Proxy-less secure sockets layer (SSL) data inspection

Information

  • Patent Grant
  • 12368703
  • Patent Number
    12,368,703
  • Date Filed
    Tuesday, September 1, 2020
    4 years ago
  • Date Issued
    Tuesday, July 22, 2025
    4 days ago
Abstract
Some embodiments of proxy-less Secure Sockets Layer (SSL) data inspection have been presented. In one embodiment, a secured connection according to a secured network protocol between a client and a responder is setup via a gateway device, which is coupled between the client and the responder. The gateway device transparently intercepts data transmitted according to the secured network protocol between the client and the responder. Furthermore, the gateway device provides flow-control and retransmission of one or more data packets of the data without self-scheduling the packet retransmissions using timeouts and based on the packet retransmission logic of either the client-side or the responder side of the connection. The gateway device is further operable to perform security screening on the data.
Description
TECHNICAL FIELD

The present invention relates to intrusion detection and prevention in a networked system, and more particularly, to providing proxy-less data inspection.


BACKGROUND


FIG. 1 illustrates a current networked system 100. Conventionally, to make a secure connection between the client 110 and a server 120, the following operations are performed. A web browser on the client is configured to point to a proxy Internet Protocol (IP) address for Hypertext Transfer Protocol Secured (HTTPS) connections. An initial CONNECT request with full Universal Resource Locator (URL) is sent by the client 110 to a proxy 130 between the client 110 and the server 120. The proxy 130 connects to the HTTPS server 120 using the full URL provided in the client's 110 request. The HTTPS server 120 sends back a certificate. The proxy 130 strips out relevant information from the certificate (e.g., common name, etc.) and creates a new certificate signed by a certification-authority certificate, which the user of the proxy 130, i.e., the client 110, has indicated to trust. Eventually, the newly generated certificate is passed to the client 110 and the client 110 accepts the certificate.


Data is decrypted on one connection, and clear-text (i.e., decrypted data) is inspected. Then the data is re-encrypted when sent on another connection. As a result, two TCP/SSL connections 115 and 125 are established, namely, a first connection 125 between the proxy 130 and the server 120, and a second connection 115 between the client 110 and the proxy 130, where each connection supports full Transmission Control Protocol (TCP) flow-control logic. Packet loss re-transmissions are handled individually for each connection and all retransmission scheduling is done on the proxy 130.


One disadvantage of the above scheme is that the client's 110 browser has to be configured with the proxy's IP address. The above scheme is not so scalable due to full TCP based flow control implemented on the inspecting device and due to the fact that sockets do not scale well for large number of connections. Furthermore, it is difficult to configure for non-HTTP protocols.





BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which:



FIG. 1 illustrates a conventional networked system with a proxy.



FIG. 2 illustrates one embodiment of a proxy-less system.



FIG. 3 illustrates one embodiment of a method to establish a secured connection between a client and a responder without a proxy.



FIG. 4 illustrates one embodiment of a method to dynamically generate a certificate.



FIG. 5 illustrates one embodiment of a method to perform proxy-less data inspection.



FIG. 6 illustrates a block diagram of an exemplary computer system, in accordance with one embodiment of the present invention.





DETAILED DESCRIPTION

Described herein are some embodiments of proxy-less Secured Sockets Layer (SSL) data inspection. In one embodiment, a TCP connection is established between a client (a.k.a. the initiator) and a HTTPS server (a.k.a. the responder). The client's web browser (or any network access application) issues a connection request, e.g., SSL Hello, to the server. A proxy-less SSL inspection appliance, such as a gateway device, intercepts the Hello request and sends an identical copy to the server. In response, the server sends a certificate to the proxy-less SSL inspection appliance. The proxy-less SSL inspection appliance strips out relevant information from the certificate (e.g., common name, etc.) and creates a new certificate signed by a certification-authority certificate, which the client has indicated to trust. The newly generated certificate is passed from the proxy-less SSL inspection appliance to the client. The client accepts the newly generated certificate because this certificate is signed by the certification-authority certificate. Packets received by the proxy-less SSL inspection appliance are decrypted and inspected by the proxy-less SSL inspection appliance using various mechanisms, such as deep packet inspection (DPI), content filtering, etc. After inspection, the proxy-less SSL inspection appliance re-encrypts the packets and forwards the packets to the client if there is no security issue with passing the packets. If potential malware or forbidden content is found in the packets, then the proxy-less SSL inspection appliance may block the packets from the client. The proxy-less SSL inspection appliance may further send a message to warn the client of its finding.


