Linux-Security-Module Archive on lore.kernel.org
 help / color / Atom feed
From: Nayna Jain <nayna@linux.ibm.com>
To: linux-integrity@vger.kernel.org, keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org,
	David Howells <dhowells@redhat.com>,
	Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	Mimi Zohar <zohar@linux.ibm.com>,
	Stefan Berger <stefanb@linux.ibm.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	David Woodhouse <dwmw2@infradead.org>,
	Nayna Jain <nayna@linux.ibm.com>
Subject: [PATCH v3 3/3] ima: enable loading of build time generated key on .ima keyring
Date: Tue, 30 Mar 2021 09:16:36 -0400
Message-ID: <20210330131636.21711-4-nayna@linux.ibm.com> (raw)
In-Reply-To: <20210330131636.21711-1-nayna@linux.ibm.com>

The kernel currently only loads the kernel module signing key onto the
builtin trusted keyring. Load the module signing key onto the IMA keyring
as well.

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
---
 certs/system_certificates.S   | 13 +++++++++-
 certs/system_keyring.c        | 47 +++++++++++++++++++++++++++--------
 include/keys/system_keyring.h |  7 ++++++
 security/integrity/digsig.c   |  2 ++
 4 files changed, 58 insertions(+), 11 deletions(-)

diff --git a/certs/system_certificates.S b/certs/system_certificates.S
index 8f29058adf93..dcad27ea8527 100644
--- a/certs/system_certificates.S
+++ b/certs/system_certificates.S
@@ -8,9 +8,11 @@
 	.globl system_certificate_list
 system_certificate_list:
 __cert_list_start:
-#ifdef CONFIG_MODULE_SIG
+__module_cert_start:
+#if defined(CONFIG_MODULE_SIG) || defined(CONFIG_IMA_APPRAISE_MODSIG)
 	.incbin "certs/signing_key.x509"
 #endif
+__module_cert_end:
 	.incbin "certs/x509_certificate_list"
 __cert_list_end:
 
@@ -35,3 +37,12 @@ system_certificate_list_size:
 #else
 	.long __cert_list_end - __cert_list_start
 #endif
+
+	.align 8
+	.globl module_cert_size
+module_cert_size:
+#ifdef CONFIG_64BIT
+	.quad __module_cert_end - __module_cert_start
+#else
+	.long __module_cert_end - __module_cert_start
+#endif
diff --git a/certs/system_keyring.c b/certs/system_keyring.c
index 4b693da488f1..bb122bf4cc17 100644
--- a/certs/system_keyring.c
+++ b/certs/system_keyring.c
@@ -27,6 +27,7 @@ static struct key *platform_trusted_keys;
 
 extern __initconst const u8 system_certificate_list[];
 extern __initconst const unsigned long system_certificate_list_size;
+extern __initconst const unsigned long module_cert_size;
 
 /**
  * restrict_link_to_builtin_trusted - Restrict keyring addition by built in CA
@@ -132,19 +133,11 @@ static __init int system_trusted_keyring_init(void)
  */
 device_initcall(system_trusted_keyring_init);
 
-/*
- * Load the compiled-in list of X.509 certificates.
- */
-static __init int load_system_certificate_list(void)
+static __init int load_cert(const u8 *p, const u8 *end, struct key *keyring)
 {
 	key_ref_t key;
-	const u8 *p, *end;
 	size_t plen;
 
-	pr_notice("Loading compiled-in X.509 certificates\n");
-
-	p = system_certificate_list;
-	end = p + system_certificate_list_size;
 	while (p < end) {
 		/* Each cert begins with an ASN.1 SEQUENCE tag and must be more
 		 * than 256 bytes in size.
@@ -159,7 +152,7 @@ static __init int load_system_certificate_list(void)
 		if (plen > end - p)
 			goto dodgy_cert;
 
-		key = key_create_or_update(make_key_ref(builtin_trusted_keys, 1),
+		key = key_create_or_update(make_key_ref(keyring, 1),
 					   "asymmetric",
 					   NULL,
 					   p,
@@ -186,6 +179,40 @@ static __init int load_system_certificate_list(void)
 	pr_err("Problem parsing in-kernel X.509 certificate list\n");
 	return 0;
 }
+
+__init int load_module_cert(struct key *keyring)
+{
+	const u8 *p, *end;
+
+	if (!IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG))
+		return 0;
+
+	pr_notice("Loading compiled-in module X.509 certificates\n");
+
+	p = system_certificate_list;
+	end = p + module_cert_size;
+
+	return load_cert(p, end, keyring);
+}
+
+/*
+ * Load the compiled-in list of X.509 certificates.
+ */
+static __init int load_system_certificate_list(void)
+{
+	const u8 *p, *end;
+
+	pr_notice("Loading compiled-in X.509 certificates\n");
+
+#ifdef CONFIG_MODULE_SIG
+	p = system_certificate_list;
+#else
+	p = system_certificate_list + module_cert_size;
+#endif
+
+	end = p + system_certificate_list_size;
+	return load_cert(p, end, builtin_trusted_keys);
+}
 late_initcall(load_system_certificate_list);
 
 #ifdef CONFIG_SYSTEM_DATA_VERIFICATION
diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
index fb8b07daa9d1..f954276c616a 100644
--- a/include/keys/system_keyring.h
+++ b/include/keys/system_keyring.h
@@ -16,9 +16,16 @@ extern int restrict_link_by_builtin_trusted(struct key *keyring,
 					    const struct key_type *type,
 					    const union key_payload *payload,
 					    struct key *restriction_key);
+extern __init int load_module_cert(struct key *keyring);
 
 #else
 #define restrict_link_by_builtin_trusted restrict_link_reject
+
+static inline __init int load_module_cert(struct key *keyring)
+{
+	return 0;
+}
+
 #endif
 
 #ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index 250fb0836156..3b06a01bd0fd 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c
@@ -111,6 +111,8 @@ static int __init __integrity_init_keyring(const unsigned int id,
 	} else {
 		if (id == INTEGRITY_KEYRING_PLATFORM)
 			set_platform_trusted_keys(keyring[id]);
+		if (id == INTEGRITY_KEYRING_IMA)
+			load_module_cert(keyring[id]);
 	}
 
 	return err;
-- 
2.29.2


  parent reply index

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-30 13:16 [PATCH v3 0/3] ima: kernel build support for loading the kernel module signing key Nayna Jain
2021-03-30 13:16 ` [PATCH v3 1/3] keys: cleanup build time module signing keys Nayna Jain
2021-03-31  2:55   ` Jarkko Sakkinen
2021-03-30 13:16 ` [PATCH v3 2/3] ima: enable signing of modules with build time generated key Nayna Jain
2021-04-02 11:27   ` Stefan Berger
2021-03-30 13:16 ` Nayna Jain [this message]
2021-04-02 11:29   ` [PATCH v3 3/3] ima: enable loading of build time generated key on .ima keyring Stefan Berger

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210330131636.21711-4-nayna@linux.ibm.com \
    --to=nayna@linux.ibm.com \
    --cc=dhowells@redhat.com \
    --cc=dwmw2@infradead.org \
    --cc=jarkko.sakkinen@linux.intel.com \
    --cc=keyrings@vger.kernel.org \
    --cc=linux-integrity@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-security-module@vger.kernel.org \
    --cc=stefanb@linux.ibm.com \
    --cc=zohar@linux.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-Security-Module Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-security-module/0 linux-security-module/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-security-module linux-security-module/ https://lore.kernel.org/linux-security-module \
		linux-security-module@vger.kernel.org
	public-inbox-index linux-security-module

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-security-module


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git