Merge pull request #21 from unmojang/evan-goode/custom-authlib-injector

Allow using custom authlib-injector JAR

README.md

@@ -100,3 +100,7 @@ AppImages are available in the [releases section](https://github.com/unmojang/Fj
 ## Building
 
 To build the launcher yourself, follow [the instructions on the Prism Launcher website](https://prismlauncher.org/wiki/development/build-instructions) but clone this repo instead.
+
+## Notes
+
+- You can easily use a custom version of authlib-injector on an instance. Select the instance in the main window, click "Edit" (or Ctrl+I/Command+I), go to the Version tab, click "Add Agents", and select your authlib-injector JAR. If your JAR is not correctly identified as authlib-injector, make sure the `Agent-Class` field in the JAR's MANIFEST.MF is `moe.yushi.authlibinjector.Premain`.

launcher/CMakeLists.txt

@@ -95,6 +95,10 @@ set(CORE_SOURCES
     MMCTime.cpp
 
     MTPixmapCache.h
+
+    # Manifest.mf parser
+    Manifest.h
+    Manifest.cpp
 )
 if (UNIX AND NOT CYGWIN AND NOT APPLE)
 set(CORE_SOURCES

launcher/LaunchController.cpp

@@ -146,9 +146,15 @@ void LaunchController::login()
     if (m_accountToUse->usesCustomApiServers()) {
         MinecraftInstancePtr inst = std::dynamic_pointer_cast<MinecraftInstance>(m_instance);
 
-        const auto& authlibInjectorVersion = inst->getPackProfile()->getComponentVersion("moe.yushi.authlibinjector");
+        bool authlibInjectorInstalled = false;
+        const auto& agents = inst->getPackProfile()->getProfile()->getAgents();
+        for (const auto& agent : agents) {
+            if (agent->library()->artifactPrefix() == "moe.yushi:authlibinjector") {
+                authlibInjectorInstalled = true;
+            }
+        }
 
-        if (authlibInjectorVersion == "") {
+        if (!authlibInjectorInstalled) {
             // Account uses custom API servers, but authlib-injector is missing
 
             int globalMissingBehavior = APPLICATION->settings()->get("MissingAuthlibInjectorBehavior").toInt();

