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>
This commit is contained in:
Dmitry Kasatkin 2014-06-17 11:56:58 +03:00 committed by Mimi Zohar
parent b3426827c8
commit ffb70f61ba
3 changed files with 25 additions and 0 deletions

View File

@ -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.

View File

@ -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

View File

@ -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,