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>
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 436fbd8..d376195 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 @@
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,