Add PluginLoader class

- PluginLoader::verify can be used to check if the plugin has a valid
(SHA512/RSA 4096) signature.
- Uses nn OpenSSL public key that is embedded during the compile.

7 files changed, 121 insertions, 15 deletions

diff --git a/linux/makepkg/PKGBUILD b/linux/makepkg/PKGBUILD
index 8c6bed3..3907ff8 100644
--- a/linux/makepkg/PKGBUILD
+++ b/linux/makepkg/PKGBUILD
@@ -14,10 +14,10 @@ license=('GPL3')
 
 depends=('qt5-webengine>=5.11.0' 'boost-libs>=1.66.0')
 optdepends=('firejail: launch a sandboxed instance')
-makedepends=('git' 'meson' 'pkg-config' 'python-kconfiglib' 'asciidoctor')
+makedepends=('git' 'meson' 'pkg-config' 'python-kconfiglib' 'asciidoctor' 'openssl')
 
 # this is the central repository
-source=("git+https://neueland.iserlohn-fortress.net/gitea/aqua/smolbote.git"
+source=("git+https://neueland.iserlohn-fortress.net/gitea/aeon/smolbote.git"
         "git+https://github.com/itay-grudev/SingleApplication.git")
 
 sha512sums=('SKIP'
@@ -32,6 +32,17 @@ prepare() {
     git submodule init
     git config submodule.3rd-party/SingleApplication/SingleApplication.git.url $srcdir/SingleApplication
     git submodule update 3rd-party/SingleApplication/SingleApplication.git
+
+    msg "Creating OpenSSL signing key"
+    mkdir $srcdir/signing
+    cd $srcdir/signing
+    # generate rsa keypair
+    openssl genrsa -out privateKey.pem 4096
+    msg2 "RSA/4096 key created in $srcdir/signing/privateKey.pem. Keep this key if you want to sign additional plugins."
+
+    openssl rsa -in privateKey.pem -pubout -out publicKey.pem
+    xxd -i publicKey.pem $srcdir/smolbote/src/plugin/publicKey.h
+    msg2 "Public key exported, and will be embedded into the resulting application. This will break reproducible builds."
 }
 
 pkgver() {
@@ -76,13 +87,9 @@ package() {
     cd $srcdir/build
     DESTDIR="$pkgdir" ninja install
 
-    #msg Creating signing key in $srcdir/build/gpg
-    #mkdir $srcdir/build/gpg
-    #gpg2 --homedir=$srcdir/build/gpg --batch --generate-key $srcdir/smolbote/tools/gpgkey.preset
-
-    #msg Signing plugins
-    #for so in $pkgdir/usr/local/lib/smolbote/plugins/*.so; do
-    #    gpg2 --homedir=$srcdir/build/gpg --batch --yes --local-user=smolbote@localhost --detach-sign --output=$so.sig $so
-    #done
+    msg Signing plugins
+    for so in $pkgdir/usr/local/lib/smolbote/plugins/*.so; do
+        openssl dgst -sha256 -sign $srcdir/signing/privateKey.pem -out $so.sig $so
+    done
 }
 
diff --git a/meson.build b/meson.build
index 9310eb0..121b472 100644
--- a/meson.build
+++ b/meson.build
@@ -1,5 +1,5 @@
 project('smolbote', 'cpp',
-    version: 'master',
+    version: '0.1.0',
     default_options: ['cpp_std=c++17', 'strip=true', 'warning_level=3'],
     license: 'GPL3',
     meson_version: '>=0.49.0'
@@ -26,6 +26,8 @@ dep_boost = dependency('boost', modules: ['program_options'])
 
 dep_spdlog = dependency('spdlog', fallback: ['spdlog', 'spdlog_dep'], version: '>=1.3.1')
 
+dep_openssl = dependency('openssl')
+
 optional_deps = []
 
 if get_option('Breakpad').enabled()
diff --git a/src/browser.cpp b/src/browser.cpp
index 69db6b2..db75fa1 100644
--- a/src/browser.cpp
+++ b/src/browser.cpp
@@ -38,6 +38,7 @@
 #include "adblock/adblocklist.h"
 #include "hostlist/hostlist.h"
 #include <spdlog/spdlog.h>
+#include "plugin/pluginloader.h"
 
 Browser::Browser(int &argc, char *argv[], bool allowSecondary)
     : SingleApplication(argc, argv, allowSecondary, SingleApplication::User | SingleApplication::SecondaryNotification | SingleApplication::ExcludeAppVersion)
@@ -150,7 +151,8 @@ QPluginLoader *Browser::addPlugin(const QString &path)
     if(path.isEmpty())
         return nullptr;
 
-    auto *loader = new QPluginLoader(path, this);
+    auto *loader = new PluginLoader(path, this);
+    spdlog::info("Verifying plugin: {}", loader->verify() ? "passed" : "failed");
     loader->load();
 
     auto *info = new PluginInfo(loader);
diff --git a/src/main.cpp b/src/main.cpp
index dfe58de..0d6f466 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -18,6 +18,7 @@
 #include <QFile>
 #include <QLibraryInfo>
 #include <QPluginLoader>
+#include "plugin/pluginloader.h"
 #include <QTranslator>
 #include <memory>
 #include <plugininterface.h>
@@ -69,8 +70,9 @@ int main(int argc, char **argv)
     CommandHash_t pluginCommands;
 
