| // Copyright 2013 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef CHROME_BROWSER_CHROMEOS_ATTESTATION_PLATFORM_VERIFICATION_FLOW_H_ |
| #define CHROME_BROWSER_CHROMEOS_ATTESTATION_PLATFORM_VERIFICATION_FLOW_H_ |
| |
| #include <string> |
| |
| #include "base/basictypes.h" |
| #include "base/callback.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/memory/scoped_ptr.h" |
| #include "base/time/time.h" |
| #include "base/timer/timer.h" |
| #include "url/gurl.h" |
| |
| class HostContentSettingsMap; |
| class PrefService; |
| |
| namespace content { |
| class WebContents; |
| } |
| |
| namespace cryptohome { |
| class AsyncMethodCaller; |
| } |
| |
| namespace user_prefs { |
| class PrefRegistrySyncable; |
| } |
| |
| namespace chromeos { |
| |
| class CryptohomeClient; |
| class UserManager; |
| class User; |
| |
| namespace attestation { |
| |
| class AttestationFlow; |
| class PlatformVerificationFlowTest; |
| |
| // This class allows platform verification for the content protection use case. |
| // All methods must only be called on the UI thread. Example: |
| // scoped_refptr<PlatformVerificationFlow> verifier = |
| // new PlatformVerificationFlow(); |
| // PlatformVerificationFlow::Callback callback = base::Bind(&MyCallback); |
| // verifier->ChallengePlatformKey(my_web_contents, "my_id", "some_challenge", |
| // callback); |
| // |
| // This class is RefCountedThreadSafe because it may need to outlive its caller. |
| // The attestation flow that needs to happen to establish a certified platform |
| // key may take minutes on some hardware. This class will timeout after a much |
| // shorter time so the caller can proceed without platform verification but it |
| // is important that the pending operation be allowed to finish. If the |
| // attestation flow is aborted at any stage, it will need to start over. If we |
| // use weak pointers, the attestation flow will stop when the next callback is |
| // run. So we need the instance to stay alive until the platform key is fully |
| // certified so the next time ChallegePlatformKey() is invoked it will be quick. |
| class PlatformVerificationFlow |
| : public base::RefCountedThreadSafe<PlatformVerificationFlow> { |
| public: |
| enum Result { |
| SUCCESS, // The operation succeeded. |
| INTERNAL_ERROR, // The operation failed unexpectedly. |
| PLATFORM_NOT_VERIFIED, // The platform cannot be verified. For example: |
| // - It is not a Chrome device. |
| // - It is not running a verified OS image. |
| USER_REJECTED, // The user explicitly rejected the operation. |
| POLICY_REJECTED, // The operation is not allowed by policy/settings. |
| TIMEOUT, // The operation timed out. |
| }; |
| |
| enum ConsentResponse { |
| CONSENT_RESPONSE_NONE, |
| CONSENT_RESPONSE_ALLOW, |
| CONSENT_RESPONSE_DENY, |
| }; |
| |
| // An interface which allows settings and UI to be abstracted for testing |
| // purposes. For normal operation the default implementation should be used. |
| class Delegate { |
| public: |
| virtual ~Delegate() {} |
| |
| // This callback will be called when a user has given a |response| to a |
| // consent request of the specified |type|. |
| typedef base::Callback<void(ConsentResponse response)> ConsentCallback; |
| |
| // Invokes consent UI within the context of |web_contents| and calls |
| // |callback| when the user responds. |
| // Precondition: The last committed URL for |web_contents| has a valid |
| // origin. |
| virtual void ShowConsentPrompt(content::WebContents* web_contents, |
| const ConsentCallback& callback) = 0; |
| }; |
| |
| // This callback will be called when a challenge operation completes. If |
| // |result| is SUCCESS then |signed_data| holds the data which was signed |
| // by the platform key (this is the original challenge appended with a random |
| // nonce) and |signature| holds the RSA-PKCS1-v1.5 signature. The |
| // |platform_key_certificate| certifies the key used to generate the |
| // signature. This key may be generated on demand and is not guaranteed to |
| // persist across multiple calls to this method. The browser does not check |
