Add native TLS for Android love.system and desktop gen1tls.

Expose a non-blocking TLS socket API to mods (WSS clients) without bundling
any game-specific multiworld content.

Co-authored-by: Cursor <cursoragent@cursor.com>

mobile/android/love/src/jni/love/src/common/android.cpp

@@ -23,6 +23,7 @@
 #ifdef LOVE_ANDROID
 
 #include <cerrno>
+#include <cstring>
 #include <unordered_map>
 
 #include <SDL.h>
@@ -324,6 +325,182 @@ bool httpDownload(const char *url, const char *destPath, const char *userAgent,
 	return result;
 }
 
+/*
+ * TLS sockets. Same resolution rule as httpDownload above -- the activity's
+ * own class, never FindClass -- and the same tolerance for an old APK: a
+ * missing method answers like a platform without TLS instead of aborting.
+ */
+static jclass tlsActivityClass(JNIEnv *env)
+{
+	jobject activityObj = (jobject) SDL_AndroidGetActivity();
+	if (activityObj == nullptr)
+		return nullptr;
+	jclass activity = env->GetObjectClass(activityObj);
+	env->DeleteLocalRef(activityObj);
+	return activity;
+}
+
+int tlsOpen(const char *host, int port)
+{
+	if (host == nullptr)
+		return -1;
+	JNIEnv *env = (JNIEnv*) SDL_AndroidGetJNIEnv();
+	jclass activity = tlsActivityClass(env);
+	if (activity == nullptr)
+		return -1;
+
+	jmethodID method = env->GetStaticMethodID(activity, "tlsOpen", "(Ljava/lang/String;I)I");
+	if (method == nullptr)
+	{
+		env->ExceptionClear();
+		env->DeleteLocalRef(activity);
+		return -1;
+	}
+
+	jstring jhost = env->NewStringUTF(host);
+	jint result = env->CallStaticIntMethod(activity, method, jhost, (jint) port);
+	env->DeleteLocalRef(jhost);
+	env->DeleteLocalRef(activity);
+	return (int) result;
+}
+
+int tlsStatus(int handle)
+{
+	JNIEnv *env = (JNIEnv*) SDL_AndroidGetJNIEnv();
+	jclass activity = tlsActivityClass(env);
+	if (activity == nullptr)
+		return -1;
+
+	jmethodID method = env->GetStaticMethodID(activity, "tlsStatus", "(I)I");
+	if (method == nullptr)
+	{
+		env->ExceptionClear();
+		env->DeleteLocalRef(activity);
+		return -1;
+	}
+
+	jint result = env->CallStaticIntMethod(activity, method, (jint) handle);
+	env->DeleteLocalRef(activity);
+	return (int) result;
+}
+
+int tlsSend(int handle, const char *data, int length)
+{
+	if (data == nullptr || length <= 0)
+		return 0;
+	JNIEnv *env = (JNIEnv*) SDL_AndroidGetJNIEnv();
+	jclass activity = tlsActivityClass(env);
+	if (activity == nullptr)
+		return -1;
+
+	jmethodID method = env->GetStaticMethodID(activity, "tlsSend", "(I[B)I");
+	if (method == nullptr)
+	{
+		env->ExceptionClear();
+		env->DeleteLocalRef(activity);
+		return -1;
+	}
+
+	jbyteArray payload = env->NewByteArray((jsize) length);
+	if (payload == nullptr)
+	{
+		env->ExceptionClear();
+		env->DeleteLocalRef(activity);
+		return -1;
+	}
+	env->SetByteArrayRegion(payload, 0, (jsize) length, (const jbyte*) data);
+
+	jint result = env->CallStaticIntMethod(activity, method, (jint) handle, payload);
+	env->DeleteLocalRef(payload);
+	env->DeleteLocalRef(activity);
+	return (int) result;
+}
+
+int tlsReceive(int handle, char *buf, int max)
+{
+	if (buf == nullptr || max <= 0)
+		return 0;
+	JNIEnv *env = (JNIEnv*) SDL_AndroidGetJNIEnv();
+	jclass activity = tlsActivityClass(env);
+	if (activity == nullptr)
+		return -1;
+
+	jmethodID method = env->GetStaticMethodID(activity, "tlsReceive", "(II)[B");
+	if (method == nullptr)
+	{
+		env->ExceptionClear();
+		env->DeleteLocalRef(activity);
+		return -1;
+	}
+
+	jobject result = env->CallStaticObjectMethod(activity, method, (jint) handle, (jint) max);
+	env->DeleteLocalRef(activity);
+	if (result == nullptr)
+		return 0;
+
+	jbyteArray bytes = (jbyteArray) result;
+	jsize length = env->GetArrayLength(bytes);
+	if (length > max)
+		length = max;
+	env->GetByteArrayRegion(bytes, 0, length, (jbyte*) buf);
+	env->DeleteLocalRef(result);
+	return (int) length;
+}
+
+bool tlsError(int handle, char *buf, int max)
+{
+	if (buf == nullptr || max <= 0)
+		return false;
+	buf[0] = '\0';
+	JNIEnv *env = (JNIEnv*) SDL_AndroidGetJNIEnv();
+	jclass activity = tlsActivityClass(env);
+	if (activity == nullptr)
+		return false;
+
+	jmethodID method = env->GetStaticMethodID(activity, "tlsError", "(I)Ljava/lang/String;");
+	if (method == nullptr)
+	{
+		env->ExceptionClear();
+		env->DeleteLocalRef(activity);
+		return false;
+	}
+
+	jobject result = env->CallStaticObjectMethod(activity, method, (jint) handle);
+	env->DeleteLocalRef(activity);
+	if (result == nullptr)
+		return false;
+
+	jstring text = (jstring) result;
+	const char *utf = env->GetStringUTFChars(text, nullptr);
+	if (utf != nullptr)
+	{
+		strncpy(buf, utf, (size_t) max - 1);
+		buf[max - 1] = '\0';
+		env->ReleaseStringUTFChars(text, utf);
+	}
+	env->DeleteLocalRef(result);
+	return buf[0] != '\0';
+}
+
+void tlsClose(int handle)
+{
+	JNIEnv *env = (JNIEnv*) SDL_AndroidGetJNIEnv();
+	jclass activity = tlsActivityClass(env);
+	if (activity == nullptr)
+		return;
+
+	jmethodID method = env->GetStaticMethodID(activity, "tlsClose", "(I)V");
+	if (method == nullptr)
+	{
+		env->ExceptionClear();
+		env->DeleteLocalRef(activity);
+		return;
+	}
+
+	env->CallStaticVoidMethod(activity, method, (jint) handle);
+	env->DeleteLocalRef(activity);
+}
+
 /*
  * Helper functions for the filesystem module
  */

