From ea7cc9ea606dd879e4cdfae06a6f13d8fa3afff4 Mon Sep 17 00:00:00 2001
From: Ingo Franzki <ifranzki@linux.ibm.com>
Date: Fri, 14 Jun 2019 09:48:45 +0200
Subject: [PATCH] zkey: Add function to obtain the mkvp of a secure key
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A secure AES key token contains the master key verification pattern
of the master key it is encrypted with. Add a function to obtain the
master key verification pattern of a secure key token.

Signed-off-by: Ingo Franzki <ifranzki@linux.ibm.com>
Reviewed-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
---
 zkey/pkey.c | 21 +++++++++++++++++++++
 zkey/pkey.h |  4 ++++
 2 files changed, 25 insertions(+)

diff --git a/zkey/pkey.c b/zkey/pkey.c
index c34203a5..8471f3d0 100644
--- a/zkey/pkey.c
+++ b/zkey/pkey.c
@@ -769,3 +769,24 @@ out:
 
 	return rc;
 }
+
+int get_master_key_verification_pattern(const u8 *secure_key,
+					size_t secure_key_size, u64 *mkvp,
+					bool verbose)
+{
+	struct secaeskeytoken *token = (struct secaeskeytoken *)secure_key;
+
+	util_assert(secure_key != NULL, "Internal error: secure_key is NULL");
+	util_assert(mkvp != NULL, "Internal error: mkvp is NULL");
+
+	if (secure_key_size < SECURE_KEY_SIZE) {
+		pr_verbose(verbose, "Size of secure key is too small: "
+			   "%lu expected %lu", secure_key_size,
+			   SECURE_KEY_SIZE);
+		return -EINVAL;
+	}
+
+	*mkvp = token->mkvp;
+
+	return 0;
+}
diff --git a/zkey/pkey.h b/zkey/pkey.h
index f1dc3014..c0aac2e8 100644
--- a/zkey/pkey.h
+++ b/zkey/pkey.h
@@ -112,4 +112,8 @@ int validate_secure_key(int pkey_fd,
 int generate_key_verification_pattern(const char *key, size_t key_size,
 				      char *vp, size_t vp_len, bool verbose);
 
+int get_master_key_verification_pattern(const u8 *secure_key,
+					size_t secure_key_size, u64 *mkvp,
+					bool verbose);
+
 #endif