# Patent

## Title
System and method for authenticating identity of discovered component in an infiniband (IB) network

## Abstract

A system and method can verify trustfulness of a fabric component in an InfiniBand (IB) fabric. A subnet manager that is responsible for authenticating the fabric component using private/public key pairs. The subnet manager can first send a first encrypted message to a fabric component in the IB fabric, wherein the first encrypted message contains a token and is encrypted using a public key associated with the fabric component. Then, the fabric component is allowed to decode the first encrypted message using a private key associated with the fabric component, and to send a second encrypted message back to the subnet manager. Finally, the subnet manager can authenticate the fabric component if the second encrypted message contains correct information.

## Background
COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
CLAIM OF PRIORITY
This application claims the benefit of priority on U.S. Provisional Patent Application No. 61/493,330, entitled “STATEFUL SUBNET MANAGER FAILOVER IN A MIDDLEWARE MACHINE ENVIRONMENT” filed Jun. 3, 2011, which application is herein incorporated by reference.
FIELD OF INVENTION
The present invention is generally related to computer systems, and is particularly related to supporting an InfiniBand (IB) network.
BACKGROUND
The interconnection network plays a beneficial role in the next generation of super computers, clusters, and data centers. High performance network technology, such as the InfiniBand (IB) technology, is replacing proprietary or low-performance solutions in the high performance computing domain, where high bandwidth and low latency are the key requirements. For example, IB installations are used in supercomputers such as Los Alamos National Laboratory's Roadrunner, Texas Advanced Computing Center's Ranger, and Forschungszcntrum Juelich's JuRoPa.
IB was first standardized in October 2000 as a merge of two older technologies called Future I/O and Next Generation I/O. Due to its low latency, high bandwidth, and efficient utilization of host-side processing resources, it has been gaining acceptance within the High Performance Computing (HPC) community as a solution to build large and scalable computer clusters. The de facto system software for IB is OpenFabrics Enterprise Distribution (OFED), which is developed by dedicated professionals and maintained by the OpenFabrics Alliance. OFED is open source and is available for both GNU/Linux and Microsoft Windows.
SUMMARY 
Described herein is a system and method that can verify trustfulness of a fabric component in an InfiniBand (IB) fabric. A subnet manager that is responsible for authenticating the fabric component using private/public key pairs. The subnet manager can first send a first encrypted message to a fabric component in the IB fabric, wherein the first encrypted message contains a token and is encrypted using a public key associated with the fabric component. Then, the fabric component is allowed to decode the first encrypted message using a private key associated with the fabric component, and to send a second encrypted message back to the subnet manager. Finally, the subnet manager can authenticate the fabric component if the second encrypted message contains correct information.



BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 shows an illustration of a fabric model in a middleware environment in accordance with an embodiment of the invention.
FIG. 2 shows an illustration of using a public/private key based scheme to authenticate discovered components in an IB fabric in accordance with an embodiment of the invention.
FIG. 3 illustrates an exemplary flow chart for using a public/private key based scheme to authenticate discovered components in an IB fabric in accordance with an embodiment of the invention.



