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authorDmitry Kasatkin <d.kasatkin@samsung.com>2014-06-17 11:56:59 +0300
committerMimi Zohar <zohar@linux.vnet.ibm.com>2014-07-17 09:35:17 -0400
commit32c4741cb66703a3c282f41d77deff4afd93342a (patch)
tree63797ca87c02956f5dbc4552a0aa9dc058d6cd52
parentffb70f61bab1482a3bd0f85fd8f1e9c9909df2ca (diff)
KEYS: validate certificate trust only with builtin keys
Instead of allowing public keys, with certificates signed by any key on the system trusted keyring, to be added to a trusted keyring, this patch further restricts the certificates to those signed only by builtin keys on the system keyring. This patch defines a new option 'builtin' for the kernel parameter 'keys_ownerid' to allow trust validation using builtin keys. Simplified Mimi's "KEYS: define an owner trusted keyring" patch Changelog v7: - rename builtin_keys to use_builtin_keys Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
-rw-r--r--Documentation/kernel-parameters.txt2
-rw-r--r--crypto/asymmetric_keys/x509_public_key.c9
-rw-r--r--include/linux/key.h1
-rw-r--r--kernel/system_keyring.c1
4 files changed, 9 insertions, 4 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index bdb193afe176..90c12c591168 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -569,7 +569,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
ca_keys= [KEYS] This parameter identifies a specific key(s) on
the system trusted keyring to be used for certificate
trust validation.
- format: id:<keyid>
+ format: { id:<keyid> | builtin }
ccw_timeout_log [S390]
See Documentation/s390/CommonIO for details.
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index d376195e1d08..927ce755ff67 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -24,6 +24,7 @@
#include "public_key.h"
#include "x509_parser.h"
+static bool use_builtin_keys;
static char *ca_keyid;
#ifndef MODULE
@@ -34,6 +35,8 @@ static int __init ca_keys_setup(char *str)
if (strncmp(str, "id:", 3) == 0)
ca_keyid = str; /* owner key 'id:xxxxxx' */
+ else if (strcmp(str, "builtin") == 0)
+ use_builtin_keys = true;
return 1;
}
@@ -180,7 +183,6 @@ EXPORT_SYMBOL_GPL(x509_check_signature);
static int x509_validate_trust(struct x509_certificate *cert,
struct key *trust_keyring)
{
- const struct public_key *pk;
struct key *key;
int ret = 1;
@@ -195,8 +197,9 @@ static int x509_validate_trust(struct x509_certificate *cert,
cert->authority,
strlen(cert->authority));
if (!IS_ERR(key)) {
- pk = key->payload.data;
- ret = x509_check_signature(pk, cert);
+ if (!use_builtin_keys
+ || test_bit(KEY_FLAG_BUILTIN, &key->flags))
+ ret = x509_check_signature(key->payload.data, cert);
key_put(key);
}
return ret;
diff --git a/include/linux/key.h b/include/linux/key.h
index 017b0826642f..65316f7ae794 100644
--- a/include/linux/key.h
+++ b/include/linux/key.h
@@ -170,6 +170,7 @@ struct key {
#define KEY_FLAG_INVALIDATED 7 /* set if key has been invalidated */
#define KEY_FLAG_TRUSTED 8 /* set if key is trusted */
#define KEY_FLAG_TRUSTED_ONLY 9 /* set if keyring only accepts links to trusted keys */
+#define KEY_FLAG_BUILTIN 10 /* set if key is builtin */
/* the key type and key description string
* - the desc is used to match a key against search criteria
diff --git a/kernel/system_keyring.c b/kernel/system_keyring.c
index 52ebc70263f4..875f64e8935b 100644
--- a/kernel/system_keyring.c
+++ b/kernel/system_keyring.c
@@ -89,6 +89,7 @@ static __init int load_system_certificate_list(void)
pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
PTR_ERR(key));
} else {
+ set_bit(KEY_FLAG_BUILTIN, &key_ref_to_ptr(key)->flags);
pr_notice("Loaded X.509 cert '%s'\n",
key_ref_to_ptr(key)->description);
key_ref_put(key);