This patchset is also available in git via:
git fetch https://git.kernel.org/pub/scm/fs/fscrypt/linux.git wrapped-keys-v9
This is a reworked version of the patchset
https://lore.kernel.org/linux-fscrypt/20241202-wrapped-keys-v7-0-67c3ca3f3282@xxxxxxxxxx/T/#u
that was recently sent by Bartosz Golaszewski. It turned out there were a lot
of things I wanted to fix, and it would have taken much too long to address them
in a code review. For now this is build-tested only; I've errored on the side
of sending this out early since others are working on this too. Besides many
miscellaneous fixes and cleanups, I've made the following notable changes:
- ufs-qcom and sdhci-msm now just initialize the blk_crypto_profile themselves,
like what ufs-exynos was doing. This avoids needing to add all the
host-specific hooks for wrapped key support to the MMC and UFS core drivers.
- When passing the blk_crypto_key further down the stack, it now replaces
parameters like the algorithm ID, to avoid creating two sources of truth.
- The module parameter qcom_ice.use_wrapped_keys should work correctly now.
- The fscrypt support no longer uses a policy flag to indicate when a file is
protected by a HW-wrapped key, since it was already implied by the file's key
identifier being that of a HW-wrapped key. Originally there was an issue
where raw and HW-wrapped keys could share key identifiers, but I had fixed
that earlier by introducing a new HKDF context byte.
- The term "standard keys" is no longer used. Now "raw keys" is consistently
used instead. I've found that people find the term "raw keys" to be more
intuitive. Also HW-wrapped keys could in principle be standardized.
- I've reordered the patchset to place preparatory patches that don't depend on
the actual HW-wrapped key support first.
My current thinking is that for 6.14 we should just aim to get the preparatory
patches 1-5 merged via the ufs and mmc trees, while the actual HW-wrapped key
support continues to be finalized and properly tested. But let me know if
anyone has any other thoughts.
A quick intro to the patchset for anyone who hasn't been following along:
This patchset adds support for hardware-wrapped inline encryption keys, a
security feature supported by some SoCs and that has already seen a lot of
real-world use downstream. It adds the block and fscrypt framework for the
feature as well as support for it with UFS on Qualcomm SoCs.
This feature is described in full detail in the included Documentation changes.
But to summarize, hardware-wrapped keys are inline encryption keys that are
wrapped (encrypted) by a key internal to the hardware so that they can only be
unwrapped (decrypted) by the hardware. Initially keys are wrapped with a
permanent hardware key, but during actual use they are re-wrapped with a
per-boot ephemeral key for improved security. The hardware supports importing
keys as well as generating keys itself.
This differs from the existing support for hardware-wrapped keys in the kernel
crypto API (which also goes by names such as "hardware-bound keys", depending on
the driver) in the same way that the crypto API differs from blk-crypto: the
crypto API is for general crypto operations, whereas blk-crypto is for inline
storage encryption.
This feature is already being used by Android downstream for several years
(https://source.android.com/docs/security/features/encryption/hw-wrapped-keys),
but on other platforms userspace support will be provided via fscryptctl and
tests via xfstests (I have some old patches for this that need to be updated).
Eric Biggers (10):
ufs: crypto: add ufs_hba_from_crypto_profile()
ufs: qcom: convert to use UFSHCD_QUIRK_CUSTOM_CRYPTO_PROFILE
mmc: crypto: add mmc_from_crypto_profile()
mmc: sdhci-msm: convert to use custom crypto profile
soc: qcom: ice: make qcom_ice_program_key() take struct blk_crypto_key
blk-crypto: add basic hardware-wrapped key support
blk-crypto: show supported key types in sysfs
blk-crypto: add ioctls to create and prepare hardware-wrapped keys
fscrypt: add support for hardware-wrapped keys
ufs: qcom: add support for wrapped keys
Gaurav Kashyap (2):
firmware: qcom: scm: add calls for wrapped key support
soc: qcom: ice: add HWKM support to the ICE driver
Documentation/ABI/stable/sysfs-block | 18 +
Documentation/block/inline-encryption.rst | 251 +++++++++++-
Documentation/filesystems/fscrypt.rst | 201 +++++++--
.../userspace-api/ioctl/ioctl-number.rst | 2 +
block/blk-crypto-fallback.c | 7 +-
block/blk-crypto-internal.h | 10 +
block/blk-crypto-profile.c | 103 +++++
block/blk-crypto-sysfs.c | 35 ++
block/blk-crypto.c | 196 ++++++++-
block/ioctl.c | 5 +
drivers/firmware/qcom/qcom_scm.c | 214 ++++++++++
drivers/firmware/qcom/qcom_scm.h | 4 +
drivers/md/dm-table.c | 1 +
drivers/mmc/host/cqhci-crypto.c | 38 +-
drivers/mmc/host/cqhci.h | 8 +-
drivers/mmc/host/sdhci-msm.c | 102 +++--
drivers/soc/qcom/ice.c | 383 +++++++++++++++++-
drivers/ufs/core/ufshcd-crypto.c | 33 +-
drivers/ufs/host/ufs-exynos.c | 3 +-
drivers/ufs/host/ufs-qcom.c | 137 +++++--
fs/crypto/fscrypt_private.h | 75 +++-
fs/crypto/hkdf.c | 4 +-
fs/crypto/inline_crypt.c | 42 +-
fs/crypto/keyring.c | 157 +++++--
fs/crypto/keysetup.c | 63 ++-
fs/crypto/keysetup_v1.c | 4 +-
include/linux/blk-crypto-profile.h | 73 ++++
include/linux/blk-crypto.h | 73 +++-
include/linux/firmware/qcom/qcom_scm.h | 8 +
include/linux/mmc/host.h | 8 +
include/soc/qcom/ice.h | 34 +-
include/uapi/linux/blk-crypto.h | 44 ++
include/uapi/linux/fs.h | 6 +-
include/uapi/linux/fscrypt.h | 7 +-
include/ufs/ufshcd.h | 11 +-
35 files changed, 2091 insertions(+), 269 deletions(-)
create mode 100644 include/uapi/linux/blk-crypto.h
base-commit: f486c8aa16b8172f63bddc70116a0c897a7f3f02
--
2.47.1