DETAILED DESCRIPTION
Described herein is a system and method that supports verifying the trustfulness of various components in an interconnected network, such as an InfiniBand (IB) network.
FIG. 1 shows an illustration of a fabric model in a middleware environment in accordance with an embodiment of the invention. As shown in FIG. 1, an interconnected network, or a fabric 100, can include switches 101-103, bridges and routers 104, host channel adapters (HCAs) 105-106 and designated management hosts 107. Additionally, the fabric can include, or be connected to, one or more hosts 108 that are not designated management hosts.
The designated management hosts 107 can be installed with HCAs 105-106, a network software stack and relevant management software in order to perform network management tasks. Furthermore, firmware and management software can be deployed on the switches 101-103, and the bridges and routers 104 to direct traffic flow in the fabric. Here, the host HCA drivers, OS and Hypervisors on hosts 108 that are not designated management hosts may be considered outside the scope of the fabric from a management perspective.
The fabric 100 can be in a single media type, e.g. an IB only fabric, and be fully connected. The physical connectivity in the fabric ensures in-band connectivity between any fabric components in the non-degraded scenarios. Alternatively, the fabric can be configured to include Ethernet (Enet) connectivity outside gateway (GW) external ports on a gateway 109. Additionally, it is also possible to have independent fabrics operating in parallel as part of a larger system. For example, the different fabrics can be only indirectly connected via different HCAs or HCA ports.
InfiniBand (IB) Architecture
IB architecture is a serial point-to-point technology. Each of the IB networks, or subnets, can include a set of hosts interconnected using switches and point-to-point links. A single subnet can be scalable to more than ten-thousand nodes and two or more subnets can be interconnected using an IB router. The hosts and switches within a subnet are addressed using local identifiers (LIDs), e.g. a single subnet may be limited to 49151 unicast addresses.
An IB subnet can employ at least one subnet manager (SM) which is responsible for initializing and starting up the sub-net including the configuration of all the IB ports residing on switches, routers and host channel adapters (HCAs) in the subset. The SM's responsibility also includes routing table calculation and deployment. Routing of the network aims at obtaining full connectivity, deadlock freedom, and load balancing between all source and destination pairs. Routing tables can be calculated at network initialization time and this process can be repeated whenever the topology changes in order to update the routing tables and ensure optimal performance.
At the time of initialization, the SM starts in the discovering phase where the SM does a sweep of the network in order to discover all switches and hosts. During the discovering phase, the SM may also discover any other SMs present and negotiate who should be the master SM. When the discovering phase is completed, the SM can enter a master phase. In the master phase, the SM proceeds with LID assignment, switch configuration, routing table calculations and deployment, and port configuration. At this point, the subnet is up and ready to use.
After the subnet is configured, the SM can monitor the network for changes (e.g. a link goes down, a device is added, or a link is removed). If a change is detected during the monitoring process, a message (e.g. a trap) can be forwarded to the SM and the SM can reconfigure the network. Part of the reconfiguration process, or a heavy sweep process, is the rerouting of the network which can be performed in order to guarantee full connectivity, deadlock freedom, and ensure proper load balancing between all source and destination pairs.
The HCAs in an IB network can communicate with each other using queue pairs (QPs). A QP is created during the communication setup, and a set of initial attributes such as QP number, HCA port, destination LID, queue sizes, and transport service are supplied. On the other hand, the QP associated with the HCAs in a communication is destroyed when the communication is over. An HCA can handle many QPs. Each QP consists of a pair of queues, a send queue (SQ) and a receive queue (RQ). There is one such pair present at each end-node that is participating in the communication. The send queue holds work requests to be transferred to the remote node, while the receive queue holds information on what to do with the data received from the remote node. In addition to the QPs, each HCA can have one or more completion queues (CQs) that are associated with a set of send and receive queues. The CQ holds completion notifications for the work requests posted to the send and receive queue.
The IB architecture is a flexible architecture. Configuring and maintaining an IB subnet can be carried out via special in-band subnet management packets (SMPs). The functionalities of a SM can, in principle, be implemented from any node in the IB subnet. Each end-port in the IB subnet can have an associated subnet management agent (SMA) that is responsible for handling SMP based request packets that are directed to it. In the IB architecture, a same port can represent a SM instance or other software component that uses SMP based communication. Thus, only a well defined sub-set of SMP operations can be handled by the SMA.
SMPs use dedicated packet buffer resources in the fabric, e.g. a special virtual lane (VL15) that is not flow-controlled (i.e. SMP packets may be dropped in the case of buffer overflow). Also, SMPs can use either the routing that the SM sets up based on end-port local Identifiers (LIDs), or SMPs can use direct routes where the route is fully defined by the sender and embedded in the packet. Using direct routes, the packet's path goes through the fabric in terms of an ordered sequence of port numbers on HCAs and switches.
