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authorDmitry Kasatkin <d.kasatkin@samsung.com>2014-06-17 11:56:58 +0300
committerMimi Zohar <zohar@linux.vnet.ibm.com>2014-07-17 09:35:16 -0400
commitffb70f61bab1482a3bd0f85fd8f1e9c9909df2ca (patch)
treef25c90a65af6441434dd70dcaacb7d204b6ea00b
parentb3426827c848d252ed4ca5f4d3085551be083e12 (diff)
downloadlinux-ffb70f61bab1482a3bd0f85fd8f1e9c9909df2ca.tar.bz2
KEYS: validate certificate trust only with selected key
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 by a particular key on the system keyring. This patch defines a new kernel parameter 'ca_keys' to identify the specific key which must be used for trust validation of certificates. Simplified Mimi's "KEYS: define an owner trusted keyring" patch. Changelog: - support for builtin x509 public keys only - export "asymmetric_keyid_match" - remove ifndefs MODULE - rename kernel boot parameter from keys_ownerid to ca_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.txt5
-rw-r--r--crypto/asymmetric_keys/asymmetric_type.c1
-rw-r--r--crypto/asymmetric_keys/x509_public_key.c19
3 files changed, 25 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 8b2ab548b6e4..bdb193afe176 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -566,6 +566,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
possible to determine what the correct size should be.
This option provides an override for these situations.
+ 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>
+
ccw_timeout_log [S390]
See Documentation/s390/CommonIO for details.
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index 1fd1d304a15a..c948df5c4ecd 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -49,6 +49,7 @@ int asymmetric_keyid_match(const char *kid, const char *id)
return 1;
}
+EXPORT_SYMBOL_GPL(asymmetric_keyid_match);
/*
* Match asymmetric keys on (part of) their name
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 436fbd8552fc..d376195e1d08 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -24,6 +24,22 @@
#include "public_key.h"
#include "x509_parser.h"
+static char *ca_keyid;
+
+#ifndef MODULE
+static int __init ca_keys_setup(char *str)
+{
+ if (!str) /* default system keyring */
+ return 1;
+
+ if (strncmp(str, "id:", 3) == 0)
+ ca_keyid = str; /* owner key 'id:xxxxxx' */
+
+ return 1;
+}
+__setup("ca_keys=", ca_keys_setup);
+#endif
+
/*
* Find a key in the given keyring by issuer and authority.
*/
@@ -171,6 +187,9 @@ static int x509_validate_trust(struct x509_certificate *cert,
if (!trust_keyring)
return -EOPNOTSUPP;
+ if (ca_keyid && !asymmetric_keyid_match(cert->authority, ca_keyid))
+ return -EPERM;
+
key = x509_request_asymmetric_key(trust_keyring,
cert->issuer, strlen(cert->issuer),
cert->authority,