// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "third_party/blink/renderer/core/loader/http_equiv.h"

#include "services/network/public/mojom/content_security_policy.mojom-blink-forward.h"
#include "third_party/blink/public/platform/web_content_settings_client.h"
#include "third_party/blink/renderer/bindings/core/v8/capture_source_location.h"
#include "third_party/blink/renderer/core/css/style_engine.h"
#include "third_party/blink/renderer/core/dom/document.h"
#include "third_party/blink/renderer/core/dom/scriptable_document_parser.h"
#include "third_party/blink/renderer/core/frame/csp/content_security_policy.h"
#include "third_party/blink/renderer/core/frame/local_dom_window.h"
#include "third_party/blink/renderer/core/frame/local_frame.h"
#include "third_party/blink/renderer/core/frame/settings.h"
#include "third_party/blink/renderer/core/html/html_meta_element.h"
#include "third_party/blink/renderer/core/inspector/console_message.h"
#include "third_party/blink/renderer/core/loader/document_loader.h"
#include "third_party/blink/renderer/core/origin_trials/origin_trial_context.h"
#include "third_party/blink/renderer/platform/heap/garbage_collected.h"
#include "third_party/blink/renderer/platform/instrumentation/use_counter.h"
#include "third_party/blink/renderer/platform/network/http_names.h"
#include "third_party/blink/renderer/platform/network/http_parsers.h"
#include "third_party/blink/renderer/platform/weborigin/kurl.h"
#include "third_party/blink/renderer/platform/weborigin/reporting_disposition.h"

namespace blink {

void HttpEquiv::Process(Document& document,
                        const AtomicString& equiv,
                        const AtomicString& content,
                        bool in_document_head_element,
                        bool is_sync_parser,
                        Element* element) {
  DCHECK(!equiv.IsNull());
  DCHECK(!content.IsNull());

  if (EqualIgnoringAsciiCase(equiv, "default-style")) {
    ProcessHttpEquivDefaultStyle(document, content);
  } else if (EqualIgnoringAsciiCase(equiv, "refresh")) {
    ProcessHttpEquivRefresh(document.domWindow(), content, element);
  } else if (EqualIgnoringAsciiCase(equiv, "set-cookie")) {
    ProcessHttpEquivSetCookie(document, content, element);
  } else if (EqualIgnoringAsciiCase(equiv, "content-language")) {
    document.SetContentLanguage(content);
  } else if (EqualIgnoringAsciiCase(equiv, "x-dns-prefetch-control")) {
    document.ParseDNSPrefetchControlHeader(content);
  } else if (EqualIgnoringAsciiCase(equiv, "x-frame-options")) {
    document.AddConsoleMessage(MakeGarbageCollected<ConsoleMessage>(
        mojom::ConsoleMessageSource::kSecurity,
        mojom::ConsoleMessageLevel::kError,
        "X-Frame-Options may only be set via an HTTP header sent along with a "
        "document. It may not be set inside <meta>."));
  } else if (EqualIgnoringAsciiCase(equiv, http_names::kAcceptCH)) {
    HTMLMetaElement::ProcessMetaCH(document, content,
                                   network::MetaCHType::HttpEquivAcceptCH,
                                   /*is_doc_preloader=*/false, is_sync_parser);
  } else if (EqualIgnoringAsciiCase(equiv, http_names::kDelegateCH)) {
    HTMLMetaElement::ProcessMetaCH(document, content,
                                   network::MetaCHType::HttpEquivDelegateCH,
                                   /*is_doc_preloader=*/false, is_sync_parser);
  } else if (EqualIgnoringAsciiCase(equiv, "content-security-policy") ||
             EqualIgnoringAsciiCase(equiv,
                                    "content-security-policy-report-only")) {
    if (in_document_head_element) {
      ProcessHttpEquivContentSecurityPolicy(document.domWindow(), equiv,
                                            content);
    } else if (auto* window = document.domWindow()) {
      window->GetContentSecurityPolicy()->ReportMetaOutsideHead(content);
    }
  } else if (EqualIgnoringAsciiCase(equiv, http_names::kOriginTrial)) {
    if (in_document_head_element) {
      ProcessHttpEquivOriginTrial(document.domWindow(), content);
    }
  }
}

