Patent Publication Number: US-10333914-B2

Title: Cross-site, TOTP-based two factor authentication

Description:
BACKGROUND 
     Technical Field 
     This disclosure relates generally to security technologies, products and services. 
     Background of the Related Art 
     Two-factor authentication (also known as 2FA) is a technology that provides identification of users by combining two different components, such as something that the user knows (e.g., username, password, PIN), and something that the user possesses (USB stick with a secret token, a bank card, a key) or something that is inseparable from the user (e.g. a fingerprint, iris, voice, typing speed, pattern in key press intervals, etc.). If, in an authentication attempt, at least one of the components is missing or supplied incorrectly, the user&#39;s identity is not established and access to the resource being protected by two-factor authentication is denied. The something possessed by the user may be a mobile device itself. 
     A number of two-factor authentication schemes use a Time-based One-time Password (TOTP) scheme, as defined Internet RFC 6238. TOTP is an algorithm that computes a one-time password from a shared secret key and the current time. TOTP is an example of a hash-based message authentication code (HMAC). It combines a secret key with the current timestamp using a cryptographic hash function to generate a one-time password. The timestamp typically increases in 30-second intervals such that passwords generated close together in time from the same secret key are the same. In a typical two-factor authentication application, a user enters his private credential (e.g., username and password) into a website, generates a one-time password (OTP) for the site using TOTP running locally on a smartphone, and types the OTP into the server as well. The server runs the same TOTP algorithm to verify the one-time password entered. The approach requires that a single secret key be shared between the server and the user&#39;s device over a secure channel ahead of time. 
     While TOTP-based two factor authentication works well, to date the known solutions have been tied to individual sites and their associated mobile apps. This is cumbersome to configure and use in practice, as end users have to manually enter the TOTP code. This approach also requires the user to maintain a dedicated mobile app for each site that uses the authentication scheme. 
     BRIEF SUMMARY 
     A TOTP-based 2FA scheme works across web sites without requiring the end user to manually enter codes, or to have a dedicated mobile app for each particular site. In this approach, an end user leverages a cloud-based service as a repository for maintaining and securing the TOTP secrets (i.e., a TOTP shared secret per user per site) that are generated as the end user interacts with various TOTP setup pages via a mobile device authenticator app. The cloud service is accessed when the end user subsequently attempts a TOTP-based login from a client browser to one of the sites (whose TOTP shared secret is already maintained in the repository). The client browser executes in a computing machine (e.g., a laptop) distinct from the end user&#39;s mobile device. To effect login, the end user opens the browser to a TOTP authentication page. The TOTP-based login attempt from the client browser is detected by a browser plug-in, and this detection initiates a push notification mechanism. In particular, the browser plug-in issues a request to the cloud service, which responds by sending a push notification to the end user mobile device authenticator app. If the end user responds to the push notification (e.g., within a given timeout), the cloud service uses the TOTP secret stored in the repository to generate the TOTP code, which code is then sent back to the browser plug-in. The browser plug-in then injects that code into an HTML login form of the TOTP authentication page, and then automatically submits the form. Thus, the user does not have to manually enter the TOTP code. The user is then logged in automatically to complete the process. This approach works for any site for which the cloud service maintains the TOTP shared secret for the end user. Thus, the cloud service enables the end user to access secure resources without requiring manual entry of TOTP codes, and by using just a single authenticator app instead of having to configure and use multiple different mobile apps across different web sites that implement this form of authentication. 
     The foregoing has outlined some of the more pertinent features of the subject disclosure. These features should be construed to be merely illustrative. Many other beneficial results can be attained by applying the disclosed subject matter in a different manner or by modifying the subject matter as will be described. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the disclosed subject matter and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  depicts the various components in which the techniques of this disclosure may be carried out; 
         FIG. 2  is a UML interaction diagram depicting a setup flow by which a TOTP shared secret per user per site is generated and maintained in the cloud service; 
         FIG. 3  is a UML interaction diagram depicting a login flow by which an end user logs into a site protected by TOTP-authentication using the technique of this disclosure; 
         FIG. 4  depicts the end user web browser and the end user mobile device interaction during the push notification operation initiated by the browser plug-in; and 
         FIG. 5  depicts the browser plug-in injecting the TOTP code into the TOTP authentication page to enable programmatic login according to this disclosure. 
