Secure high-speed communication interface between a basic input and output system and a service processor
An information handling system includes a BIOS and a service processor. The BIOS may generate, during a POST, a secret key that includes a symmetric key and a HMAC key and transmits the secret key to the service processor via an high-speed communication interface. After the POST, the BIOS transmits an SMI message that includes an encrypted message and a first hash value of the encrypted message. The encrypted message is encrypted using the symmetric key and the first hash value of the encrypted message is calculated using the HMAC key. The service processor calculate a second hash value of encrypted message based on the HMAC key and verify the encrypted message by comparing the first hash value and the second hash value. After a successful verification, the service processor decrypts the encrypted message and transmits a response to the BIOS.
1. An information handling system, comprising:
a basic input/output system (BIOS) configured to:
generate, during a power-on self-test, a secret key that includes a symmetric key and a hash-based message authentication code key, wherein the secret key is stored in a system management interrupt handler;
transmit, during the power-on self-test, the secret key to a service processor via a high-speed communication interface; and
subsequent to the power-on self-test, transmit a system management interrupt message that includes an encrypted message and a first hash value of the encrypted message via the high-speed communication interface, wherein the encrypted message is encrypted using the symmetric key and the first hash value of the encrypted message is calculated using the hash-based message authentication code key of the secret key; and
the service processor configured to:
receive the system management interrupt message from the BIOS;
calculate a second hash value of encrypted message based on the hash-based message authentication code key;
verify the encrypted message by comparing the first hash value and the second hash value;
subsequent to a successful verification that the first hash value is equal to the second hash value, decrypt the encrypted message using the symmetric key; and
transmit a response to the BIOS via the high-speed communication interface.
2. The information handling system of claim 1 , wherein the BIOS is further configured to transmit a first time stamp counter with the secret key and a second time stamp counter with the encrypted message.
3. The information handling system of claim 2 , wherein the service processor is further configured to validate that the second time stamp counter is greater than the first time stamp counter.
4. The information handling system of claim 1 , wherein the service processor is further configured to decrypt the encrypted message before a successful validation of a second time stamp counter included in the system management interrupt message.
5. The information handling system of claim 1 , wherein the system management interrupt message includes a time stamp counter.
6. The information handling system of claim 1 , wherein the service processor is further configured to generate an error log if the system management interrupt message is not valid.
7. A method comprising:
during a power-on self-test, generating, by a basic input/output system (BIOS), a secret key that includes a symmetric key and a hash-based message authentication code key and sending the secret key to a service processor via a high-speed communication interface, wherein the secret key is stored in a system management interrupt handler;
subsequent to the power-on self-test, transmitting, by the BIOS, a system management interrupt message that includes an encrypted message and a hash value of the encrypted message via the high-speed communication interface, wherein the encrypted message is encrypted using the symmetric key and the hash value of the encrypted message is calculated using the hash-based message authentication code key;
receiving, by the service processor, the system management interrupt message from the BIOS;
calculating, by the service processor, a second hash value of encrypted message based on the hash-based message authentication code key;
verifying, by the service processor, the encrypted message by comparing a first hash value and the second hash value;
subsequent to a successful verification that the first hash value is equal to the second hash value, decrypting, by the service processor, the encrypted message using the symmetric key; and
transmitting, by the service processor, a response to the BIOS via the high-speed communication interface.
8. The method of claim 7 , further comprising:
transmitting, by the BIOS, a first time stamp counter with the secret key and a second time stamp counter with the encrypted message.
9. The method of claim 8 , further comprising:
validating, by the service processor, that the second time stamp counter is greater than the first time stamp counter.
10. The method of claim 7 , further comprising:
decrypting the encrypted message before a successful validation of a second time stamp counter included in the system management interrupt message.
11. The method of claim 7 , further comprising:
receiving, by the BIOS, the response to the system management interrupt message from the service processor via the high-speed communication interface.
12. The method of claim 7 , further comprising:
generating an error log when the system management interrupt message is not valid.
13. A non-transitory computer-readable medium to store instructions that are executable to perform operations comprising:
during a power-on self-test, generating, by a basic input/output system (BIOS), a secret key that includes a symmetric key and a hash-based message authentication code key and sending the secret key to a service processor via a high-speed communication interface, wherein the secret key is stored in a system management interrupt handler;
subsequent to the power-on self-test, transmitting, by the BIOS, a system management interrupt message that includes an encrypted message and a hash value of the encrypted message via the high-speed communication interface, wherein the encrypted message is encrypted using the symmetric key and the hash value of the encrypted message is calculated using the hash-based message authentication code key;
receiving, by the service processor, the system management interrupt message from the BIOS;
calculating, by the service processor, a second hash value of encrypted message based on the hash-based message authentication code key;
verifying, by the service processor, the encrypted message by comparing a first hash value and the second hash value;
subsequent to a successful verification that the first hash value is equal to the second hash value, decrypting, by the service processor, the encrypted message using the symmetric key; and
transmitting, by the service processor, a response to the BIOS via the high-speed communication interface.
14. The non-transitory computer-readable medium of claim 13 , wherein the operations further comprise transmitting, by the BIOS, a first time stamp counter with the secret key and a second time stamp counter with the encrypted message.
15. The non-transitory computer-readable medium of claim 14 , wherein the operations further comprise validating, by the service processor, that the second time stamp counter is greater than the first time stamp counter.
16. The non-transitory computer-readable medium of claim 13 , wherein the operations further comprise decrypting the encrypted message before a successful validation of a second time stamp counter included in the system management interrupt message.
17. The non-transitory computer-readable medium of claim 13 , wherein the operations further comprise receiving, by the BIOS, the response to the system management interrupt message from the service processor via the high-speed communication interface.
18. The non-transitory computer-readable medium of claim 13 , wherein the operations further comprise generating an error log when the system management interrupt message is not valid.