Single sign-on techniques using client side encryption and decryption

An access management system (AMS) is disclosed that includes SSO capabilities for providing users secure access to protected resources within an enterprise using encryption keys generated by a client application. The AMS receives a request from a client application for a user to access a protected resource. In certain examples, the request comprises a client application identifier, a session identifier and a client public encryption key. The AMS determines if the session identifier points to a valid session and upon determining that the session identifier corresponds to a valid session, transmits information associated with the valid session to the client application. In certain examples, the information associated with the valid session is encrypted using the client public encryption key. Based on information associated with the valid session received from the client application, the AMS determines whether to grant or deny a user access to a protected resource within the enterprise.

TECHNICAL FIELD

This disclosure relates generally to access management systems. More specifically, but not by way of limitation, this disclosure describes an access management system that includes single sign-on (SSO) capabilities for providing users with secure access to protected resources within an enterprise using encryption keys generated by a client application.

BACKGROUND

An access management system enables users to access one or more different systems and applications within an enterprise. Each of these systems and applications may utilize different access control policies and request different credentials (e.g., user names and passwords). A user wanting to access a resource protected by an access management system may need to be authenticated by providing credentials to the access management system. A successful authentication gives the user authorization to access the protected resource, based on the user's access privileges. In certain instances, a user may request access to multiple protected resources within the enterprise. In such instances, upon successful user authentication, the access management system may establish a single sign-on session (SSO) for the user. Using the SSO session, the user is able to access multiple resources after initial authentication without the need to be re-authenticated each time the user requests access to a protected resource.

Existing access management systems typically rely on cookies for maintaining a user's session by storing the user's session information as a cookie on the user's device. After successful user authentication, session state information associated with the user's session is encrypted and stored in a cookie on the user's device. When the user (e.g., via a client application) connects to the access management system to gain access to a resource protected by the access management system, the cookie information is exchanged with the access management system to verify the validity of the user's session. If the user's session is valid, the access management system provides the user with SSO access to the protected resource using session information stored in the cookie without re-authenticating the user. However, the use of cookies in client applications (e.g., web browsers) can pose security or privacy concerns for an enterprise since the information stored by these cookies can be accessed by third party applications visited by the user. In many instances, the enterprise may disable or block cookies on their client applications to respond to such security or privacy considerations. However, this causes problems for web applications that require information about a user's session to provide the user access to protected resources within an enterprise.

SUMMARY

This disclosure relates generally to access management systems. More specifically, but not by way of limitation, this disclosure describes an access management system that includes SSO capabilities for providing users with secure access to protected resources within an enterprise using encryption keys generated by a client application.

In certain embodiments, an access management system is disclosed. The access management system receives a request from a client application requesting access by a user to a protected resource. In certain examples, the request comprises a client application identifier identifying the client application, a client public encryption key and a session identifier. The access management system determines, based on information stored in a data store, that the client application identifier is associated with the session identifier identifying a valid session for the user. Based on the determining, the access management system obtains an encrypted session identifier stored in the data store associated with the client application identifier. In certain examples, the encrypted session identifier is generated by the access management system by encrypting the session identifier using the client public encryption key.

In certain embodiments, the access management system transmits the encrypted session identifier to the client application and responsive to the transmitting, receives, from the client application, a response from the client application. In certain examples, the response includes information related to the valid session. In certain embodiments, the access management system determines a second session identifier from the response received from the client application and determines that the second session identifier matches the session identifier associated with the client application identifier stored in the data store. In certain embodiments, upon determining that the second session identifier matches the session identifier associated with the client application identifier stored in the data store, the access management system enables the user to access the protected resource. In certain embodiments, upon determining that the second session identifier does not match the session identifier associated with the client application identifier stored in the data store, the access management system denies the user access to the protected resource.

In certain examples, the second session identifier comprises a decrypted session identifier generated by the client application by decrypting the encrypted session identifier received from the computer system using a client private encryption key generated by the client application. In certain examples, the second session identifier comprises a second encrypted session identifier. The second encrypted session identifier is generated by the client application by decrypting the encrypted session identifier received from the computer system using a client private encryption key generated by client application and encrypting the decrypted session identifier using a public encryption key associated with the computer system to generate the second encrypted session identifier.

In certain embodiments, the access management system decrypts the second encrypted session identifier using a private encryption key associated with the access management system to generate a decrypted second session identifier, determines that the decrypted second session identifier matches the session identifier associated with the client application identifier stored in the data store and based on the determining enables the user to access the protected resource.

In certain embodiments, the access management system decrypts the second encrypted session identifier using a private encryption key associated with the access management system to generate a decrypted second session identifier, determines that the decrypted second session identifier does not match the session identifier associated with the client application identifier stored in the data store and based on the determining denies the user access to the protected resource.

In certain embodiments, the access management system performs an authentication of the user to access the protected resource. In certain examples, the authentication is performed in response to receiving an initial request from the client application prior to the request and based on determining, by the access management system that the session identifier for the client application identifier specified in the initial request is not valid. Based upon successful authentication, the access management system establishes a session for the user and enables the user to access the protected resource.

In certain embodiments, the authentication performed by the access management system comprises transmitting a credential information request to the client application, receiving credential information associated with the user from the client application, validating the credential information against stored credential information associated with the user and based on the validating, performing authentication of the user.

In certain embodiments, establishing a session for the user by the access management system comprises associating a session identifier with the session, encrypting the session identifier with the client public encryption key to generated the encrypted session identifier and associating the client application identifier to the session identifier, the encrypted session identifier and session data associated with the session. In certain embodiments, the access management system stores the client application identifier, the session identifier, the encrypted session identifier and the session data associated with the session in the data store.

Various embodiments are described herein, including methods, systems, non-transitory computer-readable storage media storing programs, code, or instructions executable by one or more processors, and the like. These illustrative embodiments are mentioned not to limit or define the disclosure, but to provide examples to aid understanding thereof. Additional embodiments are discussed in the Detailed Description, and further description is provided there.

DETAILED DESCRIPTION

The present disclosure describes improved techniques for performing access control using an access management system to enable a user to access multiple protected resources within an enterprise using encryption keys generated by a client application. As indicated in the Background section, conventional approaches for performing access control typically rely on the use of cookies in client applications to enable a user to access multiple protected resources within an enterprise. However, as noted above, since the information stored in cookies can potentially be exposed to third party applications visited by the user, the use of cookies in client applications can result in security risks for the enterprise. Some approaches avoid the use of cookies by exchanging digital certificates between the client application and the access management system to enable a user to access multiple protected resources within the enterprise. However, the use of digital certificates still requires the user to install the digital certificate on the client application and requires the validation of the digital certificate by the access management system for each user request. Other approaches involve passing a session identifier associated with the user's session as part of a Universal Resource Locator (URL) parameter instead of storing the session information as a value stored in a cookie. However, this approach can also lead to security risks for the enterprise because the URL parameter is typically stored in browser history and server logs which can be accidently exposed by users when the users access third party applications.

