[PATCH v1 02/12] kernel: generalize module signing as system data signing
From: Luis R. Rodriguez
Date: Tue May 05 2015 - 20:51:12 EST
From: "Luis R. Rodriguez" <mcgrof@xxxxxxxx>
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@xxxxxxxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Cc: Ming Lei <ming.lei@xxxxxxxxxxxxx>
Cc: Seth Forshee <seth.forshee@xxxxxxxxxxxxx>
Cc: Kyle McMartin <kyle@xxxxxxxxxx>
Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxx>
---
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@xxxxxxxxxx)
@@ -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@xxxxxxxxxx)
@@ -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
--
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