolfssl.wolfcrypt', got '$MODULE_NAME'"
+            exit 1
+          fi
+
+      - name: Verify module exports correct packages
+        run: |
+          echo "Verifying module exports..."
+          EXPORTS=$(jar --describe-module --file=lib/wolfcrypt-jni.jar 2>&1)
+          echo "$EXPORTS"
+          echo ""
+          if echo "$EXPORTS" | grep -q "exports com.wolfssl.wolfcrypt"; then
+            echo "SUCCESS: exports com.wolfssl.wolfcrypt"
+          else
+            echo "FAILURE: missing 'exports com.wolfssl.wolfcrypt'"
+            exit 1
+          fi
+          if echo "$EXPORTS" | grep -q "exports com.wolfssl.provider.jce"; then
+            echo "SUCCESS: exports com.wolfssl.provider.jce"
+          else
+            echo "FAILURE: missing 'exports com.wolfssl.provider.jce'"
+            exit 1
+          fi
+
+      - name: Test jlink can create runtime with module
+        run: |
+          echo "Testing jlink integration..."
+          jlink \
+            --module-path lib/wolfcrypt-jni.jar:$JAVA_HOME/jmods \
+            --add-modules com.wolfssl.wolfcrypt \
+            --output test-jlink-runtime \
+            --no-header-files \
+            --no-man-pages
+          echo ""
+          echo "SUCCESS: jlink created custom runtime"
+          echo "Runtime modules:"
+          ./test-jlink-runtime/bin/java --list-modules
+          echo ""
+          echo "Verifying com.wolfssl.wolfcrypt module is present..."
+          if ./test-jlink-runtime/bin/java --list-modules | grep -q "com.wolfssl.wolfcrypt"; then
+            echo "SUCCESS: com.wolfssl.wolfcrypt module found in custom runtime"
+          else
+            echo "FAILURE: com.wolfssl.wolfcrypt module not found in custom runtime"
+            exit 1
+          fi
+
+      - name: Clean up jlink test runtime
+        run: rm -rf test-jlink-runtime
+
+      - name: Run standard tests to verify module doesn't break functionality
+        run: ant test
+
+      - name: Clean ant build for Maven test
+        run: ant clean
+
+      - name: Maven build and verify module-info in JAR
+        run: |
+          echo "Building with Maven..."
+          mvn package -DskipTests -q
+          echo ""
+          MAVEN_JAR=$(ls target/wolfcrypt-jni-*.jar)
+          echo "Maven JAR: $MAVEN_JAR"
+          echo ""
+          echo "Checking for module-info.class in Maven-built JAR..."
+          if jar tf "$MAVEN_JAR" | grep -q "module-info.class"; then
+            echo "SUCCESS: module-info.class found in Maven JAR"
+          else
+            echo "FAILURE: module-info.class not found in Maven JAR"
+            jar tf "$MAVEN_JAR" | head -20
+            exit 1
+          fi
+          echo ""
+          echo "Verifying Maven JAR module descriptor..."
+          jar --describe-module --file="$MAVEN_JAR"
+
+      - name: Clean Maven build
+        run: mvn clean -q
+
+      - name: Show logs on failure
+        if: failure() || cancelled()
+        run: |
+          cat build/reports/*.txt 2>/dev/null || echo "No test reports found"
+
+  # Verify Java 8 builds do NOT include module-info.class
+  # This ensures the conditional compilation works correctly for Java 8 users
+  java8-no-module-test:
+    runs-on: ubuntu-latest
+    name: Java 8 No Module Test
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Cache JUnit dependencies
+        uses: actions/cache@v4
+        id: cache-junit
+        with:
+          path: junit
+          key: junit-jars-v1
+
+      - name: Download junit-4.13.2.jar
+        if: steps.cache-junit.outputs.cache-hit != 'true'
+        run: wget --directory-prefix=$GITHUB_WORKSPACE/junit https://repo1.maven.org/maven2/junit/junit/4.13.2/junit-4.13.2.jar
+
+      - name: Download hamcrest-all-1.3.jar
+        if: steps.cache-junit.outputs.cache-hit != 'true'
+        run: wget --directory-prefix=$GITHUB_WORKSPACE/junit https://repo1.maven.org/maven2/org/hamcrest/hamcrest-all/1.3/hamcrest-all-1.3.jar
+
+      - name: Build native wolfSSL
+        uses: wolfSSL/actions-build-autotools-project@v1
+        with:
+          repository: wolfSSL/wolfssl
+          ref: master
+          path: wolfssl
+          configure: --enable-jni
+          check: false
+          install: true
+
+      - name: Setup Java 8
+        uses: actions/setup-java@v4
+        with:
+          distribution: 'zulu'
+          java-version: '8'
+
+      - name: Set JUNIT_HOME
+        run: |
+          echo "JUNIT_HOME=$GITHUB_WORKSPACE/junit" >> "$GITHUB_ENV"
+
+      - name: Set LD_LIBRARY_PATH
+        run: |
+          echo "LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$GITHUB_WORKSPACE/build-dir/lib" >> "$GITHUB_ENV"
+
+      - name: Copy makefile
+        run: cp makefile.linux makefile
+
+      - name: Build JNI library
+        run: PREFIX=$GITHUB_WORKSPACE/build-dir make
+
+      - name: Build JAR with Java 8 (ant)
+        run: ant build-jce-release
+
+      - name: Verify module-info.class is NOT in JAR (Java 8)
+        run: |
+          echo "Checking that module-info.class is NOT in wolfcrypt-jni.jar (Java 8 build)..."