The various embodiments described in the present disclosure address the deficiencies of the above approaches by disclosing an access management system (AMS) that includes SSO capabilities for providing users with secure access to protected resources within an enterprise using encryption keys generated by a client application. In certain embodiments, when a user (e.g., via a client application) connects to an access management system to gain access to a resource protected by the access management system, the client application transmits a client application identifier and a client public encryption key as part of the request. Upon receiving the request, the AMS determines if there is a session identifier associated with the client application identifier in the request and further determines if the session identifier points to a valid session. If the AMS determines that there is no session identifier associated with the client application identifier received in the request or that the session identifier does not point to a valid session, the AMS attempts to authenticate the user requesting access to the protected resource. Upon successful user authentication, the access management system establishes a session for the user and provides the user access to the protected resource. As part of establishing a session, the AMS encrypts a session identifier associated with the session using the client public encryption key transmitted as part of the request by the client application. The AMS stores session information about the user's session for the client application identifier specified in the request. In certain examples, the session information may include the session identifier, the encrypted session identifier and session data associated with the user session.

If the AMS determines that there is a session identifier associated with the client application identifier received in the request and that the session identifier points to an active and valid session, the AMS performs SSO authentication to enable the user access to the protected resource using the encryption keys generated by the client application without requiring the user to enter credential information. As part of performing SSO authentication, the AMS presents the encrypted session identifier stored in the data store that is associated with the client application identifier to the client application. The client application decrypts the encrypted session identifier using its private encryption key. In certain embodiments, the AMS receives a decrypted session identifier from the client application and determines if the decrypted session identifier received from the client application matches the session identifier associated with the client identifier stored in the data store. If a match is found, the AMS grants access to the additional protected resources requested by the user. If a match is not found, the AMS denies access to the additional protected resources requested by the user.

The disclosed approach facilitates SSO authentication without requiring the use of specific digital certificates or cookies to be stored on the client application to enable a user access to multiple protected resources within an enterprise. Since a user's session information is stored on the server (i.e., the access management system) and the client application has the capability to encrypt/decrypt session information sent to it by the access management system, cookie information does not need to be stored on the client application or exchanged with the access management system to enable the user access to the protected resources. This results in providing increased security to services that require storing information about a user's session to provide the user access to multiple protected resources within the enterprise. Additionally, since session information is stored on the server, this information can safely be shared between web sites in different domains without posing a security threat to the enterprise. Typically, client applications (e.g., web browsers) that store session information in cookies do not allow sharing of cookies between web sites in different administrative domains due to security reasons. However, as web applications get richer, data sharing across domain boundaries becomes increasingly important.

Referring now to the drawings,FIG. 1depicts a simplified diagram of a computing environment100that includes an access management system (AMS) that includes capabilities for providing secure access to protected resources within the computing environment, according to certain embodiments. In certain embodiments, AMS110includes capabilities for providing Single Sign On (SSO) authentication for users accessing the protected resources. As used herein, SSO authentication refers to a session and user authentication service provided by AMS110that permits a user to use one set of login credentials (e.g., a username and password) to gain access to multiple resources managed and/or protected by AMS110, without the user having to re-enter log-in credentials each time to gain access to the individual protected resources. In certain examples, the protected resources may include applications, documents, files, web pages, web content, computing resources and so on within computing environment100. As shown in the embodiment depicted inFIG. 1, in certain examples, protected resources (e.g.,124A-124N) may be provided by and/or stored in a target resource system122(e.g., a resource server) within computing environment100. Target resource system122may be implemented by one or more computing systems that execute computer-readable instructions (e.g., code, program) to implement target resource system122.

Access management system (AMS)110may be implemented by one or more computing systems that execute computer-readable instructions (e.g., code, program) to implement AMS110. As depicted inFIG. 1, AMS110includes various subsystems including a Single Sign On (SSO) subsystem112and a session management subsystem114. Portions of data or information used by or generated by AMS110as part of its processing may be stored in a persistent memory such as data store118that is communicatively coupled to AMS110possibly via one or more communication networks108. For instance, data store118may store information related to SSO sessions established by AMS110for users accessing the protected resources, user credential information related to the users and so on. The systems and subsystems depicted inFIG. 1may be implemented using only software (e.g., code, instructions, program) executed by one or more processing units (e.g., processors, cores) of a computing system, hardware, or combinations thereof. The software may be stored on a non-transitory storage medium (e.g., on a memory device).

Computing environment100depicted inFIG. 1is merely an example and is not intended to unduly limit the scope of claimed embodiments. One of ordinary skill in the art would recognize many possible variations, alternatives, and modifications. For example, in some implementations, AMS110can be implemented using more or fewer subsystems than those shown inFIG. 1, may combine two or more subsystems, or may have a different configuration or arrangement of subsystems.

As depicted inFIG. 1, a user102may request access to a protected resource (e.g.,124A) within computing environment100using a client application106executed by client device104. Client device104may be of various types, including but not limited to, a mobile phone, a tablet, a desktop computer, and the like. For instance, user102may request access to a protected resource (e.g., a first application124A) stored on target resource system122using a user interface (UI) (which may be a graphical user interface (GUI)) of client application106by entering a uniform resource locator (URL) or other data identifying the requested resource. In certain embodiments, AMS110is configured to intercept the request from client application106, authenticate the user attempting to access the protected resource and upon successful authentication, create a session for the user and provide the user with access to the protected resource. In certain examples, in the same user session (i.e., while still being logged into the first application124A), user102may attempt to access another protected resource (e.g., second application124B) stored on target resource system122. Since the second application is also protected by AMS110, in certain embodiments, AMS110determines if the user is authorized to access the second application and if the second application is an SSO-enabled resource. As used herein, an SSO-enabled resource refers to a resource for which SSO processing can be enabled to provide the user access to the resource. If the user is authorized to access the second application and the second application is an SSO-enabled resource, AMS110, upon determining that the user session is active and still valid, performs SSO authentication to enable the user access to the protected resource. In some instances, AMS110may maintain a single SSO session to provide the user access to multiple resources after authentication. In certain examples, the multiple resources may represent different applications as described above. In other examples, the multiple resources may represent different websites within the same application, different webpages from the same website and so on. In certain examples, and as will be discussed in detail below, AMS110may utilize encryption keys generated by client application106to perform SSO authentication and establish an SSO session for the user to provide the user access to the multiple resources. Details related to the processing performed by the various systems and subsystems of AMS110(e.g., SSO subsystem112and session management subsystem114) are described below with respect to the figures depicted inFIGS. 2-5below and their accompanying description.

