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 class WebExtensionPolicyCore;
  43 }  // namespace extensions
  44
  45 class BasePrincipal;
  46
  47 // Content principals (and content principals embedded within expanded
  48 // principals) stored in SiteIdentifier are guaranteed to contain only the
  49 // eTLD+1 part of the original domain. This is used to determine whether two
  50 // origins are same-site: if it's possible for two origins to access each other
  51 // (maybe after mutating document.domain), then they must have the same site
  52 // identifier.
  53 class SiteIdentifier {
  54  public:
  55   void Init(BasePrincipal* aPrincipal) {
  56     MOZ_ASSERT(aPrincipal);
  57     mPrincipal = aPrincipal;
  58   }
  59
  60   bool IsInitialized() const { return !!mPrincipal; }
  61
  62   bool Equals(const SiteIdentifier& aOther) const;
  63
  64  private:
  65   friend class ::ExpandedPrincipal;
  66
  67   BasePrincipal* GetPrincipal() const {
  68     MOZ_ASSERT(IsInitialized());
  69     return mPrincipal;
  70   }
  71
  72   RefPtr<BasePrincipal> mPrincipal;
  73 };
  74
  75 /*
  76  * Base class from which all nsIPrincipal implementations inherit. Use this for
  77  * default implementations and other commonalities between principal
  78  * implementations.
  79  *
  80  * We should merge nsJSPrincipals into this class at some point.
  81  */
  82 class BasePrincipal : public nsJSPrincipals {
  83  public:
  84   // Warning: this enum impacts Principal serialization into JSON format.
  85   // Only update if you know exactly what you are doing
  86   enum PrincipalKind {
  87     eNullPrincipal = 0,
  88     eContentPrincipal,
  89     eExpandedPrincipal,
  90     eSystemPrincipal,
  91     eKindMax = eSystemPrincipal
  92   };
  93
  94   template <typename T>
  95   bool Is() const {
  96     return mKind == T::Kind();
  97   }
  98
  99   template <typename T>
 100   T* As() {
 101     MOZ_ASSERT(Is<T>());
 102     return static_cast<T*>(this);
 103   }
 104
 105   enum DocumentDomainConsideration {
 106     DontConsiderDocumentDomain,
 107     ConsiderDocumentDomain
 108   };
 109   bool Subsumes(nsIPrincipal* aOther,
 110                 DocumentDomainConsideration aConsideration);
 111
 112   NS_IMETHOD GetOrigin(nsACString& aOrigin) final;
 113   NS_IMETHOD GetAsciiOrigin(nsACString& aOrigin) override;
 114   NS_IMETHOD GetOriginNoSuffix(nsACString& aOrigin) final;
 115   NS_IMETHOD Equals(nsIPrincipal* other, bool* _retval) final;
 116   NS_IMETHOD EqualsConsideringDomain(nsIPrincipal* other, bool* _retval) final;
 117   NS_IMETHOD EqualsURI(nsIURI* aOtherURI, bool* _retval) override;
 118   NS_IMETHOD EqualsForPermission(nsIPrincipal* other, bool aExactHost,
 119                                  bool* _retval) final;
 120   NS_IMETHOD Subsumes(nsIPrincipal* other, bool* _retval) final;
 121   NS_IMETHOD SubsumesConsideringDomain(nsIPrincipal* other,
 122                                        bool* _retval) final;
 123   NS_IMETHOD SubsumesConsideringDomainIgnoringFPD(nsIPrincipal* other,
 124                                                   bool* _retval) final;
 125   NS_IMETHOD CheckMayLoad(nsIURI* uri, bool allowIfInheritsPrincipal) final;
 126   NS_IMETHOD CheckMayLoadWithReporting(nsIURI* uri,
 127                                        bool allowIfInheritsPrincipal,
 128                                        uint64_t innerWindowID) final;
 129   NS_IMETHOD GetAddonPolicy(extensions::WebExtensionPolicy** aResult) final;
