From dbcb13f473ee312998d8586024ff5a9ce9f249f2 Mon Sep 17 00:00:00 2001
From: WerWolv <werwolv98@gmail.com>
Date: Mon, 9 Jan 2023 08:38:19 +0100
Subject: [PATCH] patterns: Disallow `application/octet-stream` to be used as
 MIME type

---
 lib/libimhex/include/hex/helpers/magic.hpp         |  2 ++
 lib/libimhex/source/helpers/magic.cpp              | 14 ++++++++++++++
 plugins/builtin/source/content/pl_pragmas.cpp      |  7 ++++---
 .../source/content/views/view_pattern_editor.cpp   |  5 +++--
 4 files changed, 23 insertions(+), 5 deletions(-)

diff --git a/lib/libimhex/include/hex/helpers/magic.hpp b/lib/libimhex/include/hex/helpers/magic.hpp
index 0450b212c..97c867f18 100644
--- a/lib/libimhex/include/hex/helpers/magic.hpp
+++ b/lib/libimhex/include/hex/helpers/magic.hpp
@@ -21,4 +21,6 @@ namespace hex::magic {
     std::string getMIMEType(const std::vector<u8> &data);
     std::string getMIMEType(prv::Provider *provider, size_t size = 100_KiB);
 
+    bool isValidMIMEType(const std::string &mimeType);
+
 }
\ No newline at end of file
diff --git a/lib/libimhex/source/helpers/magic.cpp b/lib/libimhex/source/helpers/magic.cpp
index 101908669..3898c6b0d 100644
--- a/lib/libimhex/source/helpers/magic.cpp
+++ b/lib/libimhex/source/helpers/magic.cpp
@@ -96,4 +96,18 @@ namespace hex::magic {
         return getMIMEType(buffer);
     }
 
+    bool isValidMIMEType(const std::string &mimeType) {
+        // MIME types always contain a slash
+        if (!mimeType.contains("/"))
+            return false;
+
+        // The MIME type "application/octet-stream" is a fallback type for arbitrary binary data.
+        // Specifying this in a pattern would make it get suggested for every single unknown binary that's being loaded.
+        // We don't want that, so we ignore it here
+        if (mimeType == "application/octet-stream")
+            return false;
+
+        return true;
+    }
+
 }
\ No newline at end of file
diff --git a/plugins/builtin/source/content/pl_pragmas.cpp b/plugins/builtin/source/content/pl_pragmas.cpp
index 7699e3914..3da29a872 100644
--- a/plugins/builtin/source/content/pl_pragmas.cpp
+++ b/plugins/builtin/source/content/pl_pragmas.cpp
@@ -1,5 +1,6 @@
 #include <hex/api/content_registry.hpp>
 #include <hex/providers/provider.hpp>
+#include <hex/helpers/magic.hpp>
 
 #include <pl/core/evaluator.hpp>
 
@@ -8,8 +9,6 @@ namespace hex::plugin::builtin {
     void registerPatternLanguagePragmas() {
 
         ContentRegistry::PatternLanguage::addPragma("base_address", [](pl::PatternLanguage &runtime, const std::string &value) {
-            hex::unused(runtime);
-
             auto baseAddress = strtoull(value.c_str(), nullptr, 0);
 
             ImHexApi::Provider::get()->setBaseAddress(baseAddress);
@@ -18,7 +17,9 @@ namespace hex::plugin::builtin {
             return true;
         });
 
-        ContentRegistry::PatternLanguage::addPragma("MIME", [](pl::PatternLanguage&, const std::string &value) { return !value.empty(); });
+        ContentRegistry::PatternLanguage::addPragma("MIME", [](pl::PatternLanguage&, const std::string &value) {
+            return magic::isValidMIMEType(value);
+        });
     }
 
 }
\ No newline at end of file
diff --git a/plugins/builtin/source/content/views/view_pattern_editor.cpp b/plugins/builtin/source/content/views/view_pattern_editor.cpp
index 52fd2bf84..d736077e4 100644
--- a/plugins/builtin/source/content/views/view_pattern_editor.cpp
+++ b/plugins/builtin/source/content/views/view_pattern_editor.cpp
@@ -773,6 +773,9 @@ namespace hex::plugin::builtin {
                 runtime->addPragma("MIME", [&mimeType, &foundCorrectType](pl::PatternLanguage &runtime, const std::string &value) {
                     hex::unused(runtime);
 
+                    if (!magic::isValidMIMEType(value))
+                        return false;
+
                     if (value == mimeType) {
                         foundCorrectType = true;
                         return true;
@@ -802,8 +805,6 @@ namespace hex::plugin::builtin {
                     }
                 }
 
-                runtime->addPragma("MIME", [](pl::PatternLanguage&, const std::string &value) { return !value.empty(); });
-
                 if (!this->m_possiblePatternFiles.empty()) {
                     this->m_selectedPatternFile = 0;
                     EventManager::post<RequestOpenPopup>("hex.builtin.view.pattern_editor.accept_pattern"_lang);