FIG. 2depicts an example of a process200performed by the access management system for enabling a user to access protected resources within the computing environment depicted inFIG. 1, according to certain embodiments. The processing depicted inFIG. 2may be implemented in software (e.g., code, instructions, program) executed by one or more processing units (e.g., processors, cores) of the respective systems, hardware, or combinations thereof. The software may be stored on a non-transitory storage medium (e.g., on a memory device). The process200presented inFIG. 2and described below is intended to be illustrative and non-limiting. AlthoughFIG. 2depicts the various processing steps occurring in a particular sequence or order, this is not intended to be limiting. In certain alternative embodiments, the steps may be performed in some different order or some steps may also be performed in parallel. In certain embodiments, such as in the embodiment depicted inFIG. 1, the processing depicted inFIG. 2may be performed by AMS110. In certain embodiments, within AMS110, the processing in202-220inFIG. 2may be performed by SSO subsystem112and session management subsystem114depicted inFIG. 1.

At block202, processing is initiated when AMS110receives a request from client application106for a user102to access a protected resource (e.g., protected resource124A) provided by or stored in target resource system122within computing environment100. For example, as discussed inFIG. 1, user102may request access to a protected resource using a GUI of client application106by entering a uniform resource locator (URL) or other data identifying the requested resource. In certain embodiments, upon receiving the request, client application106generates a client application identifier (i.e., a unique identifier identifying the client application) and a set of encryption keys. The generation of a client application identifier by client application106may be specific to the type of implementation technique employed by client application106to generate the client application identifier. In certain examples, client application106may be configured to generate a single client application identifier and utilize the same client application identifier across multiple sessions established for the user. In other examples, client application106may be configured to generate a new client application identifier each time a session for the user is established. In one example, the set of encryption keys generated by client application106comprise a client public encryption key and a client private encryption key. Client application106may be configured to generate the set of encryption keys (i.e., the client public encryption key and the client private encryption key) using one of several encryption algorithms known in the art (for e.g., the Rivest-Shamir-Adleman (RSA) technique, the Elliptic Curve Cryptography (ECC) technique or any other asymmetric encryption technique).

In certain examples, the request (including the URL, the client application identifier, a session identifier and the client public encryption key) is then transmitted by client application106to AMS110. For example, if client application106is a web browser executed by client device104, the request comprising the URL, client application identifier, session identifier and the client public encryption key may be transmitted as part of a user agent field (e.g., as part of a user agent Hyper Text Transfer Protocol (HTTP) header) of the web browser to AMS110.

At block203, AMS110receives the request and determines if there is a session identifier associated with the client application identifier in the request received at block202. If the request includes a session identifier, at block204, AMS110determines if the session identifier points to a valid session. In certain embodiments, the processing at block204may be performed by session management subsystem114within AMS110. In certain examples, as part of session management, the processing at block204may involve, determining, by session management system114, if the session identifier corresponds to a valid (i.e., an active or unexpired) session established by AMS110by accessing sessions information120associated with the particular client application identifier from data store118. In certain examples, sessions information120for a client application identifier may include, a session identifier, an encrypted session identifier, and session data associated with the session. As described herein, a session identifier is used to refer to a globally unique string that programmatically identifies a specific session established by AMS110. In certain embodiments, the encrypted session identifier may be generated by AMS110using the client public encryption key of the client application. Details related to the generation of the encrypted session identifier is discussed in detail below. Session data may include information about the session such as session state information, session life cycle events, session expiration times and so on. In certain examples, data store118may be configured to store sessions information120comprising multiple sessions established for a user of the client application. In some examples, session management system114may be configured to associate the same client application identifier for each session established for a user. In other examples, session management system114may be configured to associate a different client application identifier for each session established for a user, which may be generated by client application106each time a new session for the user is established.

At block204, if AMS110determines that the session identifier in the request points to an active and/or valid session, at block216, AMS110determines if the resource specified in the request is a protected and SSO-enabled resource. If the resource is a protected and SSO-enabled resource, AMS110performs SSO-based authentication to enable the user access to the resource without prompting the user to re-enter credentials. Details related to the processing performed by AMS110for performing SSO authentication and establishing an SSO session are described below with respect to the figures depicted inFIGS. 4-5below and their accompanying description.

If at block203, AMS110determines that there is no session identifier associated with the client application identifier received in the request or at block204, AMS110determines that the session identifier does not point to an active and/or valid session, AMS110attempts to authenticate the user requesting access to the protected resource. For instance, as part of the authentication process, at block206, AMS110may transmit a credential information request in the form of a challenge to client application106. In some examples, AMS110may redirect the credential information request to authentication system116(which may be communicatively coupled to AMS110possibly via one or more communication networks108) which in turn may transmit the challenge to client application106to prompt the user for user credentials (e.g., a username and a password). The credential information request may include information (e.g., a URL) displayed via a UI (e.g., a web page, portal, or dashboard) of client application106to receive credential information from the user. For instance, the credential information request may cause client application106to display to the user, a login screen that enables the user to provide the credential information. Client application106then transmits the credential information to authentication subsystem116. At block208, AMS110receives the credential information from client application106. At block210, AMS110performs authentication using the received credential information. In some examples, AMS110may redirect the credential information to authentication system116which in turn may perform the authentication by validating the credential information of the user against user data stored in a user directory in data store118.

At block212, AMS110performs a check to determine if authentication was successful. Upon successful user authentication, at block214, AMS110establishes a session for the user and associates the session with a session identifier. At block216, AMS110encrypts the session identifier with the client public encryption key received in the request. At block218, AMS110stores the client application identifier, the session identifier, the encrypted session identifier and the session data associated with the session and associates the client application identifier with the session identifier, the encrypted session identifier and the session data. In certain examples, the client application identifier, the session identifier, the encrypted session identifier and the session data associated with the session are stored as part of sessions information120in data store118. At block220, AMS110enables user102to access the protected resource (e.g.,124A) using client application106.

If at block212, AMS110determines that authentication was unsuccessful, then at block222, AMS110denies the user access to the protected resource request received in block202.

