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
  31 namespace mozilla {
  32
  33 class JSONWriter;
  34
  35 namespace dom {
  36 enum class ReferrerPolicy : uint8_t;
  37 }
  38
  39 namespace extensions {
  40 class WebExtensionPolicy;
  41 class WebExtensionPolicyCore;
  42 }  // namespace extensions
  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   static constexpr char NullPrincipalKey = '0';
  94   static_assert(eNullPrincipal == 0);
  95   static constexpr char ContentPrincipalKey = '1';
  96   static_assert(eContentPrincipal == 1);
  97   static constexpr char ExpandedPrincipalKey = '2';
  98   static_assert(eExpandedPrincipal == 2);
  99   static constexpr char SystemPrincipalKey = '3';
 100   static_assert(eSystemPrincipal == 3);
 101
 102   template <typename T>
 103   bool Is() const {
 104     return mKind == T::Kind();
 105   }
 106
 107   template <typename T>
 108   T* As() {
 109     MOZ_ASSERT(Is<T>());
 110     return static_cast<T*>(this);
 111   }
 112
 113   enum DocumentDomainConsideration {
 114     DontConsiderDocumentDomain,
 115     ConsiderDocumentDomain
 116   };
 117   bool Subsumes(nsIPrincipal* aOther,
 118                 DocumentDomainConsideration aConsideration);
 119
 120   NS_IMETHOD GetOrigin(nsACString& aOrigin) final;
 121   NS_IMETHOD GetWebExposedOriginSerialization(nsACString& aOrigin) override;
 122   NS_IMETHOD GetOriginNoSuffix(nsACString& aOrigin) final;
 123   NS_IMETHOD Equals(nsIPrincipal* other, bool* _retval) final;
 124   NS_IMETHOD EqualsConsideringDomain(nsIPrincipal* other, bool* _retval) final;
 125   NS_IMETHOD EqualsURI(nsIURI* aOtherURI, bool* _retval) override;
 126   NS_IMETHOD EqualsForPermission(nsIPrincipal* other, bool aExactHost,
 127                                  bool* _retval) final;
 128   NS_IMETHOD Subsumes(nsIPrincipal* other, bool* _retval) final;
 129   NS_IMETHOD SubsumesConsideringDomain(nsIPrincipal* other,
 130                                        bool* _retval) final;
 131   NS_IMETHOD SubsumesConsideringDomainIgnoringFPD(nsIPrincipal* other,
 132                                                   bool* _retval) final;
 133   NS_IMETHOD CheckMayLoad(nsIURI* uri, bool allowIfInheritsPrincipal) final;
 134   NS_IMETHOD CheckMayLoadWithReporting(nsIURI* uri,
 135                                        bool allowIfInheritsPrincipal,
 136                                        uint64_t innerWindowID) final;
 137   NS_IMETHOD GetAddonPolicy(extensions::WebExtensionPolicy** aResult) final;
 138   NS_IMETHOD GetContentScriptAddonPolicy(
 139       extensions::WebExtensionPolicy** aResult) final;
 140   NS_IMETHOD GetIsNullPrincipal(bool* aResult) override;
 141   NS_IMETHOD GetIsContentPrincipal(bool* aResult) override;
 142   NS_IMETHOD GetIsExpandedPrincipal(bool* aResult) override;
 143   NS_IMETHOD GetIsSystemPrincipal(bool* aResult) override;
 144   NS_IMETHOD GetScheme(nsACString& aScheme) override;
 145   NS_IMETHOD SchemeIs(const char* aScheme, bool* aResult) override;
 146   NS_IMETHOD IsURIInPrefList(const char* aPref, bool* aResult) override;
 147   NS_IMETHOD IsURIInList(const nsACString& aList, bool* aResult) override;
 148   NS_IMETHOD IsContentAccessibleAboutURI(bool* aResult) override;
 149   NS_IMETHOD IsL10nAllowed(nsIURI* aURI, bool* aResult) override;
