How to access files in TA on android/emulator?

[YangRongAtGit]

Hello,

I created a pair of CA / TA application on Android 5.1.1_r30. In the TA, I am trying to read a data file from an emulator. I used the 'adb push' command to push the file on the emulator folder /data/app/MyApp. But the TA application is unable to read the file. My question is: Is the OpenTEE provide a simulated TA storage on emulator / device? I see the project emulator includes tee_storage_api, is that for access general resource files? Or maybe have to push the data file to a specific location?

---

ASOP 5.1.1_r30
gcc 4.9.x

Thanks,

Rong

[xzr]

It's been a while since I've touched the thing. But you should probably read the file in the CA and pass that buffer into the TA

[brianmcgillion]

Hi,

The TA has no understanding of a "standard" file system. GP has the Storage
API that is used for creating files. So the files are created in the TA and
then read and written from the TA also. So to provision data to a file in
the secure storage, do as Atte suggests, read the data from the CA and pass
it to the TA to store.

On a side note:: One thing to remember is that in a production device the
amount of storage that is available to the TA can be quite limited, it
ranges from a few hundred Kb to potentially a few MB (usually single
digit). Of course, this is dependent on the implementation. But it is not
the place you will store your video collection, rather you will store the
key that is used to decode the collection. The collection will be on your
normal storage, so you will have a protocol to read in encrypted bytes from
the CA and pass back the decrypted data, if that is your use case. That is
an overly simplified explanation and use case, it is more just to point out
what the secure storage is not.

On Thu, Sep 29, 2016 at 4:30 AM, r0nG [email protected] wrote:

Hello,

I created a pair of CA / TA application on Android 5.1.1_r30. In the TA, I
am trying to read a data file from an emulator. I used the 'adb push'
command to push the file on the emulator folder /data/app/MyApp. But the TA
application is unable to read the file. My question is: Is the OpenTEE
provide a simulated TA storage on emulator / device? Or maybeI have to push

the data file to a specific location?

ASOP 5.1.1_r30
gcc 4.9.x

Thanks,

Rong

—
You are receiving this because you are subscribed to this thread.
Reply to this email directly, view it on GitHub
#21, or mute the thread
https://github.com/notifications/unsubscribe-auth/AA_vJwgjUbuHRClmqkDrjJrwql9EjJhoks5quxSlgaJpZM4KJfOb
.

[YangRongAtGit]

Thanks for your reply. One more question: Is there a function that I can get the memory capacity of the trust-zone on a specific device?