The SM can monitor the network for changes using SMAs that are presented in every switch and/or every HCA. The SMAs communicate changes, such as new connections, disconnections, and port state change to the SM using traps and notices. A trap is a message sent to alert end-nodes about a certain event. A trap can contain a notice attribute with the details describing the event. Different traps can be defined for different events. In order to reduce the unnecessary distribution of traps, IB applies an event forwarding mechanism where end-nodes are required to explicitly subscribe to the traps they want to be informed about.
The subnet administrator (SA) is a subnet database associated with the master SM to store different information about a subnet. The communication with the SA can help the end-node to establish a QP by sending a general service management datagram (MAD) through a designated QP, e.g. QP1. Both sender and receiver require information such as source/destination LIDs, service level (SL), maximum transmission unit (MTU), etc. to establish a communication via a QP. This information can be retrieved from a data structure known as a path record that is provided by the SA. In order to obtain a path record, the end-node can perform a path record query to the SA, e.g. using the SubnAdmGet/SubnAdmGetable operation. Then, the SA can return the requested path records to the end-node.
The IB architecture provides partitions as a way to define which IB end-ports should be allowed to communicate with which other IB end-ports. Partitioning is defined for all non-SMP packets on the IB fabric. The use of partitions other than the default partition is optional. The partition of a packet can be defined by a 16 bit P_Key that consists of a 15 bit partition number and a single bit member type (full or limited).
The partition membership of a host port, or a HCA port, can be based on the premise that the SM sets up the P_Key table of the port with P_Key values that corresponds to the current partition membership policy for that host. In order to compensate for the possibility that the host may not be fully trusted, the IB architecture also defines that switch ports can optionally be set up to do partition enforcement. Hence, the P_Key tables of switch ports that connect to host ports can then be set up to reflect the same partitions that the host port is supposed to be a member of. (i.e. in essence equivalent to switch enforced VLAN control in Ethernet LANs.)
Since the IB architecture allows full in-band configuration and maintenance of an IB subnet via SMPs, the SMPs themselves are not subject to any partition membership restrictions. Thus, in order to avoid the possibility that any rough or compromised node on the IB fabric is able to define an arbitrary fabric configuration (including partition membership), other protection mechanisms are needed.
M_Keys can be used as the basic protection/security mechanism in the IB architecture for SMP access. An M_Key is a 64 bit value that can be associated individually with each individual node in the IB subnet, and where incoming SMP operations may be accepted or rejected by the target node depending on whether the SMP includes the correct M_Key value (i.e. unlike P_Keys, the ability to specify the correct M_Key value—like a password—represents the access control).
By using an out-of-band method for defining M_Keys associated with switches, it is possible to ensure that no host node is able to set up any switch configuration, including partition membership for the local switch port. Thus, an M_Key value is defined when the switch IB links becomes operational. Hence, as long as the M_Key value is not compromised or “guessed” and the switch out-of-band access is secure and restricted to authorized fabric administrators, the fabric is secure.
Furthermore, the M_Key enforcement policy can be set up to allow read-only SMP access for all local state information except the current M_Key value. Thus, it is possible to protect the switch based fabric from un-authorized (re-)configuration, and still allow host based tools to perform discovery and diagnostic operations.
The flexibility provided by the IB architecture allows the administrators of IB fabrics/subnets, e.g. HPC clusters, to decide whether to use embedded SM instances on one or more switches in the fabric and/or set up one or more hosts on the IB fabric to perform the SM function. Also, since the wire protocol defined by the SMPs used by the SMs is available through APIs, different tools and commands can be implemented based on use of such SMPs for discovery, diagnostics and are controlled independently of any current Subnet Manager operation.
From a security perspective, the flexibility of IB architecture indicates that there is no fundamental difference between root access to the various hosts connected to the IB fabric and the root access allowing access to the IB fabric configuration. This is fine for systems that are physically secure and stable. However, this can be problematic for system configurations where different hosts on the IB fabric are controlled by different system administrators, and where such hosts should be logically isolated from each other on the IB fabric.
Allowing the Fabric to Constantly Verify the Trustfulness of all its Components
In accordance with an embodiment of the invention, an IB fabric can constantly verify the trustfulness of its components. A site administrator can keep track of the secure firmware state of all HCAs in the system, and can simply rely on that all relevant HCAs are operating in a secure mode. Furthermore, a physically secure data center, where correct cabling is ensured by trusted individuals, can guarantee the trustfulness of all components in the fabric. Additionally, the site/fabric administrator can ensure that the out of band management interfaces are properly password protected and otherwise rely on the switch software and firmware to be trusted.
The above simple approach is sufficient for moderately sized, static configurations, but may not be sufficient for medium to large/very large sized dynamic environments with a large number of nodes, or components. In order to automate the process of verification, the fabric components are preferably able to authenticate themselves and the firmware/software version controlling them in a way that is not vulnerable to host based spyware or rough (inconsistent) host administration.
