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 IsL10nAllowed(nsIURI* aURI, bool* aResult) override;
 137   NS_IMETHOD GetAboutModuleFlags(uint32_t* flags) override;
 138   NS_IMETHOD GetIsAddonOrExpandedAddonPrincipal(bool* aResult) override;
 139   NS_IMETHOD GetOriginAttributes(JSContext* aCx,
 140                                  JS::MutableHandle<JS::Value> aVal) final;
 141   NS_IMETHOD GetAsciiSpec(nsACString& aSpec) override;
 142   NS_IMETHOD GetSpec(nsACString& aSpec) override;
 143   NS_IMETHOD GetExposablePrePath(nsACString& aResult) override;
 144   NS_IMETHOD GetExposableSpec(nsACString& aSpec) override;
 145   NS_IMETHOD GetHostPort(nsACString& aRes) override;
 146   NS_IMETHOD GetHost(nsACString& aRes) override;
 147   NS_IMETHOD GetPrePath(nsACString& aResult) override;
 148   NS_IMETHOD GetFilePath(nsACString& aResult) override;
 149   NS_IMETHOD GetOriginSuffix(nsACString& aOriginSuffix) final;
 150   NS_IMETHOD GetIsIpAddress(bool* aIsIpAddress) override;
 151   NS_IMETHOD GetIsLocalIpAddress(bool* aIsIpAddress) override;
 152   NS_IMETHOD GetIsOnion(bool* aIsOnion) override;
 153   NS_IMETHOD GetIsInIsolatedMozBrowserElement(
 154       bool* aIsInIsolatedMozBrowserElement) final;
 155   NS_IMETHOD GetUserContextId(uint32_t* aUserContextId) final;
 156   NS_IMETHOD GetPrivateBrowsingId(uint32_t* aPrivateBrowsingId) final;
 157   NS_IMETHOD GetSiteOrigin(nsACString& aSiteOrigin) final;
 158   NS_IMETHOD GetSiteOriginNoSuffix(nsACString& aSiteOrigin) override;
 159   NS_IMETHOD IsThirdPartyURI(nsIURI* uri, bool* aRes) override;
 160   NS_IMETHOD IsThirdPartyPrincipal(nsIPrincipal* uri, bool* aRes) override;
 161   NS_IMETHOD IsThirdPartyChannel(nsIChannel* aChannel, bool* aRes) override;
 162   NS_IMETHOD GetIsOriginPotentiallyTrustworthy(bool* aResult) override;
 163   NS_IMETHOD IsSameOrigin(nsIURI* aURI, bool aIsPrivateWin,
 164                           bool* aRes) override;
 165   NS_IMETHOD GetPrefLightCacheKey(nsIURI* aURI, bool aWithCredentials,
 166                                   const OriginAttributes& aOriginAttributes,
 167                                   nsACString& _retval) override;
 168   NS_IMETHOD HasFirstpartyStorageAccess(mozIDOMWindow* aCheckWindow,
 169                                         uint32_t* aRejectedReason,
 170                                         bool* aOutAllowed) override;
 171   NS_IMETHOD GetAsciiHost(nsACString& aAsciiHost) override;
 172   NS_IMETHOD GetLocalStorageQuotaKey(nsACString& aRes) override;
 173   NS_IMETHOD AllowsRelaxStrictFileOriginPolicy(nsIURI* aURI,
 174                                                bool* aRes) override;
 175   NS_IMETHOD CreateReferrerInfo(mozilla::dom::ReferrerPolicy aReferrerPolicy,
 176                                 nsIReferrerInfo** _retval) override;
 177   NS_IMETHOD GetIsScriptAllowedByPolicy(
 178       bool* aIsScriptAllowedByPolicy) override;
 179   NS_IMETHOD GetStorageOriginKey(nsACString& aOriginKey) override;
 180
 181   NS_IMETHOD GetNextSubDomainPrincipal(
 182       nsIPrincipal** aNextSubDomainPrincipal) override;
 183
 184   NS_IMETHOD GetPrecursorPrincipal(nsIPrincipal** aPrecursor) override;
 185
 186   nsresult ToJSON(nsACString& aJSON);
 187   static already_AddRefed<BasePrincipal> FromJSON(const nsACString& aJSON);
 188   // Method populates a passed Json::Value with serializable fields
