/*
 * Copyright (C) 2007, 2008 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
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 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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 */

#ifndef SecurityOrigin_h
#define SecurityOrigin_h

#include <wtf/ThreadSafeRefCounted.h>
#include <wtf/text/WTFString.h>

namespace WebCore {

class URL;

class SecurityOrigin : public ThreadSafeRefCounted<SecurityOrigin> {
public:
    enum Policy {
        AlwaysDeny = 0,
        AlwaysAllow,
        Ask
    };

    enum StorageBlockingPolicy {
        AllowAllStorage = 0,
        BlockThirdPartyStorage,
        BlockAllStorage
    };

    static PassRefPtr<SecurityOrigin> create(const URL&);
    static PassRefPtr<SecurityOrigin> createUnique();

    static PassRefPtr<SecurityOrigin> createFromDatabaseIdentifier(const String&);
    static PassRefPtr<SecurityOrigin> createFromString(const String&);
    static PassRefPtr<SecurityOrigin> create(const String& protocol, const String& host, int port);

    // Some URL schemes use nested URLs for their security context. For example,
    // filesystem URLs look like the following:
    //
    //   filesystem:http://example.com/temporary/path/to/file.png
    //
    // We're supposed to use "http://example.com" as the origin.
    //
    // Generally, we add URL schemes to this list when WebKit support them. For
    // example, we don't include the "jar" scheme, even though Firefox
    // understands that "jar" uses an inner URL for it's security origin.
    static bool shouldUseInnerURL(const URL&);
    static URL extractInnerURL(const URL&);

    // Create a deep copy of this SecurityOrigin. This method is useful
    // when marshalling a SecurityOrigin to another thread.
    PassRefPtr<SecurityOrigin> isolatedCopy() const;

    // Set the domain property of this security origin to newDomain. This
    // function does not check whether newDomain is a suffix of the current
    // domain. The caller is responsible for validating newDomain.
    void setDomainFromDOM(const String& newDomain);
    bool domainWasSetInDOM() const { return m_domainWasSetInDOM; }

    String protocol() const { return m_protocol; }
    String host() const { return m_host; }
    String domain() const { return m_domain; }
    unsigned short port() const { return m_port; }

    // Returns true if a given URL is secure, based either directly on its
    // own protocol, or, when relevant, on the protocol of its "inner URL"
    // Protocols like blob: and filesystem: fall into this latter category.
    static bool isSecure(const URL&);

    // Returns true if this SecurityOrigin can script objects in the given
    // SecurityOrigin. For example, call this function before allowing
    // script from one security origin to read or write objects from
    // another SecurityOrigin.
    bool canAccess(const SecurityOrigin*) const;

    // Returns true if this SecurityOrigin can read content retrieved from
    // the given URL. For example, call this function before issuing
    // XMLHttpRequests.
    bool canRequest(const URL&) const;

    // Returns true if drawing an image from this URL taints a canvas from
    // this security origin. For example, call this function before
    // drawing an image onto an HTML canvas element with the drawImage API.
    bool taintsCanvas(const URL&) const;

    // Returns true if this SecurityOrigin can receive drag content from the
    // initiator. For example, call this function before allowing content to be
    // dropped onto a target.
    bool canReceiveDragData(const SecurityOrigin* dragInitiator) const;    

    // Returns true if |document| can display content from the given URL (e.g.,
    // in an iframe or as an image). For example, web sites generally cannot
    // display content from the user's files system.
    bool canDisplay(const URL&) const;

    // Returns true if this SecurityOrigin can load local resources, such
    // as images, iframes, and style sheets, and can link to local URLs.
    // For example, call this function before creating an iframe to a
    // file:// URL.
    //
    // Note: A SecurityOrigin might be allowed to load local resources
    //       without being able to issue an XMLHttpRequest for a local URL.
    //       To determine whether the SecurityOrigin can issue an
    //       XMLHttpRequest for a URL, call canRequest(url).
    bool canLoadLocalResources() const { return m_canLoadLocalResources; }

    // Explicitly grant the ability to load local resources to this
    // SecurityOrigin.
    //
    // Note: This method exists only to support backwards compatibility
    //       with older versions of WebKit.
    void grantLoadLocalResources();

    // Explicitly grant the ability to access very other SecurityOrigin.
    //
    // WARNING: This is an extremely powerful ability. Use with caution!
    void grantUniversalAccess();

    void setStorageBlockingPolicy(StorageBlockingPolicy policy) { m_storageBlockingPolicy = policy; }

