s390-tools/s390-tools-06-zkey-Reject-re-enciphering-of-PVSECRET-AES-keys.patch

From a8eb2bd4e7e74445c953906b33d450c2ace5223f Mon Sep 17 00:00:00 2001
From: Ingo Franzki <ifranzki@linux.ibm.com>
Date: Mon, 19 Feb 2024 11:26:41 +0100
Subject: [PATCH] zkey: Reject re-enciphering of PVSECRET-AES keys

Keys of type PVSECRET-AES can not be reenciphered using 'zkey reencipher'
or 'zkey-cryptsetup reencipher'. Reject that with a proper error message.

Signed-off-by: Ingo Franzki <ifranzki@linux.ibm.com>
Reviewed-by: Jorg Schmidbauer <jschmidb@de.ibm.com>
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
---
 zkey/keystore.c        |  9 +++++++++
 zkey/zkey-cryptsetup.1 |  8 ++++++--
 zkey/zkey-cryptsetup.c | 16 ++++++++++++----
 zkey/zkey.1            |  4 ++++
 zkey/zkey.c            |  7 +++++++
 5 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/zkey/keystore.c b/zkey/keystore.c
index db62e0a6..4f795a28 100644
--- a/zkey/keystore.c
+++ b/zkey/keystore.c
@@ -3567,6 +3567,15 @@ static int _keystore_process_reencipher(struct keystore *keystore,
 		goto out;
 	}
 
+	if (!is_secure_key(secure_key, secure_key_size)) {
+		warnx("Key '%s' is of type %s and can not be re-enciphered, "
+		      "skipping", name, get_key_type(secure_key,
+						     secure_key_size));
+		info->num_skipped++;
+		rc = 0;
+		goto out;
+	}
+
 	apqns = properties_get(properties, PROP_NAME_APQNS);
 	if (apqns != NULL)
 		apqn_list = str_list_split(apqns);
diff --git a/zkey/zkey-cryptsetup.1 b/zkey/zkey-cryptsetup.1
index c455f845..185edab9 100644
--- a/zkey/zkey-cryptsetup.1
+++ b/zkey/zkey-cryptsetup.1
@@ -1,8 +1,8 @@
-.\" Copyright IBM Corp. 2018
+.\" Copyright IBM Corp. 2018, 2024
 .\" s390-tools is free software; you can redistribute it and/or modify
 .\" it under the terms of the MIT license. See LICENSE for details.
 .\"
-.TH ZKEY\-CRYPTSETUP 1 "May 2018" "s390-tools"
+.TH ZKEY\-CRYPTSETUP 1 "February 2024" "s390-tools"
 .SH NAME
 zkey\-cryptsetup \- Manage secure AES volume keys of volumes encrypted with
 \fBLUKS2\fP and the \fBpaes\fP cipher
@@ -115,6 +115,10 @@ command to re-encipher a secure AES volume key of a volume encrypted with
 re-enciphered when the master key of the cryptographic adapter in CCA or EP11
 coprocessor mode changes.
 .PP
+Volume keys of type \fBPVSECRET\-AES\fP can not be re-enciphered. These keys do
+not use a cryptographic adapter, thus they do not need to be re-enciphered when
+the master key of a cryptographic adapter changes.
+.PP
 The cryptographic adapter in CCA coprocessor mode has three different registers
 to store master keys:
 .RS 2
diff --git a/zkey/zkey-cryptsetup.c b/zkey/zkey-cryptsetup.c
index 8b55f7d1..2b018a2a 100644
--- a/zkey/zkey-cryptsetup.c
+++ b/zkey/zkey-cryptsetup.c
@@ -2,7 +2,7 @@
  * zkey-cryptsetup - Re-encipher or validate volume keys of volumes
  * encrypted with LUKS2 and the paes cipher.
  *
- * Copyright IBM Corp. 2018
+ * Copyright IBM Corp. 2018, 2024
  *
  * s390-tools is free software; you can redistribute it and/or modify
  * it under the terms of the MIT license. See LICENSE for details.
@@ -82,7 +82,7 @@ static const struct util_prg prg = {
 		{
 			.owner = "IBM Corp.",
 			.pub_first = 2018,
-			.pub_last = 2018,
+			.pub_last = 2024,
 		},
 		UTIL_PRG_COPYRIGHT_END
 	}
@@ -1609,14 +1609,22 @@ static int reencipher_prepare(int token)
 	if (rc < 0)
 		goto out;
 
+	securekeysize = keysize - integrity_keysize;
+
+	if (!is_secure_key((u8 *)key, securekeysize)) {
+		warnx("The volume key of device '%s' is of type %s and can "
+		      "not be re-enciphered", g.pos_arg,
+		      get_key_type((u8 *)key, securekeysize));
+		rc = -EINVAL;
+		goto out;
+	}
+
 	reenc_tok.original_keyslot = rc;
 
 	rc = ensure_is_active_keylot(reenc_tok.original_keyslot);
 	if (rc != 0)
 		goto out;
 
-	securekeysize = keysize - integrity_keysize;
-
 	rc = generate_key_verification_pattern((u8 *)key, securekeysize,
 					       reenc_tok.verification_pattern,
 					 sizeof(reenc_tok.verification_pattern),
diff --git a/zkey/zkey.1 b/zkey/zkey.1
index baaf8478..316db5f0 100644
--- a/zkey/zkey.1
+++ b/zkey/zkey.1
@@ -266,6 +266,10 @@ command to re-encipher an existing secure key with a new master key.
 A secure key must be re-enciphered when the master key of the CCA or EP11
 cryptographic adapter changes.
 .PP
+Keys of type \fBPVSECRET\-AES\fP can not be re-enciphered. These keys do not
+use a cryptographic adapter, thus they do not need to be re-enciphered when the
+master of a cryptographic adapter changes.
+.PP
 The CCA cryptographic adapter has three different registers to store
 master keys:
 .RS 2
diff --git a/zkey/zkey.c b/zkey/zkey.c
index 36bdbcc0..90b46106 100644
--- a/zkey/zkey.c
+++ b/zkey/zkey.c
@@ -2118,6 +2118,13 @@ static int command_reencipher_file(void)
 	if (secure_key == NULL)
 		return EXIT_FAILURE;
 
+	if (!is_secure_key(secure_key, secure_key_size)) {
+		warnx("A key of type %s can not be re-enciphered",
+		      get_key_type(secure_key, secure_key_size));
+		rc = EXIT_FAILURE;
+		goto out;
+	}
+
 	rc = validate_secure_key(g.pkey_fd, secure_key, secure_key_size, NULL,
 				 &is_old_mk, NULL, g.verbose);
 	if (rc != 0) {