ima: separate 'security.ima' reading functionality from collect

Instead of passing pointers to pointers to ima_collect_measurent() to
read and return the 'security.ima' xattr value, this patch moves the
functionality to the calling process_measurement() to directly read
the xattr and pass only the hash algo to the ima_collect_measurement().

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
This commit is contained in:
Dmitry Kasatkin 2014-10-30 12:39:39 +02:00 committed by Mimi Zohar
parent c75d8e96f3
commit 1525b06d99
8 changed files with 33 additions and 40 deletions

View File

@ -23,6 +23,7 @@
#include <linux/hash.h>
#include <linux/tpm.h>
#include <linux/audit.h>
#include <crypto/hash_info.h>
#include "../integrity.h"
@ -140,9 +141,7 @@ static inline unsigned long ima_hash_key(u8 *digest)
int ima_get_action(struct inode *inode, int mask, int function);
int ima_must_measure(struct inode *inode, int mask, int function);
int ima_collect_measurement(struct integrity_iint_cache *iint,
struct file *file,
struct evm_ima_xattr_data **xattr_value,
int *xattr_len);
struct file *file, enum hash_algo algo);
void ima_store_measurement(struct integrity_iint_cache *iint, struct file *file,
const unsigned char *filename,
struct evm_ima_xattr_data *xattr_value,
@ -188,8 +187,8 @@ int ima_must_appraise(struct inode *inode, int mask, enum ima_hooks func);
void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file);
enum integrity_status ima_get_cache_status(struct integrity_iint_cache *iint,
int func);
void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len,
struct ima_digest_data *hash);
enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
int xattr_len);
int ima_read_xattr(struct dentry *dentry,
struct evm_ima_xattr_data **xattr_value);
@ -221,10 +220,10 @@ static inline enum integrity_status ima_get_cache_status(struct integrity_iint_c
return INTEGRITY_UNKNOWN;
}
static inline void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
int xattr_len,
struct ima_digest_data *hash)
static inline enum hash_algo
ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len)
{
return ima_hash_algo;
}
static inline int ima_read_xattr(struct dentry *dentry,

View File

@ -18,7 +18,7 @@
#include <linux/fs.h>
#include <linux/xattr.h>
#include <linux/evm.h>
#include <crypto/hash_info.h>
#include "ima.h"
/*
@ -188,9 +188,7 @@ int ima_get_action(struct inode *inode, int mask, int function)
* Return 0 on success, error code otherwise
*/
int ima_collect_measurement(struct integrity_iint_cache *iint,
struct file *file,
struct evm_ima_xattr_data **xattr_value,
int *xattr_len)
struct file *file, enum hash_algo algo)
{
const char *audit_cause = "failed";
struct inode *inode = file_inode(file);
@ -201,9 +199,6 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
char digest[IMA_MAX_DIGEST_SIZE];
} hash;
if (xattr_value)
*xattr_len = ima_read_xattr(file->f_path.dentry, xattr_value);
if (!(iint->flags & IMA_COLLECTED)) {
u64 i_version = file_inode(file)->i_version;
@ -213,11 +208,7 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
goto out;
}
/* use default hash algorithm */
hash.hdr.algo = ima_hash_algo;
if (xattr_value)
ima_get_hash_algo(*xattr_value, *xattr_len, &hash.hdr);
hash.hdr.algo = algo;
result = ima_calc_file_hash(file, &hash.hdr);
if (!result) {

View File

@ -15,7 +15,6 @@
#include <linux/magic.h>
#include <linux/ima.h>
#include <linux/evm.h>
#include <crypto/hash_info.h>
#include "ima.h"
@ -130,36 +129,40 @@ static void ima_cache_flags(struct integrity_iint_cache *iint, int func)
}
}
void ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value, int xattr_len,
struct ima_digest_data *hash)
enum hash_algo ima_get_hash_algo(struct evm_ima_xattr_data *xattr_value,
int xattr_len)
{
struct signature_v2_hdr *sig;
if (!xattr_value || xattr_len < 2)
return;
/* return default hash algo */
return ima_hash_algo;
switch (xattr_value->type) {
case EVM_IMA_XATTR_DIGSIG:
sig = (typeof(sig))xattr_value;
if (sig->version != 2 || xattr_len <= sizeof(*sig))
return;
hash->algo = sig->hash_algo;
return ima_hash_algo;
return sig->hash_algo;
break;
case IMA_XATTR_DIGEST_NG:
hash->algo = xattr_value->digest[0];
return xattr_value->digest[0];
break;
case IMA_XATTR_DIGEST:
/* this is for backward compatibility */
if (xattr_len == 21) {
unsigned int zero = 0;
if (!memcmp(&xattr_value->digest[16], &zero, 4))
hash->algo = HASH_ALGO_MD5;
return HASH_ALGO_MD5;
else
hash->algo = HASH_ALGO_SHA1;
return HASH_ALGO_SHA1;
} else if (xattr_len == 17)
hash->algo = HASH_ALGO_MD5;
return HASH_ALGO_MD5;
break;
}
/* return default hash algo */
return ima_hash_algo;
}
int ima_read_xattr(struct dentry *dentry,
@ -296,7 +299,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
if (iint->flags & IMA_DIGSIG)
return;
rc = ima_collect_measurement(iint, file, NULL, NULL);
rc = ima_collect_measurement(iint, file, ima_hash_algo);
if (rc < 0)
return;

View File

@ -24,7 +24,7 @@
#include <linux/err.h>
#include <linux/slab.h>
#include <crypto/hash.h>
#include <crypto/hash_info.h>
#include "ima.h"
struct ahash_completion {

View File

@ -21,7 +21,7 @@
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <crypto/hash_info.h>
#include "ima.h"
/* name for boot aggregate entry */

View File

@ -24,7 +24,6 @@
#include <linux/slab.h>
#include <linux/xattr.h>
#include <linux/ima.h>
#include <crypto/hash_info.h>
#include "ima.h"
@ -163,9 +162,10 @@ static int process_measurement(struct file *file, int mask, int function,
char *pathbuf = NULL;
const char *pathname = NULL;
int rc = -ENOMEM, action, must_appraise;
struct evm_ima_xattr_data *xattr_value = NULL, **xattr_ptr = NULL;
struct evm_ima_xattr_data *xattr_value = NULL;
int xattr_len = 0;
bool violation_check;
enum hash_algo hash_algo;
if (!ima_policy_flag || !S_ISREG(inode->i_mode))
return 0;
@ -221,9 +221,12 @@ static int process_measurement(struct file *file, int mask, int function,
template_desc = ima_template_desc_current();
if ((action & IMA_APPRAISE_SUBMASK) ||
strcmp(template_desc->name, IMA_TEMPLATE_IMA_NAME) != 0)
xattr_ptr = &xattr_value;
/* read 'security.ima' */
xattr_len = ima_read_xattr(file->f_path.dentry, &xattr_value);
rc = ima_collect_measurement(iint, file, xattr_ptr, &xattr_len);
hash_algo = ima_get_hash_algo(xattr_value, xattr_len);
rc = ima_collect_measurement(iint, file, hash_algo);
if (rc != 0) {
if (file->f_flags & O_DIRECT)
rc = (iint->flags & IMA_PERMIT_DIRECTIO) ? 0 : -EACCES;

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@ -15,8 +15,6 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <crypto/hash_info.h>
#include "ima.h"
#include "ima_template_lib.h"

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@ -12,7 +12,6 @@
* File: ima_template_lib.c
* Library of supported template fields.
*/
#include <crypto/hash_info.h>
#include "ima_template_lib.h"