Forgot to remove dropped patches

This commit is contained in:
Justin M. Forbes 2019-01-07 16:23:55 -06:00
parent cc1db7f347
commit 8e8de459e7
3 changed files with 0 additions and 510 deletions

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@ -1,176 +0,0 @@
From 73e105771858bf39aeabcbcd2f7b002c24ac4bb0 Mon Sep 17 00:00:00 2001
From: Dave Howells <dhowells@redhat.com>
Date: Fri, 5 May 2017 08:21:58 +0100
Subject: [PATCH] efi: Add an EFI signature blob parser
Add a function to parse an EFI signature blob looking for elements of
interest. A list is made up of a series of sublists, where all the
elements in a sublist are of the same type, but sublists can be of
different types.
For each sublist encountered, the function pointed to by the
get_handler_for_guid argument is called with the type specifier GUID and
returns either a pointer to a function to handle elements of that type or
NULL if the type is not of interest.
If the sublist is of interest, each element is passed to the handler
function in turn.
Signed-off-by: David Howells <dhowells@redhat.com>
---
certs/Kconfig | 8 ++++
certs/Makefile | 1 +
certs/efi_parser.c | 112 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 121 insertions(+)
create mode 100644 certs/efi_parser.c
diff --git a/certs/Kconfig b/certs/Kconfig
index c94e93d8bccf..650ffcb8db79 100644
--- a/certs/Kconfig
+++ b/certs/Kconfig
@@ -83,4 +83,12 @@ config SYSTEM_BLACKLIST_HASH_LIST
wrapper to incorporate the list into the kernel. Each <hash> should
be a string of hex digits.
+config EFI_SIGNATURE_LIST_PARSER
+ bool "EFI signature list parser"
+ depends on EFI
+ select X509_CERTIFICATE_PARSER
+ help
+ This option provides support for parsing EFI signature lists for
+ X.509 certificates and turning them into keys.
+
endmenu
diff --git a/certs/Makefile b/certs/Makefile
index 5d0999b9e21b..7e5e179ac685 100644
--- a/certs/Makefile
+++ b/certs/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_hashes.o
else
obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_nohashes.o
endif
+obj-$(CONFIG_EFI_SIGNATURE_LIST_PARSER) += efi_parser.o
ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
diff --git a/certs/efi_parser.c b/certs/efi_parser.c
new file mode 100644
index 000000000000..4e396f98f5c7
--- /dev/null
+++ b/certs/efi_parser.c
@@ -0,0 +1,112 @@
+/* EFI signature/key/certificate list parser
+ *
+ * Copyright (C) 2012, 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "EFI: "fmt
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/err.h>
+#include <linux/efi.h>
+
+/**
+ * parse_efi_signature_list - Parse an EFI signature list for certificates
+ * @source: The source of the key
+ * @data: The data blob to parse
+ * @size: The size of the data blob
+ * @get_handler_for_guid: Get the handler func for the sig type (or NULL)
+ *
+ * Parse an EFI signature list looking for elements of interest. A list is
+ * made up of a series of sublists, where all the elements in a sublist are of
+ * the same type, but sublists can be of different types.
+ *
+ * For each sublist encountered, the @get_handler_for_guid function is called
+ * with the type specifier GUID and returns either a pointer to a function to
+ * handle elements of that type or NULL if the type is not of interest.
+ *
+ * If the sublist is of interest, each element is passed to the handler
+ * function in turn.
+ *
+ * Error EBADMSG is returned if the list doesn't parse correctly and 0 is
+ * returned if the list was parsed correctly. No error can be returned from
+ * the @get_handler_for_guid function or the element handler function it
+ * returns.