In accordance with an embodiment of the invention, an automatic fabric components verification process involves the use of encrypted challenge/response schemes that allow the peers to verify the identity of each other without compromising themselves by sending, e.g. private passwords, before the peer has been authenticated. For the IB switches and HCA firmware, the implementation can involve SMP based protocols that can be carried out prior to the SM enabling the port for data traffic.
In a secured IB fabric, the trustfulness of the switches is built on the premise that the management access to the switch is secured and is only available to the trusted site/fabric administrators in the first place. The trustfulness of HCAs can be secured using a special host boot image-based upgrade scheme that allows private key handling to take place based on the assumptions that once the physical host is controlled by the special boot image, the HCA effectively becomes part of the fabric security domain.
Public/Private Key Based Scheme to Authenticate the Identity of Discovered Components
In accordance with an embodiment of the invention, the automatic fabric components verification process can be based on the use of private/public key pairs.
FIG. 2 shows an illustration of using a public/private key based scheme to authenticate discovered components in an IB fabric in accordance with an embodiment of the invention. As shown in FIG. 2, a SM 201 in an IB fabric 200 can be responsible for both discovering fabric components and authenticating the discovered components, such as a HCA 202 that is associated with a host 203. The SM 201 maintains a SM public key 211 and a SM private key 212, both of which are used in the process of verifying the HCA 202.
Additionally, the SM 201 can maintain a public key for each target component to be verified, such as the HCA public key 214 for the target HCA 202. There can also be a central repository 210 that stores the public keys for every component in the fabric, e.g. HCA firmware version 204, hypervisor 206/OS 207 assigned to a tenant, etc. In one example, a specific firmware version or a range of firmware versions can have a well defined public key that is distributed when the firmware version (or range) is released, installed or deployed.
Furthermore, the HCA 202 can maintain an HCA private key 213 that is associated with the HCA public key 214 for the particular HCA 202 stored on the SM 201 side. The trustfulness of the fabric component depends on the careful distribution and storage of the private keys for relevant components. One example is to have the private keys, such as the HCA private key 213, hidden in the HCA embedded firmware binary 204 (i.e. in a way that makes it very difficult to identify by “disassembly” of the HCA binary). Additional enhanced schemes can make better use of the stable storage state from the factory, such as a tamper proof non-volatile key storage 205.
The SM 201, or any other component that controls the integrity of the target HCA 202 and its firmware 204, can be configured to send an encrypted message 221 to the HCA firmware 204. The encrypted message 221 can contain a token, such as a random byte string 220, along with the SM public key 211 owned by the SM instance.
After receiving the encrypted message 221, the challenged HCA firmware 204 can decode the received encrypted message 221 and send the random byte string 220 back to the SM 201 in an encrypted response message 222 using the supplied SM public key 211. Alternatively, after decoding the received encrypted message 221, the challenged HCA firmware 204 can send a different token, such as a different byte string, back to the SM 201 as long as the SM 201 is aware of the trustfulness of the different token.
Then, the SM 201 can decode the received message 222 using its own private key 212 and authenticate the HCA firmware 204 if the SM 201 receives the correct byte string. Thus, any fake HCA firmware or driver implementation could claim to represent the same secure version ID, but may not be able to pass the challenge as long as the real firmware version's private key is not compromised.
FIG. 3 illustrates an exemplary flow chart for using a public/private key based scheme to authenticate discovered components in an IB fabric in accordance with an embodiment of the invention. As shown in FIG. 3, at step 301, a subnet manager can first send a first encrypted message to a fabric component in the IB fabric, wherein the first encrypted message contains a token and is encrypted using a public key associated with the fabric component. Then, at step 302, the fabric component is allowed to decode the first encrypted message using a private key associated with the fabric component, and to send a second encrypted message back to the subnet manager. Finally, at step 303, the subnet manager can authenticate the fabric component if the second encrypted message contains correct information.
The present invention may be conveniently implemented using one or more conventional general purpose or specialized digital computer, computing device, machine, or microprocessor, including one or more processors, memory and/or computer readable storage media programmed according to the teachings of the present disclosure. Appropriate software coding can readily be prepared by skilled programmers based on the teachings of the present disclosure, as will be apparent to those skilled in the software art.
In some embodiments, the present invention includes a computer program product which is a storage medium or computer readable medium (media) having instructions stored thereon/in which can be used to program a computer to perform any of the processes of the present invention. The storage medium can include, but is not limited to, any type of disk including floppy disks, optical discs, DVD, CD-ROMs, microdrive, and magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic or optical cards, nanosystems (including molecular memory ICs), or any type of media or device suitable for storing instructions and/or data.
The foregoing description of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations will be apparent to the practitioner skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalence.