launcher/Manifest.cpp

@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-3.0-only
+/*
+ *  Fjord Launcher - Minecraft Launcher
+ *  Copyright (C) 2024 Evan Goode <[email protected]>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * This file incorporates work from OpenJDK, covered by the following copyright and
+ * permission notice:
+ *
+ *         Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
+ *         DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ *         This code is free software; you can redistribute it and/or modify it
+ *         under the terms of the GNU General Public License version 2 only, as
+ *         published by the Free Software Foundation.  Oracle designates this
+ *         particular file as subject to the "Classpath" exception as provided
+ *         by Oracle in the LICENSE file that accompanied this code.
+ *
+ *         This code is distributed in the hope that it will be useful, but WITHOUT
+ *         ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *         FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *         version 2 for more details (a copy is included in the LICENSE file that
+ *         accompanied this code).
+ *
+ *         You should have received a copy of the GNU General Public License version
+ *         2 along with this work; if not, write to the Free Software Foundation,
+ *         Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ *         Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ *         or visit www.oracle.com if you need additional information or have any
+ *         questions.
+ *
+ * The GNU General Public License version 2 is available at https://www.gnu.org/licenses/old-licenses/gpl-2.0.html.
+ */
+
+#include <string.h>
+#include <iostream>
+
+#include "Manifest.h"
+
+// Manifest specification:
+// https://docs.oracle.com/javase/8/docs/technotes/guides/jar/jar.html#Manifest_Specification
+
+// The implementation of the Manifest class was ported to C++ from OpenJDK:
+// https://github.com/openjdk/jdk/blob/0584af23255b6b8f49190eaf2618f3bcc299adfe/src/java.base/share/classes/java/util/jar/Manifest.java#L274
+
+Manifest::Manifest(std::istream& is)
+{
+    read(is, std::nullopt);
+}
+
+Manifest::Manifest(std::istream& is, const std::string& jar_filename)
+{
+    read(is, jar_filename);
+}
+
+bool Manifest::isValidName(const std::string& name)
+{
+    const auto len = name.length();
+    return 0 < len && len <= 70;
+}
+
+std::string Manifest::getErrorPosition(const std::optional<std::string>& filename, int line_number)
+{
+    if (!filename.has_value()) {
+        return "line " + std::to_string(line_number);
+    }
+    return "manifest of " + *filename + ":" + std::to_string(line_number);
+}
+
+int Manifest::readAttributes(manifest_section_t& section,
+                             std::istream& is,
+                             lbuf_t lbuf,
+                             const std::optional<std::string>& filename,
+                             int line_number)
+{
+    std::optional<std::string> name;
+    std::string value;
+
+    std::string full_line;
+
+    while (!is.eof() && is.getline(lbuf, MANIFEST_MAX_LINE_LENGTH)) {
+        std::size_t len = strlen(lbuf);
+
+        line_number += 1;
+
+        if (len > 0 && lbuf[len - 1] == '\r') {
+            len -= 1;
+        }
+        if (len == 0) {
+            break;
+        }
+        std::size_t i = 0;
+        if (lbuf[0] == ' ') {
+            // continuation of previous line
+            if (!name.has_value()) {
+                throw std::runtime_error("misplaced continuation line (" + getErrorPosition(filename, line_number) + ")");
+            }
+            full_line.append(lbuf + 1, len - 1);
+
+            if (is.peek() == ' ') {
+                continue;
+            }
+            value = full_line;
+            full_line.clear();
+        } else {
+            while (lbuf[i++] != ':') {
+                if (i >= len) {
+                    throw std::runtime_error("invalid header field (" + getErrorPosition(filename, line_number) + ")");
+                }
+            }
+            if (lbuf[i++] != ' ') {
+                throw std::runtime_error("invalid header field (" + getErrorPosition(filename, line_number) + ")");
+            }
+            name = std::string{ lbuf, i - 2 };
+            if (is.peek() == ' ') {
+                full_line.clear();
+                full_line.append(lbuf + i, len - i);
+                continue;
+            }
+            value = std::string{ lbuf + i, len - i };
+        }
+        if (!isValidName(*name)) {
+            throw std::runtime_error("invalid header field name (" + getErrorPosition(filename, line_number) + ")");
+        }
+        section[*name] = value;
+    }
+    if (!is.eof() && is.fail()) {
+        throw std::length_error("line too long (" + getErrorPosition(filename, line_number) + ")");
+    }
+    return line_number;
+}
+
+std::optional<std::string> Manifest::parseName(lbuf_t lbuf, std::size_t len)
+{
+    if (tolower(lbuf[0]) == 'n' && tolower(lbuf[1]) && tolower(lbuf[2]) == 'm' && tolower(lbuf[3]) && lbuf[4] == ':' && lbuf[5] == ' ') {
+        return std::string{ lbuf, 6, len - 6 };
+    }
+    return std::nullopt;
+}
+
+void Manifest::read(std::istream& is, const std::optional<std::string>& jar_filename)
+{
+    // Line buffer
+    char lbuf[MANIFEST_MAX_LINE_LENGTH];
+    // Read the main attributes for the manifest
+    int line_number = readAttributes(m_main_section, is, lbuf, jar_filename, 0);
+
+    std::optional<std::string> name;
+
+    bool skip_empty_lines = true;
+    std::optional<std::string> lastline;
+
+    while (!is.eof() && is.getline(lbuf, MANIFEST_MAX_LINE_LENGTH)) {
+        std::size_t len = strlen(lbuf);
+
+        line_number += 1;
+
+        if (len > 0 && lbuf[len - 1] == '\r') {
+            len -= 1;
+        }
+        if (len == 0 && skip_empty_lines) {
+            continue;
+        }
+        skip_empty_lines = false;
+
+        if (!name.has_value()) {
+            name = parseName(lbuf, len);
+            if (!name.has_value()) {
+                throw std::runtime_error("invalid manifest format (" + getErrorPosition(jar_filename, line_number) + ")");
+            }
+            if (is.peek() == ' ') {
+                // name is wrapped
+                lastline = std::string{ lbuf + 6, len - 6 };
+                continue;
+            }
+        } else {
+            // continuation line
+            std::string buf{ *lastline };
+            buf.append(lbuf + 1, len - 1);
+            if (is.peek() == ' ') {
+                // name is wrapped
+                lastline = buf;
+                continue;
+            }
+            name = buf;
+            lastline = std::nullopt;
+        }
+
+        manifest_section_t& attr = m_individual_sections[*name];
+        line_number = readAttributes(attr, is, lbuf, jar_filename, line_number);
+
+        name = std::nullopt;
+        skip_empty_lines = true;
+    }
+    if (!is.eof() && is.fail()) {
+        throw std::length_error("manifest line too long (" + getErrorPosition(jar_filename, line_number) + ")");
+    }
+}

