gecko/content/base/src/contentSecurityPolicy.js

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2012-05-21 04:12:37 -07:00
/* 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/. */
/**
* Content Security Policy
*
* Overview
* This is a stub component that will be fleshed out to do all the fancy stuff
* that ContentSecurityPolicy has to do.
*/
/* :::::::: Constants and Helpers ::::::::::::::: */
const Cc = Components.classes;
const Ci = Components.interfaces;
const Cr = Components.results;
const Cu = Components.utils;
const CSP_VIOLATION_TOPIC = "csp-on-violate-policy";
// Needed to support CSP 1.0 spec and our original CSP implementation - should
// be removed when our original implementation is deprecated.
const CSP_TYPE_XMLHTTPREQUEST_SPEC_COMPLIANT = "csp_type_xmlhttprequest_spec_compliant";
const CSP_TYPE_WEBSOCKET_SPEC_COMPLIANT = "csp_type_websocket_spec_compliant";
Cu.import("resource://gre/modules/XPCOMUtils.jsm");
Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/CSPUtils.jsm");
/* ::::: Policy Parsing & Data structures :::::: */
function ContentSecurityPolicy() {
CSPdebug("CSP CREATED");
this._isInitialized = false;
this._reportOnlyMode = false;
this._policy = CSPRep.fromString("default-src *");
// default options "wide open" since this policy will be intersected soon
this._policy._allowInlineScripts = true;
this._policy._allowEval = true;
this._request = "";
this._requestOrigin = "";
this._requestPrincipal = "";
this._referrer = "";
this._docRequest = null;
CSPdebug("CSP POLICY INITED TO 'default-src *'");
this._cache = { };
}
/*
* Set up mappings from nsIContentPolicy content types to CSP directives.
*/
{
let cp = Ci.nsIContentPolicy;
let csp = ContentSecurityPolicy;
let cspr_sd_old = CSPRep.SRC_DIRECTIVES_OLD;
let cspr_sd_new = CSPRep.SRC_DIRECTIVES_NEW;
csp._MAPPINGS=[];
/* default, catch-all case */
// This is the same in old and new CSP so use the new mapping.
csp._MAPPINGS[cp.TYPE_OTHER] = cspr_sd_new.DEFAULT_SRC;
/* self */
csp._MAPPINGS[cp.TYPE_DOCUMENT] = null;
/* shouldn't see this one */
csp._MAPPINGS[cp.TYPE_REFRESH] = null;
/* categorized content types */
// These are the same in old and new CSP's so just use the new mappings.
csp._MAPPINGS[cp.TYPE_SCRIPT] = cspr_sd_new.SCRIPT_SRC;
csp._MAPPINGS[cp.TYPE_IMAGE] = cspr_sd_new.IMG_SRC;
csp._MAPPINGS[cp.TYPE_STYLESHEET] = cspr_sd_new.STYLE_SRC;
csp._MAPPINGS[cp.TYPE_OBJECT] = cspr_sd_new.OBJECT_SRC;
csp._MAPPINGS[cp.TYPE_OBJECT_SUBREQUEST] = cspr_sd_new.OBJECT_SRC;
csp._MAPPINGS[cp.TYPE_SUBDOCUMENT] = cspr_sd_new.FRAME_SRC;
csp._MAPPINGS[cp.TYPE_MEDIA] = cspr_sd_new.MEDIA_SRC;
csp._MAPPINGS[cp.TYPE_FONT] = cspr_sd_new.FONT_SRC;
/* Our original CSP implementation's mappings for XHR and websocket
* These should be changed to be = cspr_sd.CONNECT_SRC when we remove
* the original implementation - NOTE: order in this array is important !!!