| // the validity of |signature| or |platform_key_certificate|. |
| typedef base::Callback<void(Result result, |
| const std::string& signed_data, |
| const std::string& signature, |
| const std::string& platform_key_certificate)> |
| ChallengeCallback; |
| |
| // A constructor that uses the default implementation of all dependencies |
| // including Delegate. |
| PlatformVerificationFlow(); |
| |
| // An alternate constructor which specifies dependent objects explicitly. |
| // This is useful in testing. The caller retains ownership of all pointers. |
| PlatformVerificationFlow(AttestationFlow* attestation_flow, |
| cryptohome::AsyncMethodCaller* async_caller, |
| CryptohomeClient* cryptohome_client, |
| UserManager* user_manager, |
| Delegate* delegate); |
| |
| // Invokes an asynchronous operation to challenge a platform key. Any user |
| // interaction will be associated with |web_contents|. The |service_id| is an |
| // arbitrary value but it should uniquely identify the origin of the request |
| // and should not be determined by that origin; its purpose is to prevent |
| // collusion between multiple services. The |challenge| is also an arbitrary |
| // value but it should be time sensitive or associated to some kind of session |
| // because its purpose is to prevent certificate replay. The |callback| will |
| // be called when the operation completes. The duration of the operation can |
| // vary depending on system state, hardware capabilities, and interaction with |
| // the user. |
| void ChallengePlatformKey(content::WebContents* web_contents, |
| const std::string& service_id, |
| const std::string& challenge, |
| const ChallengeCallback& callback); |
| |
| static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* prefs); |
| |
| void set_timeout_delay(const base::TimeDelta& timeout_delay) { |
| timeout_delay_ = timeout_delay; |
| } |
| |
| private: |
| friend class base::RefCountedThreadSafe<PlatformVerificationFlow>; |
| friend class PlatformVerificationFlowTest; |
| |
| // Holds the arguments of a ChallengePlatformKey call. This is convenient for |
| // use with base::Bind so we don't get too many arguments. |
| struct ChallengeContext { |
| ChallengeContext(content::WebContents* web_contents, |
| const std::string& service_id, |
| const std::string& challenge, |
| const ChallengeCallback& callback); |
| ~ChallengeContext(); |
| |
| content::WebContents* web_contents; |
| std::string service_id; |
| std::string challenge; |
| ChallengeCallback callback; |
| }; |
| |
| ~PlatformVerificationFlow(); |
| |
| // Checks whether we need to prompt the user for consent before proceeding and |
| // invokes the consent UI if so. The arguments to ChallengePlatformKey are |
| // in |context| and |attestation_enrolled| specifies whether attestation has |
| // been enrolled for this device. |
| void CheckConsent(const ChallengeContext& context, |
| bool attestation_enrolled); |
| |
| // A callback called when the user has given their consent response. The |
| // arguments to ChallengePlatformKey are in |context|. |consent_required| and |
| // |consent_response| indicate whether consent was required and user response, |
| // respectively. If the response indicates that the operation should proceed, |
| // this method invokes a certificate request. |
| void OnConsentResponse(const ChallengeContext& context, |
| bool consent_required, |
| ConsentResponse consent_response); |
| |
| // A callback called when an attestation certificate request operation |
| // completes. The arguments to ChallengePlatformKey are in |context|. |
| // |user_id| identifies the user for which the certificate was requested. |
| // |operation_success| is true iff the certificate request operation |
| // succeeded. |certificate| holds the certificate for the platform key on |
| // success. If the certificate request was successful, this method invokes a |
| // request to sign the challenge. If the operation timed out prior to this |
| // method being called, this method does nothing - notably, the callback is |
