Confirmed users
197
edits
Features/Platform/Iframe Sandbox: Difference between revisions
no edit summary
No edit summary |
No edit summary |
||
| Line 4: | Line 4: | ||
|Feature status=In progress | |Feature status=In progress | ||
|Feature health=OK | |Feature health=OK | ||
|Feature status note= | |Feature status note=initial implementation done, initial test suite under development | ||
}} | }} | ||
{{FeatureTeam | {{FeatureTeam | ||
| Line 12: | Line 12: | ||
|Feature security lead=Curtis Koenig | |Feature security lead=Curtis Koenig | ||
|Feature privacy lead=Sid Stamm | |Feature privacy lead=Sid Stamm | ||
}} | }} | ||
{{FeaturePageBody | {{FeaturePageBody | ||
|Feature open issues and risks= | |Feature open issues and risks=* The origin (in string form) of a null principal - this will be sent by CORS, the origin header (if/when it's implemented), postMessage etc - the HTML5 spec says that it should be a GUID in this case - need to see what gets used in these cases when content has a null principal a | ||
* The origin (in string form) of a null principal - this will be sent by CORS, the origin header (if/when it's implemented), postMessage etc - the HTML5 spec says that it should be a GUID in this case - need to see what gets used in these cases when content has a null principal | * what to do with Workers in a sandboxed frame - would probably need allow-scripts for these, and maybe allow-same-origin ? or just block them altogether, as apparently some other browsers have done | ||
* are there other methods that the ones mentioned in the HTML5 spec (target='blank_', showModalDialog() and window.open) to open new windows ? | |||
* what to do with Workers in a sandboxed frame - would probably need allow-scripts for these, and maybe allow-same- | |||
|Feature overview=The HTML5 standard specifies a new attribute for the IFRAME element, "sandbox". See also [https://bugzilla.mozilla.org/show_bug.cgi?id=341604 bug 341604] "Implement HTML5 sandbox attribute for IFRAMEs" and [https://bugzilla.mozilla.org/show_bug.cgi?id=671389 bug 671389] "Implement CSP sandbox directive" | |Feature overview=The HTML5 standard specifies a new attribute for the IFRAME element, "sandbox". See also [https://bugzilla.mozilla.org/show_bug.cgi?id=341604 bug 341604] "Implement HTML5 sandbox attribute for IFRAMEs" and [https://bugzilla.mozilla.org/show_bug.cgi?id=671389 bug 671389] "Implement CSP sandbox directive" | ||
|Feature users and use cases=Users are web developers looking for a way to isolate content on their site and preventing it from having its default same origin privileges. The HTML5 spec specifies some modifying attributes that can re-grant permissions such as executing scripts and submitting forms, etc. | |Feature users and use cases=Users are web developers looking for a way to isolate content on their site and preventing it from having its default same origin privileges and ability to execute scripts. The HTML5 spec specifies some modifying attributes that can re-grant permissions such as same origin privilege, executing scripts, navigating the top window and submitting forms, etc. | ||
|Feature requirements= | |Feature requirements=This feature should be designed and implemented in a way that makes it usable for also implementing the sandboxing required to support the CSP (Content Security Policy) sandbox value also. | ||
This feature requires a comprehensive test suite - Boris Zbarsky has suggested we also submit this test | This feature requires a comprehensive test suite, as automated as possible for inclusion in the Firefox unit tests - Boris Zbarsky has suggested we also submit this test suite to the W3C for inclusion in their HTML5 test suite. | ||
|Feature non-goals=* Providing sandboxing above and beyond what's described in the HTML5 spec | |Feature non-goals=* Providing sandboxing above and beyond what's described in the HTML5 spec | ||
* implementing the IFRAME seamless attribute and interactions between it the sandbox attribute. | * implementing the IFRAME seamless attribute and interactions between it the sandbox attribute. | ||
* implementing @sandbox on <object> - this was discussed on the whatwg list, currently we don't want to do this, since the meaning of sandbox on <object> is confusing - it would apply in some contexts and not others | * implementing @sandbox on <object> - this was discussed on the whatwg list, currently we don't want to do this, since the meaning of sandbox on <object> is confusing - it would apply in some contexts and not others | ||
|Feature functional spec=An IFRAME with the sandbox attribute (and its various modifying attributes) should behave as outlined in the HTML5 spec. See W3C Working Draft at http://www.w3.org/TR/html5/the-iframe-element.html#the-iframe-element and W3C Editor's Draft at http://dev.w3.org/html5/spec/Overview.html#the-iframe-element. This feature | * implementing @sandbox on <frame> - this was discussed on the whatwg list and @sandbox for <frame> will not be implemented at the current time (this matches at least one other implementation) | ||