*/
csp._MAPPINGS[cp.TYPE_XMLHTTPREQUEST] = cspr_sd_old.XHR_SRC;
csp._MAPPINGS[cp.TYPE_WEBSOCKET] = cspr_sd_old.XHR_SRC;
/* CSP cannot block CSP reports */
csp._MAPPINGS[cp.TYPE_CSP_REPORT] = null;
/* These must go through the catch-all */
csp._MAPPINGS[cp.TYPE_XBL] = cspr_sd_new.DEFAULT_SRC;
csp._MAPPINGS[cp.TYPE_PING] = cspr_sd_new.DEFAULT_SRC;
csp._MAPPINGS[cp.TYPE_DTD] = cspr_sd_new.DEFAULT_SRC;
/* CSP 1.0 spec compliant mappings for XHR and websocket */
// The directive name for XHR, websocket, and EventSource is different
// in the 1.0 spec than in our original implementation, these mappings
// address this. These won't be needed when we deprecate our original
// implementation.
csp._MAPPINGS[CSP_TYPE_XMLHTTPREQUEST_SPEC_COMPLIANT] = cspr_sd_new.CONNECT_SRC;
csp._MAPPINGS[CSP_TYPE_WEBSOCKET_SPEC_COMPLIANT] = cspr_sd_new.CONNECT_SRC;
// TODO : EventSource will be here and also will use connect-src
// after we fix Bug 802872 - CSP should restrict EventSource using the connect-src
// directive. For background see Bug 667490 - EventSource should use the same
// nsIContentPolicy type as XHR (which is fixed)
}
ContentSecurityPolicy.prototype = {
classID: Components.ID("{d1680bb4-1ac0-4772-9437-1188375e44f2}"),
QueryInterface: XPCOMUtils.generateQI([Ci.nsIContentSecurityPolicy]),
get isInitialized() {
return this._isInitialized;
},
set isInitialized (foo) {
this._isInitialized = foo;
},
get policy () {
return this._policy.toString();
},
get allowsInlineScript() {
return this._reportOnlyMode || this._policy.allowsInlineScripts;
},
get allowsEval() {
return this._reportOnlyMode || this._policy.allowsEvalInScripts;
},
/**
* Log policy violation on the Error Console and send a report if a report-uri
* is present in the policy
*
* @param aViolationType
* one of the VIOLATION_TYPE_* constants, e.g. inline-script or eval
* @param aSourceFile
* name of the source file containing the violation (if available)
* @param aContentSample
* sample of the violating content (to aid debugging)
* @param aLineNum
* source line number of the violation (if available)
*/
logViolationDetails:
function(aViolationType, aSourceFile, aScriptSample, aLineNum) {
// allowsInlineScript and allowsEval both return true when report-only mode
// is enabled, resulting in a call to this function. Therefore we need to
// check that the policy was in fact violated before logging any violations
switch (aViolationType) {
case Ci.nsIContentSecurityPolicy.VIOLATION_TYPE_INLINE_SCRIPT:
if (!this._policy.allowsInlineScripts)
this._asyncReportViolation('self',null,'inline script base restriction',
'violated base restriction: Inline Scripts will not execute',
aSourceFile, aScriptSample, aLineNum);
break;
case Ci.nsIContentSecurityPolicy.VIOLATION_TYPE_EVAL:
if (!this._policy.allowsEvalInScripts)
this._asyncReportViolation('self',null,'eval script base restriction',
'violated base restriction: Code will not be created from strings',
aSourceFile, aScriptSample, aLineNum);
break;
}
},
set reportOnlyMode(val) {
this._reportOnlyMode = val;
},
get reportOnlyMode () {
return this._reportOnlyMode;
},
/*
// Having a setter is a bad idea... opens up the policy to "loosening"
// Instead, use "refinePolicy."
set policy (aStr) {
this._policy = CSPRep.fromString(aStr);
},
*/
/**
* Given an nsIHttpChannel, fill out the appropriate data.
