commit fc1c9ff7c1b2defdbc039f12214767608f46423f Author: Gunes Acar gunes.acar@esat.kuleuven.be Date: Wed Dec 3 20:22:22 2014 +0100

Bug 13439: No canvas prompt for content-callers.

Both the Inspector and PDF.js raise canvas prompts although they are no danger as they are delivered with the browser itself and are no untrusted content. This patch exempts both of them from canvas prompts, too.

If calling `DescribeScriptedCaller` fails neither `scriptFile` nor `scriptLine` are logged. --- content/canvas/src/CanvasUtils.cpp | 30 ++++++++++++++++++++++-------- 1 file changed, 22 insertions(+), 8 deletions(-)

diff --git a/content/canvas/src/CanvasUtils.cpp b/content/canvas/src/CanvasUtils.cpp index 9a7a441..5a6e05e 100644 --- a/content/canvas/src/CanvasUtils.cpp +++ b/content/canvas/src/CanvasUtils.cpp @@ -54,6 +54,20 @@ bool IsImageExtractionAllowed(nsIDocument *aDocument, JSContext *aCx) if (sop && nsContentUtils::IsSystemPrincipal(sop->GetPrincipal())) return true;

+ // Don't show canvas prompt for chrome scripts (e.g. Page Inspector) + if (nsContentUtils::IsCallerChrome()) + return true; + + JS::AutoFilename scriptFile; + unsigned scriptLine = 0; + bool isScriptKnown = false; + if (JS::DescribeScriptedCaller(aCx, &scriptFile, &scriptLine)) { + isScriptKnown = true; + // Don't show canvas prompt for PDF.js + if (scriptFile.get() && + strcmp(scriptFile.get(), "resource://pdf.js/build/pdf.js") == 0) + return true; + } bool isAllowed = false; nsCOMPtr<mozIThirdPartyUtil> thirdPartyUtil = do_GetService(THIRDPARTYUTIL_CONTRACTID); @@ -87,19 +101,19 @@ bool IsImageExtractionAllowed(nsIDocument *aDocument, JSContext *aCx) rv = thirdPartyUtil->IsThirdPartyURI(uri, docURI, &isThirdParty); NS_ENSURE_SUCCESS(rv, false);

- JS::AutoFilename scriptFile;; - unsigned scriptLine = 0; - JS::DescribeScriptedCaller(aCx, &scriptFile, &scriptLine); - nsCString firstPartySpec; rv = uri->GetSpec(firstPartySpec); nsCString docSpec; docURI->GetSpec(docSpec); nsPrintfCString msg("On %s: blocked access to canvas image data" - " from document %s, script from %s:%u ", // L10n - firstPartySpec.get(), docSpec.get(), - scriptFile.get(), scriptLine); - + " from document %s, ", // L10n + firstPartySpec.get(), docSpec.get()); + if (isScriptKnown && scriptFile.get()) { + msg += nsPrintfCString("script from %s:%u", // L10n + scriptFile.get(), scriptLine); + } else { + msg += nsPrintfCString("unknown script"); // L10n + } nsCOMPtr<nsIConsoleService> console (do_GetService(NS_CONSOLESERVICE_CONTRACTID)); if (console)