From 219a3e8676f3132d27b530c7d2d6bcab89536b57 Mon Sep 17 00:00:00 2001
From: Kairui Song <kasong@redhat.com>
Date: Mon, 21 Jan 2019 17:59:28 +0800
Subject: [PATCH] integrity, KEYS: add a reference to platform keyring

commit 9dc92c45177a ("integrity: Define a trusted platform keyring")
introduced a .platform keyring for storing preboot keys, used for
verifying kernel image signatures. Currently only IMA-appraisal is able
to use the keyring to verify kernel images that have their signature
stored in xattr.

This patch exposes the .platform keyring, making it accessible for
verifying PE signed kernel images as well.

Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Kairui Song <kasong@redhat.com>
Cc: David Howells <dhowells@redhat.com>
[zohar@linux.ibm.com: fixed checkpatch errors, squashed with patch fix]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
---
 certs/system_keyring.c        | 10 ++++++++++
 include/keys/system_keyring.h |  8 ++++++++
 security/integrity/digsig.c   |  3 +++
 3 files changed, 21 insertions(+)

diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index 81728717523d..da055e901df4 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -24,6 +24,9 @@ static struct key *builtin_trusted_keys;
 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
 static struct key *secondary_trusted_keys;
 #endif
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+static struct key *platform_trusted_keys;
+#endif
 
 extern __initconst const u8 system_certificate_list[];
 extern __initconst const unsigned long system_certificate_list_size;
@@ -266,3 +269,10 @@ int verify_pkcs7_signature(const void *data, size_t len,
 EXPORT_SYMBOL_GPL(verify_pkcs7_signature);
 
 #endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
+
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+void __init set_platform_trusted_keys(struct key *keyring)
+{
+	platform_trusted_keys = keyring;
+}
+#endif
diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
index 359c2f936004..42a93eda331c 100644
--- a/include/keys/system_keyring.h
+++ b/include/keys/system_keyring.h
@@ -61,5 +61,13 @@ static inline struct key *get_ima_blacklist_keyring(void)
 }
 #endif /* CONFIG_IMA_BLACKLIST_KEYRING */
 
+#if defined(CONFIG_INTEGRITY_PLATFORM_KEYRING) && \
+	defined(CONFIG_SYSTEM_TRUSTED_KEYRING)
+extern void __init set_platform_trusted_keys(struct key *keyring);
+#else
+static inline void set_platform_trusted_keys(struct key *keyring)
+{
+}
+#endif
 
 #endif /* _KEYS_SYSTEM_KEYRING_H */
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index f45d6edecf99..e19c2eb72c51 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -87,6 +87,9 @@ static int __integrity_init_keyring(const unsigned int id, key_perm_t perm,
 		pr_info("Can't allocate %s keyring (%d)\n",
 			keyring_name[id], err);
 		keyring[id] = NULL;
+	} else {
+		if (id == INTEGRITY_KEYRING_PLATFORM)
+			set_platform_trusted_keys(keyring[id]);
 	}
 
 	return err;
-- 
2.20.1