Multi-Server Location-Independent Authentication Certificate Management System

This invention relates to the authentication of parties on a data communication system and, in particular, to the use of a third-party authentication certificate authority in Internet client-server applications, which third-party authentication certificate authority functions to issue authentication certificates to servers and, in some cases, clients to validate the identity of the parties who are participating in a data exchange via the Internet.

It is a problem to authenticate the identity of parties who are participating in a data exchange on a data communication system, such as the Internet. This is typically accomplished by the use of a third-party authenticating authority, which is termed the authentication certificate granting authority. This issue is especially pertinent to the use of Internet, where a plethora of parties have access to the medium and security is rudimentary.

The use of an authentication certificate granting authority in Internet client-server applications relates to the authentication of the identity of the parties who are participating in a data exchange via the Internet. In particular, the authentication certificate granting authority represents an independent third-party entity which functions to issue authentication certificates to servers and, in some cases, clients. The authentication certificates include the use of a private-public RSA encryption key pair and requester distinguishing information to ensure the accurate identification of the requester. The requestor generates the private-public RSA encryption key pair, requestor distinguishing information and transmits this data to the authentication certificate granting authority with a request for an authentication certificate. The authentication certificate granting authority reviews the received data, verifies the identity of the requestor and then transmits the issued (signed) authentication certificate back to the requesting party in encrypted form for installation on the requestor's server. Any client who contacts the requester can access the authentication certificate via the public RSA encryption key and receive an assurance that the party to whom they have connected is indeed the desired party, not a bogus imitator. Likewise, the client can have an authentication certificate capability so that the server can verify the identity of the client for credit/subscription verification.

Unfortunately, the authentication certificate request, issuance and use processes are presently manually executed by the users. As a result, there is a high percentage of errors and mis-installation of authentication certificates on the requestor's server. The authentication certificate process is therefore burdensome, costly and typically mismanaged. The integrity of the authentication certificate process is therefore compromised. In addition, there is presently no capability to manage authentication certificates for multiple server/multiple service installations, where the multiple services are provided and/or the services are provided by a distributed set of servers.

The multi-server, location-independent authentication certificate management system overcomes the limitations of the existing systems by automating the authentication certificate request, grant and installation processes. Much of the data used to create the authentication certificate request is readily available information, such as: requestor identification, Internet locus, date, time. The authentication certificate management system populates the authentication certificate request with the available data and then prompts the user to provide the additional data in a simple manner, verifying the form and format of the input data. This automation of the authentication certificate request generation minimizes the number of malformed authentication certificate requests. Once the authentication certificate request is completed, it is transmitted to the authentication certificate granting authority for processing.

When the authentication certificate is granted, it is returned to the requesting server and stored therein for use by the requesting party. The authentication certificate management tool is capable of being installed on a shared basis, wherein multiple servers and/or multiple services are provided with the authentication certificate from a centralized source. Thus, receipt of the authentication certificate can be shared among a plurality of users. The authentication certificate management system also automatically tracks the expiration date of the authentication certificate and also ensures the secure storage of the RSA encryption key pair as well as the authentication certificate itself.

The authentication certificate management system therefore automates the certification process, from the generation of the authentication certificate request to the management of the received authentication certificate. This automation enables the user to avoid the difficulties associated with the manual creation of a request and the associated overhead of processing both the request and the authentication certificate receipt.

The multi-server, location-independent authentication certificate management system K automates the authentication certificate request, grant and installation process by populating the authentication certificate request with available data and then prompting the user to provide the additional data in a simple manner, verifying the form and format of the input data. This automation of the authentication certificate request generation minimizes the number of malformed authentication certificate requests.

FIG. 1 illustrates in block diagram form the overall architecture of the authentication certificate management system of the present invention and an environment in which it operates;

FIG. 2 illustrates additional details of the authentication certificate management system of the present invention;

FIG. 3 illustrates in flow diagram form the operational steps taken by the authentication certificate management system of the present invention to generate and deliver an authentication certificate;

FIG. 4 illustrates in block diagram form the flow of information among the various elements which comprise the authentication certificate management system of the present invention and an environment in which it operates for the authentication certificate request generation process; and

FIG. 5 illustrates in block diagram form the flow of information among the various elements which comprise the authentication certificate management system of the present invention and an environment in which it operates for the process which installs the signed authentication certificate.

