Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 242 insertions, 0 deletions

diff --git a/dom/ipc/JSValidatorChild.cpp b/dom/ipc/JSValidatorChild.cpp
new file mode 100644
index 0000000000..5070a46492
--- /dev/null
+++ b/dom/ipc/JSValidatorChild.cpp
@@ -0,0 +1,242 @@
+/* -*- 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 "mozilla/dom/JSValidatorChild.h"
+#include "mozilla/dom/JSOracleChild.h"
+
+#include "mozilla/Encoding.h"
+#include "mozilla/dom/ScriptDecoding.h"
+#include "mozilla/ipc/Endpoint.h"
+
+#include "js/CompileOptions.h"
+#include "js/JSON.h"
+#include "js/SourceText.h"
+#include "js/experimental/CompileScript.h"
+#include "js/experimental/JSStencil.h"
+#include "xpcpublic.h"
+
+using namespace mozilla::dom;
+using Encoding = mozilla::Encoding;
+
+mozilla::UniquePtr<mozilla::Decoder> TryGetDecoder(
+    const mozilla::Span<const uint8_t>& aSourceBytes,
+    const nsACString& aContentCharset, const nsAString& aHintCharset,
+    const nsAString& aDocumentCharset) {
+  const Encoding* encoding;
+  mozilla::UniquePtr<mozilla::Decoder> unicodeDecoder;
+
+  std::tie(encoding, std::ignore) = Encoding::ForBOM(aSourceBytes);
+  if (encoding) {
+    unicodeDecoder = encoding->NewDecoderWithBOMRemoval();
+  }
+
+  if (!unicodeDecoder) {
+    encoding = Encoding::ForLabel(aContentCharset);
+    if (encoding) {
+      unicodeDecoder = encoding->NewDecoderWithoutBOMHandling();
+    }
+
+    if (!unicodeDecoder) {
+      encoding = Encoding::ForLabel(aHintCharset);
+      if (encoding) {
+        unicodeDecoder = encoding->NewDecoderWithoutBOMHandling();
+      }
+    }
+
+    if (!unicodeDecoder) {
+      encoding = Encoding::ForLabel(aDocumentCharset);
+      if (encoding) {
+        unicodeDecoder = encoding->NewDecoderWithoutBOMHandling();
+      }
+    }
+  }
+
+  if (!unicodeDecoder && !IsUtf8(mozilla::Span(reinterpret_cast<const char*>(
+                                                   aSourceBytes.Elements()),
+                                               aSourceBytes.Length()))) {
+    // Curiously, there are various callers that don't pass aDocument. The
+    // fallback in the old code was ISO-8859-1, which behaved like
+    // windows-1252.
+    unicodeDecoder = WINDOWS_1252_ENCODING->NewDecoderWithoutBOMHandling();
+  }
+
+  return unicodeDecoder;
+}
+
+mozilla::ipc::IPCResult JSValidatorChild::RecvIsOpaqueResponseAllowed(
+    IsOpaqueResponseAllowedResolver&& aResolver) {
+  mResolver.emplace(aResolver);
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult JSValidatorChild::RecvOnDataAvailable(Shmem&& aData) {
+  if (!mResolver) {
+    MOZ_ASSERT(!CanSend());
+    return IPC_OK();
+  }
+
+  if (!mSourceBytes.Append(Span(aData.get<char>(), aData.Size<char>()),
+                           mozilla::fallible)) {
+    // To prevent an attacker from flood the validation process,
+    // we don't validate here.
+    Resolve(ValidatorResult::Failure);
+  }
+  DeallocShmem(aData);
+
+  return IPC_OK();
+}
+
+mozilla::ipc::IPCResult JSValidatorChild::RecvOnStopRequest(
+    const nsresult& aReason, const nsACString& aContentCharset,
+    const nsAString& aHintCharset, const nsAString& aDocumentCharset) {
+  if (!mResolver) {
+    return IPC_OK();
+  }
+
+  if (NS_FAILED(aReason)) {
+    Resolve(ValidatorResult::Failure);
+  } else if (mSourceBytes.IsEmpty()) {
+    // The empty document parses as JavaScript.