 130   NS_IMETHOD GetContentScriptAddonPolicy(
 131       extensions::WebExtensionPolicy** aResult) final;
 132   NS_IMETHOD GetIsNullPrincipal(bool* aResult) override;
 133   NS_IMETHOD GetIsContentPrincipal(bool* aResult) override;
 134   NS_IMETHOD GetIsExpandedPrincipal(bool* aResult) override;
 135   NS_IMETHOD GetIsSystemPrincipal(bool* aResult) override;
 136   NS_IMETHOD GetScheme(nsACString& aScheme) override;
 137   NS_IMETHOD SchemeIs(const char* aScheme, bool* aResult) override;
 138   NS_IMETHOD IsURIInPrefList(const char* aPref, bool* aResult) override;
 139   NS_IMETHOD IsURIInList(const nsACString& aList, bool* aResult) override;
 140   NS_IMETHOD IsL10nAllowed(nsIURI* aURI, bool* aResult) override;
 141   NS_IMETHOD GetAboutModuleFlags(uint32_t* flags) override;
 142   NS_IMETHOD GetIsAddonOrExpandedAddonPrincipal(bool* aResult) override;
 143   NS_IMETHOD GetOriginAttributes(JSContext* aCx,
 144                                  JS::MutableHandle<JS::Value> aVal) final;
 145   NS_IMETHOD GetAsciiSpec(nsACString& aSpec) override;
 146   NS_IMETHOD GetSpec(nsACString& aSpec) override;
 147   NS_IMETHOD GetExposablePrePath(nsACString& aResult) override;
 148   NS_IMETHOD GetExposableSpec(nsACString& aSpec) override;
 149   NS_IMETHOD GetHostPort(nsACString& aRes) override;
 150   NS_IMETHOD GetHost(nsACString& aRes) override;
 151   NS_IMETHOD GetPrePath(nsACString& aResult) override;
 152   NS_IMETHOD GetFilePath(nsACString& aResult) override;
 153   NS_IMETHOD GetOriginSuffix(nsACString& aOriginSuffix) final;
 154   NS_IMETHOD GetIsIpAddress(bool* aIsIpAddress) override;
 155   NS_IMETHOD GetIsLocalIpAddress(bool* aIsIpAddress) override;
 156   NS_IMETHOD GetIsOnion(bool* aIsOnion) override;
 157   NS_IMETHOD GetIsInIsolatedMozBrowserElement(
 158       bool* aIsInIsolatedMozBrowserElement) final;
 159   NS_IMETHOD GetUserContextId(uint32_t* aUserContextId) final;
 160   NS_IMETHOD GetPrivateBrowsingId(uint32_t* aPrivateBrowsingId) final;
 161   NS_IMETHOD GetSiteOrigin(nsACString& aSiteOrigin) final;
 162   NS_IMETHOD GetSiteOriginNoSuffix(nsACString& aSiteOrigin) override;
 163   NS_IMETHOD IsThirdPartyURI(nsIURI* uri, bool* aRes) override;
 164   NS_IMETHOD IsThirdPartyPrincipal(nsIPrincipal* uri, bool* aRes) override;
 165   NS_IMETHOD IsThirdPartyChannel(nsIChannel* aChannel, bool* aRes) override;
 166   NS_IMETHOD GetIsOriginPotentiallyTrustworthy(bool* aResult) override;
 167   NS_IMETHOD GetIsLoopbackHost(bool* aResult) override;
 168   NS_IMETHOD IsSameOrigin(nsIURI* aURI, bool* aRes) override;
 169   NS_IMETHOD GetPrefLightCacheKey(nsIURI* aURI, bool aWithCredentials,
 170                                   const OriginAttributes& aOriginAttributes,
 171                                   nsACString& _retval) override;
 172   NS_IMETHOD HasFirstpartyStorageAccess(mozIDOMWindow* aCheckWindow,
 173                                         uint32_t* aRejectedReason,
 174                                         bool* aOutAllowed) override;
 175   NS_IMETHOD GetAsciiHost(nsACString& aAsciiHost) override;
 176   NS_IMETHOD GetLocalStorageQuotaKey(nsACString& aRes) override;
 177   NS_IMETHOD AllowsRelaxStrictFileOriginPolicy(nsIURI* aURI,
 178                                                bool* aRes) override;
 179   NS_IMETHOD CreateReferrerInfo(mozilla::dom::ReferrerPolicy aReferrerPolicy,
 180                                 nsIReferrerInfo** _retval) override;
 181   NS_IMETHOD GetIsScriptAllowedByPolicy(
 182       bool* aIsScriptAllowedByPolicy) override;