 189   // which represent all of the fields to deserialize the principal
 190   virtual nsresult PopulateJSONObject(Json::Value& aObject);
 191
 192   virtual bool AddonHasPermission(const nsAtom* aPerm);
 193
 194   virtual bool IsContentPrincipal() const { return false; };
 195
 196   static BasePrincipal* Cast(nsIPrincipal* aPrin) {
 197     return static_cast<BasePrincipal*>(aPrin);
 198   }
 199
 200   static BasePrincipal& Cast(nsIPrincipal& aPrin) {
 201     return *static_cast<BasePrincipal*>(&aPrin);
 202   }
 203
 204   static const BasePrincipal* Cast(const nsIPrincipal* aPrin) {
 205     return static_cast<const BasePrincipal*>(aPrin);
 206   }
 207
 208   static const BasePrincipal& Cast(const nsIPrincipal& aPrin) {
 209     return *static_cast<const BasePrincipal*>(&aPrin);
 210   }
 211
 212   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 213       const nsACString& aOrigin);
 214
 215   // These following method may not create a content principal in case it's
 216   // not possible to generate a correct origin from the passed URI. If this
 217   // happens, a NullPrincipal is returned.
 218
 219   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 220       nsIURI* aURI, const OriginAttributes& aAttrs);
 221
 222   const OriginAttributes& OriginAttributesRef() final {
 223     return mOriginAttributes;
 224   }
 225   extensions::WebExtensionPolicy* AddonPolicy();
 226   uint32_t UserContextId() const { return mOriginAttributes.mUserContextId; }
 227   uint32_t PrivateBrowsingId() const {
 228     return mOriginAttributes.mPrivateBrowsingId;
 229   }
 230   bool IsInIsolatedMozBrowserElement() const {
 231     return mOriginAttributes.mInIsolatedMozBrowser;
 232   }
 233
 234   PrincipalKind Kind() const { return mKind; }
 235
 236   already_AddRefed<BasePrincipal> CloneForcingOriginAttributes(
 237       const OriginAttributes& aOriginAttributes);
 238
 239   // If this is an add-on content script principal, returns its AddonPolicy.
 240   // Otherwise returns null.
 241   extensions::WebExtensionPolicy* ContentScriptAddonPolicy();
 242
 243   // Helper to check whether this principal is associated with an addon that
 244   // allows unprivileged code to load aURI.  aExplicit == true will prevent
 245   // use of all_urls permission, requiring the domain in its permissions.
 246   bool AddonAllowsLoad(nsIURI* aURI, bool aExplicit = false);
 247
 248   // Call these to avoid the cost of virtual dispatch.
 249   inline bool FastEquals(nsIPrincipal* aOther);
 250   inline bool FastEqualsConsideringDomain(nsIPrincipal* aOther);
 251   inline bool FastSubsumes(nsIPrincipal* aOther);
 252   inline bool FastSubsumesConsideringDomain(nsIPrincipal* aOther);
 253   inline bool FastSubsumesIgnoringFPD(nsIPrincipal* aOther);
 254   inline bool FastSubsumesConsideringDomainIgnoringFPD(nsIPrincipal* aOther);
 255
 256   // Fast way to check whether we have a system principal.
 257   inline bool IsSystemPrincipal() const;
 258
 259   // Returns the principal to inherit when a caller with this principal loads
 260   // the given URI.
 261   //
 262   // For most principal types, this returns the principal itself. For expanded
 263   // principals, it returns the first sub-principal which subsumes the given URI
 264   // (or, if no URI is given, the last allowlist principal).