|Feature implementation plan=* The general approach is to give a sandboxed IFRAME a null principal to remove its normal domain/principal. This removes its same origin privileges (unless allow-same- | * implementing @sandbox on <xul:iframe/browser/editor> - the current implementation shouldn't prevent this enhancement from being implemented but there are no plans to implement this at the current time | ||
|Feature functional spec=An IFRAME with the sandbox attribute (and its various modifying attributes) should behave as outlined in the HTML5 spec. See W3C Working Draft at http://www.w3.org/TR/html5/the-iframe-element.html#the-iframe-element and W3C Editor's Draft at http://dev.w3.org/html5/spec/Overview.html#the-iframe-element. This feature attempts to be compatible with the CSP sandbox directive (see https://wiki.mozilla.org/Security/CSP/Sandbox) by establishing infrastructure where CSP would only have to set the sandbox flags on content documents to have them sandboxed as intended. | |||
|Feature implementation plan=* The general approach is to give a sandboxed IFRAME a null principal to remove its normal domain/principal. This removes its same origin privileges (unless allow-same-origin is specified as part of the sandbox attribute) | |||
* We will use nsDocShell::SetAllowJavascript(false) to prevent scripts being executed (unless allow-scripts is specified as part of the sandbox attribute) | * We will use nsDocShell::SetAllowJavascript(false) to prevent scripts being executed (unless allow-scripts is specified as part of the sandbox attribute) | ||
* We will use nsDocShell::SetAllowPlugins(false) to prevent plugins being loaded by a sandboxed IFRAME | * We will use nsDocShell::SetAllowPlugins(false) to prevent plugins being loaded by a sandboxed IFRAME | ||
* We will create the flags as described in the HTML5 spec's description of the IFRAME sandbox attribute on both the docshell and the document when it is loaded | * We will create the flags as described in the HTML5 spec's description of the IFRAME sandbox attribute on both the docshell and the document when it is loaded | ||
** the | |||
**** | nsIDocShell.idl will contain : | ||
**** | |||
**** | + /** | ||
**** | + * This flag prevents content from navigating browsing contexts other than | ||
**** | + * the sandboxed browsing context itself (or browsing contexts further | ||
+ * nested inside it), and the top-level browsing context. | |||
+ */ | |||
+ const unsigned long SANDBOXED_NAVIGATION = 0x1; | |||
+ | |||
+ /** | |||
+ * This flag prevents content from navigating their top-level browsing | |||
+ * context. | |||
+ */ | |||
+ const unsigned long SANDBOXED_TOPLEVEL_NAVIGATION = 0x2; | |||
+ | |||
+ /** | |||
+ * This flag prevents content from instantiating plugins, whether using the | |||
+ * embed element, the object element, the applet element, or through | |||
+ * navigation of a nested browsing context, unless those plugins can be | |||
+ * secured. | |||
+ */ | |||
+ const unsigned long SANDBOXED_PLUGINS = 0x4; | |||
+ | |||
+ /** | |||
+ * This flag forces content into a unique origin, thus preventing it from | |||
+ * accessing other content from the same origin. | |||
+ * This flag also prevents script from reading from or writing to the | |||
+ * document.cookie IDL attribute, and blocks access to localStorage. | |||
+ */ | |||
+ const unsigned long SANDBOXED_ORIGIN = 0x8; | |||
+ | |||
+ /** | |||
+ * This flag blocks form submission. | |||
+ */ | |||
+ const unsigned long SANDBOXED_FORMS = 0x10; | |||
+ | |||
+ /** | |||
+ * This flag blocks script execution. | |||
+ */ | |||
+ const unsigned long SANDBOXED_SCRIPTS = 0x20; | |||
** when the sandbox attribute on an IFRAME element is modified, we will change the flags on the docshell but not the document | ** when the sandbox attribute on an IFRAME element is modified, we will change the flags on the docshell but not the document | ||
*** we will | *** we will implement this using nsGenericHTMLFrameElement::AfterSetAttr, | ||
** the document needs to keep the exact set of flags assigned at load time (these are immutable - changing sandbox attributes does NOT dynamically affect already loaded content) | ** the document needs to keep the exact set of flags assigned at load time (these are immutable - changing sandbox attributes does NOT dynamically affect already loaded content) | ||
** sandbox flags for a document are set based on the sandbox flags of its parent document and the sandbox flags of the embedding frame (stored in the docshell) | ** sandbox flags for a document are set based on the sandbox flags of its parent document and the sandbox flags of the embedding frame (stored in the docshell) | ||
* sandboxed IFRAME's need to block access (read and write) to document.cookie | * sandboxed IFRAME's need to block access (read and write) to document.cookie | ||
