topic Hi, in Intel® Software Guard Extensions (Intel® SGX)

Trusted time from enclave

Emm_D_ — Tue, 10 Jan 2017 11:54:16 GMT

Hi,

Is there a way to get the time when running in enclave mode (without a syscall) and be sure that this is not manipulated by a malicious OS? I know about the RDTSC instruction, but the TSC register can be modified from outside the enclave, so this can not be considered secure. To be more specific, I am interested if we can get the time elapsed between two instructions executed in enclave mode.

Thank you

You could use "Platform

Francisco_C_Intel — Thu, 12 Jan 2017 20:00:40 GMT

You could use "Platform Service Functions" - "sgx_get_trusted_time"

The resolution is in seconds though...

Hi,

Ofir_W_ — Fri, 13 Jan 2017 01:11:04 GMT

Hi,

I noticed that in the reference manual

https://download.01.org/intel-sgx/linux-1.7/docs/Intel_SGX_SDK_Developer_Reference_Linux_1.7_Open_Source.pdf

It says (page 199 on my version)

sgx_get_trusted_time
sgx_get_trusted_time gets trusted time from the AE service.
This API is only available in simulation mode

This is at least the case for Linux.

Hi,

Emm_D_ — Fri, 13 Jan 2017 08:28:00 GMT

Hi,

Thank you for your replies. sgx_get_trusted_time is the kind of function I was looking for and somehow missed it in the manual, Thanks again.

As of 2017, in the latest

Fatima_A_ — Fri, 15 Dec 2017 23:31:37 GMT

As of 2017, in the latest processors, the sgx_get_trusted_time is also supported in harwdare mode through PSE (Platform Service Enclaves) maintained and signed by Intel.

Hi,

kai__chi — Thu, 18 Jun 2020 11:07:19 GMT

Hi, As of SGX SDK v2.9.1 the sgx_get_trusted_time got deprecated at some point. Is there any other way to get time inside an enclave? Best, Kai

Hello Kai,

JesusG_Intel — Thu, 18 Jun 2020 15:11:31 GMT

Hello Kai,

Please see the last post in this thread.

Regards,