+ */
+int __init parse_efi_signature_list(
+ const char *source,
+ const void *data, size_t size,
+ efi_element_handler_t (*get_handler_for_guid)(const efi_guid_t *))
+{
+ efi_element_handler_t handler;
+ unsigned offs = 0;
+
+ pr_devel("-->%s(,%zu)\n", __func__, size);
+
+ while (size > 0) {
+ const efi_signature_data_t *elem;
+ efi_signature_list_t list;
+ size_t lsize, esize, hsize, elsize;
+
+ if (size < sizeof(list))
+ return -EBADMSG;
+
+ memcpy(&list, data, sizeof(list));
+ pr_devel("LIST[%04x] guid=%pUl ls=%x hs=%x ss=%x\n",
+ offs,
+ list.signature_type.b, list.signature_list_size,
+ list.signature_header_size, list.signature_size);
+
+ lsize = list.signature_list_size;
+ hsize = list.signature_header_size;
+ esize = list.signature_size;
+ elsize = lsize - sizeof(list) - hsize;
+
+ if (lsize > size) {
+ pr_devel("<--%s() = -EBADMSG [overrun @%x]\n",
+ __func__, offs);
+ return -EBADMSG;
+ }
+
+ if (lsize < sizeof(list) ||
+ lsize - sizeof(list) < hsize ||
+ esize < sizeof(*elem) ||
+ elsize < esize ||
+ elsize % esize != 0) {
+ pr_devel("- bad size combo @%x\n", offs);
+ return -EBADMSG;
+ }
+
+ handler = get_handler_for_guid(&list.signature_type);
+ if (!handler) {
+ data += lsize;
+ size -= lsize;
+ offs += lsize;
+ continue;
+ }
+
+ data += sizeof(list) + hsize;
+ size -= sizeof(list) + hsize;
+ offs += sizeof(list) + hsize;
+
+ for (; elsize > 0; elsize -= esize) {
+ elem = data;
+
+ pr_devel("ELEM[%04x]\n", offs);
+ handler(source,
+ &elem->signature_data,
+ esize - sizeof(*elem));
+
+ data += esize;
+ size -= esize;
+ offs += esize;
+ }
+ }
+
+ return 0;
+}
--
2.20.1

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@ -1,246 +0,0 @@
From 90dc66270b02981b19a085c6a9184e3452b7b3e8 Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@fedoraproject.org>
Date: Fri, 5 May 2017 08:21:59 +0100
Subject: [PATCH 3/4] MODSIGN: Import certificates from UEFI Secure Boot
Secure Boot stores a list of allowed certificates in the 'db' variable.
This imports those certificates into the system trusted keyring. This
allows for a third party signing certificate to be used in conjunction
with signed modules. By importing the public certificate into the 'db'
variable, a user can allow a module signed with that certificate to
load. The shim UEFI bootloader has a similar certificate list stored
in the 'MokListRT' variable. We import those as well.
Secure Boot also maintains a list of disallowed certificates in the 'dbx'
variable. We load those certificates into the newly introduced system
blacklist keyring and forbid any module signed with those from loading and
forbid the use within the kernel of any key with a matching hash.
This facility is enabled by setting CONFIG_LOAD_UEFI_KEYS.
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: David Howells <dhowells@redhat.com>
---
certs/Kconfig | 16 ++++++
certs/Makefile | 4 ++
certs/load_uefi.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 188 insertions(+)
create mode 100644 certs/load_uefi.c
diff --git a/certs/Kconfig b/certs/Kconfig
index 630ae09..edf9f75 100644
--- a/certs/Kconfig
+++ b/certs/Kconfig
@@ -90,4 +90,20 @@ config EFI_SIGNATURE_LIST_PARSER
This option provides support for parsing EFI signature lists for
X.509 certificates and turning them into keys.
+config LOAD_UEFI_KEYS
+ bool "Load certs and blacklist from UEFI db for module checking"
+ depends on SYSTEM_BLACKLIST_KEYRING
+ depends on SECONDARY_TRUSTED_KEYRING
+ depends on EFI
+ depends on EFI_SIGNATURE_LIST_PARSER
+ help
+ If the kernel is booted in secure boot mode, this option will cause
+ the kernel to load the certificates from the UEFI db and MokListRT
+ into the secondary trusted keyring. It will also load any X.509
+ SHA256 hashes in the dbx list into the blacklist.
+
+ The effect of this is that, if the kernel is booted in secure boot
+ mode, modules signed with UEFI-stored keys will be permitted to be
+ loaded and keys that match the blacklist will be rejected.
