[PATCH v6 3/4] x86/efi: move common keyring handler functions to new file

Eric Richter erichte at linux.ibm.com
Tue Nov 5 19:24:49 AEDT 2019


From: Nayna Jain <nayna at linux.ibm.com>

The handlers to add the keys to the .platform keyring and blacklisted
hashes to the .blacklist keyring is common for both the uefi and powerpc
mechanisms of loading the keys/hashes from the firmware.

This patch moves the common code from load_uefi.c to keyring_handler.c

Signed-off-by: Nayna Jain <nayna at linux.ibm.com>
Acked-by: Mimi Zohar <zohar at linux.ibm.com>
Signed-off-by: Eric Richter <erichte at linux.ibm.com>
---
 security/integrity/Makefile                   |  3 +-
 .../platform_certs/keyring_handler.c          | 80 +++++++++++++++++++
 .../platform_certs/keyring_handler.h          | 32 ++++++++
 security/integrity/platform_certs/load_uefi.c | 67 +---------------
 4 files changed, 115 insertions(+), 67 deletions(-)
 create mode 100644 security/integrity/platform_certs/keyring_handler.c
 create mode 100644 security/integrity/platform_certs/keyring_handler.h

diff --git a/security/integrity/Makefile b/security/integrity/Makefile
index 35e6ca773734..351c9662994b 100644
--- a/security/integrity/Makefile
+++ b/security/integrity/Makefile
@@ -11,7 +11,8 @@ integrity-$(CONFIG_INTEGRITY_SIGNATURE) += digsig.o
 integrity-$(CONFIG_INTEGRITY_ASYMMETRIC_KEYS) += digsig_asymmetric.o
 integrity-$(CONFIG_INTEGRITY_PLATFORM_KEYRING) += platform_certs/platform_keyring.o
 integrity-$(CONFIG_LOAD_UEFI_KEYS) += platform_certs/efi_parser.o \
-					platform_certs/load_uefi.o
+				      platform_certs/load_uefi.o \
+				      platform_certs/keyring_handler.o
 integrity-$(CONFIG_LOAD_IPL_KEYS) += platform_certs/load_ipl_s390.o
 
 obj-$(CONFIG_IMA)			+= ima/
diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c
new file mode 100644
index 000000000000..c5ba695c10e3
--- /dev/null
+++ b/security/integrity/platform_certs/keyring_handler.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/err.h>
+#include <linux/efi.h>
+#include <linux/slab.h>
+#include <keys/asymmetric-type.h>
+#include <keys/system_keyring.h>
+#include "../integrity.h"
+
+static efi_guid_t efi_cert_x509_guid __initdata = EFI_CERT_X509_GUID;
+static efi_guid_t efi_cert_x509_sha256_guid __initdata =
+	EFI_CERT_X509_SHA256_GUID;
+static efi_guid_t efi_cert_sha256_guid __initdata = EFI_CERT_SHA256_GUID;
+
+/*
+ * Blacklist a hash.
+ */
+static __init void uefi_blacklist_hash(const char *source, const void *data,
+				       size_t len, const char *type,
+				       size_t type_len)
+{
+	char *hash, *p;
+
+	hash = kmalloc(type_len + len * 2 + 1, GFP_KERNEL);
+	if (!hash)
+		return;
+	p = memcpy(hash, type, type_len);
+	p += type_len;
+	bin2hex(p, data, len);
+	p += len * 2;
+	*p = 0;
+
+	mark_hash_blacklisted(hash);
+	kfree(hash);
+}
+
+/*
+ * Blacklist an X509 TBS hash.
+ */
+static __init void uefi_blacklist_x509_tbs(const char *source,
+					   const void *data, size_t len)
+{
+	uefi_blacklist_hash(source, data, len, "tbs:", 4);
+}
+
+/*
+ * Blacklist the hash of an executable.
+ */
+static __init void uefi_blacklist_binary(const char *source,
+					 const void *data, size_t len)
+{
+	uefi_blacklist_hash(source, data, len, "bin:", 4);
+}
+
+/*
+ * Return the appropriate handler for particular signature list types found in
+ * the UEFI db and MokListRT tables.
+ */
+__init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type)
+{
+	if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
+		return add_to_platform_keyring;
+	return 0;
+}
+
+/*
+ * Return the appropriate handler for particular signature list types found in
+ * the UEFI dbx and MokListXRT tables.
+ */
+__init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type)
+{
+	if (efi_guidcmp(*sig_type, efi_cert_x509_sha256_guid) == 0)
+		return uefi_blacklist_x509_tbs;
+	if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0)
+		return uefi_blacklist_binary;
+	return 0;
+}
diff --git a/security/integrity/platform_certs/keyring_handler.h b/security/integrity/platform_certs/keyring_handler.h
new file mode 100644
index 000000000000..2462bfa08fe3
--- /dev/null
+++ b/security/integrity/platform_certs/keyring_handler.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef PLATFORM_CERTS_INTERNAL_H
+#define PLATFORM_CERTS_INTERNAL_H
+
+#include <linux/efi.h>
+
+void blacklist_hash(const char *source, const void *data,
+		    size_t len, const char *type,
+		    size_t type_len);
+
+/*
+ * Blacklist an X509 TBS hash.
+ */
+void blacklist_x509_tbs(const char *source, const void *data, size_t len);
+
+/*
+ * Blacklist the hash of an executable.
+ */
+void blacklist_binary(const char *source, const void *data, size_t len);
+
+/*
+ * Return the handler for particular signature list types found in the db.
+ */
+efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type);
+
+/*
+ * Return the handler for particular signature list types found in the dbx.
+ */
+efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type);
+
+#endif
diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
index 81b19c52832b..4369204a19cd 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c
@@ -9,6 +9,7 @@
 #include <keys/asymmetric-type.h>
 #include <keys/system_keyring.h>
 #include "../integrity.h"
+#include "keyring_handler.h"
 
