author Kris Maglione <>
Thu, 02 Nov 2017 19:56:27 -0700
changeset 390018 4350a326a49805c6138aabd0ed68136498bf97cd
parent 386320 28a28f017a5f8be72f91b3efb4e820abd16b949c
child 418208 3fdd267726d3db4fb48f1fbadf2ef06c99aa248b
permissions -rw-r--r--
Bug 1412345: Downgrade expanded principals before inheriting. r=bz,krizsa There are several ways that expanded principals can be used as triggering principals for requests. While that works fine for security checks, it also sometimes causes them to be inherited, and used as result principals in contexts where expanded principals aren't allowed. This patch changes our inheritance behavior so that expanded principals are downgraded to the most appropriate constituent principal when they would otherwise be inherited. The logic for choosing the most appropriate principal is a bit suspect, and may eventually need to be changed to always select the last whitelist principal, but I chose it to preserve the current principal downgrade behavior used by XMLHttpRequest for the time being. MozReview-Commit-ID: 9fvAKr2e2fa

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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 */

/* Defines the abstract interface for a principal. */

#include "nsISerializable.idl"

struct JSPrincipals;
#include "nsCOMPtr.h"
#include "nsTArray.h"
#include "mozilla/DebugOnly.h"
namespace mozilla {
class OriginAttributes;

 * Some methods have a fast path for the case when we're comparing a principal
 * to itself. The situation may happen for example with about:blank documents.

#define DECL_FAST_INLINE_HELPER(method_)                       \
  inline bool method_(nsIPrincipal* aOther)                    \
  {                                                            \
    mozilla::DebugOnly<bool> val = false;                      \
    MOZ_ASSERT_IF(this == aOther,                              \
                  NS_SUCCEEDED(method_(aOther, &val)) && val); \
    bool retVal = false;                                       \
    return                                                     \
      this == aOther ||                                        \
      (NS_SUCCEEDED(method_(aOther, &retVal)) && retVal);      \


interface nsIURI;
interface nsIContentSecurityPolicy;
interface nsIDOMDocument;

[ptr] native JSContext(JSContext);
[ptr] native JSPrincipals(JSPrincipals);
[ref] native PrincipalArray(const nsTArray<nsCOMPtr<nsIPrincipal>>);
[ref] native const_OriginAttributes(const mozilla::OriginAttributes);

[scriptable, builtinclass, uuid(f75f502d-79fd-48be-a079-e5a7b8f80c8b)]
interface nsIPrincipal : nsISerializable
     * Returns whether the other principal is equivalent to this principal.
     * Principals are considered equal if they are the same principal, or
     * they have the same origin.
    boolean equals(in nsIPrincipal other);

     * Like equals, but takes document.domain changes into account.
    boolean equalsConsideringDomain(in nsIPrincipal other);


     * Returns a hash value for the principal.
    [noscript] readonly attribute unsigned long hashValue;

     * The codebase URI to which this principal pertains.  This is
     * generally the document URI.
    readonly attribute nsIURI URI;

     * The domain URI to which this principal pertains.
     * This is null unless script successfully sets document.domain to our URI
     * or a superdomain of our URI.
     * Setting this has no effect on the URI.
     * See
    [noscript] attribute nsIURI domain;

     * Returns whether the other principal is equal to or weaker than this
     * principal. Principals are equal if they are the same object or they
     * have the same origin.
     * Thus a principal always subsumes itself.
     * The system principal subsumes itself and all other principals.
     * A null principal (corresponding to an unknown, hence assumed minimally
     * privileged, security context) is not equal to any other principal
     * (including other null principals), and therefore does not subsume
     * anything but itself.
    boolean subsumes(in nsIPrincipal other);

     * Same as the previous method, subsumes(), but takes document.domain into
     * account.
    boolean subsumesConsideringDomain(in nsIPrincipal other);

     * Same as the subsumesConsideringDomain(), but ignores the first party
     * domain in its originAttributes.
    boolean subsumesConsideringDomainIgnoringFPD(in nsIPrincipal other);


