Add support for HWKM v1 based In-line Crypto Engine

[Harshal Dev (harshaldev27)]

All Qualcomm SoCs support an In-line Crypto Engine (ICE) hardware block within either the UFS or eMMC storage controller. When storage data moves through the ICE it encrypts or decrypts it using a key programmed within its slot. This patch series introduces a Pseudo-TA for the ICE that allows the Linux side ICE driver [1] to generate a key for ICE programming via version 1 of the Hardware Key Manager (HWKM) and program it within one of its slots to enable storage encryption and decryption.

The storage key is either generated by HWKM (recommended) or imported within one of its slots via Linux. Once the storage key is available within a HWKM slot, the HWKM can directly push it into an ICE key slot after wrapping it via a Transport key (TPKEY). This ensures that the key is only ever visible to trusted software (OP-TEE) or hardware (HWKM/ICE).

Linux always obtains the storage key in a wrapped blob format, ensuring that it never leaves the trust boundary. For the purpose of wrapping the storage key, a hardware derived L4 key is used, which is derived from a per-chip unique derivation key (UKDK L4 key) available within the HWKM. When the L4 key derivation process mixes a per-boot random ephemeral seed, the returned wrapped storage key is called an ephemeral key and cannot be used across device reboots. This provides an additional layer of security by tying the wrapped blob to the current device boot session.

Outline of this patch series:

• Patch 1 adds support for generating a SWAP and TPKEY within HWKM during its initialization. The SWAP key is used for exporting a key from HWKM within software which must never leave the hardware in clear form. The TPKEY is used for wrapping keys when transporting them between HWKM and its slaves.
• Patch 2 adds support for ICE slave to the HWKM driver to allow provisioning of ICE keys directly via HWKM.
• Patches 4 to 9 add the ICE Psuedo-TA which is called by Linux to generate, prepare, program or clear the ICE key. It also allows using the ICE key to generate a software secret via standard CMAC operation.

Dependencies

This PR depends on PR #52 and will be re-based once merged. This dependency is with respect to boiler plate code added in this PR for extending the HWKM slave support via GPCE. This PR is already reviewed in #28.

Validation:

Currently, since the Linux side patch for this series is under work, only Unit testing has been done which should be sufficient for qcom-next. The test driver [2] was used to generate a hardware wrapped key, wrap it via an ephemeral key and then program it into the ICE key slot 10. Afterwards, the slot was also cleared using the same test driver. The Linux fscrypt framework [3] calls the ICE commands in the same sequence when using hardware-wrapped keys.

CMD 1: Generate a HW wrapped key.
CMD 2: Prepare the HW wrapped key via wrapping via epehemeral key.
CMD 3: Import a raw key into the HWKM slot.
CMD 4: Program the key into ICE slot 10.
CMD 5: Clear the key from ICE slot 10.
CMD 6: Use the HW wrapped key to generate a software secret.

# echo 1 > /proc/qcom_ice_pta_test
[   91.955101] qcom_ice_pta_test: cmd=2 rc=0 pta_ret=0x0 origin=0x4
[   91.961299] qcom_ice_pta_test: generated L4 wrapped key size=68
[   91.967399] qcom_ice_pta_test: blob 00000000: b6 74 7f a6 59 d0 ce 43 cf c4 f8 d4 76 44 f0 98
[   91.976164] qcom_ice_pta_test: blob 00000010: 25 63 ef f4 eb 5a b2 7e c6 db da c6 87 9d af 11
[   91.984936] qcom_ice_pta_test: blob 00000020: 55 f8 f6 d2 25 4e 6b ec db 3a 06 85 da 4b 87 54
[   91.993694] qcom_ice_pta_test: blob 00000030: 14 18 01 52 03 00 00 00 00 00 00 00 00 00 00 00
[   92.002462] qcom_ice_pta_test: blob 00000040: 00 00 00 00
[   92.008019] qcom_ice_pta_test: dumped generate (68 bytes)
[   92.013576] qcom_ice_pta_test: command 1 done
# echo 2 > /proc/qcom_ice_pta_test
[   98.163330] qcom_ice_pta_test: cmd=4 rc=0 pta_ret=0x0 origin=0x4
[   98.169523] qcom_ice_pta_test: prepared/exported ephemeral wrapped key size=68
[   98.176962] qcom_ice_pta_test: blob 00000000: 1b 4e 58 7a d7 a3 99 e6 5f fc 25 b4 4b d9 d3 89
[   98.185731] qcom_ice_pta_test: blob 00000010: 15 36 bc 03 c0 9c bd c6 fa 1e 56 90 26 a6 0d c9
[   98.194503] qcom_ice_pta_test: blob 00000020: 4e ac 33 83 89 06 5a c7 41 33 30 31 95 53 46 6c
[   98.203261] qcom_ice_pta_test: blob 00000030: 14 18 01 52 03 00 00 00 00 00 00 00 00 00 00 00
[   98.212025] qcom_ice_pta_test: blob 00000040: 00 00 00 00
[   98.217582] qcom_ice_pta_test: dumped prepare-ephemeral (68 bytes)
[   98.223942] qcom_ice_pta_test: command 2 done
# echo 4 > /proc/qcom_ice_pta_test
[  102.401444] qcom_ice_pta_test: cmd=1 rc=0 pta_ret=0x0 origin=0x4
[  102.407654] qcom_ice_pta_test: command 4 done
# echo 5 > /proc/qcom_ice_pta_test
[  107.410041] qcom_ice_pta_test: cmd=0 rc=0 pta_ret=0x0 origin=0x4
[  107.416275] qcom_ice_pta_test: command 5 done
# echo 6 > /proc/qcom_ice_pta_test
[ 1268.239465] qcom_ice_pta_test: cmd=5 rc=0 pta_ret=0x0 origin=0x4
[ 1268.245678] qcom_ice_pta_test: derived raw secret size=32
[ 1268.251250] qcom_ice_pta_test: blob 00000000: 7a 40 7d af 63 2b 12 51 40 a5 8d 27 3a 53 51 aa
[ 1268.260020] qcom_ice_pta_test: blob 00000010: 3a e7 ad 55 93 ad ce d3 59 9f 8b 92 a8 28 aa d3
[ 1268.268790] qcom_ice_pta_test: dumped raw-secret (32 bytes)
[ 1268.274525] qcom_ice_pta_test: command 6 done

References:
[1] https://elixir.bootlin.com/linux/v7.2-rc7/source/drivers/soc/qcom/ice.c
[2] harshaldev27/kernel-topics@e7b9b86
[3] https://www.kernel.org/doc/html/latest/filesystems/fscrypt.html

[Sumit Garg (b49020)]

Harshal Dev (@harshaldev27) can you rather only pick HWKM patches from Amirreza Zarrabi (@qc-azarrabi) PR which the ICE feature depends upon? This can untangle GPCE and ICE PRs.

[Harshal Dev (harshaldev27)]

Harshal Dev (Harshal Dev (@harshaldev27)) can you rather only pick HWKM patches from Amirreza Zarrabi (Amirreza Zarrabi (@qc-azarrabi)) PR which the ICE feature depends upon? This can untangle GPCE and ICE PRs.

Done, only 3 commits from his PR related to HWKM re-factoring and GPCE slave addition are now kept.