In the above scheme, TCP re-transmission logic is event driven based on retransmissions from server side and client side, rather than being scheduled by a TCP stack on each side of the TCP connection. In other words, the proxy-less SSL inspection appliance provides flow-control and retransmission of data packets without self-scheduling the packet retransmission using timeouts, but rather, based on the packet retransmission logic of either the client-side or server-side of the connection. As a result, security inspection of clear-text can take place at the proxy-less SSL inspection appliance without using a full TCP-based proxy.


In the following description, numerous details are set forth. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the present invention.


Some portions of the detailed descriptions below are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.


It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.


The present invention 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 floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMS), EPROMs, EEPROMs, flash memory, magnetic or optical cards, or any type of media suitable for storing electronic instructions, and each coupled to a computer system bus.


The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general-purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the required method steps. The required structure for a variety of these systems will appear from the description below. In addition, the present invention is not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the invention as described herein.



FIG. 2 illustrates one embodiment of a proxy-less system. The proxy-less system 200 includes a client 210, a server 220, and a gateway device 230 coupled between the client 210 and the server 220. When the client 210 initiates a connection with the server 220, the client 210 may be referred to as an initiator and the server 220 may be referred to as a responder, and vice versa. The client 210 and the server 220 may be implemented using various computing devices, such as personal computers, laptop computers, personal digital assistants (PDAs), cellular telephones, Smartphones, etc. The gateway device 230 may also be implemented using various computing devices, such as those listed above. In some embodiments, the gateway device 230 is implemented as a set-top box coupled to the client 210 locally. The gateway device 230 acts as a “middleman” device between the client 210 and the server 220.


In some embodiments, the gateway device 230 may intercept a client connection request from the initiator, say the client 210, before it reaches the intended endpoint, say the server 220, and generate IP TCP packets as replies as if they were originated from that endpoint, and to do the same for communication with the original responder endpoint. Separate TCP state is kept for communication with the initiator and responder endpoints at the gateway device 230. This state contains data allowing the gateway device 230 to do flow-control and retransmission. For example, the state may include a sequence number of the last packet received, which may be used in determining if the next packet is dropped or lost. In order to increase scalability and to simplify the gateway device 230, TCP retransmission to a receiver may only be done when a retransmit from the sender is seen in some embodiments. Data from one side is not acknowledged until it is acknowledged by the opposite endpoint.


During connection setup, the TCP handshake is allowed to complete between the two hosts, but once the client attempts to send data to negotiate a secured connection (e.g., SSL), the request is passed to an internal secured endpoint (such as the internal secured endpoint 231 or 235 in FIG. 2) on the gateway device 230. Before this endpoint continues negotiation, the gateway device 230 may first initiate a secured client connection to the responder endpoint, store the responder certificate details, and complete the key exchange.


Afterwards, secured connection certificate and/or key exchange and negotiation is completed with the initiator, optionally using a certificate dynamically generated with details from the responder certificate as discussed below. Because the gateway device 230 chooses the public keys and does the negotiation to terminate the SSL connection, it is possible for the gateway device 230 to inspect the clear text data sent by both sides. Once both connections are established, decrypted clear text data is transferred from one connection to the other as follows.


In some embodiments, the data received by the gateway device 230 from the initiator may be encrypted and sent over the responder secured connection, and vice versa. In this way, it is possible to view and/or modify the clear text data sent from one endpoint to the other. No configuration on either end (i.e., the client 210 and the server 220) is necessary because the gateway device 230 which sits on the path between the two sides can detect when to attempt secured decrypting and/or re-encrypting by detecting a connection to a known SSL TCP port, or by detecting a presence of a valid SSL Hello packet to any port. As opposed to a conventional explicit third party SSL proxy, where the connecting client must be aware of the forwarding proxy relationship and contact the proxy SSL endpoint directly, both sides' TCP and SSL states appear to be communicating with their original endpoints, so this interception is transparent to both sides.


As discussed above, the gateway device 230 may dynamically generate a certificate in the process of establishing a secured connection between the client 210 and the server 220. In some embodiments, the client 210 may use RSA encryption to verify a certificate delivered by the server 220 is “signed” by a third party authority that has previously been trusted by the client 210. For instance, the client 210 may have previously accepted a certification-authority (CA) certificate from this third party. When the gateway device 230 intercepts the secured connection and responds using its own internal secured endpoint 235, it is necessary to deliver a certificate containing a public key that the gateway device 230 has the private key for, so that key exchange is possible. The certificate also contains attributes to identify the endpoint to the client 210. In general, the client 210 may verify these attributes before continuing to negotiate further. If the attributes do not all match what is expected, the client 210 may warn the user before continuing. In order to appear legitimate, the certificate details from the responder certificate from the server 220 are stored by the gateway device 230 and a new certificate is generated that appears substantially identical, except for the public key. The newly generated certificate is then signed by the CA certificate, which the client 210 has previously trusted. In this way, all checks done by the client 210 on the certificate may pass, and the client may complete the connection and begin sending data to the server 220 via the gateway device 230.



