From: Nayna Jain <nayna@linux.ibm.com>
Date: Thu, 31 Oct 2019 03:31:29 +0000 (-0400)
Subject: powerpc/ima: Define trusted boot policy
X-Git-Tag: v5.15~5028^2~76^2~5^2~5
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=1917855f4e0658c313e280671ad87774dbfb7b24;p=platform%2Fkernel%2Flinux-starfive.git

powerpc/ima: Define trusted boot policy

This patch defines an arch-specific trusted boot only policy and a
combined secure and trusted boot policy.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-5-git-send-email-zohar@linux.ibm.com
---

diff --git a/arch/powerpc/kernel/ima_arch.c b/arch/powerpc/kernel/ima_arch.c
index d88913d..0ef5956 100644
--- a/arch/powerpc/kernel/ima_arch.c
+++ b/arch/powerpc/kernel/ima_arch.c
@@ -31,13 +31,44 @@ static const char *const secure_rules[] = {
 };
 
 /*
+ * The "trusted_rules" are enabled only on "trustedboot" enabled systems.
+ * These rules add the kexec kernel image and kernel modules file hashes to
+ * the IMA measurement list.
+ */
+static const char *const trusted_rules[] = {
+	"measure func=KEXEC_KERNEL_CHECK",
+	"measure func=MODULE_CHECK",
+	NULL
+};
+
+/*
+ * The "secure_and_trusted_rules" contains rules for both the secure boot and
+ * trusted boot. The "template=ima-modsig" option includes the appended
+ * signature, when available, in the IMA measurement list.
+ */
+static const char *const secure_and_trusted_rules[] = {
+	"measure func=KEXEC_KERNEL_CHECK template=ima-modsig",
+	"measure func=MODULE_CHECK template=ima-modsig",
+	"appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig",
+#ifndef CONFIG_MODULE_SIG_FORCE
+	"appraise func=MODULE_CHECK appraise_type=imasig|modsig",
+#endif
+	NULL
+};
+
+/*
  * Returns the relevant IMA arch-specific policies based on the system secure
  * boot state.
  */
 const char *const *arch_get_ima_policy(void)
 {
 	if (is_ppc_secureboot_enabled())
-		return secure_rules;
+		if (is_ppc_trustedboot_enabled())
+			return secure_and_trusted_rules;
+		else
+			return secure_rules;
+	else if (is_ppc_trustedboot_enabled())
+		return trusted_rules;
 
 	return NULL;
 }