From aeaa7ef76cd97e1e67044ca808a7db214067e92e Mon Sep 17 00:00:00 2001
From: Brian Bowman <seeker14491@gmail.com>
Date: Thu, 21 Jul 2022 17:46:06 -0500
Subject: [PATCH] Don't throw C++ exceptions into Rust

---
 src-tauri/mhycrypto/metadata.cpp  | 22 ++++++++++--
 src-tauri/mhycrypto/metadata.h    |  4 +--
 src-tauri/src/metadata_patcher.rs | 57 +++++++++----------------------
 3 files changed, 39 insertions(+), 44 deletions(-)

diff --git a/src-tauri/mhycrypto/metadata.cpp b/src-tauri/mhycrypto/metadata.cpp
index 392112b..d40f358 100644
--- a/src-tauri/mhycrypto/metadata.cpp
+++ b/src-tauri/mhycrypto/metadata.cpp
@@ -53,7 +53,7 @@ bool gen_global_metadata_key(uint8_t* src, size_t srcn) {
     return true;
 }
 
-extern "C" void decrypt_global_metadata(uint8_t *data, size_t size) {
+void decrypt_global_metadata_inner(uint8_t *data, size_t size) {
     uint8_t longkey[0xB00];
     uint8_t longkeyp[0xB0];
     uint8_t shortkey[16];
@@ -87,7 +87,16 @@ extern "C" void decrypt_global_metadata(uint8_t *data, size_t size) {
     recrypt_global_metadata_header_string_literals(data, size, literal_dec_key);
 }
 
-extern "C" void encrypt_global_metadata(uint8_t* data, size_t size) {
+extern "C" int decrypt_global_metadata(uint8_t *data, size_t size) {
+    try {
+        decrypt_global_metadata_inner(data, size);
+        return 0;
+    } catch (...) {
+        return -1;
+    }
+}
+
+void encrypt_global_metadata_inner(uint8_t* data, size_t size) {
     uint8_t literal_dec_key[0x5000];
 
     gen_global_metadata_key(data + size - 0x4000, 0x4000);
@@ -126,3 +135,12 @@ extern "C" void encrypt_global_metadata(uint8_t* data, size_t size) {
         }
     }
 }
+
+extern "C" int encrypt_global_metadata(uint8_t* data, size_t size) {
+    try {
+        encrypt_global_metadata_inner(data, size);
+        return 0;
+    } catch (...) {
+        return -1;
+    }
+}
diff --git a/src-tauri/mhycrypto/metadata.h b/src-tauri/mhycrypto/metadata.h
index f2c8c5b..d92c18d 100644
--- a/src-tauri/mhycrypto/metadata.h
+++ b/src-tauri/mhycrypto/metadata.h
@@ -4,7 +4,7 @@
 #include <cstdint>
 #include <cstdlib>
 
-extern "C" void decrypt_global_metadata(uint8_t *data, size_t size);
-extern "C" void encrypt_global_metadata(uint8_t *data, size_t size);
+extern "C" int decrypt_global_metadata(uint8_t *data, size_t size);
+extern "C" int encrypt_global_metadata(uint8_t *data, size_t size);
 
 #endif //METADATA_H
diff --git a/src-tauri/src/metadata_patcher.rs b/src-tauri/src/metadata_patcher.rs
index d551330..7965676 100644
--- a/src-tauri/src/metadata_patcher.rs
+++ b/src-tauri/src/metadata_patcher.rs
@@ -4,29 +4,10 @@ use std::fs::OpenOptions;
 use std::io::Read;
 use std::io::Write;
 
+// For these two functions, a non-zero return value indicates failure.
 extern "C" {
-  fn decrypt_global_metadata(data: *mut u8, size: u64);
-  fn encrypt_global_metadata(data: *mut u8, size: u64);
-}
-
-fn dll_decrypt_global_metadata(
-  data: *mut u8,
-  size: u64,
-) -> Result<bool, Box<dyn std::error::Error>> {
-  unsafe {
-    decrypt_global_metadata(data, size);
-    Ok(true)
-  }
-}
-
-fn dll_encrypt_global_metadata(
-  data: *mut u8,
-  size: u64,
-) -> Result<bool, Box<dyn std::error::Error>> {
-  unsafe {
-    encrypt_global_metadata(data, size);
-    Ok(true)
-  }
+  fn decrypt_global_metadata(data: *mut u8, size: usize) -> i32;
+  fn encrypt_global_metadata(data: *mut u8, size: usize) -> i32;
 }
 
 #[tauri::command]
@@ -89,15 +70,13 @@ fn decrypt_metadata(file_path: &str) -> Vec<u8> {
   }
 
   // Decrypt metadata file
-  match dll_decrypt_global_metadata(data.as_mut_ptr(), data.len().try_into().unwrap()) {
-    Ok(_) => {
-      println!("Successfully decrypted global-metadata");
-      data
-    }
-    Err(e) => {
-      println!("Failed to decrypt global-metadata: {}", e);
-      Vec::new()
-    }
+  let success = unsafe { decrypt_global_metadata(data.as_mut_ptr(), data.len()) } == 0;
+  if success {
+    println!("Successfully decrypted global-metadata");
+    data
+  } else {
+    println!("Failed to decrypt global-metadata");
+    Vec::new()
   }
 }
 
@@ -150,15 +129,13 @@ fn replace_rsa_key(old_data: &str, to_replace: &str, file_name: &str) -> String
 
 fn encrypt_metadata(old_data: &[u8]) -> Vec<u8> {
   let mut data = old_data.to_vec();
-  match dll_encrypt_global_metadata(data.as_mut_ptr(), data.len().try_into().unwrap()) {
-    Ok(_) => {
-      println!("Successfully encrypted global-metadata");
-      data
-    }
-    Err(e) => {
-      println!("Failed to encrypt global-metadata: {}", e);
-      Vec::new()
-    }
+  let success = unsafe { encrypt_global_metadata(data.as_mut_ptr(), data.len()) } == 0;
+  if success {
+    println!("Successfully encrypted global-metadata");
+    data
+  } else {
+    println!("Failed to encrypt global-metadata");
+    Vec::new()
   }
 }