#if ENABLE(CACHE_PARTITIONING)
    String cachePartition() const;
#endif

    bool canAccessDatabase(const SecurityOrigin* topOrigin = 0) const { return canAccessStorage(topOrigin); };
    bool canAccessSessionStorage(const SecurityOrigin* topOrigin) const { return canAccessStorage(topOrigin, AlwaysAllowFromThirdParty); }
    bool canAccessLocalStorage(const SecurityOrigin* topOrigin) const { return canAccessStorage(topOrigin); };
    bool canAccessSharedWorkers(const SecurityOrigin* topOrigin) const { return canAccessStorage(topOrigin); }
    bool canAccessPluginStorage(const SecurityOrigin* topOrigin) const { return canAccessStorage(topOrigin); }
    bool canAccessApplicationCache(const SecurityOrigin* topOrigin) const { return canAccessStorage(topOrigin); }
    bool canAccessCookies() const { return !isUnique(); }
    bool canAccessPasswordManager() const { return !isUnique(); }
    bool canAccessFileSystem() const { return !isUnique(); }
    Policy canShowNotifications() const;

    // The local SecurityOrigin is the most privileged SecurityOrigin.
    // The local SecurityOrigin can script any document, navigate to local
    // resources, and can set arbitrary headers on XMLHttpRequests.
    bool isLocal() const;

    // The origin is a globally unique identifier assigned when the Document is
    // created. http://www.whatwg.org/specs/web-apps/current-work/#sandboxOrigin
    //
    // There's a subtle difference between a unique origin and an origin that
    // has the SandboxOrigin flag set. The latter implies the former, and, in
    // addition, the SandboxOrigin flag is inherited by iframes.
    bool isUnique() const { return m_isUnique; }

    // Marks a file:// origin as being in a domain defined by its path.
    // FIXME 81578: The naming of this is confusing. Files with restricted access to other local files
    // still can have other privileges that can be remembered, thereby not making them unique.
    void enforceFilePathSeparation();

    // Convert this SecurityOrigin into a string. The string
    // representation of a SecurityOrigin is similar to a URL, except it
    // lacks a path component. The string representation does not encode
    // the value of the SecurityOrigin's domain property.
    //
    // When using the string value, it's important to remember that it might be
    // "null". This happens when this SecurityOrigin is unique. For example,
    // this SecurityOrigin might have come from a sandboxed iframe, the
    // SecurityOrigin might be empty, or we might have explicitly decided that
    // we shouldTreatURLSchemeAsNoAccess.
    String toString() const;

    // Similar to toString(), but does not take into account any factors that
    // could make the string return "null".
    String toRawString() const;

    // Serialize the security origin to a string that could be used as part of
    // file names. This format should be used in storage APIs only.
    String databaseIdentifier() const;

    // This method checks for equality between SecurityOrigins, not whether
    // one origin can access another. It is used for hash table keys.
    // For access checks, use canAccess().
    // FIXME: If this method is really only useful for hash table keys, it
    // should be refactored into SecurityOriginHash.
    bool equal(const SecurityOrigin*) const;

    // This method checks for equality, ignoring the value of document.domain
    // (and whether it was set) but considering the host. It is used for postMessage.
    bool isSameSchemeHostPort(const SecurityOrigin*) const;

    static String urlWithUniqueSecurityOrigin();

private:
    SecurityOrigin();
    explicit SecurityOrigin(const URL&);
    explicit SecurityOrigin(const SecurityOrigin*);

    // FIXME: Rename this function to something more semantic.
    bool passesFileCheck(const SecurityOrigin*) const;
    bool isThirdParty(const SecurityOrigin*) const;
    
    enum ShouldAllowFromThirdParty { AlwaysAllowFromThirdParty, MaybeAllowFromThirdParty };
    bool canAccessStorage(const SecurityOrigin*, ShouldAllowFromThirdParty = MaybeAllowFromThirdParty) const;

    String m_protocol;
    String m_host;
    String m_domain;
    String m_filePath;
    unsigned short m_port;
    bool m_isUnique;
    bool m_universalAccess;
    bool m_domainWasSetInDOM;
    bool m_canLoadLocalResources;
    StorageBlockingPolicy m_storageBlockingPolicy;
    bool m_enforceFilePathSeparation;
    bool m_needsDatabaseIdentifierQuirkForFiles;
};

} // namespace WebCore

#endif // SecurityOrigin_h