FIG. 1 illustrates in block diagram form the overall architecture of the authentication certificate management system of the present invention and an environment in which it operates, while FIG. 3 illustrates in flow diagram form the operational steps taken by the authentication certificate management system of the present invention to generate and deliver an authentication certificate. In particular, data communication networks are in common use today, and a popular publicly available network is the Internet. The Internet functions to interconnect a large plurality of parties via a data communication medium, which is typically the public switched telecommunication network. Each party either individually connects to the Internet via a modem and a dialed up connection, using the existing telecommunication subscriber loop, or via a shared processor which interconnects a plurality of parties to common processing facilities and via a pool of shared modems to the Internet and optionally, other data communication facilities, such as a private intranet. The data communication network illustrated in FIG. 1 is simplified for the purpose of this description and comprises a data communication medium, such as Internet, which interconnects a first party herein termed "server S1", with third-party authentication certificate granting authority CA1. In addition, a gateway system G functions to interconnect the Internet with a plurality of local processors, C1-Cn via a local area network LAN, with the local processors including a second party herein termed "client C1", which itself can serve a plurality of subscribers, The server S1 can implement a plurality of services, each of which is capable of being operationally independent of the other services extant on server S1. Alternatively, the services extant on server S1 can be a collection of interrelated services. In any case, the server S1 provides one or more services to the clients C1 who interconnect with server S1.

The difficulty with a client C1 using the Internet to interconnect with server S1 and exchanging data therebetween and possibly engaging in financial transactions, is that there is no way of verifying the identity of the server S1 to whom the client C1 is connected. To obviate this problem, there are presently authentication certificate granting authorities CA1 who function to validate the identity of servers S1 who are connected to the Internet. The use of an authentication certificate granting authority CA1 in Internet client-server applications relates to the authentication of the identity of the parties who are participating in a data exchange via the Internet. In particular, the authentication certificate granting authority CA1 represents an independent third-party entity connected to the Internet and which functions to issue authentication certificates to servers S1 and, in some cases, clients C1. The authentication certificates include the use of a private-public RSA encryption key pair and requestor (either client or server) distinguishing information to ensure the accurate identification of the requester.

Authentication Certificates

The authentication certificate request and granted authentication certificate are both maintained in ASCII form. The request is architected in a predefined format and includes the requestor's name, telephone number and E-Mail address. In addition, the requestor's company name, organizational unit, locality, state or province in which the company is located, and common name or acronym for the company is included in the request. The form of the request requires the exact population of the fields with this data in ASCII form to result in a completed request, an example of which is:

Thus, the most minor of errors in the data input results is an authentication certificate request that is rejected by the certificate granting authority. The certificate granting authority generates a signed authentication certificate, which is also of form, format and content similar to that of the authentication certificate request, and must be processed in a manner to comply with the defined format.

Authentication Certificate Management System

FIG. 2 illustrates the architecture of the authentication certificate management system K of the present invention which is installed on the server S1 to accomplish the automatic generation of authentication certificate requests and the management of the signed authentication certificates received from the authentication certificate granting authority CA1. FIGS. 4 and 5 illustrate, in block diagram form, the flow of information among the various elements which comprise the authentication certificate management system K for the authentication certificate request generation process and for the process which installs the signed authentication certificate on the target applications of the server S1, respectively.

The authentication certificate management system K comprises a plurality of elements which are cooperatively operative to maintain and organize cryptographic keys which are used to secure Internet communications. The authentication certificate management system K includes applications for organizing the cryptographic keys and also provides cryptographic key maintenance facilities KM, such as requesting and updating cryptographic keys and cracking basic information from the cryptographic keys. The authentication certificate management system K is implemented in the form of a user interface application UI, which includes a graphical user interface FC which drives the display D and receives data from the user input devices KK, in well known fashion. The authentication certificate management system K also includes a DLL creation tool DCT which enables the user to create the DLLs required to provide the desired authentication certificate feature. The user typically creates a plurality of DLLs using the DLL creation tool DCT, with each DLL corresponding to the protocol required for a particular service AP1 resident on server S1. The various services AP1-APm that provide secure channel communications require that the cryptographic keys be stored and accessed in different ways. The various DLLs are therefore responsible for storing the cryptographic keys for these services in such a way that the associated service can use the cryptographic key. In addition, the DLLs notify the services of changes, retrieve the cryptographic keys for the authentication certificate management system K and provide any service specific functionality that is required. The authentication certificate management system K is a Microsoft File Creation application and the DLLs created by the authentication certificate management system K are Microsoft File Creation DLLs. When looking at the user interface UI, what is of concern is the contents of the left Tree pane of the directory tree when the user interface UI displays the directory and file structure of the server S1. This directory tree represents a system of networked machines, each containing the target services AP1-APm that are supported by the authentication certificate management system K. These target services AP1-APm each have cryptographic keys associated with and stored within them as part of the authentication certificate management process. The authentication certificate management system K maintains the file objects that represent the networked machines on which the target services AP1-APm reside. The header file "KeyObjs.h" located in the authentication certificate management system K, describes the file objects that are relevant to the external DLLs. The user generated DLLs must override both the target service class and the cryptographic key class. To accomplish this, each DLL maintains one service level object and the cryptographic keys that it contains. The user can retrieve the properties of either the target services AP1-APm or the cryptographic keys, and the DLL created by the user for the target service AP1-APm has an opportunity to provide specific configuration functionality at these times.

