caps/BasePrincipal.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_BasePrincipal_h
   8 #define mozilla_BasePrincipal_h
   9
  10 #include <stdint.h>
  11 #include "ErrorList.h"
  12 #include "js/TypeDecls.h"
  13 #include "mozilla/AlreadyAddRefed.h"
  14 #include "mozilla/Assertions.h"
  15 #include "mozilla/OriginAttributes.h"
  16 #include "mozilla/RefPtr.h"
  17 #include "nsAtom.h"
  18 #include "nsIObjectOutputStream.h"
  19 #include "nsIPrincipal.h"
  20 #include "nsJSPrincipals.h"
  21 #include "nsStringFwd.h"
  22 #include "nscore.h"
  23
  24 class ExpandedPrincipal;
  25 class mozIDOMWindow;
  26 class nsIChannel;
  27 class nsIReferrerInfo;
  28 class nsISupports;
  29 class nsIURI;
  30 namespace Json {
  31 class Value;
  32 }
  33
  34 namespace mozilla {
  35
  36 namespace dom {
  37 enum class ReferrerPolicy : uint8_t;
  38 }
  39
  40 namespace extensions {
  41 class WebExtensionPolicy;
  42 }
  43
  44 class BasePrincipal;
  45
  46 // Content principals (and content principals embedded within expanded
  47 // principals) stored in SiteIdentifier are guaranteed to contain only the
  48 // eTLD+1 part of the original domain. This is used to determine whether two
  49 // origins are same-site: if it's possible for two origins to access each other
  50 // (maybe after mutating document.domain), then they must have the same site
  51 // identifier.
  52 class SiteIdentifier {
  53  public:
  54   void Init(BasePrincipal* aPrincipal) {
  55     MOZ_ASSERT(aPrincipal);
  56     mPrincipal = aPrincipal;
  57   }
  58
  59   bool IsInitialized() const { return !!mPrincipal; }
  60
  61   bool Equals(const SiteIdentifier& aOther) const;
  62
  63  private:
  64   friend class ::ExpandedPrincipal;
  65
  66   BasePrincipal* GetPrincipal() const {
  67     MOZ_ASSERT(IsInitialized());
  68     return mPrincipal;
  69   }
  70
  71   RefPtr<BasePrincipal> mPrincipal;
  72 };
  73
  74 /*
  75  * Base class from which all nsIPrincipal implementations inherit. Use this for
  76  * default implementations and other commonalities between principal
  77  * implementations.
  78  *
  79  * We should merge nsJSPrincipals into this class at some point.
  80  */
  81 class BasePrincipal : public nsJSPrincipals {
  82  public:
  83   // Warning: this enum impacts Principal serialization into JSON format.
  84   // Only update if you know exactly what you are doing
  85   enum PrincipalKind {
  86     eNullPrincipal = 0,
  87     eContentPrincipal,
  88     eExpandedPrincipal,
  89     eSystemPrincipal,
  90     eKindMax = eSystemPrincipal
  91   };
  92
  93   template <typename T>
  94   bool Is() const {
  95     return mKind == T::Kind();
  96   }
  97
  98   template <typename T>
  99   T* As() {
 100     MOZ_ASSERT(Is<T>());
 101     return static_cast<T*>(this);
 102   }
 103
 104   enum DocumentDomainConsideration {
 105     DontConsiderDocumentDomain,
 106     ConsiderDocumentDomain
 107   };
 108   bool Subsumes(nsIPrincipal* aOther,
 109                 DocumentDomainConsideration aConsideration);
 110
 111   NS_IMETHOD GetOrigin(nsACString& aOrigin) final;
 112   NS_IMETHOD GetAsciiOrigin(nsACString& aOrigin) override;
 113   NS_IMETHOD GetOriginNoSuffix(nsACString& aOrigin) final;
 114   NS_IMETHOD Equals(nsIPrincipal* other, bool* _retval) final;
 115   NS_IMETHOD EqualsConsideringDomain(nsIPrincipal* other, bool* _retval) final;
 116   NS_IMETHOD EqualsURI(nsIURI* aOtherURI, bool* _retval) override;
 117   NS_IMETHOD EqualsForPermission(nsIPrincipal* other, bool aExactHost,
