topic Hello Meysam, in Intel® Software Guard Extensions (Intel® SGX)

Passing a pointer to an enclave using user_check

Meysam_t_ — Mon, 27 Apr 2020 19:53:49 GMT

Dear All,

When we pass a pointer to a buffer as "user_check" in the EDL file, does it mean that the actual data which is pointed by that pointer will stay in the non-EPC part? Does It mean that when the enclave accesses that buffer, nor integrity verification, neither confidentiality is supported for that particular buffer?

-M

Hello Meysam,

JesusG_Intel — Tue, 28 Apr 2020 00:18:45 GMT

Hello Meysam,

You are correct. If you pass a pointer to a buffer to an enclave using user_check, the contents of that buffer are not copied into the trusted memory. The application developer must explicitly do all the pointer checking and data copying inside the enclave. With user_check, the actual, raw address of the memory location is passed.

Here is a great description of how and when to use user_check: https://software.intel.com/en-us/articles/intel-software-guard-extensions-tutorial-part-7-refining-the-enclave

Regards,

Jesus

Thank you, Jesus, I

Meysam_t_ — Tue, 28 Apr 2020 02:41:03 GMT

Thank you, Jesus, I appreciate your timely help.