 183   NS_IMETHOD GetStorageOriginKey(nsACString& aOriginKey) override;
 184
 185   NS_IMETHOD GetNextSubDomainPrincipal(
 186       nsIPrincipal** aNextSubDomainPrincipal) override;
 187
 188   NS_IMETHOD GetPrecursorPrincipal(nsIPrincipal** aPrecursor) override;
 189
 190   nsresult ToJSON(nsACString& aJSON);
 191   nsresult ToJSON(Json::Value& aObject);
 192
 193   static already_AddRefed<BasePrincipal> FromJSON(const nsACString& aJSON);
 194   static already_AddRefed<BasePrincipal> FromJSON(const Json::Value& aJSON);
 195   // Method populates a passed Json::Value with serializable fields
 196   // which represent all of the fields to deserialize the principal
 197   virtual nsresult PopulateJSONObject(Json::Value& aObject);
 198
 199   virtual bool AddonHasPermission(const nsAtom* aPerm);
 200
 201   virtual bool IsContentPrincipal() const { return false; };
 202
 203   static BasePrincipal* Cast(nsIPrincipal* aPrin) {
 204     return static_cast<BasePrincipal*>(aPrin);
 205   }
 206
 207   static BasePrincipal& Cast(nsIPrincipal& aPrin) {
 208     return *static_cast<BasePrincipal*>(&aPrin);
 209   }
 210
 211   static const BasePrincipal* Cast(const nsIPrincipal* aPrin) {
 212     return static_cast<const BasePrincipal*>(aPrin);
 213   }
 214
 215   static const BasePrincipal& Cast(const nsIPrincipal& aPrin) {
 216     return *static_cast<const BasePrincipal*>(&aPrin);
 217   }
 218
 219   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 220       const nsACString& aOrigin);
 221
 222   // This method may not create a content principal in case it's not possible to
 223   // generate a correct origin from the passed URI. If this happens, a
 224   // NullPrincipal is returned.
 225   //
 226   // If `aInitialDomain` is specified, and a ContentPrincipal is set, it will
 227   // initially have its domain set to the given value, without re-computing js
 228   // wrappers. Unlike `SetDomain()` this is safe to do off-main-thread.
 229
 230   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 231       nsIURI* aURI, const OriginAttributes& aAttrs,
 232       nsIURI* aInitialDomain = nullptr);
 233
 234   const OriginAttributes& OriginAttributesRef() final {
 235     return mOriginAttributes;
 236   }
 237   extensions::WebExtensionPolicy* AddonPolicy();
 238   RefPtr<extensions::WebExtensionPolicyCore> AddonPolicyCore();
 239   uint32_t UserContextId() const { return mOriginAttributes.mUserContextId; }
 240   uint32_t PrivateBrowsingId() const {
 241     return mOriginAttributes.mPrivateBrowsingId;
 242   }
 243   bool IsInIsolatedMozBrowserElement() const {
 244     return mOriginAttributes.mInIsolatedMozBrowser;
 245   }
 246
 247   PrincipalKind Kind() const { return mKind; }
 248
 249   already_AddRefed<BasePrincipal> CloneForcingOriginAttributes(
 250       const OriginAttributes& aOriginAttributes);
 251
 252   // If this is an add-on content script principal, returns its AddonPolicy.
 253   // Otherwise returns null.
 254   extensions::WebExtensionPolicy* ContentScriptAddonPolicy();
 255   RefPtr<extensions::WebExtensionPolicyCore> ContentScriptAddonPolicyCore();
 256
 257   // Helper to check whether this principal is associated with an addon that
 258   // allows unprivileged code to load aURI.  aExplicit == true will prevent
 259   // use of all_urls permission, requiring the domain in its permissions.
 260   bool AddonAllowsLoad(nsIURI* aURI, bool aExplicit = false);
 261
 262   // Call these to avoid the cost of virtual dispatch.