FIG. 3 illustrates one embodiment of a method to establish a secured connection between a client and a responder without a proxy. The method may be performed by processing logic that may comprise hardware (e.g., circuitry, dedicated logic, programmable logic, processing cores, etc.), software (such as instructions run on a processing core), firmware, or a combination thereof.


Initially, processing logic detects a client's attempt to send data to negotiate a secured connection with a responder (processing block 310). For example, the secured connection may be SSL. Then processing logic intercepts the client's request to responder (processing block 312). Processing logic initiates a secured client connection to the responder (processing block 314). In response, the responder may send a certificate to processing logic. Processing logic stores the responder's certificate details (processing block 316). Then processing logic completes key exchange with the responder (processing block 318). Finally, processing logic completes secured connection certificate and/or key exchange and negotiation with the client (processing block 319). To complete secured connection certificate and/or key exchange and negotiation with the client, processing logic may dynamically generate a new certificate to send to the client.



FIG. 4 illustrates one embodiment of a method to dynamically generate a certificate. The method may be performed by processing logic that may comprise hardware (e.g., circuitry, dedicated logic, programmable logic, processing cores, etc.), software (such as instructions run on a processing core), firmware, or a combination thereof.


Initially, processing logic receives a certificate from the responder at a gateway device (processing block 410). Then processing logic stores details of the certificate, such as common name, on the gateway device (processing block 412). Processing logic generates a new certificate substantially identical to the certificate from the responder at the gateway device (processing block 414). Processing logic inserts a public key into the certificate at the gateway device, where the gateway device has the private key for the public key (processing block 416). In some embodiments, the public key is pre-generated at the gateway device along with its private key pair. Finally, processing logic signs the new certificate with a certificate authority (usually a trusted third party) certificate, which the client has previously agreed to trust as a signing authority (processing block 418). Note that the same public key may be inserted into all new certificates subsequently generated at the gateway device for the current connection.



FIG. 5 illustrates one embodiment of a method to perform proxy-less data inspection. The method may be performed by processing logic that may comprise hardware (e.g., circuitry, dedicated logic, programmable logic, processing cores, etc.), software (such as instructions run on a processing core), firmware, or a combination thereof.


Initially, processing logic uses a gateway device (such as the gateway device 230 shown in FIG. 2) to set up a secured connection according to a secure network protocol (e.g., SSL) between a client and a responder (processing block 510). Details of some embodiments of the secured connection setup have been discussed in details above. Then processing logic uses the gateway device to transparently intercept data transmitted between the client and the responder (processing block 512). Processing logic further uses the gateway device to provide flow control and retransmission of data packets transmitted between the client and the responder (processing block 514). The flow control and retransmission of data may be provided without self-scheduling the packet retransmission using timeouts at the gateway device, but rather, based on the packet retransmission logic of either the client-side or the responder-side of the connection. Using the gateway device, processing logic performs security screening on data packets transmitted between the client and the responder (processing block 516). The security screening may include content filtering, deep packet inspection, etc.



FIG. 6 illustrates a diagrammatic representation of a machine in the exemplary form of a computer system 600 within which a set of instructions, for causing the machine to perform any one or more of the methodologies discussed herein, may be executed. In alternative embodiments, the machine may be connected (e.g., networked) to other machines in a LAN, an intranet, an extranet, and/or the Internet. The machine may operate in the capacity of a server or a client machine in client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine may be a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a server, a network router, a switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein.


The exemplary computer system 600 includes a processing device 602, a main memory 604 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory 606 (e.g., flash memory, static random access memory (SRAM), etc.), and a data storage device 618, which communicate with each other via a bus 632.


Processing device 602 represents one or more general-purpose processing devices such as a microprocessor, a central processing unit, or the like. More particularly, the processing device may be complex instruction set computing (CISC) microprocessor, reduced instruction set computing (RISC) microprocessor, very long instruction word (VLIW) microprocessor, or processor implementing other instruction sets, or processors implementing a combination of instruction sets. Processing device 602 may also be one or more special-purpose processing devices such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), network processor, or the like. The processing device 602 is configured to execute the processing logic 626 for performing the operations and steps discussed herein.


