Providing security for external access to a protected computer network

• US 20050091515A1
• Filed: 10/26/2004
• Published: 04/28/2005
• Est. Priority Date: 03/12/2002
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Reactivity, Inc. (Cisco Systems, Inc.)
• Inventors: Lilly, Jhon O. III, Hanson, Michael, Roddy, Brian J.
• Granted Patent: US 7,043,753 B2
• Time in Patent Office: Days
• US Class Current: 713/188
• CPC Class Codes: H04L 63/02 for separating internal from external traffic, e.g. firewalls
• CPC Class Codes: H04L 63/0218 Distributed architectures, e.g. distributed firewalls
• CPC Class Codes: H04L 63/0236 Filtering by address, protocol, port number or service, e.g. IP-address or URL
• CPC Class Codes: H04L 63/0245 Filtering by information in the payload
• CPC Class Codes: H04L 63/0464 using hop-by-hop encryption, i.e. wherein an intermediate entity decrypts the information and re-encrypts it before forwarding it
• CPC Class Codes: H04L 63/08 for authentication of entities cryptographic mechanisms or cryptographic arrangements for entity authentication H04L9/32
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 63/105 Multiple levels of security
• CPC Class Codes: H04L 63/20 for managing network security; network security policies in general filtering policies H04L63/0227

Abstract

A system and method are disclosed for providing controlled access via an external network to a resource residing on an internal network. An external request addressed to a first computer system associated with the internal network is received at the first computer system via the external network. The external request comprises a request from a requesting party for response data from a second computer system associated with the internal network. At least part of the content of the external request is analyzed at the first computer system to determine whether the request is authorized. If it is determined that the request is authorized, the request is processed.

Claims

1. A method for providing controlled access via an external network to a resource residing on an internal network, comprising:

receiving at a mediating firewall associated with the internal network an external request received via the external network and addressed to the mediating firewall, the external request comprising a request from a requesting party for response data associated with an internal computer system associated with the internal network;

analyzing at the mediating firewall at least part of the content of the external request to determine whether the request is authorized; and

if it is determined that the request is authorized, sending from the mediating firewall to the internal computer system an internal request, generated by the mediating firewall, comprising a request for said response data.

2. The method of claim 1, further comprising authenticating the request at the mediating firewall.

3. The method of claim 1, further comprising checking the integrity of the request at the mediating firewall.

4. The method of claim 1, wherein the processing comprises decrypting at least part of the request at the mediating firewall.

5. The method of claim 1, wherein the requesting party comprises a process running on an external computer system, the external computer system not being associated with the internal computer network.

6. The method of claim 1, wherein the internal request is sent using a protocol that is different than the protocol used by the requesting party to send the external request.

7. The method of claim 1, wherein the internal request comprises an authentication as having originated from the mediating firewall.

8. The method of claim 1, wherein at least part of the internal request is encrypted.

9. The method of claim 8, wherein the external request sent by the requesting party is encrypted and the encryption method used to encrypt the internal request is different than the encryption method used by the requesting party to encrypt the external request.

10. The method of claim 1, further comprising:

receiving at the mediating firewall an internal response from the internal computer system.

11. The method of claim 10, wherein the internal response comprises the response data.

12. The method of claim 10, further comprising processing the internal response.

13. The method of claim 12, wherein processing the internal response comprises decrypting the internal response.

14. The method of claim 10, further comprising preparing an external response to be sent to the requesting party.

15. The method of claim 14, wherein the external response comprises the response data.

16. The method of claim 14, further comprising sending the external response to the requesting party.

17. The method of claim 14, wherein the data format used in the external response is different from that used in the internal response.

18. The method of claim 14, wherein the protocol used to send the external response is different than the protocol used to send the internal response.

19. The method of claim 1, wherein whether the external request is authorized is based at least in part on the identity of the requesting party.

20. A system for providing controlled access via an external network to an internal network, comprising:

an external network connection configured to receive an external request sent via the external network;

a processor associated with a mediating firewall associated with the internal network, the processor being configured to;

analyze at least part of the content of the external request to determine whether the request is authorized; and

process the request in the event it is determined that the request is authorized; and

an internal network connection configured to enable an internal request to be sent via the internal network to an internal computer system associated with the internal network;

wherein the external request is addressed to the mediating firewall and comprises a request for response data from the internal computer system and wherein said processor is configured to send from the mediating firewall to the internal computer system an internal request comprising a request for said response data.

21. A computer program product for providing controlled access via an external network to an internal network, the computer program product being embodied in a computer readable medium and comprising computer instructions for:

receiving at a mediating firewall associated with the internal network an external request sent via the external network and addressed to the mediating firewall, the external request comprising a request from a requesting party for response data from a second an internal computer system associated with the internal network;

analyzing at the mediating firewall at least part of the content of the external request to determine whether the request is authorized; and

if it is determined that the request is authorized, sending from the mediating firewall to the internal computer system an internal request comprising a request for said response data.