     // Load plugins
-    for(const QString &path : Util::files(config->value<QString>("plugins.path").value())) {
-        auto *loader = new QPluginLoader(path);
+    for(const QString &path : Util::files(config->value<QString>("plugins.path").value(), {"*.so", "*.dll"})) {
+        auto *loader = new PluginLoader(path);
+        spdlog::info("Verifying plugin: {}", loader->verify() ? "passed" : "failed");
         const bool loaded = loader->load();
         spdlog::info("{} plugin {}", loaded ? "Loaded" : "Failed to load", qUtf8Printable(path));
 
diff --git a/src/meson.build b/src/meson.build
index ef0f989..960cc69 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -1,6 +1,7 @@
 # poi
 poi_moc = mod_qt5.preprocess(
     moc_headers: ['browser.h',
+        'plugin/pluginloader.h',
         'mainwindow/mainwindow.h', 'mainwindow/menubar.h', 'mainwindow/widgets/dockwidget.h', 'mainwindow/widgets/menusearch.h', 'mainwindow/widgets/navigationbar.h', 'mainwindow/widgets/searchform.h',
         'session/savesessiondialog.h', 'session/sessiondialog.h', 'session/sessionform.h',
         'subwindow/subwindow.h', 'subwindow/tabwidget.h',
@@ -13,13 +14,15 @@ poi_moc = mod_qt5.preprocess(
 
 poi = executable(get_option('poiName'), install: true,
     cpp_args: ['-DQAPPLICATION_CLASS=QApplication'],
-    dependencies: [dep_qt5, dep_boost, dep_spdlog, dep_SingleApplication, dep_genheaders, optional_deps,
+    dependencies: [dep_qt5, dep_boost, dep_spdlog, dep_openssl, dep_SingleApplication, dep_genheaders, optional_deps,
         dep_about, dep_addressbar, dep_bookmarks, dep_configuration, dep_downloads, dep_urlfilter, dep_webprofile],
     include_directories: [include],
     sources: ['main.cpp', 'builtins.cpp', 'crashhandler.cpp', poi_moc,
     'browser.cpp',
     'util.cpp', 'util.h',
 
+    'plugin/pluginloader.cpp',
+
     'mainwindow/mainwindow.cpp',
     'mainwindow/menubar.cpp',
     'mainwindow/widgets/dockwidget.cpp',
diff --git a/src/plugin/pluginloader.cpp b/src/plugin/pluginloader.cpp
new file mode 100644
index 0000000..d1626f2
--- /dev/null
+++ b/src/plugin/pluginloader.cpp
@@ -0,0 +1,77 @@
+#include "pluginloader.h"
+#include <QFile>
+#include <openssl/evp.h>
+#include <openssl/pem.h>
+#include "publicKey.h"
+#include <spdlog/spdlog.h>
+
+PluginLoader::PluginLoader(const QString &fileName, QObject *parent)
+    : QPluginLoader(fileName, parent)
+{
+}
+
+bool PluginLoader::verify(const char *hashName) const
+{
+    const QString sigName = this->fileName() + ".sig";
+    if(!QFile::exists(sigName)) {
+        spdlog::error("Signature does not exist: {}", qUtf8Printable(sigName));
+        return false;
+    }
+
+    auto *bio = BIO_new_mem_buf(publicKey_pem, publicKey_pem_len);
+    Q_CHECK_PTR(bio);
+
+    auto *key = PEM_read_bio_PUBKEY(bio, NULL, NULL, NULL);
+    Q_CHECK_PTR(key);
+
+    auto *ctx = EVP_MD_CTX_new();
+    Q_CHECK_PTR(ctx);
+
+    const auto *md = EVP_get_digestbyname(hashName);
+    Q_CHECK_PTR(md);
+
+    int rc = EVP_DigestVerifyInit(ctx, NULL, md, NULL, key);
+    if(rc != 1) {
+        spdlog::error("DigestVerifyInit failed: %i", rc);
+        return false;
+    }
+
+    // read plugin into DigestVerifyUpdate
+    QFile plugin(this->fileName());
+    plugin.open(QIODevice::ReadOnly);
+    int len = plugin.size();
+    int read = 0;
+    auto *buf = new unsigned char[1024];
+    while(len > 0) {
+        read = plugin.read((char*) buf, 1024);
+        len -= read;
+
+        rc = EVP_DigestVerifyUpdate(ctx, buf, read);
+        if(rc != 1)
+            spdlog::error("DigestVerifyUpdate failed: %i", rc);
+    }
+    delete buf;
+    plugin.close();
+
+    // read signature into DigestVerifyFinal
+    QFile sigFile(sigName);
+    sigFile.open(QIODevice::ReadOnly);
+    const int sig_len = sigFile.size();
+    const auto* sig = [&sigFile, sig_len]() {
+        auto* buf = new unsigned char[sig_len];
+        sigFile.read((char*) buf, sig_len);
+        return buf;
+    }();
+    sigFile.close();
+
+    rc = EVP_DigestVerifyFinal(ctx, sig, sig_len);
+    delete sig;
+
+    if(rc == 1)
+        return true;
+    else {
+        spdlog::error("DigestVerifyFinal failed: %i", rc);
+        return false;
+    }
+}
+
diff --git a/src/plugin/pluginloader.h b/src/plugin/pluginloader.h
new file mode 100644
index 0000000..8d186aa
--- /dev/null
+++ b/src/plugin/pluginloader.h
@@ -0,0 +1,13 @@
+#include <QPluginLoader>
+
+class PluginLoader : public QPluginLoader
+{
+    Q_OBJECT
+
+public:
+    PluginLoader(const QString &fileName, QObject *parent = nullptr);
+    ~PluginLoader() = default;
+
+    bool verify(const char *hashName = "SHA256") const;
+};
+