ipe: kunit test for parser

Add various happy/unhappy unit tests for both IPE's policy parser.

Besides, a test suite for IPE functionality is available at
https://github.com/microsoft/ipe/tree/test-suiteSigned-off-by: Deven Bowers <deven.desai@linux.microsoft.com>
Signed-off-by: Fan Wu <wufan@linux.microsoft.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

security/ipe/Kconfig

@@ -77,4 +77,21 @@ config IPE_PROP_FS_VERITY_BUILTIN_SIG
 
 endmenu
 
+config SECURITY_IPE_KUNIT_TEST
+	bool "Build KUnit tests for IPE" if !KUNIT_ALL_TESTS
+	depends on KUNIT=y
+	default KUNIT_ALL_TESTS
+	help
+	  This builds the IPE KUnit tests.
+
+	  KUnit tests run during boot and output the results to the debug log
+	  in TAP format (https://testanything.org/). Only useful for kernel devs
+	  running KUnit test harness and are not for inclusion into a
+	  production build.
+
+	  For more information on KUnit and unit tests in general please refer
+	  to the KUnit documentation in Documentation/dev-tools/kunit/.
+
+	  If unsure, say N.
+
 endif

security/ipe/Makefile

@@ -26,3 +26,6 @@ obj-$(CONFIG_SECURITY_IPE) += \
 	audit.o \
 
 clean-files := boot_policy.c \
+
+obj-$(CONFIG_SECURITY_IPE_KUNIT_TEST) += \
+	policy_tests.o \