The computer system 600 may further include a network interface device 608. The computer system 600 also may include a video display unit 610 (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device 612 (e.g., a keyboard), a cursor control device 614 (e.g., a mouse), and a signal generation device 616 (e.g., a speaker).


The data storage device 518 may include a machine-accessible storage medium 630 (also known as a machine-readable storage medium or a computer-readable medium) on which is stored one or more sets of instructions (e.g., software 622) embodying any one or more of the methodologies or functions described herein. The software 622 may also reside, completely or at least partially, within the main memory 604 and/or within the processing device 602 during execution thereof by the computer system 600, the main memory 604 and the processing device 602 also constituting machine-accessible storage media. The software 622 may further be transmitted or received over a network 620 via the network interface device 608.


While the machine-accessible storage medium 630 is shown in an exemplary embodiment to be a single medium, the term “machine-accessible storage medium” should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more sets of instructions. The term “machine-accessible storage medium” shall also be taken to include any medium that is capable of storing, encoding or carrying a set of instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies of the present invention. The term “machine-accessible storage medium” shall accordingly be taken to include, but not be limited to, solid-state memories, optical and magnetic media, etc. In some embodiments, machine-accessible storage medium may also be referred to as computer-readable storage medium.


Thus, some embodiments of cloud-based gateway anti-virus scanning have been described. It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims
  • 1. A method for establishing a proxy-less communication session, the method comprising: performing a first key exchange of a first public key between a gateway device and a server;performing a second key exchange of a second public key between the gateway device and a client device after the first key exchange;receiving a data packet at the gateway device, wherein the data packet includes information encrypted at the server using the first public key;decrypting the encrypted information included in the data packet received from the server, wherein the decrypted information is inspected in accordance with deep packet inspection by the gateway device;generating a first certificate that includes the first public key and a set of attributes associated with the client device;storing certificate details of the first certificate in gateway memory of the gateway device;generating encrypted data in response to an indication the decrypted information passes inspection;detecting when to transmit the encrypted data based on transmission information communicated from the server and the client device and verification of the set of attributes associated with the client device;sending the first certificate and the encrypted data transparently from the gateway device to the client device, wherein sending the first certificate is transparent to the server, and wherein the encrypted data are decrypted at the client device using the second public key;receiving a first acknowledgement from the client device acknowledging receipt of the encrypted data included in the data packet have been received by the gateway device;sending a second acknowledgement from the gateway device to the server based on the receipt of the first acknowledgement from the client device, wherein sending the second acknowledgement is transparent to the client device, and wherein the second acknowledgement indicates that the data packet has been received, and the second acknowledgement is not sent to the server until after the first acknowledgement is received from the client device indicating that the encrypted data included in the data packet have been received at the client device;generating a second certificate that is a modified copy of the first certificate, wherein a public key of the second certificate is different from a public key of the first certificate, and wherein a remaining portion of the second certificate is identical to a remaining portion of the first certificate; andestablishing the communication session between the client device and the server using the gateway device without a proxy based on an identification that the second certificate matches a previously trusted certificate, wherein the gateway device provides flow control of data transmitted between the client device and the server in the established communication session.
  • 2. The method of claim 1, further comprising receiving the first certificate from the server, and passing the second certificate to the client device.
  • 3. The method of claim 1, wherein the encrypted information corresponds to the data packet, and further comprising: identifying that the data packet includes data associated with a security screening based on the inspection; andexecuting the security screening using the gateway device based on the identification.
  • 4. The method of claim 3, wherein executing the security screening includes blocking a further data packet from being transmitted to the client device.
  • 5. The method of claim 3, wherein executing the security screening includes sending a warning message from the gateway device to the client device.
  • 6. The method of claim 3, wherein inspecting the decrypted information includes the deep packet inspection by the gateway device.
  • 7. The method of claim 3, wherein executing the security screening includes using the gateway device to filer content of data received from the server.
  • 8. The method of claim 1, further comprising: intercepting one or more data packets transmitted according to a secured network protocol between the client device and the server while remaining transparent to the client device and the server;maintaining a first set of state information for the client device, the first set of state information including a sequence number of a last packet received by the client device; andretransmitting the last data packet corresponding to the sequence number to the client device based on the first set of state information.
  • 9. The method of claim 8, wherein retransmitting the last data packet is further based on a retransmission received from the server.
  • 10. The method of claim 1, further comprising attempting decryption of the information that is encrypted in the data packet based on detection of a connection to a known SSL TCP port.
  • 11. The method of claim 1, further comprising attempting decryption of the information that is encrypted in the data packet based on detection of a valid secure socket layer (SSL) Hello packet to a known port.