     * Checks whether this principal is allowed to load the network resource
     * located at the given URI under the same-origin policy. This means that
     * codebase principals are only allowed to load resources from the same
     * domain, the system principal is allowed to load anything, and null
     * principals can only load URIs where they are the principal. This is
     * changed by the optional flag allowIfInheritsPrincipal (which defaults to
     * false) which allows URIs that inherit their loader's principal.
     * If the load is allowed this function does nothing. If the load is not
     * allowed the function throws NS_ERROR_DOM_BAD_URI.
     * NOTE: Other policies might override this, such as the Access-Control
     *       specification.
     * NOTE: The 'domain' attribute has no effect on the behaviour of this
     *       function.
     * @param uri    The URI about to be loaded.
     * @param report If true, will report a warning to the console service
     *               if the load is not allowed.
     * @param allowIfInheritsPrincipal   If true, the load is allowed if the
     *                                   loadee inherits the principal of the
     *                                   loader.
     * @throws NS_ERROR_DOM_BAD_URI if the load is not allowed.
    void checkMayLoad(in nsIURI uri, in boolean report,
                      in boolean allowIfInheritsPrincipal);

     * A Content Security Policy associated with this principal.
     * Use this function to query the associated CSP with this principal.
     * Please *only* use this function to *set* a CSP when you know exactly what you are doing.
     * Most likely you want to call ensureCSP instead of setCSP.
    [noscript] attribute nsIContentSecurityPolicy csp;

     * Use this function to query a CSP associated with this principal.
     * If no CSP is associated with this principal then one is created
     * internally and setRequestContext is called on the CSP using aDocument.
     * Please note if aDocument is null, then setRequestContext on the
     * CSP object is called using the current principal.
    [noscript] nsIContentSecurityPolicy ensureCSP(in nsIDOMDocument aDocument);

     * A speculative Content Security Policy associated with this
     * principal. Set during speculative loading (preloading) and
     * used *only* for preloads.
     * If you want to query the CSP associated with that principal,
     * then this is *not* what you want. Instead query 'csp'.
    [noscript] readonly attribute nsIContentSecurityPolicy preloadCsp;

     * Use this function to query a speculative CSP associated with this
     * principal. If no speculative CSP is associated with this principal
     * then one is created internally and setRequestContext is called on
     * the CSP using aDocument.
     * Please note if aDocument is null, then setRequestContext on the
     * speculative CSP object is called using the current principal.
    [noscript] nsIContentSecurityPolicy ensurePreloadCSP(in nsIDOMDocument aDocument);

     * The CSP of the principal in JSON notation.
     * Note, that the CSP itself is not exposed to JS, but script
     * should be able to obtain a JSON representation of the CSP.
    readonly attribute AString cspJSON;

     * A dictionary of the non-default origin attributes associated with this
     * nsIPrincipal.
     * Attributes are tokens that are taken into account when determining whether
     * two principals are same-origin - if any attributes differ, the principals
     * are cross-origin, even if the scheme, host, and port are the same.
     * Attributes should also be considered for all security and bucketing decisions,
     * even those which make non-standard comparisons (like cookies, which ignore
     * scheme, or quotas, which ignore subdomains).
     * If you're looking for an easy-to-use canonical stringification of the origin
     * attributes, see |originSuffix| below.
    readonly attribute jsval originAttributes;

    [noscript, notxpcom, nostdcall, binaryname(OriginAttributesRef)]
    const_OriginAttributes OriginAttributesRef();

     * A canonical representation of the origin for this principal. This
     * consists of a base string (which, for codebase principals, is of the
     * format scheme://host:port), concatenated with |originAttributes| (see
     * below).
     * We maintain the invariant that principalA.equals(principalB) if and only
     * if principalA.origin == principalB.origin.
    readonly attribute ACString origin;