FIG. 3is a sequence diagram illustrating the interactions between the various systems and subsystems shown in computing environment100ofFIG. 1for enabling a user to access a protected resource within computing environment, according to certain embodiments. The processing depicted inFIG. 3is initiated when a user (e.g.,102) requests access to a protected resource (e.g.,124A) using a client application (e.g.,106) of a client device (e.g.,104) by entering a uniform resource locator (URL) or other data identifying the requested resource. Upon receiving the request, at operation301, client application106generates a client application identifier and a set of encryption keys (i.e., a client public encryption key and a client private encryption key). For purposes of this disclosure the client private encryption key and the client public encryption key generated by client application106are referred to herein using the notations, PrK_CA and PuK_CA respectively. At operation302, client application transmits the request (including the URL, the client application identifier, a session identifier and the client public encryption key) to AMS110.

At operation303, AMS110receives the request from client application106and determines if there is a session identifier associated with the client application identifier in the request. If the request includes a session identifier associated with the client application identifier, at operation304, AMS110performs another check to determine if the session identifier points to an active and/or valid session by accessing sessions information120associated with the particular client application identifier from data store118. If AMS determines that there is no session identifier associated with the client application identifier received in the request or that the session identifier does not point to an active and/or valid session stored in data store118, AMS110attempts to authenticate the user requesting access to the protected resource. For instance, as noted above, as part of the authentication process, AMS110may transmit a credential information request in the form of a challenge to client application106.

In certain examples, at operation308, AMS110re-directs the credential information request to authentication system116which then attempts to authenticate the user requesting access to the protected resource. In certain examples, as part of the authentication process, at operation310, authentication system116transmits the credential information request to client application106. In certain examples, and as described inFIG. 2, the credential information request may cause client application106to display to the user, a login screen that enables the user to provide credential information (e.g., a username and a password). At operation312, user102completes the login process by providing credentials and client application106transmits the credential information to authentication subsystem116. At operation313, authentication system116receives the credential information performs user authentication using the received credential information. In certain examples, authentication system116performs user authentication by validating the credential information of the user against user data stored in a user directory in data store118. At operation314, authentication system116transmits a message to AMS110that authentication is complete and successful.

At operation315, AMS110establishes a session for the client application identifier specified in the request, associates the session with a session identifier and encrypts the session identifier using the client public encryption key specified in the request. At operation316, AMS110stores the client application identifier, the session identifier, the encrypted session identifier and the session data associated with the session and associates the client application identifier with the session identifier, the encrypted session identifier and the session data. In certain examples, the client application identifier, the session identifier, the encrypted session identifier and the session data associated with the session are stored as part of sessions information120in data store118. At318, AMS110receives a message from data store118that sessions information associated with the client application identifier is successfully stored. At320, AMS110enables user102to access the protected resource (e.g.,124A) using client application106by re-directing the client application to the protected resource.

FIG. 4is a sequence diagram illustrating the interactions between the different systems and subsystems shown in computing environment100ofFIG. 1for enabling a user to access a protected resource using SSO authentication, according to certain embodiments. In certain embodiments, such as in the embodiment depicted inFIG. 4, the SSO authentication may be performed by client application106and SSO subsystem112as a result of determining that an active and/or valid session exists for a user requesting access to a protected resource stored on target resource system122. At operation402, client application (e.g.,106) transmits a request (comprising a URL or other data identifying the requested resource, a client application identifier, a session identifier and a public encryption key) to AMS110. As discussed in relation toFIGS. 2 and 3, in certain embodiments, the client application identifier and the client public encryption key may be generated by client application106upon receiving a request to access a protected resource. At operation403, AMS110receives the request and determines if there is a session identifier associated with the client application identifier received in the request. If the request includes a session identifier, at operation404, AMS110performs another check to determine if the session identifier points to an active and/or valid session by accessing sessions information120associated with the particular client application identifier from data store118. If the session identifier points to an active and/or valid session, at operation406, AMS110receives a message from data store118that the session identifier for the client application identifier specified in the request is valid.

Upon determining that an active and/or valid session exists for the client identifier, at operation408, AMS110determines if the resource specified in the request is a protected and SSO-enabled resource. If the resource is a protected and SSO-enabled resource, AMS110performs SSO authentication for user102to provide the user secure access to the protected resource without prompting the user for credential information. As part of this processing, AMS110obtains the encrypted session identifier (that was encrypted using the public encryption key generated by client application106) stored in data store118and associated with the client application identifier specified as part of the request and at operation408, AMS110transmits the encrypted session identifier to client application106. In certain examples, AMS110may present client application106with the encrypted session identifier (ESID) in the form of a challenge (e.g., via a UI of the client application). At operation410, client application106decrypts the encrypted session identifier using its private encryption key (PrK_CA)) (stored in secure storage in the client application) to generate a decrypted session identifier.

In certain embodiments, as part of enabling secure communications between client application106and AMS110, AMS110may also generate a set of encryption keys (i.e., a private-public encryption key pair) which may be used by and/or made available to client application106to establish secure communications with AMS110. For purposes of this disclosure the private encryption key and the public encryption key generated by AMS110are referred to herein using the notations, PrK_AMS and PuK_AMS respectively. For example, upon generating the decrypted session identifier at operation410, instead of transmitting the decrypted session identifier in plain text format, at operation412, client application106may encrypt the decrypted session identifier (generated at operation410) with a public encryption of AMS110prior to transmitting the session identifier to AMS110. Accordingly, in certain examples, client application106may transmit a second encrypted session identifier (i.e., encrypted by client application106using the public key of AMS110) to AMS110at operation414.

At operation416, AMS110receives the second encrypted session identifier from the client application and decrypts the second encrypted session identifier using its private encryption key. At operation418, AMS110verifies that the decrypted second session identifier matches the session identifier associated with the client application identifier stored in data store118. At operation420, data store118transmits a message to AMS110that the verification was successful. At422, AMS110enables the user to access the protected resource by re-directing the client application to access the protected resource.

In certain embodiments, at operation418, if the decrypted second session identifier does not match the session identifier associated with the client application identifier, then at operation424data store118transmits a message to AMS110that the verification was unsuccessful. At426, AMS110denies the user access to the protected resource.