 263   inline bool FastEquals(nsIPrincipal* aOther);
 264   inline bool FastEqualsConsideringDomain(nsIPrincipal* aOther);
 265   inline bool FastSubsumes(nsIPrincipal* aOther);
 266   inline bool FastSubsumesConsideringDomain(nsIPrincipal* aOther);
 267   inline bool FastSubsumesIgnoringFPD(nsIPrincipal* aOther);
 268   inline bool FastSubsumesConsideringDomainIgnoringFPD(nsIPrincipal* aOther);
 269
 270   // Fast way to check whether we have a system principal.
 271   inline bool IsSystemPrincipal() const;
 272
 273   // Returns the principal to inherit when a caller with this principal loads
 274   // the given URI.
 275   //
 276   // For most principal types, this returns the principal itself. For expanded
 277   // principals, it returns the first sub-principal which subsumes the given URI
 278   // (or, if no URI is given, the last allowlist principal).
 279   nsIPrincipal* PrincipalToInherit(nsIURI* aRequestedURI = nullptr);
 280
 281   /* Returns true if this principal's CSP should override a document's CSP for
 282    * loads that it triggers. Currently true for expanded principals which
 283    * subsume the document principal, and add-on content principals regardless
 284    * of whether they subsume the document principal.
 285    */
 286   bool OverridesCSP(nsIPrincipal* aDocumentPrincipal);
 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   //
 310   // Safe to call from any thread, unlike CheckMayLoad.
 311   virtual bool MayLoadInternal(nsIURI* aURI) = 0;
 312   friend class ::ExpandedPrincipal;
 313
 314   // Helper for implementing CheckMayLoad and CheckMayLoadWithReporting.
 315   nsresult CheckMayLoadHelper(nsIURI* aURI, bool aAllowIfInheritsPrincipal,
 316                               bool aReport, uint64_t aInnerWindowID);
 317
 318   void SetHasExplicitDomain() { mHasExplicitDomain = true; }
 319   bool GetHasExplicitDomain() { return mHasExplicitDomain; }
 320
 321   // KeyValT holds a principal subtype-specific key value and the associated
 322   // parsed value after JSON parsing.
 323   template <typename SerializedKey>
 324   struct KeyValT {
 325     static_assert(sizeof(SerializedKey) == 1,
 326                   "SerializedKey should be a uint8_t");
 327     SerializedKey key;
 328     bool valueWasSerialized;
 329     nsCString value;
 330   };
 331
 332   // Common base class for all Deserializer implementations in concrete
 333   // subclasses. Subclasses will initialize `mPrincipal` in `Read`, and then
 334   // calls to `QueryInterface` will QI on the target object.
 335   class Deserializer : public nsISerializable {
 336    public:
 337     NS_DECL_ISUPPORTS
 338     NS_IMETHOD Write(nsIObjectOutputStream* aStream) override;
 339
 340    protected:
 341     virtual ~Deserializer() = default;
 342     RefPtr<BasePrincipal> mPrincipal;
 343   };
 344
 345  private:
 346   static const char* JSONEnumKeyStrings[4];
 347
 348   static void SetJSONValue(Json::Value& aObject, const char* aKey,
 349                            const nsCString& aValue);
 350
 351  protected:
 352   template <size_t EnumValue>
 353   static inline constexpr const char* JSONEnumKeyString() {
 354     static_assert(EnumValue < ArrayLength(JSONEnumKeyStrings));
 355     return JSONEnumKeyStrings[EnumValue];
 356   }
 357   template <size_t EnumValue>
 358   static void SetJSONValue(Json::Value& aObject, const nsCString& aValue) {
 359     SetJSONValue(aObject, JSONEnumKeyString<EnumValue>(), aValue);
 360   }
 361
 362  private:
 363   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 364       nsIURI* aURI, const OriginAttributes& aAttrs,
 365       const nsACString& aOriginNoSuffix, nsIURI* aInitialDomain);
 366
 367   bool FastSubsumesIgnoringFPD(nsIPrincipal* aOther,
 368                                DocumentDomainConsideration aConsideration);
 369
 370   const RefPtr<nsAtom> mOriginNoSuffix;
 371   const RefPtr<nsAtom> mOriginSuffix;
 372
 373   const OriginAttributes mOriginAttributes;
 374   const PrincipalKind mKind;
 375   std::atomic<bool> mHasExplicitDomain;
 376 };
 377
 378 inline bool BasePrincipal::FastEquals(nsIPrincipal* aOther) {
 379   MOZ_ASSERT(aOther);
 380
 381   auto other = Cast(aOther);
 382   if (Kind() != other->Kind()) {
 383     // Principals of different kinds can't be equal.