     
    
    
     DETAILED DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT 
     The technique of this disclosure enables an end user to access a set of “sites” using a conventional TOTP-based two factor authentication (2FA) scheme but without requiring the user to manually enter TOTP codes in a mobile device, or to configure and maintain separate mobile applications (apps) for each site. As used herein, the term “site” typically refers to a website (or some protected portion thereof), but the reference to a “site” should be broadly construed to refer to any protected resource available from a server or other computing entity. Typically, the end user has associated therewith both a mobile device running a mobile authenticator app, as well as a second computing machine, such as a laptop or desktop running a web browser. The mobile authenticator app need not be a dedicated mobile app for the site, or that corresponds to the site&#39;s origin. The mobile device may be a smartphone, tablet or wearable (e.g., Apple iPhone® and iPad® tablet, iWatch™, Google® Glass™, and others), an IoT device or appliance, or the like. The mobile authenticator app be downloaded and installed via a mobile application delivery service, such as the Apple® App™ Store, Google Play Store (or equivalents), or it may be provided as a native application on the mobile device. 
     Referring now to  FIG. 1 , the technique of this disclosure involves a set of computing elements: an end user mobile device  100  running a generic authenticator app  102 , a computing entity  104  running a web browser  106 , and a cloud service  108  having an identity manager  110 . The identity manager  110  includes a data repository that stores TOTP secrets (namely, a TOTP-shared secret per user per site). Each of the mobile device  100  and  110  are enabled to provide TOTP-based 2FA. As also depicted, and according to a feature of this disclosure, web browser  106  is augmented with a browser plug-in  112  that facilitates various operations to facilitate cross-site TOTP-based 2FA. Although a browser plug-in  112  is a preferred implementation, the functions of this plug-in may also be implemented in other ways, e.g., an applet, an ActiveX control, JavaScript, native code, or the like. As will be seen, the plug-in  112  obviates manual entry by the end user of the TOTP code, thereby significantly increasing ease of authentication to sites using the described scheme. 
     In one non-limiting embodiment, the cloud service  108  is implemented in associated with a remote access architecture, such as LogMeIn®. 
     Cross-Site, TOTP-Based Two Factor Authenticated Access 
     According to this disclosure, a TOTP-based 2FA scheme works across sites  114   a - n  without requiring the end user to manually enter TOTP codes, or to have a dedicated mobile app for each particular site. In this approach, an end user leverages the cloud-based service  108  as a repository for maintaining and securing the TOTP secrets (i.e., a TOTP shared secret per user per site) that are generated as the end user interacts with various TOTP setup pages via the generic mobile device authenticator app  102 . The notion of “generic” here is not intended to be limiting; it just refers to the fact that the end user need use a distinct mobile app for each site that is enabled for access using TOTP-based authentication. A TOTP code typically is based on the TOTP secret and other factors, such as current date and time. 
     The cloud service  108  is accessed when the end user subsequently attempts a TOTP-based login from the client browser  106  to one of the sites  114  (whose TOTP shared secret is already maintained in the repository). As noted, the client browser  106  executes in a computing machine (e.g., a laptop)  104  distinct from the end user&#39;s mobile device  100 . To effect TOTP-based login, the end user opens the browser  106  to a TOTP authentication page. The login attempt from the client browser is detected by the browser plug-in  112 , and this detection initiates a push notification mechanism. In particular, and in a preferred embodiment, the browser plug-in  112  issues a request to the cloud service  108 , which responds by sending a push notification to the end user mobile device authenticator app  102 . If the end user responds to the push notification (e.g., within a given timeout), the cloud service identity manager  110  uses the TOTP secret stored in the repository to generate the TOTP code, which code is then sent back to the browser plug-in  112 . Conveniently, the browser plug-in  112  then automatically injects that code into an HTML login form of the TOTP authentication page, and then automatically submits the form. Thus, the user does not have to manually enter the TOTP code or take an affirmative (physical) action to even submit the form that has been filled-in with the TOTP code. Rather, according to this disclosure, once the user responds to the push notification, both the TOTP code entry and form submission occur in an automated manner under the control of the plug-in. The user is then logged in automatically to complete the process. 