FIG. 5depicts an example of a process500performed by the AMS for providing SSO authentication to enable a user access to a protected resource within the computing environment depicted inFIG. 1, according to certain embodiments. The processing depicted inFIG. 5may be implemented in software (e.g., code, instructions, program) executed by one or more processing units (e.g., processors, cores) of the respective systems, hardware, or combinations thereof. The software may be stored on a non-transitory storage medium (e.g., on a memory device). The process500presented inFIG. 5and described below is intended to be illustrative and non-limiting. AlthoughFIG. 5depicts the various processing steps occurring in a particular sequence or order, this is not intended to be limiting. In certain alternative embodiments, the steps may be performed in some different order or some steps may also be performed in parallel. In certain embodiments, such as in the embodiment depicted inFIG. 1, the processing depicted inFIG. 5may be performed by AMS110. In certain embodiments, within AMS110, the processing in502-514inFIG. 5may be performed by SSO subsystem112and session management subsystem114depicted inFIG. 1.

In certain embodiments, the processing depicted inFIG. 5is initiated when session management subsystem114determines that an active and/or valid session exists for the client application specified in the request (e.g., as a result of executing step204ofFIG. 2). For instance, session management subsystem114may determine that the session identifier in the request corresponds to a valid (i.e., an active or unexpired) session established by AMS110by accessing session data associated with the session identifier stored as part of sessions information120for the session stored in data store118

At block502, SSO subsystem112obtains the encrypted session identifier associated with the valid session for the client application identifier specified in the request from sessions information120. At block504, SSO subsystem112transmits the encrypted session identifier to client application106. In certain examples, SSO subsystem112may present client application106with the encrypted session identifier in the form of a challenge (e.g., via a UI of the client application).

At block506, SSO subsystem112receives a response from client application106to the challenge transmitted in block504. In certain examples, the response comprises information sent by client application106related to the valid session. In one example, the information received in the response may comprise a second session identifier generated by client application106. For instance, as described inFIG. 4, in certain embodiments, the second session identifier may comprise a decrypted session identifier generated by the client application. The decrypted session identifier may be generated by the client application by decrypting the encrypted session identifier received from AMS110using a client private encryption key generated by the client application. In other embodiments, the second session identifier may comprise a second encrypted session identifier. The second encrypted session identifier may be generated by the client application by decrypting the encrypted session identifier received from the computer system using the client private encryption key generated by client application and encrypting the decrypted session identifier using a public encryption key associated with AMS110.

At block508, AMS110determines the second session identifier from the response received from the client application at block506.

At block510, AMS110performs a check to determine if the second session identifier matches the session identifier for the client identifier stored in data store118. As noted above, in some embodiments, the second session identifier may comprise a decrypted session identifier generated by the client application. In other embodiments, second session identifier may comprise a second encrypted session identifier generated by the client application.

If AMS110determines that the second session identifier matches the session identifier for the client identifier stored in the data store, at block512, AMS110enables the user to access the protected resource via the client application. If AMS110determines that the second session identifier does not match the session identifier for the client identifier stored in the data store, at block514, AMS110denies the user access the protected resource. In some examples, at block514, AMS110may re-direct the request to authentication system116which may then attempt to re-authenticate the user in order to enable the user to access the protected resource.

The disclosed approach facilitates SSO authentication without requiring the use of specific digital certificates or cookies to be stored on the client application for enabling a user access to multiple protected resources within an enterprise. Since a user's session information is stored on the server (i.e., the access management system) and the client application has the capability to encrypt/decrypt session information sent to it by the access management system, cookie information does not need to be stored on the client application or exchanged with the access management system to enable the user access to the protected resources. This results in increased security provided to services that require storing information about a user's session to enable the user access to multiple protected resources within the enterprise.

Example Implementation

FIG. 6depicts a simplified diagram of a distributed system600for implementing an embodiment. In the illustrated embodiment, distributed system600includes one or more client computing devices602,604,606, and608, coupled to a server612via one or more communication networks610. Clients computing devices602,604,606, and608may be configured to execute one or more applications.

In various embodiments, server612may be adapted to run one or more services or software applications that enable the processing described in this disclosure.

In certain embodiments, server612may also provide other services or software applications that can include non-virtual and virtual environments. In some embodiments, these services may be offered as web-based or cloud services, such as under a Software as a Service (SaaS) model to the users of client computing devices602,604,606, and/or608. Users operating client computing devices602,604,606, and/or608may in turn utilize one or more client applications to interact with server612to utilize the services provided by these components.

In the configuration depicted inFIG. 6, server612may include one or more components618,620and622that implement the functions performed by server612. These components may include software components that may be executed by one or more processors, hardware components, or combinations thereof. It should be appreciated that various different system configurations are possible, which may be different from distributed system600. The embodiment shown inFIG. 6is thus one example of a distributed system for implementing an embodiment system and is not intended to be limiting.

Users may use client computing devices602,604,606, and/or608to interact with server612in accordance with the teachings of this disclosure. A client device may provide an interface that enables a user of the client device to interact with the client device. The client device may also output information to the user via this interface. AlthoughFIG. 6depicts only four client computing devices, any number of client computing devices may be supported.

The client devices may include various types of computing systems such as portable handheld devices, general purpose computers such as personal computers and laptops, workstation computers, wearable devices, gaming systems, thin clients, various messaging devices, sensors or other sensing devices, and the like. These computing devices may run various types and versions of software applications and operating systems (e.g., Microsoft Windows®, Apple Macintosh®, UNIX® or UNIX-like operating systems, Linux or Linux-like operating systems such as Google Chrome™ OS) including various mobile operating systems (e.g., Microsoft Windows Mobile®, iOS®, Windows Phone®, Android™, BlackBerry®, Palm OS®). Portable handheld devices may include cellular phones, smartphones, (e.g., an iPhone®), tablets (e.g., iPad®), personal digital assistants (PDAs), and the like. Wearable devices may include Google Glass® head mounted display, and other devices. Gaming systems may include various handheld gaming devices, Internet-enabled gaming devices (e.g., a Microsoft Xbox® gaming console with or without a Kinect® gesture input device, Sony PlayStation® system, various gaming systems provided by Nintendo®, and others), and the like. The client devices may be capable of executing various different applications such as various Internet-related apps, communication applications (e.g., E-mail applications, short message service (SMS) applications) and may use various communication protocols.

Server612may be composed of one or more general purpose computers, specialized server computers (including, by way of example, PC (personal computer) servers, UNIX® servers, mid-range servers, mainframe computers, rack-mounted servers, etc.), server farms, server clusters, or any other appropriate arrangement and/or combination. Server612can include one or more virtual machines running virtual operating systems, or other computing architectures involving virtualization such as one or more flexible pools of logical storage devices that can be virtualized to maintain virtual storage devices for the server. In various embodiments, server612may be adapted to run one or more services or software applications that provide the functionality described in the foregoing disclosure.