*/
scanRequestData:
function(aChannel) {
if (!aChannel)
return;
// Save the docRequest for fetching a policy-uri
this._docRequest = aChannel;
// save the document URI (minus <fragment>) and referrer for reporting
let uri = aChannel.URI.cloneIgnoringRef();
try { // GetUserPass throws for some protocols without userPass
uri.userPass = '';
} catch (ex) {}
this._request = uri.asciiSpec;
this._requestOrigin = uri;
//store a reference to the principal, that can later be used in shouldLoad
this._requestPrincipal = Components.classes["@mozilla.org/scriptsecuritymanager;1"].
getService(Components.interfaces.nsIScriptSecurityManager).getChannelPrincipal(aChannel);
if (aChannel.referrer) {
let referrer = aChannel.referrer.cloneIgnoringRef();
try { // GetUserPass throws for some protocols without userPass
referrer.userPass = '';
} catch (ex) {}
this._referrer = referrer.asciiSpec;
}
},
/* ........ Methods .............. */
/**
* Given a new policy, intersects the currently enforced policy with the new
* one and stores the result. The effect is a "tightening" or refinement of
* an old policy. This is called any time a new policy is encountered and
* the effective policy has to be refined.
*/
refinePolicy:
function csp_refinePolicy(aPolicy, selfURI, aSpecCompliant) {
CSPdebug("REFINE POLICY: " + aPolicy);
CSPdebug(" SELF: " + selfURI.asciiSpec);
CSPdebug("CSP 1.0 COMPLIANT : " + aSpecCompliant);
// For nested schemes such as view-source: make sure we are taking the
// innermost URI to use as 'self' since that's where we will extract the
// scheme, host and port from
if (selfURI instanceof Ci.nsINestedURI) {
CSPdebug(" INNER: " + selfURI.innermostURI.asciiSpec);
selfURI = selfURI.innermostURI;
}
// stay uninitialized until policy merging is done
this._isInitialized = false;
// If there is a policy-uri, fetch the policy, then re-call this function.
// (1) parse and create a CSPRep object
// Note that we pass the full URI since when it's parsed as 'self' to construct a
// CSPSource only the scheme, host, and port are kept.
// If we want to be CSP 1.0 spec compliant, use the new parser.
// The old one will be deprecated in the future and will be
// removed at that time.
var newpolicy;
if (aSpecCompliant) {
newpolicy = CSPRep.fromStringSpecCompliant(aPolicy,
selfURI,
this._docRequest,
this);
} else {
newpolicy = CSPRep.fromString(aPolicy,
selfURI,
this._docRequest,
this);
}
// (2) Intersect the currently installed CSPRep object with the new one
var intersect = this._policy.intersectWith(newpolicy);
// (3) Save the result
this._policy = intersect;
this._policy._specCompliant = !!aSpecCompliant;
this._isInitialized = true;
this._cache = {};
},
/**
* Generates and sends a violation report to the specified report URIs.
*/
sendReports:
function(blockedUri, originalUri, violatedDirective,
aSourceFile, aScriptSample, aLineNum) {
var uriString = this._policy.getReportURIs();
var uris = uriString.split(/\s+/);
if (uris.length > 0) {
// see if we need to sanitize the blocked-uri
let blocked = '';
if (originalUri) {
// We've redirected, only report the blocked origin
let clone = blockedUri.clone();
clone.path = '';
blocked = clone.asciiSpec;
}
else if (blockedUri instanceof Ci.nsIURI) {
blocked = blockedUri.cloneIgnoringRef().asciiSpec;
}
else {
// blockedUri is a string for eval/inline-script violations
blocked = blockedUri;
}
// Generate report to send composed of
// {
// csp-report: {
// document-uri: "http://example.com/file.html?params",
// referrer: "...",
// blocked-uri: "...",
// violated-directive: "..."
// }
// }
var report = {
'csp-report': {
'document-uri': this._request,
'referrer': this._referrer,
'blocked-uri': blocked,
'violated-directive': violatedDirective
}
}
// extra report fields for script errors (if available)
if (originalUri)
report["csp-report"]["original-uri"] = originalUri.cloneIgnoringRef().asciiSpec;
if (aSourceFile)
report["csp-report"]["source-file"] = aSourceFile;
if (aScriptSample)
report["csp-report"]["script-sample"] = aScriptSample;
if (aLineNum)
report["csp-report"]["line-number"] = aLineNum;
var reportString = JSON.stringify(report);
CSPdebug("Constructed violation report:\n" + reportString);
var violationMessage = null;
if (blockedUri["asciiSpec"]) {
violationMessage = CSPLocalizer.getFormatStr("directiveViolatedWithURI", [violatedDirective, blockedUri.asciiSpec]);
} else {
violationMessage = CSPLocalizer.getFormatStr("directiveViolated", [violatedDirective]);
}
this._policy.warn(violationMessage,
(aSourceFile) ? aSourceFile : null,
(aScriptSample) ? decodeURIComponent(aScriptSample) : null,
(aLineNum) ? aLineNum : null);
// For each URI in the report list, send out a report.