 265   nsIPrincipal* PrincipalToInherit(nsIURI* aRequestedURI = nullptr);
 266
 267   /* Returns true if this principal's CSP should override a document's CSP for
 268    * loads that it triggers. Currently true for expanded principals which
 269    * subsume the document principal, and add-on content principals regardless
 270    * of whether they subsume the document principal.
 271    */
 272   bool OverridesCSP(nsIPrincipal* aDocumentPrincipal) {
 273     MOZ_ASSERT(aDocumentPrincipal);
 274
 275     // Expanded principals override CSP if and only if they subsume the document
 276     // principal.
 277     if (mKind == eExpandedPrincipal) {
 278       return FastSubsumes(aDocumentPrincipal);
 279     }
 280     // Extension principals always override the CSP non-extension principals.
 281     // This is primarily for the sake of their stylesheets, which are usually
 282     // loaded from channels and cannot have expanded principals.
 283     return (AddonPolicy() &&
 284             !BasePrincipal::Cast(aDocumentPrincipal)->AddonPolicy());
 285   }
 286
 287   uint32_t GetOriginNoSuffixHash() const { return mOriginNoSuffix->hash(); }
 288   uint32_t GetOriginSuffixHash() const { return mOriginSuffix->hash(); }
 289
 290   virtual nsresult GetSiteIdentifier(SiteIdentifier& aSite) = 0;
 291
 292  protected:
 293   BasePrincipal(PrincipalKind aKind, const nsACString& aOriginNoSuffix,
 294                 const OriginAttributes& aOriginAttributes);
 295   BasePrincipal(BasePrincipal* aOther,
 296                 const OriginAttributes& aOriginAttributes);
 297
 298   virtual ~BasePrincipal();
 299
 300   // Note that this does not check OriginAttributes. Callers that depend on
 301   // those must call Subsumes instead.
 302   virtual bool SubsumesInternal(nsIPrincipal* aOther,
 303                                 DocumentDomainConsideration aConsider) = 0;
 304
 305   // Internal, side-effect-free check to determine whether the concrete
 306   // principal would allow the load ignoring any common behavior implemented in
 307   // BasePrincipal::CheckMayLoad.
 308   virtual bool MayLoadInternal(nsIURI* aURI) = 0;
 309   friend class ::ExpandedPrincipal;
 310
 311   // Helper for implementing CheckMayLoad and CheckMayLoadWithReporting.
 312   nsresult CheckMayLoadHelper(nsIURI* aURI, bool aAllowIfInheritsPrincipal,
 313                               bool aReport, uint64_t aInnerWindowID);
 314
 315   void SetHasExplicitDomain() { mHasExplicitDomain = true; }
 316
 317   // KeyValT holds a principal subtype-specific key value and the associated
 318   // parsed value after JSON parsing.
 319   template <typename SerializedKey>
 320   struct KeyValT {
 321     static_assert(sizeof(SerializedKey) == 1,
 322                   "SerializedKey should be a uint8_t");
 323     SerializedKey key;
 324     bool valueWasSerialized;
 325     nsCString value;
 326   };
 327
 328   // Common base class for all Deserializer implementations in concrete
 329   // subclasses. Subclasses will initialize `mPrincipal` in `Read`, and then
 330   // calls to `QueryInterface` will QI on the target object.
 331   class Deserializer : public nsISerializable {
 332    public:
 333     NS_DECL_ISUPPORTS
 334     NS_IMETHOD Write(nsIObjectOutputStream* aStream) override;
 335
 336    protected:
 337     virtual ~Deserializer() = default;
 338     RefPtr<BasePrincipal> mPrincipal;
 339   };
 340
 341  private:
 342   static already_AddRefed<BasePrincipal> CreateContentPrincipal(
 343       nsIURI* aURI, const OriginAttributes& aAttrs,
 344       const nsACString& aOriginNoSuffix);
 345
 346   bool FastSubsumesIgnoringFPD(nsIPrincipal* aOther,
 347                                DocumentDomainConsideration aConsideration);
 348
 349   const RefPtr<nsAtom> mOriginNoSuffix;
 350   const RefPtr<nsAtom> mOriginSuffix;
 351
 352   const OriginAttributes mOriginAttributes;
 353   const PrincipalKind mKind;
 354   bool mHasExplicitDomain;
 355 };
 356
 357 inline bool BasePrincipal::FastEquals(nsIPrincipal* aOther) {
 358   MOZ_ASSERT(aOther);
 359
 360   auto other = Cast(aOther);
 361   if (Kind() != other->Kind()) {
 362     // Principals of different kinds can't be equal.