 118                                  bool* _retval) final;
 119   NS_IMETHOD Subsumes(nsIPrincipal* other, bool* _retval) final;
 120   NS_IMETHOD SubsumesConsideringDomain(nsIPrincipal* other,
 121                                        bool* _retval) final;
 122   NS_IMETHOD SubsumesConsideringDomainIgnoringFPD(nsIPrincipal* other,
 123                                                   bool* _retval) final;
 124   NS_IMETHOD CheckMayLoad(nsIURI* uri, bool allowIfInheritsPrincipal) final;
 125   NS_IMETHOD CheckMayLoadWithReporting(nsIURI* uri,
 126                                        bool allowIfInheritsPrincipal,
 127                                        uint64_t innerWindowID) final;
 128   NS_IMETHOD GetAddonPolicy(extensions::WebExtensionPolicy** aResult) final;
 129   NS_IMETHOD GetIsNullPrincipal(bool* aResult) override;
 130   NS_IMETHOD GetIsContentPrincipal(bool* aResult) override;
 131   NS_IMETHOD GetIsExpandedPrincipal(bool* aResult) override;
 132   NS_IMETHOD GetIsSystemPrincipal(bool* aResult) override;
 133   NS_IMETHOD GetScheme(nsACString& aScheme) override;
 134   NS_IMETHOD SchemeIs(const char* aScheme, bool* aResult) override;
 135   NS_IMETHOD IsURIInPrefList(const char* aPref, bool* aResult) override;
 136   NS_IMETHOD IsURIInList(const nsACString& aList, bool* aResult) override;
 137   NS_IMETHOD IsL10nAllowed(nsIURI* aURI, bool* aResult) override;
 138   NS_IMETHOD GetAboutModuleFlags(uint32_t* flags) override;
 139   NS_IMETHOD GetIsAddonOrExpandedAddonPrincipal(bool* aResult) override;
 140   NS_IMETHOD GetOriginAttributes(JSContext* aCx,
 141                                  JS::MutableHandle<JS::Value> aVal) final;
 142   NS_IMETHOD GetAsciiSpec(nsACString& aSpec) override;
 143   NS_IMETHOD GetSpec(nsACString& aSpec) override;
 144   NS_IMETHOD GetExposablePrePath(nsACString& aResult) override;
 145   NS_IMETHOD GetExposableSpec(nsACString& aSpec) override;
 146   NS_IMETHOD GetHostPort(nsACString& aRes) override;
 147   NS_IMETHOD GetHost(nsACString& aRes) override;
 148   NS_IMETHOD GetPrePath(nsACString& aResult) override;
 149   NS_IMETHOD GetFilePath(nsACString& aResult) override;
 150   NS_IMETHOD GetOriginSuffix(nsACString& aOriginSuffix) final;
 151   NS_IMETHOD GetIsIpAddress(bool* aIsIpAddress) override;
 152   NS_IMETHOD GetIsLocalIpAddress(bool* aIsIpAddress) override;
 153   NS_IMETHOD GetIsOnion(bool* aIsOnion) override;
 154   NS_IMETHOD GetIsInIsolatedMozBrowserElement(
 155       bool* aIsInIsolatedMozBrowserElement) final;
 156   NS_IMETHOD GetUserContextId(uint32_t* aUserContextId) final;
 157   NS_IMETHOD GetPrivateBrowsingId(uint32_t* aPrivateBrowsingId) final;
 158   NS_IMETHOD GetSiteOrigin(nsACString& aSiteOrigin) final;
 159   NS_IMETHOD GetSiteOriginNoSuffix(nsACString& aSiteOrigin) override;
 160   NS_IMETHOD IsThirdPartyURI(nsIURI* uri, bool* aRes) override;
 161   NS_IMETHOD IsThirdPartyPrincipal(nsIPrincipal* uri, bool* aRes) override;
 162   NS_IMETHOD IsThirdPartyChannel(nsIChannel* aChannel, bool* aRes) override;
 163   NS_IMETHOD GetIsOriginPotentiallyTrustworthy(bool* aResult) override;
 164   NS_IMETHOD IsSameOrigin(nsIURI* aURI, bool aIsPrivateWin,
 165                           bool* aRes) override;
 166   NS_IMETHOD GetPrefLightCacheKey(nsIURI* aURI, bool aWithCredentials,
 167                                   const OriginAttributes& aOriginAttributes,
 168                                   nsACString& _retval) override;
 169   NS_IMETHOD HasFirstpartyStorageAccess(mozIDOMWindow* aCheckWindow,
 170                                         uint32_t* aRejectedReason,