mobile/android/love/src/jni/love/src/common/android.h

@@ -98,6 +98,27 @@ bool restartApp();
  **/
 bool httpDownload(const char *url, const char *destPath, const char *userAgent, const char *accept);
 
+/**
+ * TLS client sockets (GameActivity.tls*, implemented by TlsSocket.java).
+ * LuaSocket, which is what LOVE ships, does TCP only, so wss:// is otherwise
+ * unreachable -- and an Archipelago room hosted on archipelago.gg accepts a
+ * plain connection only to drop it. The platform has both a TLS stack and the
+ * system trust store, so this borrows them rather than vendoring mbedTLS.
+ *
+ * tlsOpen returns a handle immediately and connects on its own thread: poll
+ * tlsStatus for 0 connecting / 1 open / 2 closed, and -1 for a handle that
+ * does not exist. Bytes given to tlsSend before the handshake finishes are
+ * queued rather than refused. tlsReceive fills buf and returns how much it
+ * took, 0 when nothing is waiting. A closed connection keeps both its reason
+ * (tlsError) and whatever arrived before it closed until tlsClose.
+ **/
+int tlsOpen(const char *host, int port);
+int tlsStatus(int handle);
+int tlsSend(int handle, const char *data, int length);
+int tlsReceive(int handle, char *buf, int max);
+bool tlsError(int handle, char *buf, int max);
+void tlsClose(int handle);
+
 /*
  * Helper functions for the filesystem module
  */

mobile/android/love/src/jni/love/src/modules/system/System.cpp

@@ -244,6 +244,72 @@ bool System::httpDownload(const char *url, const char *destPath,
 #endif
 }
 
+int System::tlsOpen(const char *host, int port) const
+{
+#ifdef LOVE_ANDROID
+	return love::android::tlsOpen(host, port);
+#else
+	LOVE_UNUSED(host);
+	LOVE_UNUSED(port);
+	return -1;
+#endif
+}
+
+int System::tlsStatus(int handle) const
+{
+#ifdef LOVE_ANDROID
+	return love::android::tlsStatus(handle);
+#else
+	LOVE_UNUSED(handle);
+	return -1;
+#endif
+}
+
+int System::tlsSend(int handle, const char *data, int length) const
+{
+#ifdef LOVE_ANDROID
+	return love::android::tlsSend(handle, data, length);
+#else
+	LOVE_UNUSED(handle);
+	LOVE_UNUSED(data);
+	LOVE_UNUSED(length);
+	return -1;
+#endif
+}
+
+int System::tlsReceive(int handle, char *buf, int max) const
+{
+#ifdef LOVE_ANDROID
+	return love::android::tlsReceive(handle, buf, max);
+#else
+	LOVE_UNUSED(handle);
+	LOVE_UNUSED(buf);
+	LOVE_UNUSED(max);
+	return -1;
+#endif
+}
+
+bool System::tlsError(int handle, char *buf, int max) const
+{
+#ifdef LOVE_ANDROID
+	return love::android::tlsError(handle, buf, max);
+#else
+	LOVE_UNUSED(handle);
+	LOVE_UNUSED(buf);
+	LOVE_UNUSED(max);
+	return false;
+#endif
+}
+
+void System::tlsClose(int handle) const
+{
+#ifdef LOVE_ANDROID
+	love::android::tlsClose(handle);
+#else
+	LOVE_UNUSED(handle);
+#endif
+}
+
 bool System::hasBackgroundMusic() const
 {
 #if defined(LOVE_ANDROID)