// We make the assumption that all of the URIs are absolute URIs; this
// should be taken care of in CSPRep.fromString (where it converts any
// relative URIs into absolute ones based on "self").
for (let i in uris) {
if (uris[i] === "")
continue;
try {
var chan = Services.io.newChannel(uris[i], null, null);
if (!chan) {
CSPdebug("Error creating channel for " + uris[i]);
continue;
}
var content = Cc["@mozilla.org/io/string-input-stream;1"]
.createInstance(Ci.nsIStringInputStream);
content.data = reportString + "\n\n";
// make sure this is an anonymous request (no cookies) so in case the
// policy URI is injected, it can't be abused for CSRF.
chan.loadFlags |= Ci.nsIChannel.LOAD_ANONYMOUS;
// we need to set an nsIChannelEventSink on the channel object
// so we can tell it to not follow redirects when posting the reports
chan.notificationCallbacks = new CSPReportRedirectSink(this._policy);
if (this._docRequest) {
chan.loadGroup = this._docRequest.loadGroup;
}
chan.QueryInterface(Ci.nsIUploadChannel)
.setUploadStream(content, "application/json", content.available());
try {
// if this is an HTTP channel, set the request method to post
chan.QueryInterface(Ci.nsIHttpChannel);
chan.requestMethod = "POST";
} catch(e) {} // throws only if chan is not an nsIHttpChannel.
// check with the content policy service to see if we're allowed to
// send this request.
try {
var contentPolicy = Cc["@mozilla.org/layout/content-policy;1"]
.getService(Ci.nsIContentPolicy);
if (contentPolicy.shouldLoad(Ci.nsIContentPolicy.TYPE_CSP_REPORT,
chan.URI, this._requestOrigin,
null, null, null, this._requestPrincipal)
!= Ci.nsIContentPolicy.ACCEPT) {
continue; // skip unauthorized URIs
}
} catch(e) {
continue; // refuse to load if we can't do a security check.
}
//send data (and set up error notifications)
chan.asyncOpen(new CSPViolationReportListener(uris[i]), null);
CSPdebug("Sent violation report to " + uris[i]);
} catch(e) {
// it's possible that the URI was invalid, just log a
// warning and skip over that.
this._policy.warn(CSPLocalizer.getFormatStr("triedToSendReport", [uris[i]]));
this._policy.warn(CSPLocalizer.getFormatStr("errorWas", [e.toString()]));
}
}
}
},
/**
* Exposed Method to analyze docShell for approved frame ancestry.
* Also sends violation reports if necessary.
* @param docShell
* the docShell for this policy's resource.
* @return
* true if the frame ancestry is allowed by this policy.
*/
permitsAncestry:
function(docShell) {
if (!docShell) { return false; }
CSPdebug(" in permitsAncestry(), docShell = " + docShell);
// walk up this docShell tree until we hit chrome
var dst = docShell.QueryInterface(Ci.nsIInterfaceRequestor)
.getInterface(Ci.nsIDocShellTreeItem);
// collect ancestors and make sure they're allowed.
var ancestors = [];
while (dst.parent) {
dst = dst.parent;
let it = dst.QueryInterface(Ci.nsIInterfaceRequestor)
.getInterface(Ci.nsIWebNavigation);
if (it.currentURI) {
if (it.currentURI.scheme === "chrome") {
break;
}
// delete any userpass
let ancestor = it.currentURI.cloneIgnoringRef();
try { // GetUserPass throws for some protocols without userPass
ancestor.userPass = '';
} catch (ex) {}
CSPdebug(" found frame ancestor " + ancestor.asciiSpec);
ancestors.push(ancestor);
}
}
// scan the discovered ancestors
// frame-ancestors is the same in both old and new source directives,
// so don't need to differentiate here.
