Add AndroidNative cinterop for syscall id SYS_getrandom (#37)

Author: 05nelsonm

build-logic/src/main/kotlin/dokka.gradle.kts

@@ -51,6 +51,6 @@ extensions.configure<DokkaExtension> {
     }
 
     pluginsConfiguration.html {
-        footerMessage.set("© 2025-${LocalDate.now().year} Copyright KotlinCrypto")
+        footerMessage.set("© 2023-${LocalDate.now().year} Copyright KotlinCrypto")
     }
 }

gradle.properties

@@ -4,6 +4,7 @@ org.gradle.caching=true
 
 kotlin.code.style=official
 kotlin.mpp.applyDefaultHierarchyTemplate=false
+kotlin.mpp.enableCInteropCommonization=true
 kotlin.mpp.stability.nowarn=true
 kotlin.native.ignoreDisabledTargets=true
 

library/crypto-rand/build.gradle.kts

@@ -13,6 +13,9 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  **/
+import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinNativeTarget
+import org.jetbrains.kotlin.konan.target.Family
+
 plugins {
     id("configuration")
 }
@@ -48,5 +51,19 @@ kmpConfiguration {
                 }
             }
         }
+
+        kotlin {
+            val cInteropDir = projectDir
+                .resolve("src")
+                .resolve("nativeInterop")
+                .resolve("cinterop")
+
+            targets.filterIsInstance<KotlinNativeTarget>().forEach target@ { target ->
+                if (target.konanTarget.family != Family.ANDROID) return@target
+                target.compilations["main"].cinterops.create("syscall") {
+                    definitionFile.set(cInteropDir.resolve("$name.def"))
+                }
+            }
+        }
     }
 }

library/crypto-rand/src/androidNativeMain/kotlin/org/kotlincrypto/random/internal/AndroidNativePlatform.kt

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2025 KotlinCrypto
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+@file:Suppress("FunctionName", "NOTHING_TO_INLINE", "KotlinRedundantDiagnosticSuppress", "SpellCheckingInspection")
+
+package org.kotlincrypto.random.internal
+
+import kotlinx.cinterop.ExperimentalForeignApi
+
+@OptIn(ExperimentalForeignApi::class)
+internal actual inline fun _SYS_getrandom(): Int = SYS_getrandom

library/crypto-rand/src/linuxAndroidMain/kotlin/org/kotlincrypto/random/internal/LinuxAndroidPlatform.kt

@@ -24,22 +24,20 @@ import kotlin.contracts.ExperimentalContracts
 import kotlin.contracts.InvocationKind
 import kotlin.contracts.contract
 
-// https://docs.piston.rs/dev_menu/libc/constant.SYS_getrandom.html
-private const val SYS_getrandom: Long = 318L
-// https://docs.piston.rs/dev_menu/libc/constant.GRND_NONBLOCK.html
-private const val GRND_NONBLOCK: UInt = 0x0001u
+@Suppress("FunctionName")
+internal expect inline fun _SYS_getrandom(): Int
 
 @OptIn(ExperimentalForeignApi::class, UnsafeNumber::class)
 private inline fun getrandom2(buf: CPointer<ByteVar>, buflen: size_t, flags: u_int): Int {
-    return syscall(SYS_getrandom.convert(), buf, buflen, flags).convert()
+    return syscall(_SYS_getrandom().convert(), buf, buflen, flags).convert()
 }
 
 // getrandom(2) available for Linux Kernel 3.17+ (Android API 23+)
 @OptIn(ExperimentalForeignApi::class, UnsafeNumber::class)
 internal val HAS_GET_RANDOM: Boolean by lazy(LazyThreadSafetyMode.SYNCHRONIZED) {
     val buf = ByteArray(1)
     val result = buf.usePinned { pinned ->
-        getrandom2(pinned.addressOf(0), buf.size.toULong().convert(), GRND_NONBLOCK)
+        getrandom2(pinned.addressOf(0), buf.size.convert(), 0x0001u /* GRND_NONBLOCK */)
     }
     if (result >= 0) return@lazy true
 

library/crypto-rand/src/linuxMain/kotlin/org/kotlincrypto/random/internal/LinuxPlatform.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2025 KotlinCrypto
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ **/
+@file:Suppress("FunctionName", "NOTHING_TO_INLINE", "KotlinRedundantDiagnosticSuppress", "SpellCheckingInspection")
+
+package org.kotlincrypto.random.internal
+
+import platform.linux.SYS_getrandom
+
+internal actual inline fun _SYS_getrandom(): Int = SYS_getrandom

library/crypto-rand/src/nativeInterop/cinterop/syscall.def

@@ -0,0 +1,3 @@
+# SYS_getrandom for AndroidNative targets
+package = org.kotlincrypto.random.internal
+headers = sys/syscall.h