 150   NS_IMETHOD GetAboutModuleFlags(uint32_t* flags) override;
 151   NS_IMETHOD GetIsAddonOrExpandedAddonPrincipal(bool* aResult) override;
 152   NS_IMETHOD GetOriginAttributes(JSContext* aCx,
 153                                  JS::MutableHandle<JS::Value> aVal) final;
 154   NS_IMETHOD GetAsciiSpec(nsACString& aSpec) override;
 155   NS_IMETHOD GetSpec(nsACString& aSpec) override;
 156   NS_IMETHOD GetExposablePrePath(nsACString& aResult) override;
 157   NS_IMETHOD GetExposableSpec(nsACString& aSpec) override;
 158   NS_IMETHOD GetHostPort(nsACString& aRes) override;
 159   NS_IMETHOD GetHost(nsACString& aRes) override;
 160   NS_IMETHOD GetPrePath(nsACString& aResult) override;
 161   NS_IMETHOD GetFilePath(nsACString& aResult) override;
 162   NS_IMETHOD GetOriginSuffix(nsACString& aOriginSuffix) final;
 163   NS_IMETHOD GetIsIpAddress(bool* aIsIpAddress) override;
 164   NS_IMETHOD GetIsLocalIpAddress(bool* aIsIpAddress) override;
 165   NS_IMETHOD GetIsOnion(bool* aIsOnion) override;
 166   NS_IMETHOD GetUserContextId(uint32_t* aUserContextId) final;
 167   NS_IMETHOD GetPrivateBrowsingId(uint32_t* aPrivateBrowsingId) final;
 168   NS_IMETHOD GetSiteOrigin(nsACString& aSiteOrigin) final;
 169   NS_IMETHOD GetSiteOriginNoSuffix(nsACString& aSiteOrigin) override;
 170   NS_IMETHOD IsThirdPartyURI(nsIURI* uri, bool* aRes) override;
 171   NS_IMETHOD IsThirdPartyPrincipal(nsIPrincipal* uri, bool* aRes) override;
 172   NS_IMETHOD IsThirdPartyChannel(nsIChannel* aChannel, bool* aRes) override;
 173   NS_IMETHOD GetIsOriginPotentiallyTrustworthy(bool* aResult) override;
 174   NS_IMETHOD GetIsLoopbackHost(bool* aResult) override;
 175   NS_IMETHOD IsSameOrigin(nsIURI* aURI, bool* aRes) override;
 176   NS_IMETHOD GetPrefLightCacheKey(nsIURI* aURI, bool aWithCredentials,
 177                                   const OriginAttributes& aOriginAttributes,
 178                                   nsACString& _retval) override;
 179   NS_IMETHOD HasFirstpartyStorageAccess(mozIDOMWindow* aCheckWindow,
 180                                         uint32_t* aRejectedReason,
 181                                         bool* aOutAllowed) override;
 182   NS_IMETHOD GetAsciiHost(nsACString& aAsciiHost) override;
 183   NS_IMETHOD GetLocalStorageQuotaKey(nsACString& aRes) override;
 184   NS_IMETHOD AllowsRelaxStrictFileOriginPolicy(nsIURI* aURI,
 185                                                bool* aRes) override;
 186   NS_IMETHOD CreateReferrerInfo(mozilla::dom::ReferrerPolicy aReferrerPolicy,
 187                                 nsIReferrerInfo** _retval) override;
 188   NS_IMETHOD GetIsScriptAllowedByPolicy(
 189       bool* aIsScriptAllowedByPolicy) override;
 190   NS_IMETHOD GetStorageOriginKey(nsACString& aOriginKey) override;
 191
 192   NS_IMETHOD GetNextSubDomainPrincipal(
 193       nsIPrincipal** aNextSubDomainPrincipal) override;
 194
 195   NS_IMETHOD GetPrecursorPrincipal(nsIPrincipal** aPrecursor) override;
 196
 197   nsresult ToJSON(nsACString& aJSON);
 198   nsresult ToJSON(JSONWriter& aWriter);
 199   nsresult WriteJSONProperties(JSONWriter& aWriter);
 200
 201   static already_AddRefed<BasePrincipal> FromJSON(const nsACString& aJSON);
 202
 203   // Method to write serializable fields which represent all of the fields to
 204   // deserialize the principal.