 static efi_guid_t efi_cert_x509_guid __initdata = EFI_CERT_X509_GUID;
 static efi_guid_t efi_cert_x509_sha256_guid __initdata =
@@ -67,72 +68,6 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
 	return db;
 }
 
-/*
- * Blacklist a hash.
- */
-static __init void uefi_blacklist_hash(const char *source, const void *data,
-				       size_t len, const char *type,
-				       size_t type_len)
-{
-	char *hash, *p;
-
-	hash = kmalloc(type_len + len * 2 + 1, GFP_KERNEL);
-	if (!hash)
-		return;
-	p = memcpy(hash, type, type_len);
-	p += type_len;
-	bin2hex(p, data, len);
-	p += len * 2;
-	*p = 0;
-
-	mark_hash_blacklisted(hash);
-	kfree(hash);
-}
-
-/*
- * Blacklist an X509 TBS hash.
- */
-static __init void uefi_blacklist_x509_tbs(const char *source,
-					   const void *data, size_t len)
-{
-	uefi_blacklist_hash(source, data, len, "tbs:", 4);
-}
-
-/*
- * Blacklist the hash of an executable.
- */
-static __init void uefi_blacklist_binary(const char *source,
-					 const void *data, size_t len)
-{
-	uefi_blacklist_hash(source, data, len, "bin:", 4);
-}
-
-/*
- * Return the appropriate handler for particular signature list types found in
- * the UEFI db and MokListRT tables.
- */
-static __init efi_element_handler_t get_handler_for_db(const efi_guid_t *
-						       sig_type)
-{
-	if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
-		return add_to_platform_keyring;
-	return 0;
-}
-
-/*
- * Return the appropriate handler for particular signature list types found in
- * the UEFI dbx and MokListXRT tables.
- */
-static __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *
-							sig_type)
-{
-	if (efi_guidcmp(*sig_type, efi_cert_x509_sha256_guid) == 0)
-		return uefi_blacklist_x509_tbs;
-	if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0)
-		return uefi_blacklist_binary;
-	return 0;
-}
-
 /*
  * Load the certs contained in the UEFI databases into the platform trusted
  * keyring and the UEFI blacklisted X.509 cert SHA256 hashes into the blacklist
-- 
2.20.1



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