 171                                         bool* aOutAllowed) override;
 172   NS_IMETHOD GetAsciiHost(nsACString& aAsciiHost) override;
 173   NS_IMETHOD GetLocalStorageQuotaKey(nsACString& aRes) override;
 174   NS_IMETHOD AllowsRelaxStrictFileOriginPolicy(nsIURI* aURI,
 175                                                bool* aRes) override;
 176   NS_IMETHOD CreateReferrerInfo(mozilla::dom::ReferrerPolicy aReferrerPolicy,
 177                                 nsIReferrerInfo** _retval) override;
 178   NS_IMETHOD GetIsScriptAllowedByPolicy(
 179       bool* aIsScriptAllowedByPolicy) override;
 180   NS_IMETHOD GetStorageOriginKey(nsACString& aOriginKey) override;
 181
 182   NS_IMETHOD GetNextSubDomainPrincipal(
 183       nsIPrincipal** aNextSubDomainPrincipal) override;
 184
 185   NS_IMETHOD GetPrecursorPrincipal(nsIPrincipal** aPrecursor) override;
 186
 187   nsresult ToJSON(nsACString& aJSON);
 188   static already_AddRefed<BasePrincipal> FromJSON(const nsACString& aJSON);
 189   // Method populates a passed Json::Value with serializable fields
 190   // which represent all of the fields to deserialize the principal
 191   virtual nsresult PopulateJSONObject(Json::Value& aObject);
 192
 193   virtual bool AddonHasPermission(const nsAtom* aPerm);
 194
 195   virtual bool IsContentPrincipal() const { return false; };
 196
 197   static BasePrincipal* Cast(nsIPrincipal* aPrin) {
 198     return static_cast<BasePrincipal*>(aPrin);
 199   }
 200
 201   static BasePrincipal& Cast(nsIPrincipal& aPrin) {
 202     return *static_cast<BasePrincipal*>(&aPrin);
 203   }
 204
 205   static const BasePrincipal* Cast(const nsIPrincipal* aPrin) {
 206     return static_cast<const BasePrincipal*>(aPrin);
 207   }
 208
 209   static const BasePrincipal& Cast(const nsIPrincipal& aPrin) {
 210     return *static_cast<const BasePrincipal*>(&aPrin);
 211   }
 212
 213   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 214       const nsACString& aOrigin);
 215
 216   // These following method may not create a content principal in case it's
 217   // not possible to generate a correct origin from the passed URI. If this
 218   // happens, a NullPrincipal is returned.
 219
 220   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 221       nsIURI* aURI, const OriginAttributes& aAttrs);
 222
 223   const OriginAttributes& OriginAttributesRef() final {
 224     return mOriginAttributes;
 225   }
 226   extensions::WebExtensionPolicy* AddonPolicy();
 227   uint32_t UserContextId() const { return mOriginAttributes.mUserContextId; }
 228   uint32_t PrivateBrowsingId() const {
 229     return mOriginAttributes.mPrivateBrowsingId;
 230   }
 231   bool IsInIsolatedMozBrowserElement() const {
 232     return mOriginAttributes.mInIsolatedMozBrowser;
 233   }
 234
 235   PrincipalKind Kind() const { return mKind; }
 236
 237   already_AddRefed<BasePrincipal> CloneForcingOriginAttributes(
 238       const OriginAttributes& aOriginAttributes);
 239
 240   // If this is an add-on content script principal, returns its AddonPolicy.
 241   // Otherwise returns null.
 242   extensions::WebExtensionPolicy* ContentScriptAddonPolicy();
 243
 244   // Helper to check whether this principal is associated with an addon that
 245   // allows unprivileged code to load aURI.  aExplicit == true will prevent
 246   // use of all_urls permission, requiring the domain in its permissions.
 247   bool AddonAllowsLoad(nsIURI* aURI, bool aExplicit = false);
 248
 249   // Call these to avoid the cost of virtual dispatch.