launcher/Manifest.h

@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-3.0-only
+/*
+ *  Fjord Launcher - Minecraft Launcher
+ *  Copyright (C) 2024 Evan Goode <[email protected]>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <map>
+#include <optional>
+#include <string>
+
+constexpr const int MANIFEST_MAX_LINE_LENGTH = 512;
+using lbuf_t = char[MANIFEST_MAX_LINE_LENGTH];
+
+using manifest_section_t = std::map<std::string, std::string>;
+using manifest_sections_t = std::map<std::string, manifest_section_t>;
+
+class Manifest {
+   public:
+    Manifest(std::istream& is);
+    Manifest(std::istream& is, const std::string& jar_filename);
+    Manifest(const Manifest& other)
+    {
+        m_main_section = other.m_main_section;
+        m_individual_sections = other.m_individual_sections;
+    }
+    manifest_section_t& getMainAttributes() { return m_main_section; }
+    manifest_sections_t& getEntries() { return m_individual_sections; }
+    manifest_section_t& getAttributes(const std::string& name) { return m_individual_sections.at(name); }
+    Manifest& operator=(const Manifest& other)
+    {
+        if (this == &other) {
+            return *this;
+        }
+        m_main_section = other.m_main_section;
+        m_individual_sections = other.m_individual_sections;
+        return *this;
+    }
+    bool operator==(const Manifest& other) const
+    {
+        return m_main_section == other.m_main_section && m_individual_sections == other.m_individual_sections;
+    }
+
+   private:
+    static std::string getErrorPosition(const std::optional<std::string>& filename, int line_number);
+    static std::optional<std::string> parseName(lbuf_t lbuf, std::size_t len);
+    static bool isValidName(const std::string& name);
+    int readAttributes(manifest_section_t& section,
+                       std::istream& is,
+                       lbuf_t lbuf,
+                       const std::optional<std::string>& jar_filename,
+                       int line_number);
+    void read(std::istream& is, const std::optional<std::string>& jar_filename);
+    manifest_section_t m_main_section;
+    manifest_sections_t m_individual_sections;
+};

launcher/minecraft/Agent.h

@@ -1,9 +1,14 @@
 #pragma once
 
 #include <QString>
+#include <unordered_set>
 
 #include "Library.h"
 
+static const std::unordered_set<std::string> MANAGED_AGENTS = { "moe.yushi:authlibinjector" };
+static const std::map<std::string, std::string> AGENT_CLASS_TO_MANAGED_AGENT = { { "moe.yushi.authlibinjector.Premain",
+                                                                                   "moe.yushi:authlibinjector" } };
+
 class Agent;
 
 using AgentPtr = std::shared_ptr<Agent>;

launcher/minecraft/MinecraftInstance.h

@@ -38,13 +38,10 @@
 #include <java/JavaVersion.h>
 #include <QDir>
 #include <QProcess>
-#include <unordered_set>
 #include "BaseInstance.h"
 #include "minecraft/launch/MinecraftServerTarget.h"
 #include "minecraft/mod/Mod.h"
 
-const std::unordered_set<std::string> MANAGED_AGENTS = { "moe.yushi:authlibinjector" };
-
 class ModFolderModel;
 class ResourceFolderModel;
 class ResourcePackFolderModel;