  • 12. A non-transitory computer-readable storage medium having embodied thereon a program executable by a processor for implementing a method for establishing a proxy-less communication session, the method comprising: performing a first key exchange of a first public key between a gateway device and a server;performing a second key exchange of a second public key between the gateway device and a client device after the first key exchange;receiving a data packet at the gateway device, wherein the data packet includes information encrypted at the server using the first public key;decrypting the encrypted information included in the data packet received from the server, wherein the decrypted information is inspected in accordance with deep packet inspection by the gateway device;generating a first certificate that includes the first public key and a set of attributes associated with the client device;storing certificate details of the first certificate in gateway memory of the gateway device;generating encrypted data in response to an indication the decrypted information passes inspection;detecting when to transmit the encrypted data based on transmission information communicated from the server and the client device and verification of the set of attributes associated with the client device;sending the first certificate and the encrypted data transparently from the gateway device to the client device, wherein sending the first certificate is transparent to the server, and wherein the encrypted data are decrypted at the client device using the second public key;receiving a first acknowledgement from the client device acknowledging receipt of the encrypted data included in the data packet have been received by the gateway device;sending a second acknowledgement from the gateway device to the server based on the receipt of the first acknowledgement from the client device, wherein sending the second acknowledgement is transparent to the client device, and wherein the second acknowledgement indicates that the data packet has been received, and the second acknowledgement is not sent to the server until after the first acknowledgement is received from the client device indicating that the encrypted data included in the data packet have been received at the client device;generating a second certificate that is a modified copy of the first certificate, wherein a public key of the second certificate is different from a public key of the first certificate, and wherein a remaining portion of the second certificate is identical to a remaining portion of the first certificate; andestablishing the communication session between the client device and the server using the gateway device without a proxy based on an identification that the second certificate matches a previously trusted certificate, wherein the gateway device provides flow control of data transmitted between the client device and the server in the established communication session.
  • 13. The non-transitory computer-readable storage medium of claim 12, wherein the encrypted information corresponds to the data packet, and further comprising instructions executable to: identify that the data packet includes data associated with a security screening based on the inspection; andexecute the security screening using the gateway device based on the identification.
  • 14. The non-transitory computer-readable storage medium of claim 13, wherein executing the security screening includes blocking a further data packet from being transmitted to the client device.
  • 15. The non-transitory computer-readable storage medium of claim 13, wherein executing the security screening includes sending a warning message from the gateway device to the client device.
  • 16. The non-transitory computer-readable storage medium of claim 13, wherein executing the security screening includes using the gateway device to filter content of data received from the server.
  • 17. The non-transitory computer-readable storage medium of claim 13, wherein inspecting the decrypted information includes the deep packet inspection by the gateway device.
  • 18. The non-transitory computer-readable storage medium of claim 12, further comprising instructions executable to: intercept one or more data packets transmitted according to a secured network protocol between the client device and the server while remaining transparent to the client device and the server;maintain a first set of state information for the client device, the first set of state information including a sequence number of a last packet received by the client device; andretransmit the last data packet corresponding to the sequence number to the client device based on the first set of state information.
  • 19. The non-transitory computer-readable storage medium of claim 18, wherein retransmitting the last data packet is also based on receiving a retransmission from the server.
  • 20. A gateway apparatus for establishing a proxy-less communication session, the gateway apparatus comprising: a memory;a communication interface that communicates over a communication network to: perform a first key exchange of a first public key with a server, andperform a second key exchange of a second public key with a client device; anda processor that executes instructions out of the memory to: access a received data packet that includes information encrypted at the server using the first public key,decrypt the encrypted information included in the data packet received from the server, wherein the decrypted information is inspected in accordance with deep packet inspection,generate a first certificate that includes the first public key and a set of attributes associated with the client device,store certificate details of the first certificate in the memory,generate the encrypted data in response to an indication the decrypted information passes inspection, wherein the encrypted data are decrypted at the client device using the second public key, wherein the communication interface sends the first certificate including the encrypted data transparently to the client device, wherein sending the first certificate is also transparent to the server,detect when to transmit the encrypted data based on transmission information communicated from the server and the client device and verification of the set of attributes associated with the client device, wherein the communication interface further:sends the first certificate and the encrypted data transparently to the client device, wherein sending the first certificate is transparent to the server, and wherein the encrypted data is decrypted at the client device using the second public key,receives a first acknowledgement from the client device acknowledging receipt of the encrypted data included in the data packet has been received, andsends a second acknowledgement to the server based on the receipt of the first acknowledgement from the client device, wherein sending the second acknowledgement is transparent to the client device, and wherein the second acknowledgement indicating that the data packet has been received, and the second acknowledgement is not sent to the server until after the first acknowledgement is received from the client device indicating that the encrypted data included in the data packet has been received at the client device,generate a second certificate for transmission to the client device that is a modified copy of the first certificate, wherein a public key of the second certificate is different from a public key of the first certificate, and wherein a remaining portion of the second certificate is identical to a remaining portion of the first certificate, andestablish the communication session between the client device and the server without a proxy based on an identification that the second certificate matches a previously trusted certificate, wherein flow control is provided for data transmitted between the client device and the server in the established communication session.
CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 15/685,768 filed on Aug. 24, 2017, now U.S. Pat. No. 10,764,274 which is a Continuation of U.S. patent application Ser. No. 12/497,328 filed on Jul. 2, 2009, now U.S. Pat. No. 9,769,149, the entire content of each of which is incorporated herein by reference.

