Automatic re-authentication

• US 7,475,421 B2
• Filed: 01/25/2006
• Issued: 01/06/2009
• Est. Priority Date: 04/01/2002
• Status: Expired due to Fees

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Garms, Jason, Field, Scott A., Abdo, Nadim Y., Loh, Alvin, Overton, Adam J., Parsons, John E. Jr.
• Primary Examiner(s): Revak; Christopher A
• Application Number:
  US11/275,711
• Publication Number:
  US 20060117106A1
• Time in Patent Office: 1,077 Days
• Field of Search: None
• US Class Current: 726/3
• CPC Class Codes: G06F 13/107 Terminal emulation
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/126 the source of the received data
• CPC Class Codes: H04L 67/14 Session management for real-time applications in data packet communications networks H04L65/1066

Abstract

Upon successfully authenticating a client device with a server system, the client device and server system share auto-reconnect data. Upon subsequently losing and re-establishing communications with the server system, the client sends an auto-authenticate request to the server. The auto-authenticate request includes a session verifier that is based at least in part on the shared auto-reconnect data. The server validates the session verifier. If the validation is successful, the server automatically re-authenticates the client device.

Claims

1. A server system programmed to perform actions comprising:

authenticating a client device for a particular server session;

sharing auto-reconnect data with the client device, the auto-reconnect data including a session ID associated with the particular server session and a first random number;

after losing communications with the client device, sharing a second random number with the client device, and receiving from the client device the session ID and a session verifier that is derived at least in part from the first and second random numbers;

validating the session verifier;

upon successfully validating the session verifier, automatically re-authenticating the client device for the particular server session.

2. A server system as recited in claim 1, wherein said re-authenticating is performed without requesting user credentials.

3. A server system as recited in claim 1, wherein said sharing auto-reconnect data is performed through a secure data communications channel.

4. A server system as recited in claim 1, wherein automatically re-authenticating the client device for the particular server session includes automatically re-authenticating the client device based at least partially on the session ID.

5. A server system as recited in claim 1, wherein

the session verifier comprises a one-way hash based at least in part on the first and second random numbers.

6. A server system as recited in claim 1, wherein said actions further comprise periodically changing at least a portion of the auto-reconnect data and sending at least said changed portion to the client device.

7. A server system as recited in claim 1, further comprising periodically changing the first random number and sending it to the client device.

8. A client device programmed to perform actions comprising:

providing user credentials to a server system to authenticate the client device with the server system;

initiating a server session on a server system, the server session being associated with the client device;

sharing auto-reconnect data with the server system, the auto-reconnect data including a session ID and a first random number;

after losing and re-establishing communications with the server system, sharing a second random number with the server system, and deriving a session verifier at least in part from the first and second random numbers;

requesting automatic re-authentication by the server system without providing user credentials, wherein said requesting comprises sending the session ID and the session verifier to the server system.

9. A client device as recited in claim 8, wherein said actions further comprise periodically sharing a changed first random number with the server system.

10. A client device as recited in claim 8, wherein the auto-reconnect data is received from the server system.

11. A methods comprising:

establishing data communications between a client device and a server system;

authenticating the client device for a particular server session;

sharing auto-reconnect data between client device and the server system, the auto-reconnect data including a session ID associated with the particular server session and a first random number;

re-establishing data communications between the client device and the server system after a communications failure;

after re-establishing data communications, sharing a second random number between the client device and the server device;

deriving a client session verifier at the client device at least in part from the first and second random numbers;

providing the client session verifier and the session ID from the client device to the server system;

deriving a server session verifier at the server system at least in part from the first and second random numbers;

validating the client session verifier by comparing it to the server session verifier;

upon successfully validating the session verifier, automatically re-authenticating the client device for the particular server session.

12. A method as recited in claim 11, wherein

the client session verifier and server session verifier comprise a one-way hash based at least in part on the first and second random numbers.

13. A method as recited in claim 11, further comprising periodically changing at least a portion of the auto-reconnect data and sharing at least said changed portion between the client device and the server device.

14. A method as recited in claim 11, further comprising periodically changing the first random number and sharing it between the client device and the server device.