The computing systems in server612may run one or more operating systems including any of those discussed above, as well as any commercially available server operating system. Server612may also run any of a variety of additional server applications and/or mid-tier applications, including HTTP (hypertext transport protocol) servers, FTP (file transfer protocol) servers, CGI (common gateway interface) servers, JAVA® servers, database servers, and the like. Exemplary database servers include without limitation those commercially available from Oracle®, Microsoft®, Sybase®, IBM® (International Business Machines), and the like.

In some implementations, server612may include one or more applications to analyze and consolidate data feeds and/or event updates received from users of client computing devices602,604,606, and608. As an example, data feeds and/or event updates may include, but are not limited to, Twitter® feeds, Facebook® updates or real-time updates received from one or more third party information sources and continuous data streams, which may include real-time events related to sensor data applications, financial tickers, network performance measuring tools (e.g., network monitoring and traffic management applications), clickstream analysis tools, automobile traffic monitoring, and the like. Server612may also include one or more applications to display the data feeds and/or real-time events via one or more display devices of client computing devices602,604,606, and608.

Distributed system600may also include one or more data repositories614,616. These data repositories may be used to store data and other information in certain embodiments. For example, one or more of the data repositories614,616may be used to store data or information generated by the processing described herein and/or data or information used for the processing described herein. Data repositories614,616may reside in a variety of locations. For example, a data repository used by server612may be local to server612or may be remote from server612and in communication with server612via a network-based or dedicated connection. Data repositories614,616may be of different types. In certain embodiments, a data repository used by server612may be a database, for example, a relational database, such as databases provided by Oracle Corporation® and other vendors. One or more of these databases may be adapted to enable storage, update, and retrieval of data to and from the database in response to SQL-formatted commands.

In certain embodiments, one or more of data repositories614,616may also be used by applications to store application data. The data repositories used by applications may be of different types such as, for example, a key-value store repository, an object store repository, or a general storage repository supported by a file system.

In certain embodiments, the SSO functionalities described in this disclosure may be offered as services via a cloud environment.FIG. 7is a simplified block diagram of a cloud-based system environment in which functionalities described herein may be offered as cloud services, in accordance with certain embodiments. In the embodiment depicted inFIG. 7, cloud infrastructure system702may provide one or more cloud services that may be requested by users using one or more client computing devices704,706, and708. Cloud infrastructure system702may comprise one or more computers and/or servers that may include those described above for server612. The computers in cloud infrastructure system702may be organized as general purpose computers, specialized server computers, server farms, server clusters, or any other appropriate arrangement and/or combination.

Network(s)710may facilitate communication and exchange of data between clients704,706, and708and cloud infrastructure system702. Network(s)710may include one or more networks. The networks may be of the same or different types. Network(s)710may support one or more communication protocols, including wired and/or wireless protocols, for facilitating the communications.

The embodiment depicted inFIG. 7is only one example of a cloud infrastructure system and is not intended to be limiting. It should be appreciated that, in some other embodiments, cloud infrastructure system702may have more or fewer components than those depicted inFIG. 7, may combine two or more components, or may have a different configuration or arrangement of components. For example, althoughFIG. 7depicts three client computing devices, any number of client computing devices may be supported in alternative embodiments.

The term cloud service is generally used to refer to a service that is made available to users on demand and via a communication network such as the Internet by systems (e.g., cloud infrastructure system702) of a service provider. Typically, in a public cloud environment, servers and systems that make up the cloud service provider's system are different from the customer's own on-premise servers and systems. The cloud service provider's systems are managed by the cloud service provider. Customers can thus avail themselves of cloud services provided by a cloud service provider without having to purchase separate licenses, support, or hardware and software resources for the services. For example, a cloud service provider's system may host an application, and a user may, via the Internet, on demand, order and use the application without the user having to buy infrastructure resources for executing the application. Cloud services are designed to provide easy, scalable access to applications, resources and services. Several providers offer cloud services. For example, several cloud services are offered by Oracle Corporation® of Redwood Shores, Calif., such as middleware services, database services, Java cloud services, and others.

In certain embodiments, cloud infrastructure system702may provide one or more cloud services using different models such as under a Software as a Service (SaaS) model, a Platform as a Service (PaaS) model, an Infrastructure as a Service (IaaS) model, and others, including hybrid service models. Cloud infrastructure system702may include a suite of applications, middleware, databases, and other resources that enable provision of the various cloud services.

A SaaS model enables an application or software to be delivered to a customer over a communication network like the Internet, as a service, without the customer having to buy the hardware or software for the underlying application. For example, a SaaS model may be used to provide customers access to on-demand applications that are hosted by cloud infrastructure system702. Examples of SaaS services provided by Oracle Corporation® include, without limitation, various services for human resources/capital management, customer relationship management (CRM), enterprise resource planning (ERP), supply chain management (SCM), enterprise performance management (EPM), analytics services, social applications, and others.

An IaaS model is generally used to provide infrastructure resources (e.g., servers, storage, hardware and networking resources) to a customer as a cloud service to provide elastic compute and storage capabilities. Various IaaS services are provided by Oracle Corporation®.

A PaaS model is generally used to provide, as a service, platform and environment resources that enable customers to develop, run, and manage applications and services without the customer having to procure, build, or maintain such resources. Examples of PaaS services provided by Oracle Corporation® include, without limitation, Oracle Java Cloud Service (JCS), Oracle Database Cloud Service (DBCS), data management cloud service, various application development solutions services, and others.

Cloud services are generally provided on an on-demand self-service basis, subscription-based, elastically scalable, reliable, highly available, and secure manner. For example, a customer, via a subscription order, may order one or more services provided by cloud infrastructure system702. Cloud infrastructure system702then performs processing to provide the services requested in the customer's subscription order. Cloud infrastructure system702may be configured to provide one or even multiple cloud services.

Cloud infrastructure system702may provide the cloud services via different deployment models. In a public cloud model, cloud infrastructure system702may be owned by a third party cloud services provider and the cloud services are offered to any general public customer, where the customer can be an individual or an enterprise. In certain other embodiments, under a private cloud model, cloud infrastructure system702may be operated within an organization (e.g., within an enterprise organization) and services provided to customers that are within the organization. For example, the customers may be various departments of an enterprise such as the Human Resources department, the Payroll department, etc. or even individuals within the enterprise. In certain other embodiments, under a community cloud model, the cloud infrastructure system702and the services provided may be shared by several organizations in a related community. Various other models such as hybrids of the above mentioned models may also be used.

Client computing devices704,706, and708may be of different types (such as devices602,604,606, and608depicted inFIG. 1) and may be capable of operating one or more client applications. A user may use a client device to interact with cloud infrastructure system702, such as to request a service provided by cloud infrastructure system702.

