From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Cheng Zhao <zcbenz@gmail.com>
Date: Thu, 4 Oct 2018 14:57:02 -0700
Subject: feat: support wasm-eval csp behind WebAssemblyCSP flag

This is a minimal backport of
https://chromium.googlesource.com/chromium/src/+/83913676803db53648b6a47d159102a7cf1dac36

The tracking issue in Chromium is
https://bugs.chromium.org/p/chromium/issues/detail?id=948834

diff --git a/third_party/blink/renderer/core/frame/csp/content_security_policy.cc b/third_party/blink/renderer/core/frame/csp/content_security_policy.cc
index 8b7360ea023691c9da089fe781410f82c55ed37e..c96f57f6ae5f0c4b0d9326ca43517cb778422251 100644
--- a/third_party/blink/renderer/core/frame/csp/content_security_policy.cc
+++ b/third_party/blink/renderer/core/frame/csp/content_security_policy.cc
@@ -293,7 +293,8 @@ ContentSecurityPolicy::DidReceiveHeaders(
     const ContentSecurityPolicyResponseHeaders& headers) {
   scoped_refptr<SecurityOrigin> self_origin =
       SecurityOrigin::Create(headers.ResponseUrl());
-  if (headers.ShouldParseWasmEval())
+  if (RuntimeEnabledFeatures::WebAssemblyCSPEnabled() ||
+      headers.ShouldParseWasmEval())
     supports_wasm_eval_ = true;
 
   Vector<network::mojom::blink::ContentSecurityPolicyPtr> parsed_policies;
diff --git a/third_party/blink/renderer/core/frame/csp/csp_directive_list.cc b/third_party/blink/renderer/core/frame/csp/csp_directive_list.cc
index 0312872536aca8ec4c2f57754b6d6836b00e75df..d34331b948f7d1252f8eb26f731c4b20fce6c582 100644
--- a/third_party/blink/renderer/core/frame/csp/csp_directive_list.cc
+++ b/third_party/blink/renderer/core/frame/csp/csp_directive_list.cc
@@ -625,10 +625,15 @@ bool CheckEval(const network::mojom::blink::CSPSourceList* directive) {
   return !directive || directive->allow_eval;
 }
 
+bool SupportsWasmEval(const ContentSecurityPolicy* policy) {
+  return RuntimeEnabledFeatures::WebAssemblyCSPEnabled() ||
+         policy->SupportsWasmEval();
+}
+
 bool CheckWasmEval(const network::mojom::blink::CSPSourceList* directive,
                    const ContentSecurityPolicy* policy) {
   return !directive || directive->allow_eval ||
-         (policy->SupportsWasmEval() && directive->allow_wasm_eval);
+         (SupportsWasmEval(policy) && directive->allow_wasm_eval);
 }
 
 bool CheckHash(const network::mojom::blink::CSPSourceList* directive,
@@ -1091,7 +1096,7 @@ bool CSPDirectiveListAllowWasmCodeGeneration(
     ContentSecurityPolicy::ExceptionStatus exception_status,
     const String& content) {
   if (reporting_disposition == ReportingDisposition::kReport) {
-    String infix = policy->SupportsWasmEval()
+    String infix = SupportsWasmEval(policy)
                        ? "neither 'wasm-eval' nor 'unsafe-eval' is"
                        : "'unsafe-eval' is not";
     return CheckWasmEvalAndReportViolation(
diff --git a/third_party/blink/renderer/core/frame/csp/source_list_directive.cc b/third_party/blink/renderer/core/frame/csp/source_list_directive.cc
index 17ae1426ef9662f6f640c36d8ae8bca8e443a15a..de93eb3cf7321e00351f5cfe1d7cde6635ce2b4d 100644
--- a/third_party/blink/renderer/core/frame/csp/source_list_directive.cc
+++ b/third_party/blink/renderer/core/frame/csp/source_list_directive.cc
@@ -403,10 +403,15 @@ bool ParseSource(const UChar* begin,
     return true;
   }
 
-  if (policy->SupportsWasmEval() &&
-      EqualIgnoringASCIICase("'wasm-eval'", token)) {
-    source_list.allow_wasm_eval = true;
-    return true;
+  // Temporarily behind a runtime feature
+  if (EqualIgnoringASCIICase("'wasm-eval'", token)) {
+    if (RuntimeEnabledFeatures::WebAssemblyCSPEnabled() ||
+        policy->SupportsWasmEval()) {
+      source_list.allow_wasm_eval = true;
+      return true;
+    } else {
+      return false;
+    }
   }
 
   if (EqualIgnoringASCIICase("'strict-dynamic'", token)) {
diff --git a/third_party/blink/renderer/platform/runtime_enabled_features.json5 b/third_party/blink/renderer/platform/runtime_enabled_features.json5
index 2447c80eece6fa84f01d4d84b136a7c6a799c696..6680e614b5985b6774e47472957a9b4ac2d50354 100644
--- a/third_party/blink/renderer/platform/runtime_enabled_features.json5
+++ b/third_party/blink/renderer/platform/runtime_enabled_features.json5
@@ -2146,6 +2146,9 @@
     {
       name: "WebAppWindowControlsOverlay",
     },
+    {
+      name: "WebAssemblyCSP",
+    },
     {
       name: "WebAssemblyExceptions",
       origin_trial_feature_name: "WebAssemblyExceptions",