+    Resolve(ValidatorResult::JavaScript);
+  } else {
+    UniquePtr<Decoder> unicodeDecoder = TryGetDecoder(
+        mSourceBytes, aContentCharset, aHintCharset, aDocumentCharset);
+
+    if (!unicodeDecoder) {
+      Resolve(ShouldAllowJS(mSourceBytes));
+    } else {
+      BufferUniquePtr<Utf8Unit[]> buffer;
+      auto result = GetUTF8EncodedContent(mSourceBytes, buffer, unicodeDecoder);
+      if (result.isErr()) {
+        Resolve(ValidatorResult::Failure);
+      } else {
+        Resolve(ShouldAllowJS(result.unwrap()));
+      }
+    }
+  }
+
+  return IPC_OK();
+}
+
+void JSValidatorChild::ActorDestroy(ActorDestroyReason aReason) {
+  if (mResolver) {
+    Resolve(ValidatorResult::Failure);
+  }
+};
+
+void JSValidatorChild::Resolve(ValidatorResult aResult) {
+  MOZ_ASSERT(mResolver);
+  Maybe<Shmem> data = Nothing();
+  if (aResult == ValidatorResult::JavaScript && !mSourceBytes.IsEmpty()) {
+    Shmem sharedData;
+    nsresult rv =
+        JSValidatorUtils::CopyCStringToShmem(this, mSourceBytes, sharedData);
+    if (NS_SUCCEEDED(rv)) {
+      data = Some(std::move(sharedData));
+    }
+  }
+
+  mResolver.ref()(std::tuple<mozilla::Maybe<Shmem>&&, const ValidatorResult&>(
+      std::move(data), aResult));
+  mResolver.reset();
+}
+
+mozilla::Result<mozilla::Span<const char>, nsresult>
+JSValidatorChild::GetUTF8EncodedContent(
+    const mozilla::Span<const uint8_t>& aData,
+    BufferUniquePtr<Utf8Unit[]>& aBuffer, UniquePtr<Decoder>& aDecoder) {
+  MOZ_ASSERT(aDecoder);
+  // We need the output buffer to be UTF8
+  CheckedInt<size_t> bufferLength =
+      ScriptDecoding<Utf8Unit>::MaxBufferLength(aDecoder, aData.Length());
+  if (!bufferLength.isValid()) {
+    return mozilla::Err(NS_ERROR_FAILURE);
+  }
+
+  CheckedInt<size_t> bufferByteSize = bufferLength * sizeof(Utf8Unit);
+  if (!bufferByteSize.isValid()) {
+    return mozilla::Err(NS_ERROR_FAILURE);
+  }
+
+  aBuffer.reset(static_cast<Utf8Unit*>(js_malloc(bufferByteSize.value())));
+  if (!aBuffer) {
+    return mozilla::Err(NS_ERROR_FAILURE);
+  }
+
+  size_t written = ScriptDecoding<Utf8Unit>::DecodeInto(
+      aDecoder, aData, Span(aBuffer.get(), bufferLength.value()),
+      /* aEndOfSource = */ true);
+  MOZ_ASSERT(written <= bufferLength.value());
+  MOZ_ASSERT(
+      IsUtf8(Span(reinterpret_cast<const char*>(aBuffer.get()), written)));
+
+  return Span(reinterpret_cast<const char*>(aBuffer.get()), written);
+}
+
+JSValidatorChild::ValidatorResult JSValidatorChild::ShouldAllowJS(
+    const mozilla::Span<const char>& aSpan) const {
+  MOZ_ASSERT(!aSpan.IsEmpty());
+
+  MOZ_DIAGNOSTIC_ASSERT(IsUtf8(aSpan));
+
+  JS::FrontendContext* fc = JSOracleChild::JSFrontendContext();
+  if (!fc) {
+    return ValidatorResult::Failure;
+  }
+
+  JS::SourceText<Utf8Unit> srcBuf;
+  if (!srcBuf.init(fc, aSpan.Elements(), aSpan.Length(),
+                   JS::SourceOwnership::Borrowed)) {
+    JS::ClearFrontendErrors(fc);
+    return ValidatorResult::Failure;
+  }
+
+  // Parse to JavaScript
+  JS::PrefableCompileOptions prefableOptions;
+  xpc::SetPrefableCompileOptions(prefableOptions);
+  // For the syntax validation purpose, asm.js doesn't need to be enabled.
+  prefableOptions.setAsmJSOption(JS::AsmJSOption::DisabledByAsmJSPref);
+
+  JS::CompileOptions options(prefableOptions);
+  JS::CompilationStorage storage;
+  RefPtr<JS::Stencil> stencil =
+      JS::CompileGlobalScriptToStencil(fc, options, srcBuf, storage);
+
+  if (!stencil) {
+    JS::ClearFrontendErrors(fc);
+    return ValidatorResult::Other;
+  }
+
+  MOZ_ASSERT(!aSpan.IsEmpty());
+
+  // Parse to JSON
+  if (IsAscii(aSpan)) {
+    // Ascii is a subset of Latin1, and JS_ParseJSON can take Latin1 directly
+    if (JS::IsValidJSON(
+            reinterpret_cast<const JS::Latin1Char*>(aSpan.Elements()),
+            aSpan.Length())) {
+      return ValidatorResult::JSON;
+    }
+  } else {
+    nsString decoded;
+    nsresult rv = UTF_8_ENCODING->DecodeWithBOMRemoval(
+        Span(reinterpret_cast<const uint8_t*>(aSpan.Elements()),
+             aSpan.Length()),
+        decoded);
+    if (NS_FAILED(rv)) {
+      return ValidatorResult::Failure;
+    }
+
+    if (JS::IsValidJSON(decoded.BeginReading(), decoded.Length())) {
+      return ValidatorResult::JSON;
+    }
+  }
+
+  // Since the JSON parsing failed, we confirmed the file is Javascript and not
+  // JSON.
+  return ValidatorResult::JavaScript;
+}