ima: load x509 certificate from the kernel

Define configuration option to load X509 certificate into the
IMA trusted kernel keyring. It implements ima_load_x509() hook
to load X509 certificate into the .ima trusted kernel keyring
from the root filesystem.

Changes in v3:
* use ima_policy_flag in ima_get_action()
  ima_load_x509 temporarily clears ima_policy_flag to disable
  appraisal to load key. Use it to skip appraisal rules.
* Key directory path changed to /etc/keys (Mimi)
* Expand IMA_LOAD_X509 Kconfig help

Changes in v2:
* added '__init'
* use ima_policy_flag to disable appraisal to load 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 2014-11-05 17:01:14 +02:00 committed by Mimi Zohar
parent 65d543b233
commit fd5f4e9054
4 changed files with 44 additions and 2 deletions

View File

@ -131,3 +131,21 @@ config IMA_TRUSTED_KEYRING
help
This option requires that all keys added to the .ima
keyring be signed by a key on the system trusted keyring.
config IMA_LOAD_X509
bool "Load X509 certificate onto the '.ima' trusted keyring"
depends on IMA_TRUSTED_KEYRING
default n
help
File signature verification is based on the public keys
loaded on the .ima trusted keyring. These public keys are
X509 certificates signed by a trusted key on the
.system keyring. This option enables X509 certificate
loading from the kernel onto the '.ima' trusted keyring.
config IMA_X509_PATH
string "IMA X509 certificate path"
depends on IMA_LOAD_X509
default "/etc/keys/x509_ima.der"
help
This option defines IMA X509 certificate path.

View File

@ -173,8 +173,7 @@ int ima_get_action(struct inode *inode, int mask, int function)
{
int flags = IMA_MEASURE | IMA_AUDIT | IMA_APPRAISE;
if (!ima_appraise)
flags &= ~IMA_APPRAISE;
flags &= ima_policy_flag;
return ima_match_policy(inode, function, mask, flags);
}

View File

@ -24,6 +24,12 @@
#include <crypto/hash_info.h>
#include "ima.h"
#ifdef CONFIG_IMA_X509_PATH
#define IMA_X509_PATH CONFIG_IMA_X509_PATH
#else
#define IMA_X509_PATH "/etc/keys/x509_ima.der"
#endif
/* name for boot aggregate entry */
static const char *boot_aggregate_name = "boot_aggregate";
int ima_used_chip;
@ -91,6 +97,17 @@ err_out:
return result;
}
#ifdef CONFIG_IMA_LOAD_X509
void __init ima_load_x509(void)
{
int unset_flags = ima_policy_flag & IMA_APPRAISE;
ima_policy_flag &= ~unset_flags;
integrity_load_x509(INTEGRITY_KEYRING_IMA, IMA_X509_PATH);
ima_policy_flag |= unset_flags;
}
#endif
int __init ima_init(void)
{
u8 pcr_i[TPM_DIGEST_SIZE];

View File

@ -162,6 +162,14 @@ static inline int asymmetric_verify(struct key *keyring, const char *sig,
}
#endif
#ifdef CONFIG_IMA_LOAD_X509
void __init ima_load_x509(void);
#else
static inline void ima_load_x509(void)
{
}
#endif
#ifdef CONFIG_INTEGRITY_AUDIT
/* declarations */
void integrity_audit_msg(int audit_msgno, struct inode *inode,