[PATCH 05/10] scsi: ufs: prepare to support wrapped keys

Gaurav Kashyap
2021-12-06T22:59:08Z

Adds support in ufshcd-core for wrapped keys.
1. Change program key vop to support wrapped key sizes by
using blk_crypto_key directly instead of using ufs_crypto_cfg
which is not suitable for wrapped keys.
2. Add derive_sw_secret vop and derive_sw_secret crypto_profile op.

Signed-off-by: Gaurav Kashyap <quic_gaurkash@quicinc.com>
---
drivers/scsi/ufs/ufshcd-crypto.c | 52 +++++++++++++++++++++++++-------
drivers/scsi/ufs/ufshcd.h | 9 +++++-
2 files changed, 49 insertions(+), 12 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd-crypto.c b/drivers/scsi/ufs/ufshcd-crypto.c
index 0ed82741f981..9d68621a0eb4 100644
--- a/drivers/scsi/ufs/ufshcd-crypto.c
+++ b/drivers/scsi/ufs/ufshcd-crypto.c
@@ -18,16 +18,23 @@ static const struct ufs_crypto_alg_entry {
};

static int ufshcd_program_key(struct ufs_hba *hba,
+ const struct blk_crypto_key *key,
const union ufs_crypto_cfg_entry *cfg, int slot)
{
int i;
u32 slot_offset = hba->crypto_cfg_register + slot * sizeof(*cfg);
int err = 0;
+ bool evict = false;

ufshcd_hold(hba, false);

if (hba->vops && hba->vops->program_key) {
- err = hba->vops->program_key(hba, cfg, slot);
+ if (!(cfg->config_enable & UFS_CRYPTO_CONFIGURATION_ENABLE))
+ evict = true;
+ err = hba->vops->program_key(hba, key, slot,
+ cfg->data_unit_size,
+ cfg->crypto_cap_idx,
+ evict);
goto out;
}

@@ -80,16 +87,18 @@ static int ufshcd_crypto_keyslot_program(struct blk_crypto_profile *profile,
cfg.crypto_cap_idx = cap_idx;
cfg.config_enable = UFS_CRYPTO_CONFIGURATION_ENABLE;

- if (ccap_array[cap_idx].algorithm_id == UFS_CRYPTO_ALG_AES_XTS) {
- /* In XTS mode, the blk_crypto_key's size is already doubled */
- memcpy(cfg.crypto_key, key->raw, key->size/2);
- memcpy(cfg.crypto_key + UFS_CRYPTO_KEY_MAX_SIZE/2,
- key->raw + key->size/2, key->size/2);
- } else {
- memcpy(cfg.crypto_key, key->raw, key->size);
+ if (key->crypto_cfg.key_type != BLK_CRYPTO_KEY_TYPE_HW_WRAPPED) {
+ if (ccap_array[cap_idx].algorithm_id == UFS_CRYPTO_ALG_AES_XTS) {
+ /* In XTS mode, the blk_crypto_key's size is already doubled */
+ memcpy(cfg.crypto_key, key->raw, key->size/2);
+ memcpy(cfg.crypto_key + UFS_CRYPTO_KEY_MAX_SIZE/2,
+ key->raw + key->size/2, key->size/2);
+ } else {
+ memcpy(cfg.crypto_key, key->raw, key->size);
+ }
}

- err = ufshcd_program_key(hba, &cfg, slot);
+ err = ufshcd_program_key(hba, key, &cfg, slot);

memzero_explicit(&cfg, sizeof(cfg));
return err;
@@ -103,7 +112,7 @@ static int ufshcd_clear_keyslot(struct ufs_hba *hba, int slot)
*/
union ufs_crypto_cfg_entry cfg = {};

- return ufshcd_program_key(hba, &cfg, slot);
+ return ufshcd_program_key(hba, NULL, &cfg, slot);
}

static int ufshcd_crypto_keyslot_evict(struct blk_crypto_profile *profile,
@@ -126,9 +135,25 @@ bool ufshcd_crypto_enable(struct ufs_hba *hba)
return true;
}

+static int ufshcd_crypto_derive_sw_secret(struct blk_crypto_profile *profile,
+ const u8 *wrapped_key,
+ unsigned int wrapped_key_size,
+ u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE])
+{
+ struct ufs_hba *hba =
+ container_of(profile, struct ufs_hba, crypto_profile);
+
+ if (hba->vops && hba->vops->derive_secret)
+ return hba->vops->derive_secret(hba, wrapped_key,
+ wrapped_key_size, sw_secret);
+
+ return -EOPNOTSUPP;
+}
+
static const struct blk_crypto_ll_ops ufshcd_crypto_ops = {
.keyslot_program = ufshcd_crypto_keyslot_program,
.keyslot_evict = ufshcd_crypto_keyslot_evict,
+ .derive_sw_secret = ufshcd_crypto_derive_sw_secret,
};

static enum blk_crypto_mode_num
@@ -190,7 +215,12 @@ int ufshcd_hba_init_crypto_capabilities(struct ufs_hba *hba)
hba->crypto_profile.ll_ops = ufshcd_crypto_ops;
/* UFS only supports 8 bytes for any DUN */
hba->crypto_profile.max_dun_bytes_supported = 8;
- hba->crypto_profile.key_types_supported = BLK_CRYPTO_KEY_TYPE_STANDARD;
+ if (hba->hw_wrapped_keys_supported)
+ hba->crypto_profile.key_types_supported =
+ BLK_CRYPTO_KEY_TYPE_HW_WRAPPED;
+ else
+ hba->crypto_profile.key_types_supported =
+ BLK_CRYPTO_KEY_TYPE_STANDARD;
hba->crypto_profile.dev = hba->dev;

/*
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index df5439b12208..095c2d660aa7 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -320,6 +320,7 @@ struct ufs_pwr_mode_info {
* @device_reset: called to issue a reset pulse on the UFS device
* @program_key: program or evict an inline encryption key
* @event_notify: called to notify important events
+ * @derive_secret: derive sw secret from wrapped inline encryption key
*/
struct ufs_hba_variant_ops {
const char *name;
@@ -353,9 +354,14 @@ struct ufs_hba_variant_ops {
struct devfreq_dev_profile *profile,
void *data);
int (*program_key)(struct ufs_hba *hba,
- const union ufs_crypto_cfg_entry *cfg, int slot);
+ const struct blk_crypto_key *crypto_key,
+ int slot, u8 data_unit_size, int capid,
+ bool evict);
void (*event_notify)(struct ufs_hba *hba,
enum ufs_event_type evt, void *data);
+ int (*derive_secret)(struct ufs_hba *hba, const u8 *wrapped_key,
+ unsigned int wrapped_key_size,
+ u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE]);
};

/* clock gating state */
@@ -906,6 +912,7 @@ struct ufs_hba {
union ufs_crypto_cap_entry *crypto_cap_array;
u32 crypto_cfg_register;
struct blk_crypto_profile crypto_profile;
+ bool hw_wrapped_keys_supported;
#endif
#ifdef CONFIG_DEBUG_FS
struct dentry *debugfs_root;
--
2.17.1