Re: PKCS#11 TA needs userland supplicant?

On 10.04.26 09:59, Jan Kiszka wrote:
> On 10.04.26 07:45, Jan Kiszka wrote:
>> On 10.04.26 07:37, Jens Wiklander wrote:
>>> Hi,
>>>
>>> On Thu, Apr 9, 2026 at 7:41 PM Jan Kiszka via OP-TEE
>>> <[email protected]> wrote:
>>>>
>>>> Hi all,
>>>>
>>>> to avoid that I'm debugging further this error I get during boot with
>>>> CONFIG_RPMB=y in the kernel and CFG_IN_TREE_EARLY_TAS=pkcs11/fd02c9da...:
>>>>
>>>> [    0.359372] mmcblk0boot0: mmc0:0001 QEMU!! 4.00 MiB
>>>> [    0.361779] mmcblk0boot1: mmc0:0001 QEMU!! 4.00 MiB
>>>> [    0.363761] mmcblk0rpmb: mmc0:0001 QEMU!! 2.00 MiB, chardev (248:0)
>>>> D/TC:? 0 tee_ta_init_session_with_context:569 Re-open trusted service 7011a688-ddde-4053-a5a9-7b3c4ddf13b8
>>>> D/TC:? 0 legacy_rpmb_init:1143 Trying legacy RPMB init
>>>
>>> The in-kernel routing didn't initialize as expected, so OP-TEE is
>>> falling back to the tee-supplicant based RPMB communication.
>>>
>>>
>>>> E/TC:? 0 get_rpc_alloc_res:646 RPC allocation failed. Non-secure world result: ret=0xffff000c ret_origin=0x2
>>>> D/TC:? 0 tee_ta_invoke_command:830 Error: f0100003 of 4
>>>> D/TC:? 0 tee_ta_close_session:469 csess 0xc0210910 id 1
>>>> D/TC:? 0 tee_ta_close_session:488 Destroy session
>>>>
>>>> Is it possible at all to run the PKCS#11 TA without userland tee-
>>>> supplicant? I thought it only needs the supplicant for RPMB, thus should
>>>> be fine with the in-kernel routing (which is active), but maybe that is
>>>> not true.
>>>
>>> Yes, I think so. I haven't tried it myself, though. Anyway, the log
>>> tells that OP-TEE isn't using in-kernel routing. You can also check
>>> /sys/class/tee/teepriv0/rpmb_routing_model to see what the driver has
>>> negotiated.
>>>
>>
>> # cat /sys/class/tee/teepriv0/rpmb_routing_model
>> kernel
>>
>> And if I build optee as module and load it later, then call "pkcs1-tool
>> --module /usr/lib/libckteec.so.0 -I", it also waits for userspace tee here:
>>
>> ...
>> F/TC:? 0 trace_syscall:147 syscall #8 (syscall_check_access_rights)
>> F/TC:? 0 trace_syscall:147 syscall #41 (syscall_storage_obj_open)
>> D/TC:? 0 legacy_rpmb_init:1143 Trying legacy RPMB init
>> I/TC: thread_rpc_alloc 0, arg->ret ffff0000
>> I/TC: get_rpc_alloc_res: bt 0 size 8192
>>
> 
> I instrumented further, and I'm getting an OPTEE_RPC_CMD_SHM_ALLOC with
> OPTEE_RPC_SHM_TYPE_APPL, not OPTEE_RPC_SHM_TYPE_KERNEL - this is where
> things are failing or blocking.
> 

I think I'm getting closer: We have key-writing enabled for the QEMU
target (key is not persisted there yet), and that seems to enforce
legacy init all the time:

https://github.com/OP-TEE/optee_os/blob/15bbaa331fb6d69466c4880a1af1e8e9580c95f1/core/tee/tee_rpmb_fs.c#L1248

If I got it right, legacy_rpmb_init requires a userspace supplicant,
doesn't it?

Jan

-- 
Siemens AG, Foundational Technologies
Linux Expert Center