Hi Robert,
On Thu, Sep 14, 2023 at 11:58 AM Robert Delien r.delien@payter.nl wrote:
Hi,
For legislative purposes, one of our Trusted Applications needs to show a checksum to the end-user on our secure screen, to allow verification. Albeit a bit unconventional use of it, we thought that the TA's own checksum would be ideal for that, but we're having difficulties figuring how to access that, if at all possible.
So I have to turn to you guys here: Is there any way for a TA to access its own checksum? And if yes, could somebody please give me some pointers on how to do this?
TEE core could compute the checksum as part of loading the TA, the crux would be how to expose that to others. A possible solution would be to store it in memory as a dictionary containing the uuid and checksum. Then a pseudo TA [1] could hand out this information to clients, like other TA's or even normal world clients, when needed. I.e., pseudo TA implements and exposes a function (in pseudo code), looking something like this : TEE_Result get_checksum_for_ta(uuid, *checksum) { // Get checksum from memory *checksum = checksum_list[uuid]; return ... }
[1] https://optee.readthedocs.io/en/latest/faq/faq.html?#q-what-is-a-pseudo-ta-a...
With kind regards,
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