1 files changed, 64 insertions, 0 deletions
diff --git a/modules/woff2/RLBoxWOFF2Sandbox.cpp b/modules/woff2/RLBoxWOFF2Sandbox.cpp
new file mode 100644
index 0000000000..3ce947af07
--- /dev/null
+++ b/modules/woff2/RLBoxWOFF2Sandbox.cpp
@@ -0,0 +1,64 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include <woff2/decode.h>
+#include <cassert>
+#include "RLBoxWOFF2Sandbox.h"
+
+bool RLBoxConvertWOFF2ToTTF(const char* aData, unsigned long aLength,
+                            unsigned long aDecompressedSize,
+                            unsigned long* aResultSize, void** aResultOwningStr,
+                            char** aResultData) {
+  std::unique_ptr<std::string> buf =
+      std::make_unique<std::string>(aDecompressedSize, 0);
+  woff2::WOFF2StringOut out(buf.get());
+  if (!woff2::ConvertWOFF2ToTTF(reinterpret_cast<const uint8_t*>(aData),
+                                aLength, &out)) {
+    return false;
+  }
+  *aResultSize = out.Size();
+  // Return the string and its underlying C string. We need both to make sure we
+  // can free the string (which we do with RLBoxDeleteWOFF2String).
+  *aResultData = buf->data();
+  *aResultOwningStr = static_cast<void*>(buf.release());
+  return true;
+}
+
+void RLBoxDeleteWOFF2String(void** aStr) {
+  std::string* buf = static_cast<std::string*>(*aStr);
+  delete buf;
+}
+
+BrotliDecompressCallback* sRLBoxBrotliDecompressCallback = nullptr;
+
+void RegisterWOFF2Callback(BrotliDecompressCallback* aCallback) {
+#ifdef MOZ_IN_WASM_SANDBOX
+  // When Woff2 is wasmboxed, we need to register a callback for brotli
+  // decompression. The easiest way to store this is in a static variable. This
+  // is thread-safe because each (potentially-concurrent) woff2 instance gets
+  // its own sandbox with its own copy of the statics.
+  //
+  // When the sandbox is disabled (replaced with the noop sandbox), setting the
+  // callback is actually racey. However, we don't actually need a callback in
+  // that case, and can just invoke brotli directly.
+  sRLBoxBrotliDecompressCallback = aCallback;
+#endif
+}
+
+BrotliDecoderResult RLBoxBrotliDecoderDecompress(size_t aEncodedSize,
+                                                 const uint8_t* aEncodedBuffer,
+                                                 size_t* aDecodedSize,
+                                                 uint8_t* aDecodedBuffer) {
+#ifdef MOZ_IN_WASM_SANDBOX
+  assert(sRLBoxBrotliDecompressCallback);
+  return sRLBoxBrotliDecompressCallback(
+      aEncodedSize, reinterpret_cast<const char*>(aEncodedBuffer), aDecodedSize,
+      reinterpret_cast<char*>(aDecodedBuffer));
+#else
+  return BrotliDecoderDecompress(aEncodedSize, aEncodedBuffer, aDecodedSize,
+                                 aDecodedBuffer);
+#endif
+}