US Referenced Citations (131)
Number Name Date Kind
5796833 Chen Aug 1998 A
5796942 Esbensen Aug 1998 A
5945933 Kalkstein Aug 1999 A
6088803 Tso et al. Jul 2000 A
6108782 Fletcher et al. Aug 2000 A
6119236 Shipley Sep 2000 A
6178448 Gray et al. Jan 2001 B1
6219706 Fan et al. Apr 2001 B1
6449723 Elgressy et al. Sep 2002 B1
6675296 Boeyen Jan 2004 B1
6851061 Holland et al. Feb 2005 B1
7134143 Stellenberg et al. Nov 2006 B2
7136359 Coile Nov 2006 B1
7152164 Loukas Dec 2006 B1
7185368 Copeland Jul 2007 B2
7249377 Lita Jul 2007 B1
7304996 Swenson et al. Dec 2007 B1
7360091 Aikawa Apr 2008 B2
7461250 Duane Dec 2008 B1
7506368 Kersey Mar 2009 B1
7600257 Dubrovsky Oct 2009 B2
7643480 Liu et al. Jan 2010 B2
7698453 Samuels et al. Apr 2010 B2
7809386 Stirbu Oct 2010 B2
7835361 Dubrovsky Nov 2010 B1
7839859 Kim et al. Nov 2010 B2
7849502 Bloch et al. Dec 2010 B1
8086846 Brabson Dec 2011 B2
8130747 Li et al. Mar 2012 B2
8190879 Wang May 2012 B2
8214635 Wang Jul 2012 B2
8244855 Walsh Aug 2012 B1
8478986 Merugu Jul 2013 B2
8549157 Schnellbaecher Oct 2013 B2
8650631 Guo Feb 2014 B2
8700892 Bollay Apr 2014 B2
8707043 Wason Apr 2014 B2
8782393 Rothstein Jul 2014 B1
8843750 Sokolov Sep 2014 B1
9160718 Martini Oct 2015 B2
9467424 Gluck Oct 2016 B2
9602498 Wang Mar 2017 B2
9680801 Martini Jun 2017 B1
9755825 O'Brien Sep 2017 B2
9769149 Brady Sep 2017 B1
9961103 Williams May 2018 B2
10033529 Pahl Jul 2018 B2
10063591 Jiang Aug 2018 B1
10116634 Golshan Oct 2018 B2
10291651 Chaubey May 2019 B1
10341357 Martini Jul 2019 B2
10397006 Bowen Aug 2019 B2
10412055 Thomson Sep 2019 B2
10419348 du Toit Sep 2019 B2
10764274 Brady Sep 2020 B2
10862869 Frid Dec 2020 B2
11245685 Konda Feb 2022 B2
20020035681 Maturana Mar 2002 A1
20020069129 Akutsu Jun 2002 A1
20020083331 Krumel Jun 2002 A1
20020166069 Zendzian Nov 2002 A1
20020199098 Davis Dec 2002 A1
20030014623 Freed Jan 2003 A1
20030014628 Freed Jan 2003 A1
20030065800 Wyschogrod et al. Apr 2003 A1
20030084328 Tarquini et al. May 2003 A1
20030110208 Wyschogrod et al. Jun 2003 A1
20030145228 Suuronen et al. Jul 2003 A1
20030154399 Zuk et al. Aug 2003 A1
20030200437 Oishi Oct 2003 A1
20040093513 Cantrell et al. May 2004 A1
20040123155 Etoh et al. Jun 2004 A1
20040199790 Lingafelt et al. Oct 2004 A1
20040255163 Swimmer et al. Dec 2004 A1
20050021999 Touitou Jan 2005 A1
20050050362 Peles Mar 2005 A1
20050086504 You Apr 2005 A1
20050108411 Kliland et al. May 2005 A1
20050120243 Palmer et al. Jun 2005 A1
20050135380 Sahita et al. Jun 2005 A1
20050187916 Levin et al. Aug 2005 A1
20050216770 Rowett et al. Sep 2005 A1
20050262556 Waisman et al. Nov 2005 A1
20060020595 Norton et al. Jan 2006 A1
20060064750 Kersey Mar 2006 A1
20060069787 Sinclair Mar 2006 A1
20060077979 Dubrovsky Apr 2006 A1
20060090074 Matoba Apr 2006 A1
20060206707 Kostal Sep 2006 A1
20060272014 McRae Nov 2006 A1
20070058551 Brusotti et al. Mar 2007 A1
20070113079 Ito May 2007 A1
20070133803 Saito Jun 2007 A1
20080034073 McCloy et al. Feb 2008 A1
20080086633 Anderson Apr 2008 A1
20080126794 Wang May 2008 A1
20080178278 Grinstein et al. Jul 2008 A1