mobile/android/love/src/jni/love/src/modules/system/System.h

@@ -149,6 +149,20 @@ public:
 	virtual bool httpDownload(const char *url, const char *destPath,
 		const char *userAgent = nullptr, const char *accept = nullptr) const;
 
+	/**
+	 * TLS client sockets (Android only; every call fails elsewhere, where
+	 * LuaSec or another provider is the answer). Non-blocking by contract:
+	 * tlsOpen returns a handle and connects on its own thread, tlsStatus
+	 * reports 0 connecting / 1 open / 2 closed / -1 unknown, and bytes sent
+	 * before the handshake completes are queued rather than refused.
+	 **/
+	virtual int tlsOpen(const char *host, int port) const;
+	virtual int tlsStatus(int handle) const;
+	virtual int tlsSend(int handle, const char *data, int length) const;
+	virtual int tlsReceive(int handle, char *buf, int max) const;
+	virtual bool tlsError(int handle, char *buf, int max) const;
+	virtual void tlsClose(int handle) const;
+
 	/**
 	 * Gets if the user is playing music on background.
 	 * Throws an exception on unsupported platforms.

mobile/android/love/src/jni/love/src/modules/system/wrap_System.cpp

@@ -139,6 +139,79 @@ int w_hasBackgroundMusic(lua_State *L)
 	return 1;
 }
 
+/*
+ * TLS sockets. Deliberately a handle-and-poll API rather than an object:
+ * the caller is a per-frame pump that must never block, and everything with
+ * a thread behind it lives on the Java side.
+ */
+int w_tlsOpen(lua_State *L)
+{
+	const char *host = luaL_checkstring(L, 1);
+	int port = (int) luaL_checknumber(L, 2);
+	lua_pushnumber(L, instance()->tlsOpen(host, port));
+	return 1;
+}
+
+int w_tlsStatus(lua_State *L)
+{
+	int handle = (int) luaL_checknumber(L, 1);
+	lua_pushnumber(L, instance()->tlsStatus(handle));
+	return 1;
+}
+
+int w_tlsSend(lua_State *L)
+{
+	int handle = (int) luaL_checknumber(L, 1);
+	size_t length = 0;
+	const char *data = luaL_checklstring(L, 2, &length);
+	lua_pushnumber(L, instance()->tlsSend(handle, data, (int) length));
+	return 1;
+}
+
+int w_tlsReceive(lua_State *L)
+{
+	int handle = (int) luaL_checknumber(L, 1);
+	int max = (int) luaL_optnumber(L, 2, 8192);
+	if (max <= 0)
+	{
+		lua_pushliteral(L, "");
+		return 1;
+	}
+	// A frame's worth of a busy room, on the C stack rather than the heap:
+	// this runs every frame and an allocation per poll is not worth it.
+	if (max > 65536)
+		max = 65536;
+	char buf[65536];
+	int got = instance()->tlsReceive(handle, buf, max);
+	if (got < 0)
+	{
+		lua_pushnil(L);
+		return 1;
+	}
+	lua_pushlstring(L, buf, (size_t) got);
+	return 1;
+}
+
+int w_tlsError(lua_State *L)
+{
+	int handle = (int) luaL_checknumber(L, 1);
+	char buf[512];
+	if (!instance()->tlsError(handle, buf, (int) sizeof(buf)))
+	{
+		lua_pushnil(L);
+		return 1;
+	}
+	lua_pushstring(L, buf);
+	return 1;
+}
+
+int w_tlsClose(lua_State *L)
+{
+	int handle = (int) luaL_checknumber(L, 1);
+	instance()->tlsClose(handle);
+	return 0;
+}
+
 static const luaL_Reg functions[] =
 {
 	{ "getOS", w_getOS },
@@ -153,6 +226,12 @@ static const luaL_Reg functions[] =
 	{ "syncHealthSteps", w_syncHealthSteps },
 	{ "restartApp", w_restartApp },
 	{ "httpDownload", w_httpDownload },
+	{ "tlsOpen", w_tlsOpen },
+	{ "tlsStatus", w_tlsStatus },
+	{ "tlsSend", w_tlsSend },
+	{ "tlsReceive", w_tlsReceive },
+	{ "tlsError", w_tlsError },
+	{ "tlsClose", w_tlsClose },
 	{ "hasBackgroundMusic", w_hasBackgroundMusic },
 	{ 0, 0 }
 };