[wireless-regdb] [PATCH v1 02/12] kernel: generalize module signing as system data signing

["Luis R. Rodriguez" <mcgrof@do-not-panic.com>]

From: "Luis R. Rodriguez" <mcgrof@suse.com>

This generalizes the module signing code as helpers, we do
this as we'll later re-use this same code for firmware and
other system data signing.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: David Howells <dhowells@redhat.com>
Cc: Ming Lei <ming.lei@canonical.com>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Kyle McMartin <kyle@kernel.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
---
 init/Kconfig                                     | 22 ++++---
 kernel/Makefile                                  |  2 +-
 kernel/module.c                                  |  4 +-
 kernel/{module-internal.h => sysdata-internal.h} |  4 +-
 kernel/{module_signing.c => sysdata_signing.c}   | 76 ++++++++++++------------
 kernel/system_keyring.c                          |  2 +-
 6 files changed, 57 insertions(+), 53 deletions(-)
 rename kernel/{module-internal.h => sysdata-internal.h} (79%)
 rename kernel/{module_signing.c => sysdata_signing.c} (76%)

diff --git a/init/Kconfig b/init/Kconfig
index f5dbc6d..862d5ad7 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1769,6 +1769,18 @@ config BASE_SMALL
 	default 0 if BASE_FULL
 	default 1 if !BASE_FULL
 
+config SYSDATA_SIG
+	def_bool y
+	select SYSTEM_TRUSTED_KEYRING
+	select KEYS
+	select CRYPTO
+	select ASYMMETRIC_KEY_TYPE
+	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+	select PUBLIC_KEY_ALGO_RSA
+	select ASN1
+	select OID_REGISTRY
+	select X509_CERTIFICATE_PARSER
+
 menuconfig MODULES
 	bool "Enable loadable module support"
 	option modules
@@ -1842,15 +1854,7 @@ config MODULE_SRCVERSION_ALL
 config MODULE_SIG
 	bool "Module signature verification"
 	depends on MODULES
-	select SYSTEM_TRUSTED_KEYRING
-	select KEYS
-	select CRYPTO
-	select ASYMMETRIC_KEY_TYPE
-	select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
-	select PUBLIC_KEY_ALGO_RSA
-	select ASN1
-	select OID_REGISTRY
-	select X509_CERTIFICATE_PARSER
+	select SYSDATA_SIG
 	help
 	  Check modules for valid signatures upon load: the signature
 	  is simply appended to the module. For more information see
diff --git a/kernel/Makefile b/kernel/Makefile
index 1408b33..e24c9d6 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -45,7 +45,7 @@ endif
 obj-$(CONFIG_UID16) += uid16.o
 obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o
 obj-$(CONFIG_MODULES) += module.o
-obj-$(CONFIG_MODULE_SIG) += module_signing.o
+obj-$(CONFIG_SYSDATA_SIG) += sysdata_signing.o
 obj-$(CONFIG_KALLSYMS) += kallsyms.o
 obj-$(CONFIG_BSD_PROCESS_ACCT) += acct.o
 obj-$(CONFIG_KEXEC) += kexec.o
diff --git a/kernel/module.c b/kernel/module.c
index 23b2b65..eb61c10 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -60,7 +60,7 @@
 #include <linux/pfn.h>
 #include <linux/bsearch.h>
 #include <uapi/linux/module.h>
-#include "module-internal.h"
+#include "sysdata-internal.h"
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/module.h>
@@ -2404,7 +2404,7 @@ static int module_sig_check(struct load_info *info)
 	    memcmp(mod + info->len - markerlen, MODULE_SIG_STRING, markerlen) == 0) {
 		/* We truncate the module to discard the signature */
 		info->len -= markerlen;
-		err = mod_verify_sig(mod, &info->len);
+		err = sysdata_verify_sig(mod, &info->len);
 	}
 
 	if (!err) {
diff --git a/kernel/module-internal.h b/kernel/sysdata-internal.h
similarity index 79%
rename from kernel/module-internal.h
rename to kernel/sysdata-internal.h
index 915e123..0aa573e 100644
--- a/kernel/module-internal.h
+++ b/kernel/sysdata-internal.h
@@ -1,4 +1,4 @@
-/* Module internals
+/* System Data internals
  *
  * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
@@ -9,4 +9,4 @@
  * 2 of the Licence, or (at your option) any later version.
  */
 