+
endmenu
diff --git a/certs/Makefile b/certs/Makefile
index 738151a..a5e057a 100644
--- a/certs/Makefile
+++ b/certs/Makefile
@@ -11,6 +11,10 @@ obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_nohashes.o
endif
obj-$(CONFIG_EFI_SIGNATURE_LIST_PARSER) += efi_parser.o
+obj-$(CONFIG_LOAD_UEFI_KEYS) += load_uefi.o
+$(obj)/load_uefi.o: KBUILD_CFLAGS += -fshort-wchar
+
+
ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
$(eval $(call config_filename,SYSTEM_TRUSTED_KEYS))
diff --git a/certs/load_uefi.c b/certs/load_uefi.c
new file mode 100644
index 0000000..b44e464
--- /dev/null
+++ b/certs/load_uefi.c
@@ -0,0 +1,168 @@
+#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 "internal.h"
+
+static __initdata efi_guid_t efi_cert_x509_guid = EFI_CERT_X509_GUID;
+static __initdata efi_guid_t efi_cert_x509_sha256_guid = EFI_CERT_X509_SHA256_GUID;
+static __initdata efi_guid_t efi_cert_sha256_guid = EFI_CERT_SHA256_GUID;
+
+/*
+ * Get a certificate list blob from the named EFI variable.
+ */
+static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
+ unsigned long *size)
+{
+ efi_status_t status;
+ unsigned long lsize = 4;
+ unsigned long tmpdb[4];
+ void *db;
+
+ status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb);
+ if (status != EFI_BUFFER_TOO_SMALL) {
+ pr_err("Couldn't get size: 0x%lx\n", status);
+ return NULL;
+ }
+
+ db = kmalloc(lsize, GFP_KERNEL);
+ if (!db) {
+ pr_err("Couldn't allocate memory for uefi cert list\n");
+ return NULL;
+ }
+
+ status = efi.get_variable(name, guid, NULL, &lsize, db);
+ if (status != EFI_SUCCESS) {
+ kfree(db);
+ pr_err("Error reading db var: 0x%lx\n", status);
+ return NULL;
+ }
+
+ *size = lsize;
+ return db;
+}
+
+/*
+ * Blacklist an X509 TBS hash.
+ */
+static __init void uefi_blacklist_x509_tbs(const char *source,
+ const void *data, size_t len)
+{
+ char *hash, *p;
+
+ hash = kmalloc(4 + len * 2 + 1, GFP_KERNEL);
+ if (!hash)
+ return;
+ p = memcpy(hash, "tbs:", 4);
+ p += 4;
+ bin2hex(p, data, len);
+ p += len * 2;
+ *p = 0;
+
+ mark_hash_blacklisted(hash);
+ kfree(hash);
+}
+
+/*
+ * Blacklist the hash of an executable.
+ */
+static __init void uefi_blacklist_binary(const char *source,
+ const void *data, size_t len)
+{
+ char *hash, *p;
+
+ hash = kmalloc(4 + len * 2 + 1, GFP_KERNEL);
+ if (!hash)
+ return;
+ p = memcpy(hash, "bin:", 4);
+ p += 4;
+ bin2hex(p, data, len);
+ p += len * 2;
+ *p = 0;
+
+ mark_hash_blacklisted(hash);
+ kfree(hash);
+}
+
+/*
+ * 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_trusted_secondary_key;
+ 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
+ */
+static int __init load_uefi_certs(void)
+{
+ efi_guid_t secure_var = EFI_IMAGE_SECURITY_DATABASE_GUID;
+ efi_guid_t mok_var = EFI_SHIM_LOCK_GUID;
+ void *db = NULL, *dbx = NULL, *mok = NULL;
+ unsigned long dbsize = 0, dbxsize = 0, moksize = 0;
+ int rc = 0;
+
+ if (!efi.get_variable)
+ return false;
+
+ /* Get db, MokListRT, and dbx. They might not exist, so it isn't
+ * an error if we can't get them.
