KTOR-6182 Support throwing UnknownServiceException if there is no cleartext traffic permitted

ktor-client/ktor-client-plugins/ktor-client-platform/api/ktor-client-platform.api

@@ -0,0 +1,4 @@
+public final class io/ktor/client/plugins/platform/PlatformingKt {
+	public static final fun getPlatforming ()Lio/ktor/client/plugins/api/ClientPlugin;
+}
+

ktor-client/ktor-client-plugins/ktor-client-platform/build.gradle.kts

@@ -0,0 +1,7 @@
+/*
+ * Copyright 2014-2024 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+description = "Ktor client platform support"
+
+useJdkVersionForJvmTests(11)

ktor-client/ktor-client-plugins/ktor-client-platform/common/src/Platform.kt

@@ -0,0 +1,10 @@
+/*
+ * Copyright 2014-2024 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package io.ktor.client.plugins.platform
+
+internal expect object Platform {
+
+    fun isCleartextTrafficPermitted(hostname: String): Boolean
+}

ktor-client/ktor-client-plugins/ktor-client-platform/common/src/Platforming.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2014-2024 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package io.ktor.client.plugins.platform
+
+import io.ktor.client.plugins.api.ClientPlugin
+import io.ktor.client.plugins.api.createClientPlugin
+import io.ktor.client.request.host
+import io.ktor.utils.io.errors.UnknownServiceException
+
+public val Platforming: ClientPlugin<Any> = createClientPlugin("Platforming", ::Any) {
+    onRequest { request, _ ->
+        val host = request.host
+        if (!Platform.isCleartextTrafficPermitted(host)) {
+            throw UnknownServiceException(
+                "CLEARTEXT communication to $host not permitted by network security policy"
+            )
+        }
+    }
+}

ktor-client/ktor-client-plugins/ktor-client-platform/jvm/src/Platform.kt

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2014-2024 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package io.ktor.client.plugins.platform
+
+import java.lang.reflect.InvocationTargetException
+
+internal actual object Platform {
+    /**
+     * This explicit check avoids activating in Android Studio with Android specific classes available when running plugins inside the IDE.
+     */
+    private val isAndroid: Boolean = System.getProperty("java.vm.name") == "Dalvik"
+
+    actual fun isCleartextTrafficPermitted(hostname: String): Boolean {
+        if (!isAndroid) return true
+        return try {
+            val networkPolicyClass = Class.forName("android.security.NetworkSecurityPolicy")
+            val getInstanceMethod = networkPolicyClass.getMethod("getInstance").apply { isAccessible = true }
+            val networkSecurityPolicy = getInstanceMethod.invoke(null)
+            api24IsCleartextTrafficPermitted(hostname, networkPolicyClass, networkSecurityPolicy)
+        } catch (_: ClassNotFoundException) {
+            true
+        } catch (_: NoSuchMethodException) {
+            true
+        } catch (e: IllegalAccessException) {
+            throw AssertionError("unable to determine cleartext support", e)
+        } catch (e: IllegalArgumentException) {
+            throw AssertionError("unable to determine cleartext support", e)
+        } catch (e: InvocationTargetException) {
+            throw AssertionError("unable to determine cleartext support", e)
+        }
+    }
+
+    @Throws(InvocationTargetException::class, IllegalAccessException::class)
+    private fun api24IsCleartextTrafficPermitted(
+        hostname: String,
+        networkPolicyClass: Class<*>,
+        networkSecurityPolicy: Any
+    ): Boolean = try {
+        val isCleartextTrafficPermittedMethod = networkPolicyClass
+            .getMethod("isCleartextTrafficPermitted", String::class.java)
+            .apply { isAccessible = true }
+        isCleartextTrafficPermittedMethod.invoke(networkSecurityPolicy, hostname) as Boolean
+    } catch (_: NoSuchMethodException) {
+        api23IsCleartextTrafficPermitted(networkPolicyClass, networkSecurityPolicy)
+    }
+
+    @Throws(InvocationTargetException::class, IllegalAccessException::class)
+    private fun api23IsCleartextTrafficPermitted(
+        networkPolicyClass: Class<*>,
+        networkSecurityPolicy: Any
+    ): Boolean = try {
+        val isCleartextTrafficPermittedMethod = networkPolicyClass
+            .getMethod("isCleartextTrafficPermitted")
+            .apply { isAccessible = true }
+        isCleartextTrafficPermittedMethod.invoke(networkSecurityPolicy) as Boolean
+    } catch (_: NoSuchMethodException) {
+        true
+    }
+}

ktor-client/ktor-client-plugins/ktor-client-platform/nonJvm/src/Platform.kt

@@ -0,0 +1,10 @@
+/*
+ * Copyright 2014-2024 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package io.ktor.client.plugins.platform
+
+internal actual object Platform {
+
+    fun isCleartextTrafficPermitted(hostname: String): Boolean = false
+}

ktor-io/common/src/io/ktor/utils/io/errors/Errors.kt

@@ -5,3 +5,5 @@ public expect open class IOException(message: String, cause: Throwable?) : Excep
 }
 
 public expect open class EOFException(message: String) : IOException
+
+public expect open class UnknownServiceException(message: String) : IOException

ktor-io/jvm/src/io/ktor/utils/io/errors/IOException.kt

@@ -3,3 +3,5 @@ package io.ktor.utils.io.errors
 public actual typealias IOException = java.io.IOException
 
 public actual typealias EOFException = java.io.EOFException
+
+public actual typealias UnknownServiceException = java.net.UnknownServiceException

settings.gradle.kts

@@ -92,6 +92,7 @@ include(":ktor-client:ktor-client-plugins:ktor-client-json:ktor-client-serializa
 include(":ktor-client:ktor-client-plugins:ktor-client-auth")
 include(":ktor-client:ktor-client-plugins:ktor-client-call-id")
 include(":ktor-client:ktor-client-plugins:ktor-client-logging")
+include(":ktor-client:ktor-client-plugins:ktor-client-platform")
 include(":ktor-client:ktor-client-plugins:ktor-client-encoding")
 include(":ktor-client:ktor-client-plugins:ktor-client-websockets")
 include(":ktor-client:ktor-client-plugins:ktor-client-content-negotiation")