[PATCH v4 00/15] Hardware wrapped key support for qcom ice and ufs

Gaurav Kashyap
2024-01-27T23:29:42Z

The fourth iteration of patches that add support to Qualcomm ICE (Inline Crypto Engine) for hardware wrapped keys using Qualcomm Hardware Key Manager (HWKM)

These patches do the following:
- Address comments from previous versions (https://lore.kernel.org/linux-arm-msm/20231122053817.3401748-1-quic_gaurkash@quicinc.com/)
- Tested on top of Eric's latest fscrypt and block set: https://lore.kernel.org/all/20231104211259.17448-1-ebiggers@kernel.org/
- Rebased and tested on top of Linaro's SHMBridge patches: (https://lkml.org/lkml/2023/11/20/555)

Explanation and use of hardware-wrapped-keys can be found here:
Documentation/block/inline-encryption.rst (https://lore.kernel.org/all/20231104211259.17448-1-ebiggers@kernel.org/)

Testing:
Test platform: SM8650 MTP

The changes were tested by mounting initramfs and running the fscryptctl
tool (Ref: https://github.com/ebiggers/fscryptctl/tree/wip-wrapped-keys) to
generate and prepare keys, as well as to set policies on folders, which
consequently invokes disk encryption flows through UFS.

Tested both standard and wrapped keys (Removing qcom,ice-use-hwkm from dtsi will support using standard keys)

Steps to test:

The following configs were enabled:
CONFIG_BLK_INLINE_ENCRYPTION=y
CONFIG_QCOM_INLINE_CRYPTO_ENGINE=m
CONFIG_FS_ENCRYPTION_INLINE_CRYPT=y
CONFIG_SCSI_UFS_CRYPTO=y

Flash boot image to shell and run the following commands

Creating and preparing keys
- mkfs.ext4 -F -O encrypt,stable_inodes /dev/disk/by-partlabel/userdata
- mount /dev/disk/by-partlabel/userdata -o inlinecrypt /mnt
- ./fscryptctl generate_hw_wrapped_key /dev/disk/by-partlabel/userdata > /mnt/key.longterm OR
dd if=/dev/zero bs=32 count=1 | tr '\0' 'X' \ | fscryptctl import_hw_wrapped_key /dev/disk/by-partlabel/userdata > /mnt/key.longterm
- ./fscryptctl prepare_hw_wrapped_key /dev/disk/by-partlabel/userdata < /mnt/key.longterm > /tmp/key.ephemeral
- ./fscryptctl add_key --hw-wrapped-key < /tmp/key.ephemeral /mnt

Create a folder and associate created keys with the folder
- rm -rf /mnt/dir
- mkdir /mnt/dir
- ./fscryptctl set_policy --hw-wrapped-key --iv-ino-lblk-64 "$keyid" /mnt/dir
- dmesg > /mnt/dir/test.txt
- sync

- Reboot
- mount /dev/disk/by-partlabel/userdata -o inlinecrypt /mnt
- ls /mnt/dir (You should see an encrypted file)
- ./fscryptctl prepare_hw_wrapped_key /dev/disk/by-partlabel/userdata < /mnt/key.longterm > /tmp/key.ephemeral
- ./fscryptctl add_key --hw-wrapped-key < /tmp/key.ephemeral /mnt
- cat /mnt/dir/test.txt

NOTE: Evicting a key with HWKM is not supported in the current SCM call for HWKM v2 chipsets, TZ already supports a different call for this.
Changes will be added separately for these after further internal discussions. But this should not stop merging the existing patches.

Merge Strategy:

This is an open-ended question to the community and the respective component maintainers.
The changes have the following components.

- Fscrypt and block patches (From Eric Biggers)
- SHMBridge patches (Bartosz Golaszewski)
- Qualcomm SCM (This patchset)
- Qualcomm ICE (This patchset)
- UFS Core ((This patchset))
- Qualcomm UFS Host (This patchset)

It would be ideal if one maintainer can take in all the changes together since working with many immutable branches shared with each other might get tricky.

Gaurav Kashyap (15):
ice, ufs, mmc: use blk_crypto_key for program_key
qcom_scm: scm call for deriving a software secret
qcom_scm: scm call for create, prepare and import keys
soc: qcom: ice: add hwkm support in ice
soc: qcom: ice: support for hardware wrapped keys
soc: qcom: ice: support for generate, import and prepare key
ufs: core: support wrapped keys in ufs core
ufs: core: add support to derive software secret
ufs: core: add support for generate, import and prepare keys
ufs: host: wrapped keys support in ufs qcom
ufs: host: implement derive sw secret vop in ufs qcom
ufs: host: support for generate, import and prepare key
dt-bindings: crypto: ice: document the hwkm property
arm64: dts: qcom: sm8650: add hwkm support to ufs ice
arm64: dts: qcom: sm8550: add hwkm support to ufs ice

.../crypto/qcom,inline-crypto-engine.yaml | 10 +
arch/arm64/boot/dts/qcom/sm8550.dtsi | 3 +-
arch/arm64/boot/dts/qcom/sm8650.dtsi | 3 +-
drivers/firmware/qcom/qcom_scm.c | 247 ++++++++++++++
drivers/firmware/qcom/qcom_scm.h | 4 +
drivers/mmc/host/cqhci-crypto.c | 7 +-
drivers/mmc/host/cqhci.h | 2 +
drivers/mmc/host/sdhci-msm.c | 6 +-
drivers/soc/qcom/ice.c | 315 +++++++++++++++++-
drivers/ufs/core/ufshcd-crypto.c | 87 ++++-
drivers/ufs/host/ufs-qcom.c | 61 +++-
include/linux/firmware/qcom/qcom_scm.h | 7 +
include/soc/qcom/ice.h | 18 +-
include/ufs/ufshcd.h | 22 ++
14 files changed, 754 insertions(+), 38 deletions(-)

--
2.43.0