gecko-dev/extensions/cookie/nsCookiePermission.cpp

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 sw=2 et: */
/* 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/. */

#include "nsCookiePermission.h"

#include "mozIThirdPartyUtil.h"
#include "nsICookie2.h"
#include "nsIServiceManager.h"
#include "nsICookieManager.h"
#include "nsNetUtil.h"
#include "nsIInterfaceRequestorUtils.h"
#include "nsIProtocolHandler.h"
#include "nsIURI.h"
#include "nsIPrefService.h"
#include "nsIPrefBranch.h"
#include "nsIChannel.h"
#include "nsIHttpChannelInternal.h"
#include "nsIDOMWindow.h"
#include "nsIPrincipal.h"
#include "nsString.h"
#include "nsCRT.h"
#include "nsILoadContext.h"
#include "nsIScriptObjectPrincipal.h"
#include "nsNetCID.h"
#include "prtime.h"
#include "mozilla/StaticPtr.h"

/****************************************************************
 ************************ nsCookiePermission ********************
 ****************************************************************/

// values for mCookiesLifetimePolicy
// 0 == accept normally
// 1 == ask before accepting, no more supported, treated like ACCEPT_NORMALLY
// (Bug 606655). 2 == downgrade to session 3 == limit lifetime to N days
static const uint32_t ACCEPT_NORMALLY = 0;
static const uint32_t ACCEPT_SESSION = 2;

static const bool kDefaultPolicy = true;
static const char kCookiesLifetimePolicy[] = "network.cookie.lifetimePolicy";

static const char kPermissionType[] = "cookie";

namespace {
mozilla::StaticRefPtr<nsCookiePermission> gSingleton;
}

NS_IMPL_ISUPPORTS(nsCookiePermission, nsICookiePermission, nsIObserver)

// static
already_AddRefed<nsICookiePermission> nsCookiePermission::GetOrCreate() {
  if (!gSingleton) {
    gSingleton = new nsCookiePermission();
  }
  return do_AddRef(gSingleton);
}

// static
void nsCookiePermission::Shutdown() { gSingleton = nullptr; }

bool nsCookiePermission::Init() {
  // Initialize nsIPermissionManager and fetch relevant prefs. This is only
  // required for some methods on nsICookiePermission, so it should be done
  // lazily.
  nsresult rv;
  mPermMgr = do_GetService(NS_PERMISSIONMANAGER_CONTRACTID, &rv);
  if (NS_FAILED(rv)) return false;
  mThirdPartyUtil = do_GetService(THIRDPARTYUTIL_CONTRACTID, &rv);
  if (NS_FAILED(rv)) return false;

  // failure to access the pref service is non-fatal...
  nsCOMPtr<nsIPrefBranch> prefBranch = do_GetService(NS_PREFSERVICE_CONTRACTID);
  if (prefBranch) {
    prefBranch->AddObserver(kCookiesLifetimePolicy, this, false);
    PrefChanged(prefBranch, nullptr);
  }

  return true;
}

void nsCookiePermission::PrefChanged(nsIPrefBranch *aPrefBranch,
                                     const char *aPref) {
  int32_t val;

#define PREF_CHANGED(_P) (!aPref || !strcmp(aPref, _P))

  if (PREF_CHANGED(kCookiesLifetimePolicy) &&
      NS_SUCCEEDED(aPrefBranch->GetIntPref(kCookiesLifetimePolicy, &val))) {
    if (val != static_cast<int32_t>(ACCEPT_SESSION)) {
      val = ACCEPT_NORMALLY;
    }
    mCookiesLifetimePolicy = val;
  }
}

NS_IMETHODIMP
nsCookiePermission::SetAccess(nsIURI *aURI, nsCookieAccess aAccess) {
  // Lazily initialize ourselves
  if (!EnsureInitialized()) return NS_ERROR_UNEXPECTED;

  //
  // NOTE: nsCookieAccess values conveniently match up with
  //       the permission codes used by nsIPermissionManager.
  //       this is nice because it avoids conversion code.
  //
  return mPermMgr->Add(aURI, kPermissionType, aAccess,
                       nsIPermissionManager::EXPIRE_NEVER, 0);
}