 205   virtual nsresult WriteJSONInnerProperties(JSONWriter& aWriter);
 206
 207   virtual bool AddonHasPermission(const nsAtom* aPerm);
 208
 209   virtual bool IsContentPrincipal() const { return false; };
 210
 211   static BasePrincipal* Cast(nsIPrincipal* aPrin) {
 212     return static_cast<BasePrincipal*>(aPrin);
 213   }
 214
 215   static BasePrincipal& Cast(nsIPrincipal& aPrin) {
 216     return *static_cast<BasePrincipal*>(&aPrin);
 217   }
 218
 219   static const BasePrincipal* Cast(const nsIPrincipal* aPrin) {
 220     return static_cast<const BasePrincipal*>(aPrin);
 221   }
 222
 223   static const BasePrincipal& Cast(const nsIPrincipal& aPrin) {
 224     return *static_cast<const BasePrincipal*>(&aPrin);
 225   }
 226
 227   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 228       const nsACString& aOrigin);
 229
 230   // This method may not create a content principal in case it's not possible to
 231   // generate a correct origin from the passed URI. If this happens, a
 232   // NullPrincipal is returned.
 233   //
 234   // If `aInitialDomain` is specified, and a ContentPrincipal is set, it will
 235   // initially have its domain set to the given value, without re-computing js
 236   // wrappers. Unlike `SetDomain()` this is safe to do off-main-thread.
 237
 238   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 239       nsIURI* aURI, const OriginAttributes& aAttrs,
 240       nsIURI* aInitialDomain = nullptr);
 241
 242   const OriginAttributes& OriginAttributesRef() final {
 243     return mOriginAttributes;
 244   }
 245   extensions::WebExtensionPolicy* AddonPolicy();
 246   RefPtr<extensions::WebExtensionPolicyCore> AddonPolicyCore();
 247   uint32_t UserContextId() const { return mOriginAttributes.mUserContextId; }
 248   uint32_t PrivateBrowsingId() const {
 249     return mOriginAttributes.mPrivateBrowsingId;
 250   }
 251
 252   PrincipalKind Kind() const { return mKind; }
 253
 254   already_AddRefed<BasePrincipal> CloneForcingOriginAttributes(
 255       const OriginAttributes& aOriginAttributes);
 256
 257   // If this is an add-on content script principal, returns its AddonPolicy.
 258   // Otherwise returns null.
 259   extensions::WebExtensionPolicy* ContentScriptAddonPolicy();
 260   RefPtr<extensions::WebExtensionPolicyCore> ContentScriptAddonPolicyCore();
 261
 262   // Helper to check whether this principal is associated with an addon that
 263   // allows unprivileged code to load aURI.  aExplicit == true will prevent
 264   // use of all_urls permission, requiring the domain in its permissions.
 265   bool AddonAllowsLoad(nsIURI* aURI, bool aExplicit = false);
 266
 267   // Call these to avoid the cost of virtual dispatch.
 268   inline bool FastEquals(nsIPrincipal* aOther);
 269   inline bool FastEqualsConsideringDomain(nsIPrincipal* aOther);
 270   inline bool FastSubsumes(nsIPrincipal* aOther);
 271   inline bool FastSubsumesConsideringDomain(nsIPrincipal* aOther);
 272   inline bool FastSubsumesIgnoringFPD(nsIPrincipal* aOther);
 273   inline bool FastSubsumesConsideringDomainIgnoringFPD(nsIPrincipal* aOther);
 274
 275   // Fast way to check whether we have a system principal.
 276   inline bool IsSystemPrincipal() const;
 277
 278   // Returns the principal to inherit when a caller with this principal loads
 279   // the given URI.
 280   //
 281   // For most principal types, this returns the principal itself. For expanded
 282   // principals, it returns the first sub-principal which subsumes the given URI
 283   // (or, if no URI is given, the last allowlist principal).
 284   nsIPrincipal* PrincipalToInherit(nsIURI* aRequestedURI = nullptr);
 285
 286   /* Returns true if this principal's CSP should override a document's CSP for
 287    * loads that it triggers. Currently true for expanded principals which
 288    * subsume the document principal, and add-on content principals regardless
 289    * of whether they subsume the document principal.