In some embodiments, the processing performed by cloud infrastructure system702may involve big data analysis. This analysis may involve using, analyzing, and manipulating large data sets to detect and visualize various trends, behaviors, relationships, etc. within the data. This analysis may be performed by one or more processors, possibly processing the data in parallel, performing simulations using the data, and the like. The data used for this analysis may include structured data (e.g., data stored in a database or structured according to a structured model) and/or unstructured data (e.g., data blobs (binary large objects)).

As depicted in the embodiment inFIG. 7, cloud infrastructure system702may include infrastructure resources730that are utilized for facilitating the provision of various cloud services offered by cloud infrastructure system702. Infrastructure resources730may include, for example, processing resources, storage or memory resources, networking resources, and the like.

In certain embodiments, to facilitate efficient provisioning of these resources for supporting the various cloud services provided by cloud infrastructure system702for different customers, the resources may be bundled into sets of resources or resource modules (also referred to as “pods”). Each resource module or pod may comprise a pre-integrated and optimized combination of resources of one or more types. In certain embodiments, different pods may be pre-provisioned for different types of cloud services. For example, a first set of pods may be provisioned for a database service, a second set of pods, which may include a different combination of resources than a pod in the first set of pods, may be provisioned for Java service, and the like. For some services, the resources allocated for provisioning the services may be shared between the services.

Cloud infrastructure system702may itself internally use services732that are shared by different components of cloud infrastructure system702and which facilitate the provisioning of services by cloud infrastructure system702. These internal shared services may include, without limitation, a security and identity service, an integration service, an enterprise repository service, an enterprise manager service, a virus scanning and white list service, a high availability, backup and recovery service, service for enabling cloud support, an email service, a notification service, a file transfer service, and the like.

Cloud infrastructure system702may comprise multiple subsystems. These subsystems may be implemented in software, or hardware, or combinations thereof. As depicted inFIG. 7, the subsystems may include a user interface subsystem712that enables users or customers of cloud infrastructure system702to interact with cloud infrastructure system702. User interface subsystem712may include various different interfaces such as a web interface714, an online store interface216where cloud services provided by cloud infrastructure system702are advertised and are purchasable by a consumer, and other interfaces718. For example, a customer may, using a client device, request (service request734) one or more services provided by cloud infrastructure system702using one or more of interfaces714,716, and718. For example, a customer may access the online store, browse cloud services offered by cloud infrastructure system702, and place a subscription order for one or more services offered by cloud infrastructure system702that the customer wishes to subscribe to. The service request may include information identifying the customer and one or more services that the customer desires to subscribe to.

In certain embodiments, such as the embodiment depicted inFIG. 7, cloud infrastructure system702may comprise an order management subsystem (OMS)720that is configured to process the new order. As part of this processing, OMS720may be configured to: create an account for the customer, if not done already; receive billing and/or accounting information from the customer that is to be used for billing the customer for providing the requested service to the customer; verify the customer information; upon verification, book the order for the customer; and orchestrate various workflows to prepare the order for provisioning.

Once properly validated, OMS720may then invoke the order provisioning subsystem (OPS)724that is configured to provision resources for the order including processing, memory, and networking resources. The provisioning may include allocating resources for the order and configuring the resources to facilitate the service requested by the customer order. The manner in which resources are provisioned for an order and the type of the provisioned resources may depend upon the type of cloud service that has been ordered by the customer. For example, according to one workflow, OPS724may be configured to determine the particular cloud service being requested and identify a number of pods that may have been pre-configured for that particular cloud service. The number of pods that are allocated for an order may depend upon the size/amount/level/scope of the requested service. For example, the number of pods to be allocated may be determined based upon the number of users to be supported by the service, the duration of time for which the service is being requested, and the like. The allocated pods may then be customized for the particular requesting customer for providing the requested service.

Cloud infrastructure system702may send a response or notification744to the requesting customer to indicate when the requested service is now ready for use. In some instances, information (e.g., a link) may be sent to the customer that enables the customer to start using and availing the benefits of the requested services.

Cloud infrastructure system702may provide services to multiple customers. For each customer, cloud infrastructure system702is responsible for managing information related to one or more subscription orders received from the customer, maintaining customer data related to the orders, and providing the requested services to the customer. Cloud infrastructure system702may also collect usage statistics regarding a customer's use of subscribed services. For example, statistics may be collected for the amount of storage used, the amount of data transferred, the number of users, and the amount of system up time and system down time, and the like. This usage information may be used to bill the customer. Billing may be done, for example, on a monthly cycle.

Cloud infrastructure system702may provide services to multiple customers in parallel. Cloud infrastructure system702may store information for these customers, including possibly proprietary information. In certain embodiments, cloud infrastructure system702comprises an identity management subsystem (IMS)728that is configured to manage customers information and provide the separation of the managed information such that information related to one customer is not accessible by another customer. IMS728may be configured to provide various security-related services such as identity services, such as information access management, authentication and authorization services, services for managing customer identities and roles and related capabilities, and the like.

FIG. 8illustrates an exemplary computer system800that may be used to implement certain embodiments. For example, in some embodiments, computer system800may be used to implement any of the system and subsystems for performing processing according to the present disclosure. As shown inFIG. 8, computer system800includes various subsystems including a processing subsystem804that communicates with a number of other subsystems via a bus subsystem802. These other subsystems may include a processing acceleration unit806, an I/O subsystem808, a storage subsystem818, and a communications subsystem824. Storage subsystem818may include non-transitory computer-readable storage media including storage media822and a system memory810.

Processing subsystem804controls the operation of computer system800and may comprise one or more processors, application specific integrated circuits (ASICs), or field programmable gate arrays (FPGAs). The processors may include be single core or multicore processors. The processing resources of computer system800can be organized into one or more processing units832,834, etc. A processing unit may include one or more processors, one or more cores from the same or different processors, a combination of cores and processors, or other combinations of cores and processors. In some embodiments, processing subsystem804can include one or more special purpose co-processors such as graphics processors, digital signal processors (DSPs), or the like. In some embodiments, some or all of the processing units of processing subsystem804can be implemented using customized circuits, such as application specific integrated circuits (ASICs), or field programmable gate arrays (FPGAs).

In some embodiments, the processing units in processing subsystem804can execute instructions stored in system memory810or on computer readable storage media822. In various embodiments, the processing units can execute a variety of programs or code instructions and can maintain multiple concurrently executing programs or processes. At any given time, some or all of the program code to be executed can be resident in system memory810and/or on computer-readable storage media822including potentially on one or more storage devices. Through suitable programming, processing subsystem804can provide various functionalities described above. In instances where computer system800is executing one or more virtual machines, one or more processing units may be allocated to each virtual machine.