 384     return false;
 385   }
 386
 387   // Two principals are considered to be equal if their origins are the same.
 388   // If the two principals are content principals, their origin attributes
 389   // (aka the origin suffix) must also match.
 390   if (Kind() == eSystemPrincipal) {
 391     return this == other;
 392   }
 393
 394   if (Kind() == eContentPrincipal || Kind() == eNullPrincipal) {
 395     return mOriginNoSuffix == other->mOriginNoSuffix &&
 396            mOriginSuffix == other->mOriginSuffix;
 397   }
 398
 399   MOZ_ASSERT(Kind() == eExpandedPrincipal);
 400   return mOriginNoSuffix == other->mOriginNoSuffix;
 401 }
 402
 403 inline bool BasePrincipal::FastEqualsConsideringDomain(nsIPrincipal* aOther) {
 404   MOZ_ASSERT(aOther);
 405
 406   // If neither of the principals have document.domain set, we use the fast path
 407   // in Equals().  Otherwise, we fall back to the slow path below.
 408   auto other = Cast(aOther);
 409   if (!mHasExplicitDomain && !other->mHasExplicitDomain) {
 410     return FastEquals(aOther);
 411   }
 412
 413   // Principals of different kinds can't be equal.
 414   if (Kind() != other->Kind()) {
 415     return false;
 416   }
 417
 418   // Only ContentPrincipals should have mHasExplicitDomain set to true, so test
 419   // that we haven't ended up here instead of FastEquals by mistake.
 420   MOZ_ASSERT(IsContentPrincipal(),
 421              "Only content principals can set mHasExplicitDomain");
 422
 423   return Subsumes(aOther, ConsiderDocumentDomain) &&
 424          other->Subsumes(this, ConsiderDocumentDomain);
 425 }
 426
 427 inline bool BasePrincipal::FastSubsumes(nsIPrincipal* aOther) {
 428   MOZ_ASSERT(aOther);
 429
 430   // If two principals are equal, then they both subsume each other.
 431   if (FastEquals(aOther)) {
 432     return true;
 433   }
 434
 435   // Otherwise, fall back to the slow path.
 436   return Subsumes(aOther, DontConsiderDocumentDomain);
 437 }
 438
 439 inline bool BasePrincipal::FastSubsumesConsideringDomain(nsIPrincipal* aOther) {
 440   MOZ_ASSERT(aOther);
 441
 442   // If neither of the principals have document.domain set, we hand off to
 443   // FastSubsumes() which has fast paths for some special cases. Otherwise, we
 444   // fall back to the slow path below.
 445   if (!mHasExplicitDomain && !Cast(aOther)->mHasExplicitDomain) {
 446     return FastSubsumes(aOther);
 447   }
 448
 449   return Subsumes(aOther, ConsiderDocumentDomain);
 450 }
 451
 452 inline bool BasePrincipal::FastSubsumesIgnoringFPD(nsIPrincipal* aOther) {
 453   return FastSubsumesIgnoringFPD(aOther, DontConsiderDocumentDomain);
 454 }
 455
 456 inline bool BasePrincipal::FastSubsumesConsideringDomainIgnoringFPD(
 457     nsIPrincipal* aOther) {
 458   return FastSubsumesIgnoringFPD(aOther, ConsiderDocumentDomain);
 459 }
 460
 461 inline bool BasePrincipal::IsSystemPrincipal() const {
 462   return Kind() == eSystemPrincipal;
 463 }
 464
 465 }  // namespace mozilla
 466
 467 inline bool nsIPrincipal::IsSystemPrincipal() const {
 468   return mozilla::BasePrincipal::Cast(this)->IsSystemPrincipal();
 469 }
 470
 471 #endif /* mozilla_BasePrincipal_h */