 290    */
 291   bool OverridesCSP(nsIPrincipal* aDocumentPrincipal);
 292
 293   uint32_t GetOriginNoSuffixHash() const { return mOriginNoSuffix->hash(); }
 294   uint32_t GetOriginSuffixHash() const { return mOriginSuffix->hash(); }
 295
 296   virtual nsresult GetSiteIdentifier(SiteIdentifier& aSite) = 0;
 297
 298  protected:
 299   BasePrincipal(PrincipalKind aKind, const nsACString& aOriginNoSuffix,
 300                 const OriginAttributes& aOriginAttributes);
 301   BasePrincipal(BasePrincipal* aOther,
 302                 const OriginAttributes& aOriginAttributes);
 303
 304   virtual ~BasePrincipal();
 305
 306   // Note that this does not check OriginAttributes. Callers that depend on
 307   // those must call Subsumes instead.
 308   virtual bool SubsumesInternal(nsIPrincipal* aOther,
 309                                 DocumentDomainConsideration aConsider) = 0;
 310
 311   // Internal, side-effect-free check to determine whether the concrete
 312   // principal would allow the load ignoring any common behavior implemented in
 313   // BasePrincipal::CheckMayLoad.
 314   //
 315   // Safe to call from any thread, unlike CheckMayLoad.
 316   virtual bool MayLoadInternal(nsIURI* aURI) = 0;
 317   friend class ::ExpandedPrincipal;
 318
 319   // Helper for implementing CheckMayLoad and CheckMayLoadWithReporting.
 320   nsresult CheckMayLoadHelper(nsIURI* aURI, bool aAllowIfInheritsPrincipal,
 321                               bool aReport, uint64_t aInnerWindowID);
 322
 323   void SetHasExplicitDomain() { mHasExplicitDomain = true; }
 324   bool GetHasExplicitDomain() { return mHasExplicitDomain; }
 325
 326   // KeyValT holds a principal subtype-specific key value and the associated
 327   // parsed value after JSON parsing.
 328   template <typename SerializedKey>
 329   struct KeyValT {
 330     static_assert(sizeof(SerializedKey) == 1,
 331                   "SerializedKey should be a uint8_t");
 332     SerializedKey key;
 333     bool valueWasSerialized;
 334     nsCString value;
 335   };
 336
 337   // Common base class for all Deserializer implementations in concrete
 338   // subclasses. Subclasses will initialize `mPrincipal` in `Read`, and then
 339   // calls to `QueryInterface` will QI on the target object.
 340   class Deserializer : public nsISerializable {
 341    public:
 342     NS_DECL_ISUPPORTS
 343     NS_IMETHOD Write(nsIObjectOutputStream* aStream) override;
 344
 345    protected:
 346     virtual ~Deserializer() = default;
 347     RefPtr<BasePrincipal> mPrincipal;
 348   };
 349
 350  private:
 351   static constexpr Span<const char> JSONEnumKeyStrings[4] = {
 352       MakeStringSpan("0"),
 353       MakeStringSpan("1"),
 354       MakeStringSpan("2"),
 355       MakeStringSpan("3"),
 356   };
 357
 358   static void WriteJSONProperty(JSONWriter& aWriter,
 359                                 const Span<const char>& aKey,
 360                                 const nsCString& aValue);
 361
 362  protected:
 363   template <size_t EnumValue>
 364   static inline constexpr const Span<const char>& JSONEnumKeyString() {
 365     static_assert(EnumValue < ArrayLength(JSONEnumKeyStrings));
 366     return JSONEnumKeyStrings[EnumValue];
 367   }
 368   template <size_t EnumValue>
 369   static void WriteJSONProperty(JSONWriter& aWriter, const nsCString& aValue) {
 370     WriteJSONProperty(aWriter, JSONEnumKeyString<EnumValue>(), aValue);
 371   }
 372
 373  private:
 374   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 375       nsIURI* aURI, const OriginAttributes& aAttrs,
 376       const nsACString& aOriginNoSuffix, nsIURI* aInitialDomain);
 377
 378   bool FastSubsumesIgnoringFPD(nsIPrincipal* aOther,
 379                                DocumentDomainConsideration aConsideration);
 380
 381   const RefPtr<nsAtom> mOriginNoSuffix;
 382   const RefPtr<nsAtom> mOriginSuffix;
 383
 384   const OriginAttributes mOriginAttributes;
 385   const PrincipalKind mKind;
 386   std::atomic<bool> mHasExplicitDomain;
 387 };
 388
 389 inline bool BasePrincipal::FastEquals(nsIPrincipal* aOther) {
 390   MOZ_ASSERT(aOther);
 391
 392   auto other = Cast(aOther);
 393   if (Kind() != other->Kind()) {
 394     // Principals of different kinds can't be equal.