     The above-described approach works for any site  114  for which the cloud service maintains the TOTP shared secret for the end user. In this manner, the cloud service  108  enables the end user to access secure resources without tedious end user physical interaction with the mobile app. In addition, the approach enables the end user to obtain these advantages using just a single authenticator app  102  (running the TOTP authentication scheme) instead of having to configure and use multiple different mobile apps across different web sites that implement this form of authentication. 
       FIG. 2  depicts a preferred embodiment of a process flow by which the user obtains a TOTP shared secret for a site. As depicted, the site includes a TOTP setup page  200 . The setup process begins when the user  202  visits the TOTP setup page  200  at step (1). That setup page displays a QR (or equivalent) code that is then scanned by the user&#39;s authenticator app  204  running on the end user&#39;s mobile device (which the user is assumed to possess). The authenticator app  204  obtains the scanned QR code at step (3) and uses it to generate the TOTP secret for the user for the site. In an alternative, the user may manually enter information from which the TOTP secret for the user for the site is generated. At step (4), the TOTP secret (for the user for the site) is sent to the cloud service  206 , which stores it in its associated identity manager. The cloud service  206  also uses the TOTP secret to generate a TOTP code, which is then returns to the authenticator app  204  at step (5). The authenticator app  204  then outputs the TOTP code to the user at step (6). At step (7), the end user types the code into the TOTP setup page  200 . As described, during the actual site authentication the end user does not need to enter any code manually, as the browser plug-in is used for this purpose. At step (8), the TOTP setup page returns an indication that setup is complete. As a result, the authenticator app  204  is now enabled to access the site using TOTP-based authentication. This process is then repeated for each site; as a consequence, the cloud service data repository stores a set of TOTP secrets for the end user (one per site). There may be as many TOTP secrets stored in the repository as there are TOTP-based 2FA accessible sites, but only the single authenticator app  204  is required to enable this configuration. 
       FIG. 3  depicts a preferred embodiment of a process flow by which the user obtains TOTP-based authenticated access to one of the sites protected by the authentication scheme. The process assumes that the setup flow shown in  FIG. 2  has been executed for a number of sites. 
     The routine begins at step (1) with the user  300  opening his or her browser  302  to the site&#39;s TOTP authentication page, which may require a previous login. At step (2), the browser plug-in  304  detects the TOTP authentication page being rendered in the browser  302 . At step (3), the browser plug-in  304  calls an application programming interface (API) of the cloud service  306  to request push authentication. At step (4), the cloud service  306  sends a push notification to the end user&#39;s mobile device authenticator app  308 , which is the same app used during the setup flow. At step (5), the user confirms the authentication request. At step (6), the authenticator app notifies the cloud service  306  that the user has approved the authentication request. The cloud service  306  then uses the stored TOTP shared secret for the user for the site to generate a TOTP code that will remain valid for a given time (e.g., 30 seconds). At step (7), the cloud service  306  sends that TOTP code back to the browser plug-in  304 . 
     At step (8), and according to this disclosure, the browser plug-in automatically injects the received TOTP code into the appropriate element of the HTML DOM (document object model) of the TOTP authentication page. Typically, this element is an HTML fill-in form. In this manner, the user does not need to type in the TOTP code manually; rather, at step (9), the browser plug-in  304  also programmatically submits the HTML form (e.g., by mimicking the “click to submit” button on the TOTP form), and by this action the user is logged in at step (10) automatically. This completes the process for the user&#39;s TOTP-authentication to this site. 
     Using just the single mobile device authenticator app, a similar login process may then be carried out at any other site for which the cloud service maintains the TOTP shared secret for the user. 
     Thus, according to this technique, the cloud service is augmented to store a TOTP shared secret per user per site. The cloud service also is enabled, e.g., through a cloud service API, to send back to the browser plug-in calculated TOTP codes. The authenticator app is augmented to provide the capability to call the cloud service API to store the TOTP shared secret per user per site in the cloud repository. The browser is augmented to include the browser plug-in (or equivalent code), which provides various functions to automate and streamline the TOTP mechanism, namely: the ability to detect if the user is visiting a TOTP authentication page, the ability to call the cloud service API to send out a push notification to the authenticator app, the ability to poll the cloud service, e.g., through a web API, to determine if the user confirmed (allowed) the authentication request, the ability to inject the TOTP code to the proper HTML element of the TOTP authentication page, and the ability to mimic the click on submit button of the TOTP form. 