20080235755 Blaisdell et al. Sep 2008 A1
20080288458 Sun Nov 2008 A1
20080320297 Sabo Dec 2008 A1
20090201813 Speight Aug 2009 A1
20090271613 Brabson Oct 2009 A1
20100017848 Pomerantz Jan 2010 A1
20100325418 Kanekar Dec 2010 A1
20100325419 Kanekar Dec 2010 A1
20120131330 Tonsing et al. May 2012 A1
20120272058 Wang Oct 2012 A1
20120290833 Clegg Nov 2012 A1
20140075186 Austen Mar 2014 A1
20140095865 Yerra Apr 2014 A1
20140129828 Rhee May 2014 A1
20140143852 Cottrell May 2014 A1
20150172064 Takenaka Jun 2015 A1
20150288514 Pahl Oct 2015 A1
20160057114 Unagami Feb 2016 A1
20160119374 Williams Apr 2016 A1
20160142211 Metke May 2016 A1
20160226827 Bohannon Aug 2016 A1
20160337321 Lin Nov 2016 A1
20170163633 Yang Jun 2017 A1
20170163736 Jiang Jun 2017 A1
20170339118 Hwang Nov 2017 A1
20170374062 Brady Dec 2017 A1
20180131525 Kass May 2018 A1
20180288009 Yang Oct 2018 A1
20180351997 Lee Dec 2018 A1
20200084029 Yang Mar 2020 A1
20210320940 Batta Oct 2021 A1
20220224782 Wu Jul 2022 A1
20230269099 Medvinsky Aug 2023 A1
20240250815 Underwood Jul 2024 A1
Foreign Referenced Citations (3)
Number Date Country
1 122 932 Aug 2001 EP
1 528 743 May 2005 EP
WO 9739399 Oct 1997 WO
Non-Patent Literature Citations (38)
Entry
Aggarwal, N., “Improving the Efficiency of Network Intrusion Detection System”, Indian Institute of Technology, pp. 1-40, May 3, 2006.
Bellovin, S., “Firewall-Friendly FTP,” Network Working Group, RFC No. 1579, AT&T Bell Laboratories, Feb. 1994, Http://www.ietf.org/rfc1579.txt?number=1579, downloaded Jul. 15, 2002, 4 pages.
Blyth, Andrew, “Detecting Intrusion”, School of Computing, University of Glamorgan, 14 pages.
Branch, Joel, “Denial of Service Intrusion Detection Using Time Dependent Deterministic Finite Automata”, RPI Graduate Research Conference 2002, Oct. 17, 2002. 7 pages.
Gateway Anti-Virus, Anti-Spyware and Intrusion Prevention Service, Unified Threat Management, Intelligent Real-time Protection, © 2005, 2 pp.
Giles, C., “Learning a Class of Large Finite State Machines with a Recurrent Neural Network”, Neural Networks, vol. 8., No. 9, pp. 1359-1365, 1995.
Holzmann, G., “A Minimized Automaton Representation of Reachable States”, Int J STTT 2, pp. 270-278, 1999.
Juniper Networks, “Architecture,” www.juniper.net/products/intrusion/architecture.html, downloaded Jun. 11, 2004, 3 pages.
Juniper Networks, “Attack Detection,” www.juniper.net/products/intrusion/detection.html, downloaded Jun. 11, 2004, 7 pages.
Juniper Networks, “Attack Prevention,” www.juniper.net/products/intrusion/prevention.html, downloaded Jun. 11, 2004, 2 pages.
Juniper Networks, “Intrusion Detection and Prevention,” www.juniper.net/products/intrusion/ downloaded Jun. 11, 2004, 2 pages.
Juniper Networks, “Juniper Networks NetScreen-IDP 10/100/500/1000,” Intrusion Detection and Prevention, Spec Sheet, Apr. 2004, 2 pages.
Lucas, S., “Learning Deterministic Finite Automata with a Smart State Labeling Evolutionary Algorithm”, IEEE Transaction on Pattern Analysis and Machine Intelligence , vol. 27, No. 7, pp. 1063-1074 Jul. 2005.