let cspContext = CSPRep.SRC_DIRECTIVES_NEW.FRAME_ANCESTORS;
for (let i in ancestors) {
let ancestor = ancestors[i];
if (!this._policy.permits(ancestor, cspContext)) {
// report the frame-ancestor violation
let directive = this._policy._directives[cspContext];
let violatedPolicy = (directive._isImplicit
? 'default-src' : 'frame-ancestors ')
+ directive.toString();
this._asyncReportViolation(ancestors[i], null, violatedPolicy);
// need to lie if we are testing in report-only mode
return this._reportOnlyMode;
}
}
return true;
},
/**
* Delegate method called by the service when sub-elements of the protected
* document are being loaded. Given a bit of information about the request,
* decides whether or not the policy is satisfied.
*/
shouldLoad:
function csp_shouldLoad(aContentType,
aContentLocation,
aRequestOrigin,
aContext,
aMimeTypeGuess,
aOriginalUri) {
let key = aContentLocation.spec + "!" + aContentType;
if (this._cache[key]) {
return this._cache[key];
}
#ifndef MOZ_B2G
// Try to remove as much as possible from the hot path on b2g.
CSPdebug("shouldLoad location = " + aContentLocation.asciiSpec);
CSPdebug("shouldLoad content type = " + aContentType);
#endif
// interpret the context, and then pass off to the decision structure
var cspContext = ContentSecurityPolicy._MAPPINGS[aContentType];
// The mapping for XHR and websockets is different between our original
// implementation and the 1.0 spec, we handle this here.
var cspContext;
let cp = Ci.nsIContentPolicy;
#ifndef MOZ_B2G
CSPdebug("policy is " + (this._policy._specCompliant ?
"1.0 compliant" : "pre-1.0"));
#endif
if (aContentType == cp.TYPE_XMLHTTPREQUEST && this._policy._specCompliant) {
cspContext = ContentSecurityPolicy._MAPPINGS[CSP_TYPE_XMLHTTPREQUEST_SPEC_COMPLIANT];
} else if (aContentType == cp.TYPE_WEBSOCKET && this._policy._specCompliant) {
cspContext = ContentSecurityPolicy._MAPPINGS[CSP_TYPE_WEBSOCKET_SPEC_COMPLIANT];
} else {
cspContext = ContentSecurityPolicy._MAPPINGS[aContentType];
}
CSPdebug("shouldLoad cspContext = " + cspContext);
// if the mapping is null, there's no policy, let it through.
if (!cspContext) {
return Ci.nsIContentPolicy.ACCEPT;
}
// otherwise, honor the translation
// var source = aContentLocation.scheme + "://" + aContentLocation.hostPort;
var res = this._policy.permits(aContentLocation, cspContext)
? Ci.nsIContentPolicy.ACCEPT
: Ci.nsIContentPolicy.REJECT_SERVER;
// frame-ancestors is taken care of early on (as this document is loaded)
// If the result is *NOT* ACCEPT, then send report
if (res != Ci.nsIContentPolicy.ACCEPT) {
CSPdebug("blocking request for " + aContentLocation.asciiSpec);
try {
let directive = this._policy._directives[cspContext];
let violatedPolicy = (directive._isImplicit
? 'default-src' : cspContext)
+ ' ' + directive.toString();
this._asyncReportViolation(aContentLocation, aOriginalUri, violatedPolicy);
} catch(e) {
CSPdebug('---------------- ERROR: ' + e);
}
}
let ret = this._cache[key] =
(this._reportOnlyMode ? Ci.nsIContentPolicy.ACCEPT : res);
return ret;
},
shouldProcess:
function csp_shouldProcess(aContentType,
aContentLocation,
aRequestOrigin,
aContext,
aMimeType,
aExtra) {
// frame-ancestors check is done outside the ContentPolicy
var res = Ci.nsIContentPolicy.ACCEPT;
CSPdebug("shouldProcess aContext=" + aContext);
return res;
},
/**
* Asynchronously notifies any nsIObservers listening to the CSP violation
* topic that a violation occurred. Also triggers report sending. All
* asynchronous on the main thread.