In certain embodiments, a processing acceleration unit806may optionally be provided for performing customized processing or for off-loading some of the processing performed by processing subsystem804so as to accelerate the overall processing performed by computer system800.

Storage subsystem818provides a repository or data store for storing information and data that is used by computer system800. Storage subsystem818provides a tangible non-transitory computer-readable storage medium for storing the basic programming and data constructs that provide the functionality of some embodiments. Storage subsystem818may store software (e.g., programs, code modules, instructions) that when executed by processing subsystem804provides the functionality described above. The software may be executed by one or more processing units of processing subsystem804. Storage subsystem818may also provide a repository for storing data used in accordance with the teachings of this disclosure.

Storage subsystem818may include one or more non-transitory memory devices, including volatile and non-volatile memory devices. As shown inFIG. 8, storage subsystem818includes a system memory810and a computer-readable storage media822. System memory810may include a number of memories including a volatile main random access memory (RAM) for storage of instructions and data during program execution and a non-volatile read only memory (ROM) or flash memory in which fixed instructions are stored. In some implementations, a basic input/output system (BIOS), containing the basic routines that help to transfer information between elements within computer system800, such as during start-up, may typically be stored in the ROM. The RAM typically contains data and/or program modules that are presently being operated and executed by processing subsystem804. In some implementations, system memory810may include multiple different types of memory, such as static random access memory (SRAM), dynamic random access memory (DRAM), and the like.

By way of example, and not limitation, as depicted inFIG. 8, system memory810may load application programs812that are being executed, which may include various applications such as Web browsers, mid-tier applications, relational database management systems (RDBMS), etc., program data814, and an operating system816. By way of example, operating system816may include various versions of Microsoft Windows®, Apple Macintosh®, and/or Linux operating systems, a variety of commercially-available UNIX® or UNIX-like operating systems (including without limitation the variety of GNU/Linux operating systems, the Google Chrome® OS, and the like) and/or mobile operating systems such as iOS, Windows® Phone, Android® OS, BlackBerry® OS, Palm® OS operating systems, and others.

In certain embodiments, storage subsystem818may also include a computer-readable storage media reader820that can further be connected to computer-readable storage media822. Reader820may receive and be configured to read data from a memory device such as a disk, a flash drive, etc.

In certain embodiments, computer system800may support virtualization technologies, including but not limited to virtualization of processing and memory resources. For example, computer system800may provide support for executing one or more virtual machines. In certain embodiments, computer system800may execute a program such as a hypervisor that facilitated the configuring and managing of the virtual machines. Each virtual machine may be allocated memory, compute (e.g., processors, cores), I/O, and networking resources. Each virtual machine generally runs independently of the other virtual machines. A virtual machine typically runs its own operating system, which may be the same as or different from the operating systems executed by other virtual machines executed by computer system800. Accordingly, multiple operating systems may potentially be run concurrently by computer system800.

Communications subsystem824provides an interface to other computer systems and networks. Communications subsystem824serves as an interface for receiving data from and transmitting data to other systems from computer system800. For example, communications subsystem824may enable computer system800to establish a communication channel to one or more client devices via the Internet for receiving and sending information from and to the client devices.

Communication subsystem824may support both wired and/or wireless communication protocols. For example, in certain embodiments, communications subsystem824may include radio frequency (RF) transceiver components for accessing wireless voice and/or data networks (e.g., using cellular telephone technology, advanced data network technology, such as 3G, 4G or EDGE (enhanced data rates for global evolution), WiFi (IEEE 802.XX family standards, or other mobile communication technologies, or any combination thereof), global positioning system (GPS) receiver components, and/or other components. In some embodiments communications subsystem824can provide wired network connectivity (e.g., Ethernet) in addition to or instead of a wireless interface.

Communication subsystem824can receive and transmit data in various forms. For example, in some embodiments, in addition to other forms, communications subsystem824may receive input communications in the form of structured and/or unstructured data feeds826, event streams828, event updates830, and the like. For example, communications subsystem824may be configured to receive (or send) data feeds826in real-time from users of social media networks and/or other communication services such as Twitter® feeds, Facebook® updates, web feeds such as Rich Site Summary (RSS) feeds, and/or real-time updates from one or more third party information sources.

Communications subsystem824may also be configured to communicate data from computer system800to other computer systems or networks. The data may be communicated in various different forms such as structured and/or unstructured data feeds826, event streams828, event updates830, and the like to one or more databases that may be in communication with one or more streaming data source computers coupled to computer system800.

Computer system800can be one of various types, including a handheld portable device (e.g., an iPhone® cellular phone, an iPad® computing tablet, a PDA), a wearable device (e.g., a Google Glass® head mounted display), a personal computer, a workstation, a mainframe, a kiosk, a server rack, or any other data processing system. Due to the ever-changing nature of computers and networks, the description of computer system800depicted inFIG. 8is intended only as a specific example. Many other configurations having more or fewer components than the system depicted inFIG. 8are possible. Based on the disclosure and teachings provided herein, a person of ordinary skill in the art will appreciate other ways and/or methods to implement the various embodiments.

Although specific embodiments have been described, various modifications, alterations, alternative constructions, and equivalents are possible. Embodiments are not restricted to operation within certain specific data processing environments, but are free to operate within a plurality of data processing environments. Additionally, although certain embodiments have been described using a particular series of transactions and steps, it should be apparent to those skilled in the art that this is not intended to be limiting. Although some flowcharts describe operations as a sequential process, many of the operations can be performed in parallel or concurrently. In addition, the order of the operations may be rearranged. A process may have additional steps not included in the figure. Various features and aspects of the above-described embodiments may be used individually or jointly.

Further, while certain embodiments have been described using a particular combination of hardware and software, it should be recognized that other combinations of hardware and software are also possible. Certain embodiments may be implemented only in hardware, or only in software, or using combinations thereof. The various processes described herein can be implemented on the same processor or different processors in any combination.

Specific details are given in this disclosure to provide a thorough understanding of the embodiments. However, embodiments may be practiced without these specific details. For example, well-known circuits, processes, algorithms, structures, and techniques have been shown without unnecessary detail in order to avoid obscuring the embodiments. This description provides example embodiments only, and is not intended to limit the scope, applicability, or configuration of other embodiments. Rather, the preceding description of the embodiments will provide those skilled in the art with an enabling description for implementing various embodiments. Various changes may be made in the function and arrangement of elements.