Krugal, Christopher, “Using Decision Trees to Improve Signature-Based Intrusion Detection”, Sep. 8, 2003, RAID 2003: recent Advance in Intrusion Detection, 20 pages.
Roberts, Paul, “NetScreen Announces Deep Inspection Firewall,” IDG News Service, Oct. 20, 2003, http://www.nwfusion.com/news/2003/1020netscannou.html, downloaded Jun. 11, 2004, 5 pages.
Roesch, Martin and Green, Chris, “Snort Users Manual,” Snort Release 2.0.0, M. Roesch, C. Green, Copyright 1998-2003 M. Roesch, Copyright 2001-2003 C. Green, Copyright 2003 Sourcefire, Inc. dated Dec. 8, 2003 (53 pgs).
“Snort™: The Open Source Network Intrusion Detection System”, accessed at: http://www.snort.org/about.html on Jun. 23, 2004, last updated Jun. 23, 2004, 2 pages.
SonicWALL Complete Anti-Virus, Automated and Enforced Anti-Virus Protection, © 2005, 2 pp.
SonicWALL Content Filtering Service, Comprehensive Internet Security™,© 2005, 2 pp.
SonicWALL Content Security Manager Series, Easy-to-use, Affordable, Content Security and Internet Threat Protection, © 2006, Dec. 2006. 4 pp.
SonicWALL Endpoint Security: Anti-Virus, Automated and Enforced Anti-Virus and Anti- Spyware Protection, © 2007, Mar. 2007, 2 pp.
SonicWALL Internet Security Appliances, “Content Security Manager Integrated Solutions Guide”, Version 3.0, © 2007, 160 pp.
SonicWALL Internet Security Appliances, “SonicOS 3.8 Standard Administrator's Guide”, © 2007, 362 pp.
SonicOS Standard 3.8.0.2 Release Notes, SonicWALL secure Anti-Virus Router 80 Series, SonicWALL, Inc., Software Release: Apr. 11, 2007, 13 pp.
“The Ultimate Internet Sharing Solution, WinProxy, User Manual,” Copyright 1996-2002 Osistis Software, Inc., dated Feb. 2002 (290 pgs).
Van Engelen, R., “Constructing Finite State Automata for High-Performance XML Web Services”, International Symposium on Web Services and Applications, pp. 1-7, 2004.
Villa, Oreste. Feb. 2008. IBM Research Report: Too many words, too little time: Accelerating real-time keyword scanning wth multi-core processors. Retrieved from http://domino.research.ibm.com/library/cyberdignsf/papers/9EB4740B4B0739CF852573F5005A6311/$Filelrc24488.pdf. Retrieval data Mar. 5, 2012, 6 pgs.
CN Application No. 093133045, Republic of China Search Report dated Aug. 5, 2011, 1 pg.
EP Application No. EP 04 02 5579, European Search Report dated May 23, 2005, 3 pages.
Taiwan Application No. 093133045; Office Action dated Sep. 8, 2011.
U.S. Appl. No. 12/497,328; Final Office Action mailed Nov. 17, 2016.
U.S. Appl. No. 12/497,328; Office Action mailed Dec. 30, 2015.
U.S. Appl. No. 12/497,328; Final Office Action mailed Mar. 17, 2015.
U.S. Appl. No. 12/497,328; Office Action mailed Aug. 14, 2014.
U.S. Appl. No. 12/497,328; Final Office Action mailed Aug. 15, 2013.
U.S. Appl. No. 12/497,328; Office Action mailed Jan. 31, 2012.
U.S. Appl. No. 15/685,768; Final Office Action mailed Jan. 24, 2020.
U.S. Appl. No. 15/685,768; Office Action mailed Jun. 10, 2019.
Related Publications (1)
Number Date Country
20200403988 A1 Dec 2020 US
Continuations (2)
Number Date Country
Parent 15685768 Aug 2017 US
Child 17009606 US
Parent 12497328 Jul 2009 US
Child 15685768 US