 395     return false;
 396   }
 397
 398   // Two principals are considered to be equal if their origins are the same.
 399   // If the two principals are content principals, their origin attributes
 400   // (aka the origin suffix) must also match.
 401   if (Kind() == eSystemPrincipal) {
 402     return this == other;
 403   }
 404
 405   if (Kind() == eContentPrincipal || Kind() == eNullPrincipal) {
 406     return mOriginNoSuffix == other->mOriginNoSuffix &&
 407            mOriginSuffix == other->mOriginSuffix;
 408   }
 409
 410   MOZ_ASSERT(Kind() == eExpandedPrincipal);
 411   return mOriginNoSuffix == other->mOriginNoSuffix;
 412 }
 413
 414 inline bool BasePrincipal::FastEqualsConsideringDomain(nsIPrincipal* aOther) {
 415   MOZ_ASSERT(aOther);
 416
 417   // If neither of the principals have document.domain set, we use the fast path
 418   // in Equals().  Otherwise, we fall back to the slow path below.
 419   auto other = Cast(aOther);
 420   if (!mHasExplicitDomain && !other->mHasExplicitDomain) {
 421     return FastEquals(aOther);
 422   }
 423
 424   // Principals of different kinds can't be equal.
 425   if (Kind() != other->Kind()) {
 426     return false;
 427   }
 428
 429   // Only ContentPrincipals should have mHasExplicitDomain set to true, so test
 430   // that we haven't ended up here instead of FastEquals by mistake.
 431   MOZ_ASSERT(IsContentPrincipal(),
 432              "Only content principals can set mHasExplicitDomain");
 433
 434   return Subsumes(aOther, ConsiderDocumentDomain) &&
 435          other->Subsumes(this, ConsiderDocumentDomain);
 436 }
 437
 438 inline bool BasePrincipal::FastSubsumes(nsIPrincipal* aOther) {
 439   MOZ_ASSERT(aOther);
 440
 441   // If two principals are equal, then they both subsume each other.
 442   if (FastEquals(aOther)) {
 443     return true;
 444   }
 445
 446   // Otherwise, fall back to the slow path.
 447   return Subsumes(aOther, DontConsiderDocumentDomain);
 448 }
 449
 450 inline bool BasePrincipal::FastSubsumesConsideringDomain(nsIPrincipal* aOther) {
 451   MOZ_ASSERT(aOther);
 452
 453   // If neither of the principals have document.domain set, we hand off to
 454   // FastSubsumes() which has fast paths for some special cases. Otherwise, we
 455   // fall back to the slow path below.
 456   if (!mHasExplicitDomain && !Cast(aOther)->mHasExplicitDomain) {
 457     return FastSubsumes(aOther);
 458   }
 459
 460   return Subsumes(aOther, ConsiderDocumentDomain);
 461 }
 462
 463 inline bool BasePrincipal::FastSubsumesIgnoringFPD(nsIPrincipal* aOther) {
 464   return FastSubsumesIgnoringFPD(aOther, DontConsiderDocumentDomain);
 465 }
 466
 467 inline bool BasePrincipal::FastSubsumesConsideringDomainIgnoringFPD(
 468     nsIPrincipal* aOther) {
 469   return FastSubsumesIgnoringFPD(aOther, ConsiderDocumentDomain);
 470 }
 471
 472 inline bool BasePrincipal::IsSystemPrincipal() const {
 473   return Kind() == eSystemPrincipal;
 474 }
 475
 476 }  // namespace mozilla
 477
 478 inline bool nsIPrincipal::IsSystemPrincipal() const {
 479   return mozilla::BasePrincipal::Cast(this)->IsSystemPrincipal();
 480 }
 481
 482 #endif /* mozilla_BasePrincipal_h */