and local storage unless the allow-same- | and local and session storage unless the allow-same-origin keyword is specified | ||
* sandboxed IFRAME's are also supposed to block access to content automatically doing something, the examples given automatically playing a video or automatically focusing a form control (unless allow-scripts is specified since scripts can do this anyways) - while disabling JS will take care of many of these cases, HTML5 video autoplay may need to be handled separately and there could be many other edge cases here as well ! | * sandboxed IFRAME's are also supposed to block access to content automatically doing something, the examples given automatically playing a video or automatically focusing a form control (unless allow-scripts is specified since scripts can do this anyways) - while disabling JS will take care of many of these cases, HTML5 video autoplay may need to be handled separately and there could be many other edge cases here as well ! - i would prefer to address this in a follow-up patch/bug as playing video or auto focusing a text field doesn't IMO diminish the security benefits provided by landing the rest of the functionality as defined in the HTML5 spec | ||
* nsFrameLoader will be modified to assign the null principal to a sandboxed IFRAME (if allow-same-origin is not specified) | * nsFrameLoader will be modified to assign the null principal to a sandboxed IFRAME (if allow-same-origin is not specified) | ||
** this also requires modifying surrounding code to be able to force an owner to be set on the loading channel. | ** this also requires modifying surrounding code to be able to force an owner to be set on the loading channel. | ||
| Line 56: | Line 90: | ||
* for CSP sandbox, the flags will only be stored on the document itself - when content is navigated to, the CSP sandbox flags won't be persisted (unless the new content also specifies a CSP sandbox directive) | * for CSP sandbox, the flags will only be stored on the document itself - when content is navigated to, the CSP sandbox flags won't be persisted (unless the new content also specifies a CSP sandbox directive) | ||
* the HTML5 spec provides examples of how to apply flags with nested IFRAMEs, abarth has proposed that if both CSP and IFRAME sandbox can apply to content, the algorithm used in these example should be used to merge the policies which sounds reasonable | * the HTML5 spec provides examples of how to apply flags with nested IFRAMEs, abarth has proposed that if both CSP and IFRAME sandbox can apply to content, the algorithm used in these example should be used to merge the policies which sounds reasonable | ||
|Feature security review=This feature will | |Feature security review=This feature will definitely need a full security review from the secteam. I suggest discussing the spec and making sure other means to do actions like opening windows or 'doing something automatically' are also covered by the implementation and test suite. | ||
|Feature qa review=We will need a test suite for this feature. Microsoft has released test cases for sandboxing publically that have been submitted to the W3C for inclusion in the HTML5 test suite. We will definitely want to compare our implementation to other browsers' implementation for consistency etc. and | |Feature qa review=We will need a test suite for this feature. Microsoft has released test cases for sandboxing publically that have been submitted to the W3C for inclusion in the HTML5 test suite. We will definitely want to compare our implementation to other browsers' implementation for consistency etc. and address inconsistencies via suggested modifications to the HTML5 spec and discussion on the whatwg list. Boris Zbarsky has suggested submitting our sandbox test suite to the W3C also. | ||
A mochitest test suite will be written to provide consistent automated testing for this feature. | |||
|Feature implementation notes=See https://bugzilla.mozilla.org/show_bug.cgi?id=341604 for a patch that attempts to implement HTML5 iframe sandbox. tests will be posted in that bug as well when complete. | |||
|Feature landing criteria=* Needs a test suite | |Feature landing criteria=* Needs a test suite | ||
* Needs to be compared against other implementations and public test suites for consistency | * Needs to be compared against other implementations and public test suites for consistency | ||
| Line 69: | Line 107: | ||
|Feature engineering team=Security | |Feature engineering team=Security | ||
}} | }} | ||
{{FeatureTeamStatus}} | {{FeatureTeamStatus | ||
|Feature engineering status=In Progress | |||
|Feature engineering notes=Initial implementation done, has received feedback from 3 people. Experimental prototype was rewritten after initial feedback. Test suite under development, will be looking for feedback soon. | |||
}} | |||