The RPMB authentication key is derived from the dev_id handed to the RPMB subsystem. OP-TEE implements the eMMC RPMB flow, where the dev_id is the eMMC CID, a fixed 16-byte value, and it derives the key on that assumption.
The UFS RPMB id built here is "<device_id>-R<region>", which is variable length and longer than 16 bytes. Passing it verbatim would tie the derived key to a length OP-TEE does not expect and diverge from the fixed-CID eMMC ABI, requiring OP-TEE to be taught about variable-length UFS ids.
Hash the UFS id into a fixed 16-byte dev_id with blake2s instead. This keeps the derived key stable and unique per region while matching the eMMC CID layout OP-TEE relies on, so the key-derivation ABI stays identical and no OP-TEE change is needed.
Select CRYPTO_LIB_BLAKE2S when RPMB is enabled since ufs-rpmb.c now depends on it.
Signed-off-by: Jorge Ramirez-Ortiz jorge.ramirez@oss.qualcomm.com --- drivers/ufs/Kconfig | 1 + drivers/ufs/core/ufs-rpmb.c | 19 +++++++++++++++++-- 2 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/ufs/Kconfig b/drivers/ufs/Kconfig index f662e7ce71f1..0a050565872d 100644 --- a/drivers/ufs/Kconfig +++ b/drivers/ufs/Kconfig @@ -7,6 +7,7 @@ menuconfig SCSI_UFSHCD tristate "Universal Flash Storage Controller" depends on SCSI && SCSI_DMA depends on RPMB || !RPMB + select CRYPTO_LIB_BLAKE2S if RPMB select PM_DEVFREQ select DEVFREQ_GOV_SIMPLE_ONDEMAND select NLS diff --git a/drivers/ufs/core/ufs-rpmb.c b/drivers/ufs/core/ufs-rpmb.c index adbec80cf381..a7595be0884c 100644 --- a/drivers/ufs/core/ufs-rpmb.c +++ b/drivers/ufs/core/ufs-rpmb.c @@ -10,6 +10,7 @@ * Can Guo can.guo@oss.qualcomm.com */
+#include <crypto/blake2s.h> #include <linux/module.h> #include <linux/device.h> #include <linux/kernel.h> @@ -21,6 +22,7 @@ #include <linux/unaligned.h> #include "ufshcd-priv.h"
+#define UFS_RPMB_ID_LEN 16 /* Match eMMC CID Length */ #define UFS_RPMB_SEC_PROTOCOL 0xEC /* JEDEC UFS application */ #define UFS_RPMB_SEC_PROTOCOL_ID 0x01 /* JEDEC UFS RPMB protocol ID, CDB byte3 */
@@ -156,6 +158,7 @@ int ufs_rpmb_probe(struct ufs_hba *hba) { struct ufs_rpmb_dev *ufs_rpmb, *it, *tmp; struct rpmb_dev *rdev; + char *dev_id = NULL; char *cid = NULL; int region; u32 cap; @@ -215,8 +218,17 @@ int ufs_rpmb_probe(struct ufs_hba *hba) goto err_out; }
- descr.dev_id = cid; - descr.dev_id_len = strlen(cid); + dev_id = kzalloc(UFS_RPMB_ID_LEN, GFP_KERNEL); + if (!dev_id) { + device_unregister(&ufs_rpmb->dev); + ret = -ENOMEM; + goto err_out; + } + + blake2s(NULL, 0, cid, strlen(cid), dev_id, UFS_RPMB_ID_LEN); + + descr.dev_id = dev_id; + descr.dev_id_len = UFS_RPMB_ID_LEN; descr.capacity = cap;
/* Register RPMB device */ @@ -230,6 +242,8 @@ int ufs_rpmb_probe(struct ufs_hba *hba)
kfree(cid); cid = NULL; + kfree(dev_id); + dev_id = NULL;
ufs_rpmb->rdev = rdev; ufs_rpmb->region_id = region; @@ -242,6 +256,7 @@ int ufs_rpmb_probe(struct ufs_hba *hba) return 0; err_out: kfree(cid); + kfree(dev_id); list_for_each_entry_safe(it, tmp, &hba->rpmbs, node) { list_del(&it->node); device_unregister(&it->dev);