+ */
+ db = get_cert_list(L"db", &secure_var, &dbsize);
+ if (!db) {
+ pr_err("MODSIGN: Couldn't get UEFI db list\n");
+ } else {
+ rc = parse_efi_signature_list("UEFI:db",
+ db, dbsize, get_handler_for_db);
+ if (rc)
+ pr_err("Couldn't parse db signatures: %d\n", rc);
+ kfree(db);
+ }
+
+ mok = get_cert_list(L"MokListRT", &mok_var, &moksize);
+ if (!mok) {
+ pr_info("MODSIGN: Couldn't get UEFI MokListRT\n");
+ } else {
+ rc = parse_efi_signature_list("UEFI:MokListRT",
+ mok, moksize, get_handler_for_db);
+ if (rc)
+ pr_err("Couldn't parse MokListRT signatures: %d\n", rc);
+ kfree(mok);
+ }
+
+ dbx = get_cert_list(L"dbx", &secure_var, &dbxsize);
+ if (!dbx) {
+ pr_info("MODSIGN: Couldn't get UEFI dbx list\n");
+ } else {
+ rc = parse_efi_signature_list("UEFI:dbx",
+ dbx, dbxsize,
+ get_handler_for_dbx);
+ if (rc)
+ pr_err("Couldn't parse dbx signatures: %d\n", rc);
+ kfree(dbx);
+ }
+
+ return rc;
+}
+late_initcall(load_uefi_certs);
--
2.9.3

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@ -1,88 +0,0 @@
From 9f1958a0cc911e1f79b2733ee5029dbd819ff328 Mon Sep 17 00:00:00 2001
From: Josh Boyer <jwboyer@fedoraproject.org>
Date: Fri, 5 May 2017 08:21:59 +0100
Subject: [PATCH 4/4] MODSIGN: Allow the "db" UEFI variable to be suppressed
If a user tells shim to not use the certs/hashes in the UEFI db variable
for verification purposes, shim will set a UEFI variable called
MokIgnoreDB. Have the uefi import code look for this and ignore the db
variable if it is found.
Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: David Howells <dhowells@redhat.com>
---
certs/load_uefi.c | 44 ++++++++++++++++++++++++++++++++++----------
1 file changed, 34 insertions(+), 10 deletions(-)
diff --git a/certs/load_uefi.c b/certs/load_uefi.c
index b44e464..3d88459 100644
--- a/certs/load_uefi.c
+++ b/certs/load_uefi.c
@@ -13,6 +13,26 @@ static __initdata efi_guid_t efi_cert_x509_sha256_guid = EFI_CERT_X509_SHA256_GU
static __initdata efi_guid_t efi_cert_sha256_guid = EFI_CERT_SHA256_GUID;
/*
+ * Look to see if a UEFI variable called MokIgnoreDB exists and return true if
+ * it does.
+ *
+ * This UEFI variable is set by the shim if a user tells the shim to not use
+ * the certs/hashes in the UEFI db variable for verification purposes. If it
+ * is set, we should ignore the db variable also and the true return indicates
+ * this.
+ */
+static __init bool uefi_check_ignore_db(void)
+{
+ efi_status_t status;
+ unsigned int db = 0;
+ unsigned long size = sizeof(db);
+ efi_guid_t guid = EFI_SHIM_LOCK_GUID;
+
+ status = efi.get_variable(L"MokIgnoreDB", &guid, NULL, &size, &db);
+ return status == EFI_SUCCESS;
+}
+
+/*
* Get a certificate list blob from the named EFI variable.
*/
static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
@@ -113,7 +133,9 @@ static __init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_ty
}
/*
- * Load the certs contained in the UEFI databases
+ * Load the certs contained in the UEFI databases into the secondary trusted
+ * keyring and the UEFI blacklisted X.509 cert SHA256 hashes into the blacklist
+ * keyring.
*/
static int __init load_uefi_certs(void)
{
@@ -129,15 +151,17 @@ static int __init load_uefi_certs(void)
/* Get db, MokListRT, and dbx. They might not exist, so it isn't
* an error if we can't get them.
*/
- db = get_cert_list(L"db", &secure_var, &dbsize);
- if (!db) {
- pr_err("MODSIGN: Couldn't get UEFI db list\n");
- } else {
- rc = parse_efi_signature_list("UEFI:db",
- db, dbsize, get_handler_for_db);
- if (rc)
- pr_err("Couldn't parse db signatures: %d\n", rc);
- kfree(db);
+ if (!uefi_check_ignore_db()) {
+ db = get_cert_list(L"db", &secure_var, &dbsize);
+ if (!db) {
+ pr_err("MODSIGN: Couldn't get UEFI db list\n");
+ } else {
+ rc = parse_efi_signature_list("UEFI:db",
+ db, dbsize, get_handler_for_db);
+ if (rc)
+ pr_err("Couldn't parse db signatures: %d\n", rc);
+ kfree(db);
+ }
}
mok = get_cert_list(L"MokListRT", &mok_var, &moksize);
--
2.9.3