*
* @param blockedContentSource
* Either a CSP Source (like 'self', as string) or nsIURI: the source
* of the violation.
* @param originalUri
* The original URI if the blocked content is a redirect, else null
* @param violatedDirective
* the directive that was violated (string).
* @param observerSubject
* optional, subject sent to the nsIObservers listening to the CSP
* violation topic.
* @param aSourceFile
* name of the file containing the inline script violation
* @param aScriptSample
* a sample of the violating inline script
* @param aLineNum
* source line number of the violation (if available)
*/
_asyncReportViolation:
function(blockedContentSource, originalUri, violatedDirective, observerSubject,
aSourceFile, aScriptSample, aLineNum) {
// if optional observerSubject isn't specified, default to the source of
// the violation.
if (!observerSubject)
observerSubject = blockedContentSource;
// gotta wrap things that aren't nsISupports, since it's sent out to
// observers as such. Objects that are not nsISupports are converted to
// strings and then wrapped into a nsISupportsCString.
if (!(observerSubject instanceof Ci.nsISupports)) {
let d = observerSubject;
observerSubject = Cc["@mozilla.org/supports-cstring;1"]
.createInstance(Ci.nsISupportsCString);
observerSubject.data = d;
}
var reportSender = this;
Services.tm.mainThread.dispatch(
function() {
Services.obs.notifyObservers(observerSubject,
CSP_VIOLATION_TOPIC,
violatedDirective);
reportSender.sendReports(blockedContentSource, originalUri,
violatedDirective,
aSourceFile, aScriptSample, aLineNum);
}, Ci.nsIThread.DISPATCH_NORMAL);
},
};
// The POST of the violation report (if it happens) should not follow
// redirects, per the spec. hence, we implement an nsIChannelEventSink
// with an object so we can tell XHR to abort if a redirect happens.
function CSPReportRedirectSink(policy) {
this._policy = policy;
}
CSPReportRedirectSink.prototype = {
QueryInterface: function requestor_qi(iid) {
if (iid.equals(Ci.nsISupports) ||
iid.equals(Ci.nsIInterfaceRequestor) ||
iid.equals(Ci.nsIChannelEventSink))
return this;
throw Cr.NS_ERROR_NO_INTERFACE;
},
// nsIInterfaceRequestor
getInterface: function requestor_gi(iid) {
if (iid.equals(Ci.nsIChannelEventSink))
return this;
throw Components.results.NS_ERROR_NO_INTERFACE;
},
// nsIChannelEventSink
asyncOnChannelRedirect: function channel_redirect(oldChannel, newChannel,
flags, callback) {
this._policy.warn(CSPLocalizer.getFormatStr("reportPostRedirect", [oldChannel.URI.asciiSpec]));
// cancel the old channel so XHR failure callback happens
oldChannel.cancel(Cr.NS_ERROR_ABORT);
// notify an observer that we have blocked the report POST due to a redirect,
// used in testing, do this async since we're in an async call now to begin with
Services.tm.mainThread.dispatch(
function() {
observerSubject = Cc["@mozilla.org/supports-cstring;1"]
.createInstance(Ci.nsISupportsCString);
observerSubject.data = oldChannel.URI.asciiSpec;
Services.obs.notifyObservers(observerSubject,
CSP_VIOLATION_TOPIC,
"denied redirect while sending violation report");
}, Ci.nsIThread.DISPATCH_NORMAL);
// throw to stop the redirect happening
throw Cr.NS_BINDING_REDIRECTED;
}
};
this.NSGetFactory = XPCOMUtils.generateNSGetFactory([ContentSecurityPolicy]);