## Claims

1. A method for verifying trustfulness of a fabric component in an InfiniBand (IB) fabric, comprising:
discovering, via a subnet manager executing on one or more microprocessors, a fabric component of a plurality of fabric components on a node in an IB fabric, wherein each of the plurality of fabric components is associated with a public key stored in a central repository connected to the subnet manager;
retrieving, based on an identity of the fabric component, a public key associated with the fabric component from the central repository to the subnet manager,
wherein the public key is distributed to the central repository when the fabric component is released, installed or deployed, and
wherein the identity of the fabric component includes version information for the fabric component;
sending a first encrypted message from the subnet manager to the fabric component, wherein the first encrypted message contains a first token and is encrypted using the public key associated with the fabric component, and wherein the fabric component decodes the first encrypted message using a private key associated with the fabric component;
receiving from the fabric component to the subnet manager a second encrypted message that contains a second token;
decoding the second encrypted message using a private key associated with the subnet manager to retrieve the second token; and
authenticating, via the subnet manager, the fabric component if the second token is the same as the first token or is recognized by the subnet manager.

2. The method according to claim 1, wherein the fabric component is a host channel adapter (HCA) firmware or a hypervisor/OS assigned to a tenant.

3. The method according to claim 1, wherein the first token contained in the first encrypted message is a random byte string.

4. The method according to claim 1, wherein the fabric component hides the private key associated with the fabric component in an embedded firmware.

5. The method according to claim 1, wherein the fabric component stores the private key associated with the fabric component in a tamper proof non-volatile key storage.

6. The method according to claim 1, further comprising:
sending a public key associated with the subnet manager along with the first encrypted message to the fabric component.

7. The method according to claim 6, wherein the fabric component encrypts the second encrypted message using the public key associated with the subnet manager.

8. A system for verifying trustfulness of a fabric component in an InfiniBand (IB) fabric, comprising:
a computer with memory and one or more microprocessors;
a subnet manager, executing on the computer, that is responsible for authenticating a fabric component in the IB fabric,
wherein the subnet manager is configured to
discover the fabric component from a plurality of fabric components in on a node in an IB fabric, wherein each of the plurality of fabric components is associated with a public key stored in a central repository connected to the subnet manager,
retrieve, based on an identity of the fabric component, a public key associated with the fabric component from the central repository to the subnet manager,
wherein the public key is distributed to the central repository when the fabric component is released, installed or deployed, and
wherein the identity of the fabric component includes version information for the fabric component,
send a first encrypted message from the subnet manager to the fabric component in the IB fabric, wherein the first encrypted message contains a first token and is encrypted using the public key associated with the fabric component, and wherein the fabric component decodes the first encrypted message using a private key associated with the fabric component,
receive from the fabric component to the subnet manager a second encrypted message that contains a second token,
decode the second encrypted message using a private key associated with the subnet manager to retrieve the second token, and
authenticate the fabric component if the second token is the same as the first token or is recognized by the subnet manager.

9. The system according to claim 8, wherein the fabric component is a host channel adapter (HCA) firmware or a hypervisor/OS assigned to a tenant.

10. The system according to claim 8, wherein the first token contained in the first encrypted message is a random byte string.

11. The system according to claim 8, wherein the fabric component hides the private key associated with the fabric component in an embedded firmware.

12. The system according to claim 8, wherein the fabric component stores the private key associated with the fabric component in a tamper proof non-volatile key storage.

13. The system according to claim 8, wherein a public key associated with the subnet manager is sent along with the first encrypted message to the fabric component.

14. The system according to claim 13, wherein the fabric component operates to encrypt the second encrypted message using the public key associated with the subnet manager.

15. A non-transitory machine readable storage medium having instructions stored thereon that when executed cause a system to perform the steps comprising:
discovering, via a subnet manager executing on one or more microprocessors, a fabric component of a plurality of fabric components on a node in an IB fabric, wherein each of the plurality of fabric components is associated with a public key stored in a central repository connected to the subnet manager;
retrieving, based on an identity of the fabric component, a public key associated with the fabric component from the central repository to the subnet manager,
wherein the public key is distributed to the central repository when the fabric component is released, installed or deployed, and
wherein the identity of the fabric component includes version information for the fabric component;
sending a first encrypted message from the subnet manager to the fabric component, wherein the first encrypted message contains a first token and is encrypted using the public key associated with the fabric component, and wherein the fabric component decodes the first encrypted message using a private key associated with the fabric component;
receiving from the fabric component to the subnet manager a second encrypted message that contains a second token;
decoding the second encrypted message using a private key associated with the subnet manager to retrieve the second token; and
authenticating, via the subnet manager, the fabric component if the second token is the same as the first token or is recognized by the subnet manager.

16. The non-transitory machine readable storage medium of claim 15, wherein the first token contained in the first encrypted message is a random byte string.

17. The non-transitory machine readable storage medium of claim 15, wherein the fabric component hides the private key associated with the fabric component in an embedded firmware.

18. The non-transitory machine readable storage medium of claim 15, wherein the fabric component stores the private key associated with the fabric component in a tamper proof non-volatile key storage.

19. The non-transitory machine readable storage medium of claim 15, wherein a public key associated with the subnet manager is sent along with the first encrypted message to the fabric component.