security/ipe/policy_tests.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2024 Microsoft Corporation. All rights reserved.
+ */
+
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <kunit/test.h>
+#include "policy.h"
+struct policy_case {
+	const char *const policy;
+	int errno;
+	const char *const desc;
+};
+
+static const struct policy_case policy_cases[] = {
+	{
+		"policy_name=allowall policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW",
+		0,
+		"basic",
+	},
+	{
+		"policy_name=trailing_comment policy_version=152.0.0 #This is comment\n"
+		"DEFAULT action=ALLOW",
+		0,
+		"trailing comment",
+	},
+	{
+		"policy_name=allowallnewline policy_version=0.2.0\n"
+		"DEFAULT action=ALLOW\n"
+		"\n",
+		0,
+		"trailing newline",
+	},
+	{
+		"policy_name=carriagereturnlinefeed policy_version=0.0.1\n"
+		"DEFAULT action=ALLOW\n"
+		"\r\n",
+		0,
+		"clrf newline",
+	},
+	{
+		"policy_name=whitespace policy_version=0.0.0\n"
+		"DEFAULT\taction=ALLOW\n"
+		"     \t     DEFAULT \t    op=EXECUTE      action=DENY\n"
+		"op=EXECUTE boot_verified=TRUE action=ALLOW\n"
+		"# this is a\tcomment\t\t\t\t\n"
+		"DEFAULT \t op=KMODULE\t\t\t  action=DENY\r\n"
+		"op=KMODULE boot_verified=TRUE action=ALLOW\n",
+		0,
+		"various whitespaces and nested default",
+	},
+	{
+		"policy_name=boot_verified policy_version=-1236.0.0\n"
+		"DEFAULT\taction=ALLOW\n",
+		-EINVAL,
+		"negative version",
+	},
+	{
+		"policy_name=$@!*&^%%\\:;{}() policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW",
+		0,
+		"special characters",
+	},
+	{
+		"policy_name=test policy_version=999999.0.0\n"
+		"DEFAULT action=ALLOW",
+		-ERANGE,
+		"overflow version",
+	},
+	{
+		"policy_name=test policy_version=255.0\n"
+		"DEFAULT action=ALLOW",
+		-EBADMSG,
+		"incomplete version",
+	},
+	{
+		"policy_name=test policy_version=111.0.0.0\n"
+		"DEFAULT action=ALLOW",
+		-EBADMSG,
+		"extra version",
+	},
+	{
+		"",
+		-EBADMSG,
+		"0-length policy",
+	},
+	{
+		"policy_name=test\0policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW",
+		-EBADMSG,
+		"random null in header",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"\0DEFAULT action=ALLOW",
+		-EBADMSG,
+		"incomplete policy from NULL",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=DENY\n\0"
+		"op=EXECUTE dmverity_signature=TRUE action=ALLOW\n",
+		0,
+		"NULL truncates policy",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE dmverity_signature=abc action=ALLOW",
+		-EBADMSG,
+		"invalid property type",
+	},
+	{
+		"DEFAULT action=ALLOW",
+		-EBADMSG,
+		"missing policy header",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n",
+		-EBADMSG,
+		"missing default definition",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"dmverity_signature=TRUE op=EXECUTE action=ALLOW",
+		-EBADMSG,
+		"invalid rule ordering"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"action=ALLOW op=EXECUTE dmverity_signature=TRUE",
+		-EBADMSG,
+		"invalid rule ordering (2)",
+	},
+	{
+		"policy_name=test policy_version=0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE dmverity_signature=TRUE action=ALLOW",
+		-EBADMSG,
+		"invalid version",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=UNKNOWN dmverity_signature=TRUE action=ALLOW",
+		-EBADMSG,
+		"unknown operation",
+	},
+	{
+		"policy_name=asdvpolicy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n",
+		-EBADMSG,
+		"missing space after policy name",
+	},
+	{
+		"policy_name=test\xFF\xEF policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE dmverity_signature=TRUE action=ALLOW",
+		0,
+		"expanded ascii",
+	},
+	{
+		"policy_name=test\xFF\xEF policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE dmverity_roothash=GOOD_DOG action=ALLOW",
+		-EBADMSG,
+		"invalid property value (2)",
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"policy_name=test policy_version=0.1.0\n"
+		"DEFAULT action=ALLOW",
+		-EBADMSG,
+		"double header"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"DEFAULT action=ALLOW\n",
+		-EBADMSG,
+		"double default"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"DEFAULT op=EXECUTE action=DENY\n"
+		"DEFAULT op=EXECUTE action=ALLOW\n",
+		-EBADMSG,
+		"double operation default"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"DEFAULT op=EXECUTE action=DEN\n",
+		-EBADMSG,
+		"invalid action value"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"DEFAULT op=EXECUTE action\n",
+		-EBADMSG,
+		"invalid action value (2)"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"UNKNOWN value=true\n",
+		-EBADMSG,
+		"unrecognized statement"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE dmverity_roothash=1c0d7ee1f8343b7fbe418378e8eb22c061d7dec7 action=DENY\n",
+		-EBADMSG,
+		"old-style digest"
+	},
+	{
+		"policy_name=test policy_version=0.0.0\n"
+		"DEFAULT action=ALLOW\n"
+		"op=EXECUTE fsverity_digest=1c0d7ee1f8343b7fbe418378e8eb22c061d7dec7 action=DENY\n",
+		-EBADMSG,
+		"old-style digest"
+	}
+};
+
+static void pol_to_desc(const struct policy_case *c, char *desc)
+{
+	strscpy(desc, c->desc, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(ipe_policies, policy_cases, pol_to_desc);
+
+/**
+ * ipe_parser_unsigned_test - Test the parser by passing unsigned policies.
+ * @test: Supplies a pointer to a kunit structure.
+ *
+ * This is called by the kunit harness. This test does not check the correctness
+ * of the policy, but ensures that errors are handled correctly.
+ */
+static void ipe_parser_unsigned_test(struct kunit *test)
+{
+	const struct policy_case *p = test->param_value;
+	struct ipe_policy *pol;
+
+	pol = ipe_new_policy(p->policy, strlen(p->policy), NULL, 0);
+
+	if (p->errno) {
+		KUNIT_EXPECT_EQ(test, PTR_ERR(pol), p->errno);
+		return;
+	}
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pol);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, pol->parsed);
+	KUNIT_EXPECT_STREQ(test, pol->text, p->policy);
+	KUNIT_EXPECT_PTR_EQ(test, NULL, pol->pkcs7);
+	KUNIT_EXPECT_EQ(test, 0, pol->pkcs7len);
+
+	ipe_free_policy(pol);
+}
+
+/**
+ * ipe_parser_widestring_test - Ensure parser fail on a wide string policy.
+ * @test: Supplies a pointer to a kunit structure.
+ *
+ * This is called by the kunit harness.
+ */
+static void ipe_parser_widestring_test(struct kunit *test)
+{
+	const unsigned short policy[] = L"policy_name=Test policy_version=0.0.0\n"
+					L"DEFAULT action=ALLOW";
+	struct ipe_policy *pol = NULL;
+
+	pol = ipe_new_policy((const char *)policy, (ARRAY_SIZE(policy) - 1) * 2, NULL, 0);
+	KUNIT_EXPECT_TRUE(test, IS_ERR_OR_NULL(pol));
+
+	ipe_free_policy(pol);
+}
+
+static struct kunit_case ipe_parser_test_cases[] = {
+	KUNIT_CASE_PARAM(ipe_parser_unsigned_test, ipe_policies_gen_params),
+	KUNIT_CASE(ipe_parser_widestring_test),
+};
+
+static struct kunit_suite ipe_parser_test_suite = {
+	.name = "ipe-parser",
+	.test_cases = ipe_parser_test_cases,
+};
+
+kunit_test_suite(ipe_parser_test_suite);