void HttpEquiv::ProcessHttpEquivContentSecurityPolicy(
    LocalDOMWindow* window,
    const AtomicString& equiv,
    const AtomicString& content) {
  if (!window || !window->GetFrame())
    return;
  if (window->GetFrame()->GetSettings()->GetBypassCSP())
    return;
  if (EqualIgnoringAsciiCase(equiv, "content-security-policy")) {
    Vector<network::mojom::blink::ContentSecurityPolicyPtr> parsed =
        ParseContentSecurityPolicies(
            content, network::mojom::blink::ContentSecurityPolicyType::kEnforce,
            network::mojom::blink::ContentSecurityPolicySource::kMeta,
            *(window->GetSecurityOrigin()));
    window->GetContentSecurityPolicy()->AddPolicies(mojo::Clone(parsed));

    // Generate a new initiator state token to pass to the browser process and
    // to update `window`.
    base::UnguessableToken new_initiator_state_token =
        base::UnguessableToken::Create();
    window->GetPolicyContainer()->AddContentSecurityPolicies(
        std::move(parsed), new_initiator_state_token);
    window->SetInitiatorStateToken(new_initiator_state_token);
  } else if (EqualIgnoringAsciiCase(equiv,
                                    "content-security-policy-report-only")) {
    window->GetContentSecurityPolicy()->ReportReportOnlyInMeta(content);
  } else {
    NOTREACHED();
  }
}

void HttpEquiv::ProcessHttpEquivDefaultStyle(Document& document,
                                             const AtomicString& content) {
  document.GetStyleEngine().SetHttpDefaultStyle(content);
}

void HttpEquiv::ProcessHttpEquivOriginTrial(LocalDOMWindow* window,
                                            const AtomicString& content) {
  if (!window)
    return;
  // For meta tags injected by script, process the token with the origin of the
  // external script, if available. Get the top 3 script urls from the stack, as
  // the script that injected the meta tag might not be topmost. For example,
  // due to a script that overrides builtin functions, like Node.appendChild().
  // See crbug.com/1193888.
  // NOTE: The external script origin is not considered security-critical. See
  // the comment thread in the design doc for details:
  // https://docs.google.com/document/d/1xALH9W7rWmX0FpjudhDeS2TNTEOXuPn4Tlc9VmuPdHA/edit?disco=AAAAJyG8StI
  Vector<String> candidate_scripts = CaptureScriptUrlsFromCurrentStack(
      window->GetIsolate(), /*unique_url_count=*/3);
  Vector<scoped_refptr<SecurityOrigin>> external_origins;
  for (const String& external_script : candidate_scripts) {
    KURL external_script_url(external_script);
    if (!external_script_url.IsValid())
      continue;
    external_origins.push_back(SecurityOrigin::Create(external_script_url));
  }

  if (external_origins.size() > 0) {
    window->GetOriginTrialContext()->AddTokenFromExternalScript(
        content, external_origins);
    return;
  }

  // Process token as usual, without an external script origin.
  window->GetOriginTrialContext()->AddToken(content);
}

void HttpEquiv::ProcessHttpEquivRefresh(LocalDOMWindow* window,
                                        const AtomicString& content,
                                        Element* element) {
  if (!window)
    return;
  UseCounter::Count(window, WebFeature::kMetaRefresh);
  if (!window->GetContentSecurityPolicy()->AllowInline(
          ContentSecurityPolicy::InlineType::kScript, element, "" /* content */,
          "" /* nonce */, NullUrl(), OrdinalNumber::First(),
          ReportingDisposition::kSuppressReporting)) {
    UseCounter::Count(window,
                      WebFeature::kMetaRefreshWhenCSPBlocksInlineScript);
  }

  window->document()->MaybeHandleHttpRefresh(content,
                                             Document::kHttpRefreshFromMetaTag);
}

void HttpEquiv::ProcessHttpEquivSetCookie(Document& document,
                                          const AtomicString& content,
                                          Element* element) {
  document.AddConsoleMessage(MakeGarbageCollected<ConsoleMessage>(
      mojom::ConsoleMessageSource::kSecurity,
      mojom::ConsoleMessageLevel::kError,
      StrCat({"Blocked setting the `", content,
              "` cookie from a `<meta>` tag."})));
}

}  // namespace blink