       FIG. 4  depicts the browser  400  and the associated TOTP authentication page  402 , and the mobile device authenticator app  404  upon receipt by the mobile device of the push notification. As depicted, preferably the push notification page includes allow and deny buttons, together with a timer that displays a timeout for the notification. 
     Once the user selects allow (thus accepting the push notification),  FIG. 5  depicts that browser plug-in operation by which the TOTP code is automatically populated in the HTML fill-in form and the form submitted to complete the programmatic login. 
     The solution enables push notification-based TOTP authentication even for cloud applications that do not otherwise support two factor authentication. 
     Enabling Technologies 
     A mobile device comprises a CPU (central processing unit), computer memory, such as RAM, and a drive. The device software includes an operating system (e.g., Apple iOS, Google® Android™, or the like), and generic support applications and utilities. The device may also include a graphics processing unit (GPU). It also includes a touch-sensing device or interface configured to receive input from a user&#39;s touch and to send this information to processor. The touch-sensing device typically is a touch screen. The touch-sensing device or interface recognizes touches, as well as the position, motion and magnitude of touches on a touch sensitive surface (gestures). The device typically also comprises a high-resolution camera for capturing images (e.g., QR codes), an accelerometer, a gyroscope, and the like. 
     The push notification may be provided to the mobile device in any convenient manner, e.g., Apple Push Notification (APN) Service (APN), Google push notification services (for iOS or Android), or the like. 
     The authenticator app may be the LastPass® mobile password manager authenticator app (or equivalent), which is augmented to include the capability to call the cloud service to store the TOTP shared secret per user per site, as described above. 
     The TOTP secrets per site per user are securely stored in the cloud service using a secure repository, such as LogMeIn Cubby® or equivalent. 
     The cloud service may be associated with a remote access technology platform and service, such as LogMeIn. 
     In one embodiment, a cloud service provider provides the cloud service, the mobile device authenticator app, and the browser plug-in. 
     In another embodiment, the cloud service provider provides the cloud service and the mobile device authenticator app. 
     The cloud service is a technology platform that may comprise co-located hardware and software resources, or resources that are physically, logically, virtually and/or geographically distinct. Communication networks used to communicate to and from the platform services may be packet-based, non-packet based, and secure or non-secure, or some combination thereof. 
     More generally, the cloud service comprises a set of one or more computing-related entities (systems, machines, processes, programs, libraries, functions, or the like) that together facilitate or provide the described functionality described above. In a typical implementation, a representative machine on which the software executes comprises commodity hardware, an operating system, an application runtime environment, and a set of applications or processes and associated data, that provide the functionality of a given system or subsystem. As described, the functionality may be implemented in a standalone machine, or across a distributed set of machines. 
     The computing entity on which the browser and its associated browser plug-in run may be any network-accessible computing entity that is other than the mobile device that runs the authenticator app itself. Representative entities includes laptops, desktops, workstations, other mobile devices or machines associated with such other mobile devices, and the like. 
     While the above describes a particular order of operations performed by certain embodiments of the invention, it should be understood that such order is exemplary, as alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations, or the like. References in the specification to a given embodiment indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. 
     While the disclosed subject matter has been described in the context of a method or process, the subject disclosure also relates to apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes, or it may comprise a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including an optical disk, a CD-ROM, and a magnetic-optical disk, a read-only memory (ROM), a random access memory (RAM), a magnetic or optical card, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus. 
     While given components of the system have been described separately, one of ordinary skill will appreciate that some of the functions may be combined or shared in given instructions, program sequences, code portions, and the like. 
     The described commercial products, systems and services are provided for illustrative purposes only and are not intended to limit the scope of this disclosure. 
     The described technique may include other variants. In yet another alternative, the TOTP secret need not be maintained in the cloud service, but rather is maintained at the host (e.g., in a secure data store). After the push notification, the locally-stored secret is then used to generate the TOTP code, which is then populated (once again by the plug-in) into the fill-in form. In this example variant, the various operations involving the cloud service are not required. 
     In another variant, the dynamic generation and injection of the TOTP code (derived from the shared secret) occurs in a single device solution, in which case even the push notification may not be required. 
     The techniques herein provide for improvements to technology or technical field, namely, cloud-based access control, as well as improvements to various technologies such as secure authentication, and the like, all as described. 
     Having described our invention, what we now claim is as follows.