| // not invoked. |
| void OnCertificateReady(const ChallengeContext& context, |
| const std::string& user_id, |
| scoped_ptr<base::Timer> timer, |
| bool operation_success, |
| const std::string& certificate); |
| |
| // A callback run after a constant delay to handle timeouts for lengthy |
| // certificate requests. |context.callback| will be invoked with a TIMEOUT |
| // result. |
| void OnCertificateTimeout(const ChallengeContext& context); |
| |
| // A callback called when a challenge signing request has completed. The |
| // |certificate| is the platform certificate for the key which signed the |
| // |challenge|. The arguments to ChallengePlatformKey are in |context|. |
| // |operation_success| is true iff the challenge signing operation was |
| // successful. If it was successful, |response_data| holds the challenge |
| // response and the method will invoke |context.callback|. |
| void OnChallengeReady(const ChallengeContext& context, |
| const std::string& certificate, |
| bool operation_success, |
| const std::string& response_data); |
| |
| // Gets prefs associated with the given |web_contents|. If prefs have been |
| // set explicitly using set_testing_prefs(), then these are always returned. |
| // If no prefs are associated with |web_contents| then NULL is returned. |
| PrefService* GetPrefs(content::WebContents* web_contents); |
| |
| // Gets the URL associated with the given |web_contents|. If a URL as been |
| // set explicitly using set_testing_url(), then this value is always returned. |
| const GURL& GetURL(content::WebContents* web_contents); |
| |
| // Gets the user associated with the given |web_contents|. NULL may be |
| // returned. If |web_contents| is NULL (e.g. during testing), then the |
| // current active user will be returned. |
| User* GetUser(content::WebContents* web_contents); |
| |
| // Gets the content settings map associated with the given |web_contents|. If |
| // |testing_content_settings_| is set, then this is always returned. |
| HostContentSettingsMap* GetContentSettings( |
| content::WebContents* web_contents); |
| |
| // Checks whether policy or profile settings associated with |web_contents| |
| // have attestation for content protection explicitly disabled. |
| bool IsAttestationEnabled(content::WebContents* web_contents); |
| |
| // Updates user settings for the profile associated with |web_contents| based |
| // on the |consent_response| to the request of type |consent_type|. |
| bool UpdateSettings(content::WebContents* web_contents, |
| ConsentResponse consent_response); |
| |
| // Finds the domain-specific consent pref in |content_settings| for |url|. If |
| // a pref exists for the domain, returns true and sets |pref_value| if it is |
| // not NULL. |
| bool GetDomainPref(HostContentSettingsMap* content_settings, |
| const GURL& url, |
| bool* pref_value); |
| |
| // Records the domain-specific consent pref in |content_settings| for |url|. |
| // The pref will be set to |allow_domain|. |
| void RecordDomainConsent(HostContentSettingsMap* content_settings, |
| const GURL& url, |
| bool allow_domain); |
| |
| void set_testing_prefs(PrefService* testing_prefs) { |
| testing_prefs_ = testing_prefs; |
| } |
| |
| void set_testing_url(const GURL& testing_url) { |
| testing_url_ = testing_url; |
| } |
| |
| void set_testing_content_settings(HostContentSettingsMap* settings) { |
| testing_content_settings_ = settings; |
| } |
| |
| AttestationFlow* attestation_flow_; |
| scoped_ptr<AttestationFlow> default_attestation_flow_; |
| cryptohome::AsyncMethodCaller* async_caller_; |
| CryptohomeClient* cryptohome_client_; |
| UserManager* user_manager_; |
| Delegate* delegate_; |
| scoped_ptr<Delegate> default_delegate_; |
| PrefService* testing_prefs_; |
| GURL testing_url_; |
| HostContentSettingsMap* testing_content_settings_; |
| base::TimeDelta timeout_delay_; |
| |
| DISALLOW_COPY_AND_ASSIGN(PlatformVerificationFlow); |
| }; |
| |
| } // namespace attestation |
| } // namespace chromeos |
| |
| #endif // CHROME_BROWSER_CHROMEOS_ATTESTATION_PLATFORM_VERIFICATION_FLOW_H_ |