-extern int mod_verify_sig(const void *mod, unsigned long *_modlen);
+extern int sysdata_verify_sig(const void *data, unsigned long *_len);
diff --git a/kernel/module_signing.c b/kernel/sysdata_signing.c
similarity index 76%
rename from kernel/module_signing.c
rename to kernel/sysdata_signing.c
index be5b8fa..8ba09aa 100644
--- a/kernel/module_signing.c
+++ b/kernel/sysdata_signing.c
@@ -1,4 +1,4 @@
-/* Module signature checker
+/* System Data signature checker
  *
  * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
  * Written by David Howells (dhowells@redhat.com)
@@ -15,10 +15,10 @@
 #include <crypto/hash.h>
 #include <keys/asymmetric-type.h>
 #include <keys/system_keyring.h>
-#include "module-internal.h"
+#include "sysdata-internal.h"
 
 /*
- * Module signature information block.
+ * System Data signature information block.
  *
  * The constituents of the signature section are, in order:
  *
@@ -27,7 +27,7 @@
  *	- Signature data
  *	- Information block
  */
-struct module_signature {
+struct sysdata_signature {
 	u8	algo;		/* Public-key crypto algorithm [enum pkey_algo] */
 	u8	hash;		/* Digest algorithm [enum hash_algo] */
 	u8	id_type;	/* Key identifier type [enum pkey_id_type] */
@@ -38,11 +38,11 @@ struct module_signature {
 };
 
 /*
- * Digest the module contents.
+ * Digest the system data contents.
  */
-static struct public_key_signature *mod_make_digest(enum hash_algo hash,
-						    const void *mod,
-						    unsigned long modlen)
+static struct public_key_signature *data_make_digest(enum hash_algo hash,
+						    const void *data,
+						    unsigned long len)
 {
 	struct public_key_signature *pks;
 	struct crypto_shash *tfm;
@@ -51,7 +51,7 @@ static struct public_key_signature *mod_make_digest(enum hash_algo hash,
 	int ret;
 
 	pr_devel("==>%s()\n", __func__);
-	
+
 	/* Allocate the hashing algorithm we're going to need and find out how
 	 * big the hash operational data will be.
 	 */
@@ -82,7 +82,7 @@ static struct public_key_signature *mod_make_digest(enum hash_algo hash,
 	if (ret < 0)
 		goto error;
 
-	ret = crypto_shash_finup(desc, mod, modlen, pks->digest);
+	ret = crypto_shash_finup(desc, data, len, pks->digest);
 	if (ret < 0)
 		goto error;
 
@@ -105,8 +105,8 @@ error_no_pks:
  *
  * RSA signatures only have one MPI, so currently we only read one.
  */
-static int mod_extract_mpi_array(struct public_key_signature *pks,
-				 const void *data, size_t len)
+static int data_extract_mpi_array(struct public_key_signature *pks,
+				  const void *data, size_t len)
 {
 	size_t nbytes;
 	MPI mpi;
@@ -161,7 +161,7 @@ static struct key *request_asymmetric_key(const char *signer, size_t signer_len,
 	key = keyring_search(make_key_ref(system_trusted_keyring, 1),
 			     &key_type_asymmetric, id);
 	if (IS_ERR(key))
-		pr_warn("Request for unknown module key '%s' err %ld\n",
+		pr_warn("Request for unknown system data key '%s' err %ld\n",
 			id, PTR_ERR(key));
 	kfree(id);
 
@@ -182,58 +182,58 @@ static struct key *request_asymmetric_key(const char *signer, size_t signer_len,
 }
 
