Microsoft Technology Licensing, LLC

Other

William H Dixon

Brian D Swander

Abolade Gbadegesin

Abhishek Abhishek

Jeromy Scott Statia

Krishna Ganugapati

Lee Walker

Christopher J Engdahl

A secure DNS query may be made by establishing a secure connection with a specific DNS server to determine an address for a hostname. A client device may have a database that may contain a record of a secure DNS server for one or more hostnames. When a DNS request contains one of the specified hostnames, an authenticated session may be created with the designated secure DNS server and a network address for the hostname is returned using the session. The authenticated session may authenticate a client device to the server as well as authenticate the server to the client. In some embodiments, the secure DNS server may accept connections from authenticated clients and may disregard connection requests from non authenticated clients.

Secure DNS query

A method and system is disclosed for managing and implementing a plurality of network policies in a network device. Each of the plurality of policies are defined by one or more filters. The filters are installed in a policy engine. A layer identifies the network policy to be applied to a packet by sending a request to the policy engine. The policy engine then returns the policy to the requesting layer. The method and system may be used to implement a programmable, host-based, distributed, authenticating firewall that enables security and other policies to be applied at several protocol layers.

Method and framework for integrating a plurality of network policies

A method and system for mapping security parameters to a plurality of network sessions is provided. A responding computer maps the security parameters to the combination of packet parameters and a mapped port value used in each of the plurality of sessions. The packet parameters includes IP source and destination addresses, application source and destination ports and protocol type. The mapped port value is assigned by the responding computer to maintain a unique mapping between each security association and each network session.

Method for mapping security associations to clients operating behind a network address translation device

The invention uses a three phase IKE protocol main mode negotiation to implement a port float algorithm that permits UDP encapsulated ESP traffic to traverse an IPSec-aware NAT. The NAT is connected to a plurality of client computers on a private network and provides an interface between the client computers and a server connected to a public network. In a first phase, a client and the server determine whether both are capable of sending UDP encapsulated ESP packets. In a second phase, the client and server conduct NAT discovery and determine whether the client, server, or both operate behind a NAT. In a third phase, the client and server initiate a port float algorithm, moving a destination UDP port specified in IKE packets from a first port value to a second port value. The server maintains a data structure that allows the server to identify the client sending IKE packets after exiting the second phase and entering the third phase.

Method and apparatus for traversing a translation device with a security protocol

A method of network security policy administration for a network client uses a finite state machine to maintain the security policy information of the network client. Security policy information may originate in a remote source such a directory storage as well as, or alternatively, locally in cache and local store locations. The finite state machine has four states, Initial, DS, Cache, and Local, and transitions between states responsive to the availability of security policy information from the various policy information sources. Furthermore, security policy updates occur via a differencing mechanism, wherein only filters that have changed are updated, minimizing impact on unchanged policy filters and the traffic protected by them, and minimizing lulls in policy coverage.

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Seattle, WA, United States of America

William H Dixon