Merge tag 'libnvdimm-for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull libnvdimm updates from Dan Williams:
 "The vast bulk of this update is the new support for the security
  capabilities of some nvdimms.

  The userspace tooling for this capability is still a work in progress,
  but the changes survive the existing libnvdimm unit tests. The changes
  also pass manual checkout on hardware and the new nfit_test emulation
  of the security capability.

  The touches of the security/keys/ files have received the necessary
  acks from Mimi and David. Those changes were necessary to allow for a
  new generic encrypted-key type, and allow the nvdimm sub-system to
  lookup key material referenced by the libnvdimm-sysfs interface.

  Summary:

   - Add support for the security features of nvdimm devices that
     implement a security model similar to ATA hard drive security. The
     security model supports locking access to the media at
     device-power-loss, to be unlocked with a passphrase, and
     secure-erase (crypto-scramble).

     Unlike the ATA security case where the kernel expects device
     security to be managed in a pre-OS environment, the libnvdimm
     security implementation allows key provisioning and key-operations
     at OS runtime. Keys are managed with the kernel's encrypted-keys
     facility to provide data-at-rest security for the libnvdimm key
     material. The usage model mirrors fscrypt key management, but is
     driven via libnvdimm sysfs.

   - Miscellaneous updates for api usage and comment fixes"

* tag 'libnvdimm-for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (21 commits)
  libnvdimm/security: Quiet security operations
  libnvdimm/security: Add documentation for nvdimm security support
  tools/testing/nvdimm: add Intel DSM 1.8 support for nfit_test
  tools/testing/nvdimm: Add overwrite support for nfit_test
  tools/testing/nvdimm: Add test support for Intel nvdimm security DSMs
  acpi/nfit, libnvdimm/security: add Intel DSM 1.8 master passphrase support
  acpi/nfit, libnvdimm/security: Add security DSM overwrite support
  acpi/nfit, libnvdimm: Add support for issue secure erase DSM to Intel nvdimm
  acpi/nfit, libnvdimm: Add enable/update passphrase support for Intel nvdimms
  acpi/nfit, libnvdimm: Add disable passphrase support to Intel nvdimm.
  acpi/nfit, libnvdimm: Add unlock of nvdimm support for Intel DIMMs
  acpi/nfit, libnvdimm: Add freeze security support to Intel nvdimm
  acpi/nfit, libnvdimm: Introduce nvdimm_security_ops
  keys-encrypted: add nvdimm key format type to encrypted keys
  keys: Export lookup_user_key to external users
  acpi/nfit, libnvdimm: Store dimm id as a member to struct nvdimm
  libnvdimm, namespace: Replace kmemdup() with kstrndup()
  libnvdimm, label: Switch to bitmap_zalloc()
  ACPI/nfit: Adjust annotation for why return 0 if fail to find NFIT at start
  libnvdimm, bus: Check id immediately following ida_simple_get
  ...

security/keys/encrypted-keys/encrypted.c

@@ -45,6 +45,7 @@ static const char hmac_alg[] = "hmac(sha256)";
 static const char blkcipher_alg[] = "cbc(aes)";
 static const char key_format_default[] = "default";
 static const char key_format_ecryptfs[] = "ecryptfs";
+static const char key_format_enc32[] = "enc32";
 static unsigned int ivsize;
 static int blksize;
 
@@ -54,6 +55,7 @@ static int blksize;
 #define HASH_SIZE SHA256_DIGEST_SIZE
 #define MAX_DATA_SIZE 4096
 #define MIN_DATA_SIZE  20
+#define KEY_ENC32_PAYLOAD_LEN 32
 
 static struct crypto_shash *hash_tfm;
 
@@ -62,12 +64,13 @@ enum {
 };
 
 enum {
-	Opt_error = -1, Opt_default, Opt_ecryptfs
+	Opt_error = -1, Opt_default, Opt_ecryptfs, Opt_enc32
 };
 
 static const match_table_t key_format_tokens = {
 	{Opt_default, "default"},
 	{Opt_ecryptfs, "ecryptfs"},
+	{Opt_enc32, "enc32"},
 	{Opt_error, NULL}
 };
 
@@ -195,6 +198,7 @@ static int datablob_parse(char *datablob, const char **format,
 	key_format = match_token(p, key_format_tokens, args);
 	switch (key_format) {
 	case Opt_ecryptfs:
+	case Opt_enc32:
 	case Opt_default:
 		*format = p;
 		*master_desc = strsep(&datablob, " \t");
@@ -625,15 +629,22 @@ static struct encrypted_key_payload *encrypted_key_alloc(struct key *key,
 	format_len = (!format) ? strlen(key_format_default) : strlen(format);
 	decrypted_datalen = dlen;
 	payload_datalen = decrypted_datalen;
-	if (format && !strcmp(format, key_format_ecryptfs)) {
-		if (dlen != ECRYPTFS_MAX_KEY_BYTES) {
-			pr_err("encrypted_key: keylen for the ecryptfs format "
-			       "must be equal to %d bytes\n",
-			       ECRYPTFS_MAX_KEY_BYTES);
-			return ERR_PTR(-EINVAL);
+	if (format) {
+		if (!strcmp(format, key_format_ecryptfs)) {
+			if (dlen != ECRYPTFS_MAX_KEY_BYTES) {
+				pr_err("encrypted_key: keylen for the ecryptfs format must be equal to %d bytes\n",
+					ECRYPTFS_MAX_KEY_BYTES);
+				return ERR_PTR(-EINVAL);
+			}
+			decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES;
+			payload_datalen = sizeof(struct ecryptfs_auth_tok);
+		} else if (!strcmp(format, key_format_enc32)) {
+			if (decrypted_datalen != KEY_ENC32_PAYLOAD_LEN) {
+				pr_err("encrypted_key: enc32 key payload incorrect length: %d\n",
+						decrypted_datalen);
+				return ERR_PTR(-EINVAL);
+			}
 		}
-		decrypted_datalen = ECRYPTFS_MAX_KEY_BYTES;
-		payload_datalen = sizeof(struct ecryptfs_auth_tok);
 	}
 
 	encrypted_datalen = roundup(decrypted_datalen, blksize);