 /*
- * Verify the signature on a module.
+ * Verify the signature on system data.
  */
-int mod_verify_sig(const void *mod, unsigned long *_modlen)
+int sysdata_verify_sig(const void *data, unsigned long *_len)
 {
 	struct public_key_signature *pks;
-	struct module_signature ms;
+	struct sysdata_signature ds;
 	struct key *key;
 	const void *sig;
-	size_t modlen = *_modlen, sig_len;
+	size_t len = *_len, sig_len;
 	int ret;
 
-	pr_devel("==>%s(,%zu)\n", __func__, modlen);
+	pr_devel("==>%s(,%zu)\n", __func__, len);
 
-	if (modlen <= sizeof(ms))
+	if (len <= sizeof(ds))
 		return -EBADMSG;
 
-	memcpy(&ms, mod + (modlen - sizeof(ms)), sizeof(ms));
-	modlen -= sizeof(ms);
+	memcpy(&ds, data + (len - sizeof(ds)), sizeof(ds));
+	len -= sizeof(ds);
 
-	sig_len = be32_to_cpu(ms.sig_len);
-	if (sig_len >= modlen)
+	sig_len = be32_to_cpu(ds.sig_len);
+	if (sig_len >= len)
 		return -EBADMSG;
-	modlen -= sig_len;
-	if ((size_t)ms.signer_len + ms.key_id_len >= modlen)
+	len -= sig_len;
+	if ((size_t)ds.signer_len + ds.key_id_len >= len)
 		return -EBADMSG;
-	modlen -= (size_t)ms.signer_len + ms.key_id_len;
+	len -= (size_t)ds.signer_len + ds.key_id_len;
 
-	*_modlen = modlen;
-	sig = mod + modlen;
+	*_len = len;
+	sig = data + len;
 
 	/* For the moment, only support RSA and X.509 identifiers */
-	if (ms.algo != PKEY_ALGO_RSA ||
-	    ms.id_type != PKEY_ID_X509)
+	if (ds.algo != PKEY_ALGO_RSA ||
+	    ds.id_type != PKEY_ID_X509)
 		return -ENOPKG;
 
-	if (ms.hash >= PKEY_HASH__LAST ||
-	    !hash_algo_name[ms.hash])
+	if (ds.hash >= PKEY_HASH__LAST ||
+	    !hash_algo_name[ds.hash])
 		return -ENOPKG;
 
-	key = request_asymmetric_key(sig, ms.signer_len,
-				     sig + ms.signer_len, ms.key_id_len);
+	key = request_asymmetric_key(sig, ds.signer_len,
+				     sig + ds.signer_len, ds.key_id_len);
 	if (IS_ERR(key))
 		return PTR_ERR(key);
 
-	pks = mod_make_digest(ms.hash, mod, modlen);
+	pks = data_make_digest(ds.hash, data, len);
 	if (IS_ERR(pks)) {
 		ret = PTR_ERR(pks);
 		goto error_put_key;
 	}
 
-	ret = mod_extract_mpi_array(pks, sig + ms.signer_len + ms.key_id_len,
-				    sig_len);
+	ret = data_extract_mpi_array(pks, sig + ds.signer_len + ds.key_id_len,
+				     sig_len);
 	if (ret < 0)
 		goto error_free_pks;
 
@@ -246,5 +246,5 @@ error_free_pks:
 error_put_key:
 	key_put(key);
 	pr_devel("<==%s() = %d\n", __func__, ret);
-	return ret;	
+	return ret;
 }
diff --git a/kernel/system_keyring.c b/kernel/system_keyring.c
index 875f64e..1eb0c86 100644
--- a/kernel/system_keyring.c
+++ b/kernel/system_keyring.c
@@ -16,7 +16,7 @@
 #include <linux/err.h>
 #include <keys/asymmetric-type.h>
 #include <keys/system_keyring.h>
-#include "module-internal.h"
+#include "sysdata-internal.h"
 
 struct key *system_trusted_keyring;
 EXPORT_SYMBOL_GPL(system_trusted_keyring);
-- 
2.3.2.209.gd67f9d5.dirty


_______________________________________________
wireless-regdb mailing list
wireless-regdb@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/wireless-regdb