 363     return false;
 364   }
 365
 366   // Two principals are considered to be equal if their origins are the same.
 367   // If the two principals are content principals, their origin attributes
 368   // (aka the origin suffix) must also match.
 369   if (Kind() == eSystemPrincipal) {
 370     return this == other;
 371   }
 372
 373   if (Kind() == eContentPrincipal || Kind() == eNullPrincipal) {
 374     return mOriginNoSuffix == other->mOriginNoSuffix &&
 375            mOriginSuffix == other->mOriginSuffix;
 376   }
 377
 378   MOZ_ASSERT(Kind() == eExpandedPrincipal);
 379   return mOriginNoSuffix == other->mOriginNoSuffix;
 380 }
 381
 382 inline bool BasePrincipal::FastEqualsConsideringDomain(nsIPrincipal* aOther) {
 383   MOZ_ASSERT(aOther);
 384
 385   // If neither of the principals have document.domain set, we use the fast path
 386   // in Equals().  Otherwise, we fall back to the slow path below.
 387   auto other = Cast(aOther);
 388   if (!mHasExplicitDomain && !other->mHasExplicitDomain) {
 389     return FastEquals(aOther);
 390   }
 391
 392   return Subsumes(aOther, ConsiderDocumentDomain) &&
 393          other->Subsumes(this, ConsiderDocumentDomain);
 394 }
 395
 396 inline bool BasePrincipal::FastSubsumes(nsIPrincipal* aOther) {
 397   MOZ_ASSERT(aOther);
 398
 399   // If two principals are equal, then they both subsume each other.
 400   if (FastEquals(aOther)) {
 401     return true;
 402   }
 403
 404   // Otherwise, fall back to the slow path.
 405   return Subsumes(aOther, DontConsiderDocumentDomain);
 406 }
 407
 408 inline bool BasePrincipal::FastSubsumesConsideringDomain(nsIPrincipal* aOther) {
 409   MOZ_ASSERT(aOther);
 410
 411   // If neither of the principals have document.domain set, we hand off to
 412   // FastSubsumes() which has fast paths for some special cases. Otherwise, we
 413   // fall back to the slow path below.
 414   if (!mHasExplicitDomain && !Cast(aOther)->mHasExplicitDomain) {
 415     return FastSubsumes(aOther);
 416   }
 417
 418   return Subsumes(aOther, ConsiderDocumentDomain);
 419 }
 420
 421 inline bool BasePrincipal::FastSubsumesIgnoringFPD(nsIPrincipal* aOther) {
 422   return FastSubsumesIgnoringFPD(aOther, DontConsiderDocumentDomain);
 423 }
 424
 425 inline bool BasePrincipal::FastSubsumesConsideringDomainIgnoringFPD(
 426     nsIPrincipal* aOther) {
 427   return FastSubsumesIgnoringFPD(aOther, ConsiderDocumentDomain);
 428 }
 429
 430 inline bool BasePrincipal::IsSystemPrincipal() const {
 431   return Kind() == eSystemPrincipal;
 432 }
 433
 434 }  // namespace mozilla
 435
 436 inline bool nsIPrincipal::IsSystemPrincipal() const {
 437   return mozilla::BasePrincipal::Cast(this)->IsSystemPrincipal();
 438 }
 439
 440 #endif /* mozilla_BasePrincipal_h */