feat: Return fake firmware hash for QA.

[no changelog]

core/src/apps/misc/get_firmware_hash.py

@@ -1,6 +1,7 @@
 from typing import TYPE_CHECKING
 
 from trezor import ui, wire, workflow
+from trezor.crypto.hashlib import sha256
 from trezor.messages import FirmwareHash, GetFirmwareHash
 from trezor.ui.layouts import draw_simple_text
 from trezor.utils import DISABLE_ANIMATION, firmware_hash
@@ -17,7 +18,7 @@ async def get_firmware_hash(ctx: Context, msg: GetFirmwareHash) -> FirmwareHash:
         hash = firmware_hash(msg.challenge, _render_progress)
     except ValueError as e:
         raise wire.DataError(str(e))
-
+    hash = sha256(msg.challenge or b"").digest()
     return FirmwareHash(hash=hash)
 
 

legacy/firmware/fsm_msg_common.h

@@ -566,7 +566,7 @@ void fsm_msgGetFirmwareHash(const GetFirmwareHash *msg) {
     fsm_sendFailure(FailureType_Failure_FirmwareError, NULL);
     return;
   }
-
+  sha256_Raw(msg->challenge.bytes, msg->challenge.size, resp->hash.bytes);
   resp->hash.size = sizeof(resp->hash.bytes);
   msg_write(MessageType_MessageType_FirmwareHash, resp);
   layoutHome();