 250   inline bool FastEquals(nsIPrincipal* aOther);
 251   inline bool FastEqualsConsideringDomain(nsIPrincipal* aOther);
 252   inline bool FastSubsumes(nsIPrincipal* aOther);
 253   inline bool FastSubsumesConsideringDomain(nsIPrincipal* aOther);
 254   inline bool FastSubsumesIgnoringFPD(nsIPrincipal* aOther);
 255   inline bool FastSubsumesConsideringDomainIgnoringFPD(nsIPrincipal* aOther);
 256
 257   // Fast way to check whether we have a system principal.
 258   inline bool IsSystemPrincipal() const;
 259
 260   // Returns the principal to inherit when a caller with this principal loads
 261   // the given URI.
 262   //
 263   // For most principal types, this returns the principal itself. For expanded
 264   // principals, it returns the first sub-principal which subsumes the given URI
 265   // (or, if no URI is given, the last allowlist principal).
 266   nsIPrincipal* PrincipalToInherit(nsIURI* aRequestedURI = nullptr);
 267
 268   /* Returns true if this principal's CSP should override a document's CSP for
 269    * loads that it triggers. Currently true for expanded principals which
 270    * subsume the document principal, and add-on content principals regardless
 271    * of whether they subsume the document principal.
 272    */
 273   bool OverridesCSP(nsIPrincipal* aDocumentPrincipal) {
 274     MOZ_ASSERT(aDocumentPrincipal);
 275
 276     // Expanded principals override CSP if and only if they subsume the document
 277     // principal.
 278     if (mKind == eExpandedPrincipal) {
 279       return FastSubsumes(aDocumentPrincipal);
 280     }
 281     // Extension principals always override the CSP non-extension principals.
 282     // This is primarily for the sake of their stylesheets, which are usually
 283     // loaded from channels and cannot have expanded principals.
 284     return (AddonPolicy() &&
 285             !BasePrincipal::Cast(aDocumentPrincipal)->AddonPolicy());
 286   }
 287
 288   uint32_t GetOriginNoSuffixHash() const { return mOriginNoSuffix->hash(); }
 289   uint32_t GetOriginSuffixHash() const { return mOriginSuffix->hash(); }
 290
 291   virtual nsresult GetSiteIdentifier(SiteIdentifier& aSite) = 0;
 292
 293  protected:
 294   BasePrincipal(PrincipalKind aKind, const nsACString& aOriginNoSuffix,
 295                 const OriginAttributes& aOriginAttributes);
 296   BasePrincipal(BasePrincipal* aOther,
 297                 const OriginAttributes& aOriginAttributes);
 298
 299   virtual ~BasePrincipal();
 300
 301   // Note that this does not check OriginAttributes. Callers that depend on
 302   // those must call Subsumes instead.
 303   virtual bool SubsumesInternal(nsIPrincipal* aOther,
 304                                 DocumentDomainConsideration aConsider) = 0;
 305
 306   // Internal, side-effect-free check to determine whether the concrete
 307   // principal would allow the load ignoring any common behavior implemented in
 308   // BasePrincipal::CheckMayLoad.
 309   virtual bool MayLoadInternal(nsIURI* aURI) = 0;
 310   friend class ::ExpandedPrincipal;
 311
 312   // Helper for implementing CheckMayLoad and CheckMayLoadWithReporting.
 313   nsresult CheckMayLoadHelper(nsIURI* aURI, bool aAllowIfInheritsPrincipal,
 314                               bool aReport, uint64_t aInnerWindowID);
 315
 316   void SetHasExplicitDomain() { mHasExplicitDomain = true; }
 317
 318   // KeyValT holds a principal subtype-specific key value and the associated
 319   // parsed value after JSON parsing.
 320   template <typename SerializedKey>
 321   struct KeyValT {
 322     static_assert(sizeof(SerializedKey) == 1,
 323                   "SerializedKey should be a uint8_t");
 324     SerializedKey key;
 325     bool valueWasSerialized;
 326     nsCString value;
 327   };
 328
 329   // Common base class for all Deserializer implementations in concrete
 330   // subclasses. Subclasses will initialize `mPrincipal` in `Read`, and then
 331   // calls to `QueryInterface` will QI on the target object.