+          if jar tf lib/wolfcrypt-jni.jar | grep -q "module-info.class"; then
+            echo "FAILURE: module-info.class should NOT be in Java 8 JAR"
+            exit 1
+          else
+            echo "SUCCESS: module-info.class correctly absent from Java 8 JAR"
+          fi
+
+      - name: Run standard tests to verify Java 8 compatibility
+        run: ant test
+
+      - name: Show logs on failure
+        if: failure() || cancelled()
+        run: |
+          cat build/reports/*.txt 2>/dev/null || echo "No test reports found"

README.md

@@ -225,6 +225,51 @@ on the current release):
 ```
 
 
+### Java 9+ Module Support (JPMS)
+---------
+
+wolfCrypt JNI/JCE supports the Java Platform Module System (JPMS) introduced
+in Java 9. This enables use with `jlink` for creating custom, minimal Java
+runtimes.
+
+**Module Information:**
+
+- Module name: `com.wolfssl.wolfcrypt`
+- Exported packages: `com.wolfssl.wolfcrypt`, `com.wolfssl.provider.jce`
+- Service provider: `java.security.Provider` (WolfCryptProvider)
+
+**Conditional Compilation:**
+
+The `module-info.java` is conditionally compiled based on the JDK version used
+to build:
+
+| JDK Used to Build | Resulting JAR |
+|-------------------|---------------|
+| Java 8 | Standard JAR (no module-info.class) |
+| Java 9+ | Modular JAR (includes module-info.class) |
+
+When building with Java 8, the `module-info.java` is automatically excluded
+from compilation, and the resulting JAR works as a standard classpath JAR.
+
+**Using with jlink:**
+
+When built with Java 9+, the wolfCrypt JNI/JCE JAR can be used with `jlink` to
+create a custom Java runtime that includes the wolfCrypt module:
+
+```
+$ jlink \
+    --module-path lib/wolfcrypt-jni.jar:$JAVA_HOME/jmods \
+    --add-modules com.wolfssl.wolfcrypt \
+    --output custom-runtime \
+    --no-header-files \
+    --no-man-pages
+
+$ ./custom-runtime/bin/java --list-modules
+```
+
+**Note:** The native wolfCrypt JNI shared library (`libwolfcryptjni.so/dylib`)
+must still be available on the native library path at runtime.
+
 ### Example / Test Code
 ---------
 

build.xml

@@ -23,6 +23,7 @@
 
     <!-- set properties for this build -->
     <property name="src.dir" value="src/main/java/" />
+    <property name="src.java9.dir" value="src/java9/" />
     <property name="jni.dir" value="jni/include/" />
     <property name="lib.dir" value="lib/" />
     <property name="build.dir" value="build" />
@@ -48,6 +49,18 @@
 
     <property environment="env" />
 
+    <!-- Detect Java 9+ for module-info.java compilation -->
+    <condition property="isJava9Plus">
+        <not>
+            <or>
+                <equals arg1="${ant.java.version}" arg2="1.5"/>
+                <equals arg1="${ant.java.version}" arg2="1.6"/>
+                <equals arg1="${ant.java.version}" arg2="1.7"/>
+                <equals arg1="${ant.java.version}" arg2="1.8"/>
+            </or>
+        </not>
+    </condition>
+
     <!-- Detect if running on Windows host -->
     <condition property="isWindows">
         <os family="windows" />
@@ -161,8 +174,24 @@
         </copy>
     </target>
 
+    <!-- Compile module-info.java for Java 9+ module support.
+         Only runs when building with Java 9 or later. When building with
+         Java 8 or earlier, this target is skipped and the resulting JAR
+         will be a standard (non-modular) JAR file. -->
+    <target name="compile-module-info" if="isJava9Plus"
+            description="Compile module-info.java for Java 9+ (skipped on Java 8)">
+        <javac srcdir="${src.java9.dir}"
+               destdir="${build.dir}"
+               release="9"
+               modulepath="${build.dir}"
+               includeantruntime="false">
+            <include name="module-info.java"/>
+        </javac>
+        <echo message="Compiled module-info.java for Java 9+ module support"/>
+    </target>
+
     <!-- create JAR with ONLY JNI classes, not to be used with JCE -->
-    <target name="jar-jni" depends="compile-nativeheaderdir, compile-javah">
+    <target name="jar-jni" depends="compile-nativeheaderdir, compile-javah, compile-module-info">
         <jar jarfile="${lib.dir}/wolfcrypt-jni.jar">
             <manifest>
                 <attribute name="Implementation-Title"
@@ -174,12 +203,13 @@
             </manifest>
             <fileset dir="${build.dir}">
                 <include name="com/wolfssl/wolfcrypt/*.class"/>
+                <include name="module-info.class"/>
             </fileset>
         </jar>
     </target>
 
     <!-- create JAR with JNI and JCE classes, use this when wanting JCE -->
-    <target name="jar-jce" depends="compile-nativeheaderdir, compile-javah">
+    <target name="jar-jce" depends="compile-nativeheaderdir, compile-javah, compile-module-info">
         <jar jarfile="${lib.dir}/wolfcrypt-jni.jar" basedir="${build.dir}">
             <manifest>
                 <attribute name="Implementation-Title"