SMI FOR ELECTRONIC GAMING MACHINE SECURITY AND STABILITY
A system and method for providing security services to an electronic gaming machine (EGM) utilizes system management interrupts (SMIs) triggered by security events to invoke execution by the EGM processor of one or more SMI handlers configured to provide a security service. Security events include the opening of an access panel on the EGM, an AC power loss to the EGM, a request for security attestation, a request for a secure encryption key, and other events requiring a secure operation to be carried out.
1 . An electronic gaming machine (EGM) comprising:
a processor for executing tasks within the EGM, the processor being configured to provide a system management mode (SMM) triggered via a system management interrupt (SMI);
a nonvolatile memory having therein a basic input/output system (BIOS), the BIOS including one or more SMI handlers, the one or more SMI handlers being configured to provide a security service to the EGM; and
a volatile memory wherein the BIOS is loaded upon start-up of the processor and wherein an operating system (OS) kernel memory data is stored.
2 . The EGM in accordance with claim 1 , wherein at least one of the one or more SMI handlers is configured to attempt to verify the validity of information associated with the EGM.
3 . The EGM in accordance with claim 2 , wherein the at least one of the one or more SMI handlers is configured to issue a resume instruction (RSM) when the validity of the information is verified.
4 . The EGM in accordance with claim 3 , wherein the at least one of the one or more SMI handlers is configured to maintain the processor in the SMM when the validity of the OS kernel memory data is not verified.
5 . The EGM in accordance with claim 4 , wherein the OS includes an OS watchdog component, and wherein maintaining the processor in the SMM includes periodically sending a tickler to the OS watchdog component.
6 . The EGM in accordance with claim 1 , wherein at least one of the one or more SMI handlers is configured to obtain cryptographic key material on behalf of the OS by retrieving the cryptographic key material from a secure location, storing the retrieved cryptographic key material in a memory location accessible to the OS, and issuing an RSM instruction.
7 . The EGM in accordance with claim 1 , wherein the nonvolatile memory of The EGM further includes a nonvolatile RAM (NVRAM), and wherein at least one of the one or more SMI handlers is configured to prevent the OS from writing to the NVRAM in the event of an AC power failure.
8 . The EGM in accordance with claim 1 , wherein the EGM is further configured to communicate with a remote attesting server, and wherein at least one of the one or more SMI handlers is configured to communicate with the remote attesting server to provide a remote security attestation.
9 . A non-transitory computer readable medium associated with an EGM and having thereon computer executable instructions, the instructions comprising:
instructions for generating an SMI to a processor of the EGM when a security event is detected, causing the processor to enter SMM; and
instructions embodying one or more SMI handlers corresponding to the SMI, the one or more SMI handlers being configured to provide a security service to the EGM.
10 . The non-transitory computer readable medium in accordance with claim 9 , wherein at least one of the one or more SMI handlers is configured to attempt to verify the validity of information associated with the EGM.
11 . The non-transitory computer readable medium in accordance with claim 10 , wherein the at least one of the one or more SMI handlers is configured to issue an RSM instruction when the validity of the information is verified.
12 . The non-transitory computer readable medium in accordance with claim 11 , wherein the at least one of the one or more SMI handlers is configured to maintain the processor in the SMM when the validity of the OS kernel memory data is not verified.
13 . The non-transitory computer readable medium in accordance with claim 12 , wherein maintaining the processor in the SMM includes periodically sending a tickler to an OS watchdog component.
14 . The non-transitory computer readable medium in accordance with claim 9 , wherein at least one of the one or more SMI handlers is configured to obtain cryptographic key material by retrieving the cryptographic key material from a secure location, storing the retrieved cryptographic key material in a memory location accessible to an OS, and issuing an RSM instruction.
15 . The non-transitory computer readable medium in accordance with claim 9 , wherein at least one of the one or more SMI handlers is configured to prevent writing to a NVRAM in the event of an AC power failure.
16 . The non-transitory computer readable medium in accordance with claim 9 , wherein at least one of the one or more SMI handlers is configured to communicate with a remote attesting server to provide a remote security attestation.
17 . A method of providing a security service to an electronic gaming machine EGM comprising:
retrieving instructions from a BIOS memory by a processor associated with the EGM;
installing by the processor one or more SMI handlers in keeping with the retrieved instructions, wherein the one or more SMI handlers are configured to provide a security service with respect to the EGM; and
receiving at the processor an SMI signal at a processor and executing at the processor at least one of the one or more SMI handlers.
18 . The method according to claim 17 , wherein the at least one of the one or more SMI handlers is configured to attempt to verify the validity of OS kernel memory data, to issue an RSM instruction when the validity of the OS kernel memory data is verified, and to maintain the processor in the SMM when the validity of the OS kernel memory data is not verified.
19 . The method according to claim 17 , wherein at least one of the one or more SMI handlers is configured to obtain cryptographic key material by retrieving the cryptographic key material from a secure location, storing the retrieved cryptographic key material in a memory location accessible to an OS, and issuing an RSM instruction.
20 . The method according to claim 17 , wherein at least one of the one or more SMI handlers is configured to prevent writing to a NVRAM of the EGM in the event of an AC power failure.