Class Structure

The interface for the authentication certificate management system K extensions consists of an application which defines a plurality of classes that the user must override to provide the specific functionality. The base class for all objects that can be in the tree view is the CTreeItem class. The objects included in this group are machines, target services, cryptographic keys and cryptographic key folders. In this structure, each tree item objects can contain other tree item objects. Thus, the user can add services to machines and cryptographic keys to services.

The CTreeItem class is defined in the authentication certificate management system K, and its purpose is to provide a base set of functionality for managing the object items in the tree. For example: given any CTreeItem derived object (that has been added to the tree), tree children can be added to this object, these tree children can be searched, parent object of this object can be retrieved, the name and icon of this object can be set, and the like. All these routines are described in the CTreeItem section of the header file.

All the sub-classes of the CTreeItem class have the option of allowing customizable properties through the OnUpdateProperties and OnProperties methods. If the user overrides these methods and treats them like a normal Microsoft File Creation command handler, the Properties item in the context menu is available and the user has the ability to process the Properties item as is well known.

Service Objects

The first thing the DLL generated by the user in the DLL creation tool DCT must do is create a service object and attach it to a machine. This service object is represented as the mid-level item in the directory tree. The service object must be a sub-class of the provided CService class, which is defined in the KeyObjs.h file. The main purpose of the service object is to provide the basic interface to the specific service on the target machine. The target machine can be a WWW server, pop3, nmtp and the like. When the authentication certificate management system K first attempts to establish contact with the target machine, it creates a CMachine object which targets that machine and asks all the extension DLLs to attach service objects to it. The authentication certificate management system K accomplishes this by calling the exported Load Service routine in the DLL and passing it the machine. This is the only explicitly exported routine that must be supported. The remainder of the process is achieved by the use of virtual tables.

If the selected service can be targeted to the designated machine, the user creates a CService object and adds this to the target machine by using the FAddToTree operation. At this time, the custom icons and the like can be installed on the target machine. The authentication certificate management system K must also override the PNewKey method in the user's service class. The cryptographic key class is also overridden. After adding the selected service object to the designated target machine, and returning from the LoadService routine, the user's service LoadKeys method is called. The parental CMachine is passed to this method if not previously loaded. The LoadKeys method enables the user to define the methodology used to access the designated service. This is accomplished by creating the necessary cryptographic keys and using the CKey process created objects by attaching them to the service object.

Once the user changes the cryptographic keys, the FCommitChangesNow method is called to write all of the cryptographic keys out to the designated service on the target machine. When the authentication certificate management system K disconnects from a target machine, it calls the CloseConnection method of all of the services attached to that machine object.

Cryptographic Key and CMachine Objects

The cryptographic key objects are the primary place that the sensitive cryptographic key information is stored. As the service object loads the stored cryptographic keys, the service object creates a plurality of cryptographic key objects and attaches these cryptographic key objects to the service object. The cryptographic key object is used to provide access to the public cryptographic key information and to maintain the cryptographic key's data. The cryptographic key object contains four pieces of information that must be securely stored and retrieved for each cryptographic key. This information comprises: private cryptographic key, public cryptographic key, certificate request data, and password. The authentication certificate management system K provided the user with the capability to copy/cut/paste cryptographic keys within and between services.

CMachine objects are created, held and maintained exclusively within the authentication certificate management system K. They are the parents of the service objects and are available for the user to obtain information regarding the target machine.

CKeyCrackedData Objects

CKeyCrackedData Objects is a utility object provided to give easy access to the contents of a cryptographic key's public certificate. The user creates an instance of CKeyCrackedData and calls CrackKey to pass the cryptographic key of interest.

System Operation

In operation, as shown in flow diagram form in FIG. 3 and in block diagram form in FIGS. 4 and 5, the requester, a user at server S1 in this example, initiates the authentication certificate request generation process at step 301 by selecting the certificate generation process for activation and inputing a predetermined set of requestor distinguishing information and a password 401 to the user interface UI. The user interface UI verifies the format of the requestor distinguishing information and forwards this received information to the security provider SP application resident on server S1. At step 302, the security provider application SP of the server S1 generates the private-public RSA encryption cryptographic key pair 404, and the authentication certificate request 405 which includes the user distinguishing information and the public cryptographic key. Both the private-public RSA encryption cryptographic key pair 404, and the authentication certificate request 405 are stored in the memory SM of the server S1 for future reference. At step 303, the server S1 transmits the authentication certificate request 405 to the authentication certificate granting authority CA1 in the form of a request for an authentication certificate.

