lkml.org 
[lkml]   [2014]   [Jun]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v1a 1/2] KEYS: validate certificate trust only with selected owner key
Date
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 'keys_ownerid' to specify
owner's key id which must be used for trust validation of certificates.

Idea belongs to Mimi Zohar.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
---
Documentation/kernel-parameters.txt | 5 +++++
crypto/asymmetric_keys/x509_public_key.c | 23 +++++++++++++++++++++++
2 files changed, 28 insertions(+)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 7116fda..7a810d3 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1434,6 +1434,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
use the HighMem zone if it exists, and the Normal
zone if it does not.

+ keys_ownerid=[KEYS] This parameter identifies a specific key(s) on
+ the system trusted keyring to be used for certificate
+ trust validation.
+ format: id:<keyid>
+
kgdbdbgp= [KGDB,HW] kgdb over EHCI usb debug port.
Format: <Controller#>[,poll interval]
The controller # is the number of the ehci usb debug
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 7a9b386..d46b790 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -24,6 +24,19 @@
#include "public_key.h"
#include "x509_parser.h"

+static char *owner_keyid;
+static int __init default_owner_keyid_set(char *str)
+{
+ if (!str) /* default system keyring */
+ return 1;
+
+ if (strncmp(str, "id:", 3) == 0)
+ owner_keyid = str; /* owner local key 'id:xxxxxx' */
+
+ return 1;
+}
+__setup("keys_ownerid=", default_owner_keyid_set);
+
/*
* Find a key in the given keyring by issuer and authority.
*/
@@ -169,6 +182,16 @@ static int x509_validate_trust(struct x509_certificate *cert,
if (!trust_keyring)
return -EOPNOTSUPP;

+ if (owner_keyid) {
+ /* validate trust only with the owner_keyid if specified */
+ /* partial match of keyid according to the asymmetric_type.c */
+ int idlen = strlen(owner_keyid) - 3; /* - id: */
+ int authlen = strlen(cert->authority);
+ char *auth = cert->authority + authlen - idlen;
+ if (idlen > authlen || strcasecmp(owner_keyid + 3, auth))
+ return -EPERM;
+ }
+
key = x509_request_asymmetric_key(trust_keyring,
cert->issuer, strlen(cert->issuer),
cert->authority,
--
1.9.1


\
 
 \ /
  Last update: 2014-06-12 22:41    [W:0.045 / U:8.416 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site