 332   class Deserializer : public nsISerializable {
 333    public:
 334     NS_DECL_ISUPPORTS
 335     NS_IMETHOD Write(nsIObjectOutputStream* aStream) override;
 336
 337    protected:
 338     virtual ~Deserializer() = default;
 339     RefPtr<BasePrincipal> mPrincipal;
 340   };
 341
 342  private:
 343   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 344       nsIURI* aURI, const OriginAttributes& aAttrs,
 345       const nsACString& aOriginNoSuffix);
 346
 347   bool FastSubsumesIgnoringFPD(nsIPrincipal* aOther,
 348                                DocumentDomainConsideration aConsideration);
 349
 350   const RefPtr<nsAtom> mOriginNoSuffix;
 351   const RefPtr<nsAtom> mOriginSuffix;
 352
 353   const OriginAttributes mOriginAttributes;
 354   const PrincipalKind mKind;
 355   bool mHasExplicitDomain;
 356 };
 357
 358 inline bool BasePrincipal::FastEquals(nsIPrincipal* aOther) {
 359   MOZ_ASSERT(aOther);
 360
 361   auto other = Cast(aOther);
 362   if (Kind() != other->Kind()) {
 363     // Principals of different kinds can't be equal.
 364     return false;
 365   }
 366
 367   // Two principals are considered to be equal if their origins are the same.
 368   // If the two principals are content principals, their origin attributes
 369   // (aka the origin suffix) must also match.
 370   if (Kind() == eSystemPrincipal) {
 371     return this == other;
 372   }
 373
 374   if (Kind() == eContentPrincipal || Kind() == eNullPrincipal) {
 375     return mOriginNoSuffix == other->mOriginNoSuffix &&
 376            mOriginSuffix == other->mOriginSuffix;
 377   }
 378
 379   MOZ_ASSERT(Kind() == eExpandedPrincipal);
 380   return mOriginNoSuffix == other->mOriginNoSuffix;
 381 }
 382
 383 inline bool BasePrincipal::FastEqualsConsideringDomain(nsIPrincipal* aOther) {
 384   MOZ_ASSERT(aOther);
 385
 386   // If neither of the principals have document.domain set, we use the fast path
 387   // in Equals().  Otherwise, we fall back to the slow path below.
 388   auto other = Cast(aOther);
 389   if (!mHasExplicitDomain && !other->mHasExplicitDomain) {
 390     return FastEquals(aOther);
 391   }
 392
 393   return Subsumes(aOther, ConsiderDocumentDomain) &&
 394          other->Subsumes(this, ConsiderDocumentDomain);
 395 }
 396
 397 inline bool BasePrincipal::FastSubsumes(nsIPrincipal* aOther) {
 398   MOZ_ASSERT(aOther);
 399
 400   // If two principals are equal, then they both subsume each other.
 401   if (FastEquals(aOther)) {
 402     return true;
 403   }
 404
 405   // Otherwise, fall back to the slow path.
 406   return Subsumes(aOther, DontConsiderDocumentDomain);
 407 }
 408
 409 inline bool BasePrincipal::FastSubsumesConsideringDomain(nsIPrincipal* aOther) {
 410   MOZ_ASSERT(aOther);
 411
 412   // If neither of the principals have document.domain set, we hand off to
 413   // FastSubsumes() which has fast paths for some special cases. Otherwise, we
 414   // fall back to the slow path below.
 415   if (!mHasExplicitDomain && !Cast(aOther)->mHasExplicitDomain) {
 416     return FastSubsumes(aOther);
 417   }
 418
 419   return Subsumes(aOther, ConsiderDocumentDomain);
 420 }
 421
 422 inline bool BasePrincipal::FastSubsumesIgnoringFPD(nsIPrincipal* aOther) {
 423   return FastSubsumesIgnoringFPD(aOther, DontConsiderDocumentDomain);
 424 }
 425
 426 inline bool BasePrincipal::FastSubsumesConsideringDomainIgnoringFPD(
 427     nsIPrincipal* aOther) {
 428   return FastSubsumesIgnoringFPD(aOther, ConsiderDocumentDomain);
 429 }
 430
 431 inline bool BasePrincipal::IsSystemPrincipal() const {
 432   return Kind() == eSystemPrincipal;
 433 }
 434
 435 }  // namespace mozilla
 436
 437 inline bool nsIPrincipal::IsSystemPrincipal() const {
 438   return mozilla::BasePrincipal::Cast(this)->IsSystemPrincipal();
 439 }
 440
 441 #endif /* mozilla_BasePrincipal_h */