nsIPrincipal.idl

/* -*- 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 http://mozilla.org/MPL/2.0/. */

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

#include "nsISerializable.idl"

%{C++
struct JSPrincipals;
#include "nsCOMPtr.h"
#include "nsTArray.h"
%}

interface nsIURI;
interface nsIContentSecurityPolicy;

[ptr] native JSContext(JSContext);
[ptr] native JSPrincipals(JSPrincipals);
[ptr] native PrincipalArray(nsTArray<nsCOMPtr<nsIPrincipal> >);

[scriptable, builtinclass, uuid(264fe8ca-c382-11e4-95a6-782bcbaebb28)]
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);

    %{C++
    inline bool Equals(nsIPrincipal* aOther) {
      bool equal = false;
      return NS_SUCCEEDED(Equals(aOther, &equal)) && equal;
    }

    inline bool EqualsConsideringDomain(nsIPrincipal* aOther) {
      bool equal = false;
      return NS_SUCCEEDED(EqualsConsideringDomain(aOther, &equal)) && equal;
    }
    %}

    /**
     * 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 congruent with HTMLDocument.domain, and may be null.
     * Setting this has no effect on the URI.
     */
    [noscript] attribute nsIURI domain;

    /**
     * The origin of this principal's codebase URI.
     * An origin is defined as: scheme + host + port.
     */
    // XXXcaa this should probably be turned into an nsIURI.
    // The system principal's origin should be some caps namespace
    // with a chrome URI.  All of chrome should probably be the same.
    readonly attribute string origin;

    /**
     * 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);

    %{C++
    inline bool Subsumes(nsIPrincipal* aOther) {
      bool subsumes = false;
      return NS_SUCCEEDED(Subsumes(aOther, &subsumes)) && subsumes;
    }

    inline bool SubsumesConsideringDomain(nsIPrincipal* aOther) {
      bool subsumes = false;
      return NS_SUCCEEDED(SubsumesConsideringDomain(aOther, &subsumes)) && subsumes;
    }
    %}

    /**
     * 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.
     */
    [noscript] attribute nsIContentSecurityPolicy csp;

    /**
     * Returns the jar prefix of the principal.
     * The jar prefix is a string that can be used to isolate data or
     * permissions between different principals while taking into account
     * parameters like the app id or the fact that the principal is embedded in
     * a mozbrowser.
     * Some principals will return an empty string.
     * Some principals will assert if you try to access the jarPrefix.
     *
     * The jarPrefix is intended to be an opaque identifier. It is currently
     * "human-readable" but no callers should assume it will stay as is and
     * it might be crypto-hashed at some point.
     */
    readonly attribute AUTF8String jarPrefix;

    /**
     * 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;

    const short APP_STATUS_NOT_INSTALLED = 0;
    const short APP_STATUS_INSTALLED     = 1;
    const short APP_STATUS_PRIVILEGED    = 2;
    const short APP_STATUS_CERTIFIED     = 3;

    /**
     * Gets the principal's app status, which indicates whether the principal
     * corresponds to "app code", and if it does, how privileged that code is.
     * This method returns one of the APP_STATUS constants above.
     *
     * Note that a principal may have
     *
     *   appId != nsIScriptSecurityManager::NO_APP_ID &&
     *   appId != nsIScriptSecurityManager::UNKNOWN_APP_ID
     *
     * and still have appStatus == APP_STATUS_NOT_INSTALLED.  That's because
     * appId identifies the app that contains this principal, but a window
     * might be contained in an app and not be running code that the app has
     * vouched for.  For example, the window might be inside an <iframe
     * mozbrowser>, or the window's origin might not match the app's origin.
     *
     * If you're doing a check to determine "does this principal correspond to
     * app code?", you must check appStatus; checking appId != NO_APP_ID is not
     * sufficient.
     */
    [infallible] readonly attribute unsigned short appStatus;

    /**
     * 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.
     *
     * If you're doing a security check based on appId, you must check
     * appStatus as well.
     */
    [infallible] readonly attribute unsigned long appId;

    /**
     * Returns true iff the principal is inside a browser element.  (<iframe
     * mozbrowser mozapp> does not count as a browser element.)
     */
    [infallible] readonly attribute boolean isInBrowserElement;

    /**
     * Returns true if this principal has an unknown appId. This shouldn't
     * generally be used. We only expose it due to not providing the correct
     * appId everywhere where we construct principals.
     */
    [infallible] readonly attribute boolean unknownAppId;

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

    /**
     * Returns true if this principal's origin is recognized as being on the
     * whitelist of sites that can use the CSS Unprefixing Service.
     *
     * (This interface provides a trivial implementation, just returning false;
     * subclasses can implement something more complex as-needed.)
     */
    [noscript,notxpcom,nostdcall] bool IsOnCSSUnprefixingWhitelist();
};

/**
 * If nsSystemPrincipal is too risky to use, but we want a principal to access
 * more than one origin, nsExpandedPrincipals letting us define an array of
 * principals it subsumes. So script with an nsExpandedPrincipals will gain
 * same origin access when at least one of its principals it contains gained
 * sameorigin acccess. An nsExpandedPrincipal will be subsumed by the system
 * principal, and by another nsExpandedPrincipal 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
 */
[uuid(f3e177Df-6a5e-489f-80a7-2dd1481471d8)]
interface nsIExpandedPrincipal : nsISupports
{
  /**
   * An array of principals that the expanded principal subsumes.
   * Note: this list is not reference counted, it is shared, so
   * should not be changed and should only be used ephemerally.
   */
  [noscript] readonly attribute PrincipalArray whiteList;
};