The authentication certificate granting authority CA1 receives the transmitted data at step 304, reviews the received data, verifies the identity of the requestor. If the received data matches the requester validating information that is available to the authentication certificate granting authority CA1, the authentication certificate authority CA1 generates the signed authentication certificate. At step 305, the authentication certificate granting authority CA1 transmits the issued authentication certificate 502 back to the requesting party, server S1, in encrypted form for installation on the requestor's processor.

This process is accomplished by the server S1 as shown in steps 306-307 of FIG. 3 and in block diagram form in FIG. 5. At step 306, the signed authentication certificate 502, received from the authentication certificate granting authority CA1 is available for installation on one or more application processes AP1-APm on one or more target machines, such as server S1. This is accomplished by the user accessing the user interface UI and activating the install certificate option. The user is prompted by the user interface UI for the location of the signed authentication certificate 502 as well as the password for unlocking the cryptographic key pair. The user interface UI uses this information to activate the validate certificate process which interfaces with the security provider application SP. The validation occurs in the security provider application SP which matches the signed authentication certificate 502 with the private-public RSA encryption cryptographic key pair 506 and the validated authentication certificate request 405. At step 307, the server S1 stores the signed authentication certificate in memory for future access by clients by calling the service specific extension 507 which receives the cryptographic key pair 506 and the signed authentication certificate 502, and loads the signed authentication certificate on the target system S1. This is accomplished by the authentication certificate management system K querying the service specific extension 507 for the identity of the server S1 that it has previously connected to for an enumeration of the signed certificates that the service specific extension 507 maintains on the specified server S1. The authentication certificate management system K checks the expiration date of the signed authentication certificate 502 and if the date is within a predetermined time range or has expired, the authentication certificate management system K displays a graphical warning to the user about pending or actual expiration of the signed authentication certificate 502. The signed authentication certificate 502 can be moved and/or copied by use of the graphical interface on the user interface UI via the cut, copy and paste operations active thereon. Any client C1 who contacts the requester, server S1, can access the signed authentication certificate 502 via the public RSA encryption cryptographic key and receive an assurance that the party to whom they have connected is indeed the desired party, not a bogus imitator. Likewise, the client can have an authentication certificate capability so that the server S1 can verify the identity of the client for credit/subscription verification.

Typical Implementation Of A C++ User Interface

The following represents a C++ implementation of a typical DLL creation tool DCT in the user interface UI. This example illustrates the various elements which comprise the DLL creation tool DCT.

//protect this file against multiple inclusion

#ifndef KEYRINGOBJECTS

#define -KEYRINGOBJECTS-

/* STARTING

When creating your dll using this api, you will be mostly concerned the CService and CKey object classes. You are expected to override both of these and provide functionality for storing/retrieving the cryptographic keys and maintaining any service specific properties. Your dll needs only one exported routine "LoadService" defined below. This routine creates your overridden service object, populates it with retrieve cryptographic keys, and connects it to its host machine. The Machine object is passed in to this routine and the service is returned. If the host machine does not have your service on it, simply return from LoadService without attaching a service object to it.

PROPERTIES

You can enable the properties item in the context menu for either your cryptographic keys or your service by overriding the classes' OnUpdateProperties and OnProperties routines. These are very similar to MFC command handlers. In fact, they are just passed in from a command handler. You can do whatever you feel like in the OnProperties routine, although some sort of dialog is probably appropriate;

INFO STRING

Services and Cryptographic Keys also have the option of displaying a one-line information string in the right-hand pand of the cryptographic keyring application. To do this, override the GetlnfoString method and return something.

Cryptographic key NAMES

All cryptographic keys have names and you are expected to store/retrieve them. The name is automatically editable in the right-hand pane of the main app. The name, however, can be different from the caption in the tree view. To do this, override the UpdateCaption routine and use it to call FSetCaption with a modified string name. An example can be seen in the W3 server, which displays the name of the cryptographic key followed by the ip address it is attached to in brackets. MyKey<100.200.150.250>

CUSTOM ICONS IN TREEVIEW

You can add your own custom icons to the tree view in addition to the standard machine, cryptographic key, unfinished cryptographic key icons. To do this, get the CTreeCtrl object by calling PGetTreeCtrl. Then use that to get the CImageList. From there, you can add your own icons (making sure to note down the starting index) See CTreeCtrl and CImageList docs for details.