acpi/nfit, libnvdimm: Add unlock of nvdimm support for Intel DIMMs

Add support to unlock the dimm via the kernel key management APIs. The
passphrase is expected to be pulled from userspace through keyutils.
The key management and sysfs attributes are libnvdimm generic.

Encrypted keys are used to protect the nvdimm passphrase at rest. The
master key can be a trusted-key sealed in a TPM, preferred, or an
encrypted-key, more flexible, but more exposure to a potential attacker.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 42c815f97c02..0f0ab276134e 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -163,9 +163,21 @@ enum nvdimm_security_state {
 	NVDIMM_SECURITY_OVERWRITE,
 };
 
+#define NVDIMM_PASSPHRASE_LEN		32
+#define NVDIMM_KEY_DESC_LEN		22
+
+struct nvdimm_key_data {
+	u8 data[NVDIMM_PASSPHRASE_LEN];
+};
+
 struct nvdimm_security_ops {
 	enum nvdimm_security_state (*state)(struct nvdimm *nvdimm);
 	int (*freeze)(struct nvdimm *nvdimm);
+	int (*change_key)(struct nvdimm *nvdimm,
+			const struct nvdimm_key_data *old_data,
+			const struct nvdimm_key_data *new_data);
+	int (*unlock)(struct nvdimm *nvdimm,
+			const struct nvdimm_key_data *key_data);
 };
 
 void badrange_init(struct badrange *badrange);