[mbed-tls] Re: PSA crypto driver - KEY LOCATIONS

-- Gilles Peskine Mbed TLS developer and PSA Crypto architect On 16/10/2023 15:38, Ruchika Gupta via mbed-tls wrote: > > Hi, > > For the crypto accelerator, we are developing for our SoC, we have a > use-case where the same driver can support multiple/range of KEY > LOCATIONS. We want a mechanism such that, the a common function in > driver is called which can then take the necessary option based on the > key location. > > The way jsons are currently structured, what I understand is that for > every key location, we will need to create a separate json with a > different driver prefix. This would lead to a lot of code duplication > for us. > > For eg { to define 3 locations X, Y and Z , I need to create 3 json > files -> these all refer to same crypto sub-system I my case} > > #define TEST_DRIVER_X_OPAQUE_DRIVER_ID > > #define TEST_DRIVER_Y_OPAQUE_DRIVER_ID > > #define TEST_DRIVER_Z_OPAQUE_DRIVER_ID > > Switch (key_location) > > Case x: > >                 Test_driver_x_ opaque_import_key(); > >                 break; > > Case y: > >                 Test_driver_y_ opaque_import_key(); > >                 break; > > Case z: > >                 Test_driver_z_ opaque_import_key(); > >                 break; > > This is resulting in a lot of code duplication and overhead. What we > want to have the flexibility to achieve is : > > #define TEST_DRIVER_OPAQUE_DRIVER_ID > > Switch (key_location) > > Case x: > > Case y: > > Case z: > > Test_driver_opaque_import_key(); > > If we can support multiple locations from a driver json file for a > given driver, this issue would be resolved. *This would give the > driver writers flexibility on how and where they want to handle the > locations.* > > Please let us know your views on the same. > > Regards, > > Ruchika > >