     * The base part of |origin| without the concatenation with |originSuffix|.
     * This doesn't have the important invariants described above with |origin|,
     * and as such should only be used for legacy situations.
    readonly attribute ACString originNoSuffix;

     * A string of the form !key1=value1&key2=value2, where each pair represents
     * an attribute with a non-default value. If all attributes have default
     * values, this is the empty string.
     * The value of .originSuffix is automatically serialized into .origin, so any
     * consumers using that are automatically origin-attribute-aware. Consumers with
     * special requirements must inspect and compare .originSuffix manually.
    readonly attribute AUTF8String originSuffix;

     * The base domain of the codebase URI to which this principal pertains
     * (generally the document URI), handling null principals and
     * non-hierarchical schemes correctly.
    readonly attribute ACString baseDomain;

     * Gets the id of the app this principal is inside.  If this principal is
     * not inside an app, returns nsIScriptSecurityManager::NO_APP_ID.
     * Note that this principal does not necessarily have the permissions of
     * the app identified by appId.  For example, this principal might
     * correspond to an iframe whose origin differs from that of the app frame
     * containing it.  In this case, the iframe will have the appId of its
     * containing app frame, but the iframe must not run with the app's
     * permissions.
     * Similarly, this principal might correspond to an <iframe mozbrowser>
     * inside an app frame; in this case, the content inside the iframe should
     * not have any of the app's permissions, even if the iframe is at the same
     * origin as the app.
    [infallible] readonly attribute unsigned long appId;

     * Gets the ID of the add-on this principal belongs to.
    readonly attribute AString addonId;

    readonly attribute nsISupports addonPolicy;

     * Gets the id of the user context this principal is inside.  If this
     * principal is inside the default userContext, this returns
     * nsIScriptSecurityManager::DEFAULT_USER_CONTEXT_ID.
    [infallible] readonly attribute unsigned long userContextId;

     * Gets the id of the private browsing state of the context containing
     * this principal. If the principal has a private browsing value of 0, it
     * is not in private browsing.
    [infallible] readonly attribute unsigned long privateBrowsingId;

     * Returns true iff the principal is inside an isolated mozbrowser element.
     * <xul:browser> is not considered to be a mozbrowser element.
     * <iframe mozbrowser noisolation> does not count as isolated since
     * isolation is disabled.  Isolation can only be disabled if the
     * containing document is chrome.
    [infallible] readonly attribute boolean isInIsolatedMozBrowserElement;

     * Returns true iff this is a null principal (corresponding to an
     * unknown, hence assumed minimally privileged, security context).
    [infallible] readonly attribute boolean isNullPrincipal;

     * Returns true iff this principal corresponds to a codebase origin.
    [infallible] readonly attribute boolean isCodebasePrincipal;

     * Returns true iff this is an expanded principal.
    [infallible] readonly attribute boolean isExpandedPrincipal;

     * Returns true iff this is the system principal.
    [infallible] readonly attribute boolean isSystemPrincipal;

 * If SystemPrincipal is too risky to use, but we want a principal to access
 * more than one origin, ExpandedPrincipals letting us define an array of
 * principals it subsumes. So script with an ExpandedPrincipals will gain
 * same origin access when at least one of its principals it contains gained
 * sameorigin acccess. An ExpandedPrincipal will be subsumed by the system
 * principal, and by another ExpandedPrincipal that has all its principals.
 * It is added for jetpack content-scripts to let them interact with the
 * content and a well defined set of other domains, without the risk of
 * leaking out a system principal to the content. See: Bug 734891
interface nsIExpandedPrincipal : nsISupports
   * An array of principals that the expanded principal subsumes.
   * When an expanded principal is used as a triggering principal for a
   * request that inherits a security context, one of its constitutent
   * principals is inherited rather than the expanded principal itself. The
   * last principal in the whitelist is the default principal to inherit.
   * Note: this list is not reference counted, it is shared, so
   * should not be changed and should only be used ephemerally.
  [noscript, notxpcom, nostdcall]
  PrincipalArray WhiteList();