NS_IMETHODIMP
nsCookiePermission::CanAccess(nsIPrincipal *aPrincipal,
                              nsCookieAccess *aResult) {
  // Check this protocol doesn't allow cookies
  bool hasFlags;
  nsCOMPtr<nsIURI> uri;
  aPrincipal->GetURI(getter_AddRefs(uri));
  nsresult rv = NS_URIChainHasFlags(
      uri, nsIProtocolHandler::URI_FORBIDS_COOKIE_ACCESS, &hasFlags);
  if (NS_FAILED(rv) || hasFlags) {
    *aResult = ACCESS_DENY;
    return NS_OK;
  }

  // Lazily initialize ourselves
  if (!EnsureInitialized()) return NS_ERROR_UNEXPECTED;

  // finally, check with permission manager...
  rv = mPermMgr->TestPermissionFromPrincipal(aPrincipal, kPermissionType,
                                             (uint32_t *)aResult);
  if (NS_SUCCEEDED(rv)) {
    if (*aResult == nsICookiePermission::ACCESS_SESSION) {
      *aResult = nsICookiePermission::ACCESS_ALLOW;
    }
  }

  return rv;
}

NS_IMETHODIMP
nsCookiePermission::CanSetCookie(nsIURI *aURI, nsIChannel *aChannel,
                                 nsICookie2 *aCookie, bool *aIsSession,
                                 int64_t *aExpiry, bool *aResult) {
  NS_ASSERTION(aURI, "null uri");

  *aResult = kDefaultPolicy;

  // Lazily initialize ourselves
  if (!EnsureInitialized()) return NS_ERROR_UNEXPECTED;

  uint32_t perm;
  mPermMgr->TestPermission(aURI, kPermissionType, &perm);
  bool isThirdParty = false;
  switch (perm) {
    case nsICookiePermission::ACCESS_SESSION:
      *aIsSession = true;
      MOZ_FALLTHROUGH;

    case nsICookiePermission::ACCESS_ALLOW:
      *aResult = true;
      break;

    case nsICookiePermission::ACCESS_DENY:
      *aResult = false;
      break;

    case nsICookiePermission::ACCESS_ALLOW_FIRST_PARTY_ONLY:
      mThirdPartyUtil->IsThirdPartyChannel(aChannel, aURI, &isThirdParty);
      // If it's third party, we can't set the cookie
      if (isThirdParty) *aResult = false;
      break;

    case nsICookiePermission::ACCESS_LIMIT_THIRD_PARTY:
      mThirdPartyUtil->IsThirdPartyChannel(aChannel, aURI, &isThirdParty);
      // If it's third party, check whether cookies are already set
      if (isThirdParty) {
        nsresult rv;
        nsCOMPtr<nsICookieManager> cookieManager =
            do_GetService(NS_COOKIEMANAGER_CONTRACTID, &rv);
        if (NS_FAILED(rv)) {
          *aResult = false;
          break;
        }
        uint32_t priorCookieCount = 0;
        nsAutoCString hostFromURI;
        aURI->GetHost(hostFromURI);
        cookieManager->CountCookiesFromHost(hostFromURI, &priorCookieCount);
        *aResult = priorCookieCount != 0;
      }
      break;

    default:
      // the permission manager has nothing to say about this cookie -
      // so, we apply the default prefs to it.
      NS_ASSERTION(perm == nsIPermissionManager::UNKNOWN_ACTION,
                   "unknown permission");

      // now we need to figure out what type of accept policy we're dealing with
      // if we accept cookies normally, just bail and return
      if (mCookiesLifetimePolicy == ACCEPT_NORMALLY) {
        *aResult = true;
        return NS_OK;
      }

      // declare this here since it'll be used in all of the remaining cases
      int64_t currentTime = PR_Now() / PR_USEC_PER_SEC;
      int64_t delta = *aExpiry - currentTime;

      // We are accepting the cookie, but,
      // if it's not a session cookie, we may have to limit its lifetime.
      if (!*aIsSession && delta > 0) {
        if (mCookiesLifetimePolicy == ACCEPT_SESSION) {
          // limit lifetime to session
          *aIsSession = true;
        }
      }
  }

  return NS_OK;
}

NS_IMETHODIMP
nsCookiePermission::Observe(nsISupports *aSubject, const char *aTopic,
                            const char16_t *aData) {
  nsCOMPtr<nsIPrefBranch> prefBranch = do_QueryInterface(aSubject);
  NS_ASSERTION(!nsCRT::strcmp(NS_PREFBRANCH_PREFCHANGE_TOPIC_ID, aTopic),
               "unexpected topic - we only deal with pref changes!");

  if (prefBranch)
    PrefChanged(prefBranch, NS_LossyConvertUTF16toASCII(aData).get());
  return NS_OK;
}