lkml.org 
[lkml]   [2012]   [Mar]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 10/11] ima: add support for different security.ima data types
Date
IMA-appraisal currently verifies the integrity of a file based on a
known 'good' measurement value. This patch reserves the first byte
of 'security.ima' as a place holder for the type of method used for
verifying file data integrity.

Changelog v1:
- Use the newly defined 'struct evm_ima_xattr_data'

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@nokia.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
security/integrity/ima/ima_api.c | 6 +++---
security/integrity/ima/ima_appraise.c | 23 +++++++++++++----------
security/integrity/integrity.h | 2 +-
3 files changed, 17 insertions(+), 14 deletions(-)
diff --git a/security/integrity/ima/ima_api.c b/security/integrity/ima/ima_api.c
index 646e92d..f3423ee 100644
--- a/security/integrity/ima/ima_api.c
+++ b/security/integrity/ima/ima_api.c
@@ -147,8 +147,8 @@ int ima_collect_measurement(struct integrity_iint_cache *iint,
if (!(iint->flags & IMA_COLLECTED)) {
u64 i_version = file->f_dentry->d_inode->i_version;

- memset(iint->digest, 0, IMA_DIGEST_SIZE);
- result = ima_calc_hash(file, iint->digest);
+ iint->ima_xattr.type = IMA_XATTR_DIGEST;
+ result = ima_calc_hash(file, iint->ima_xattr.digest);
if (!result) {
iint->version = i_version;
iint->flags |= IMA_COLLECTED;
@@ -196,7 +196,7 @@ void ima_store_measurement(struct integrity_iint_cache *iint,
return;
}
memset(&entry->template, 0, sizeof(entry->template));
- memcpy(entry->template.digest, iint->digest, IMA_DIGEST_SIZE);
+ memcpy(entry->template.digest, iint->ima_xattr.digest, IMA_DIGEST_SIZE);
strncpy(entry->template.file_name, filename, IMA_EVENT_NAME_LEN_MAX);

result = ima_store_template(entry, violation, inode);
diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
index 62527e3..253a0c2 100644
--- a/security/integrity/ima/ima_appraise.c
+++ b/security/integrity/ima/ima_appraise.c
@@ -45,9 +45,9 @@ int ima_must_appraise(struct inode *inode, enum ima_hooks func, int mask)
static void ima_fix_xattr(struct dentry *dentry,
struct integrity_iint_cache *iint)
{
- iint->digest[0] = IMA_XATTR_DIGEST;
- __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA,
- iint->digest, IMA_DIGEST_SIZE + 1, 0);
+ iint->ima_xattr.type = IMA_XATTR_DIGEST;
+ __vfs_setxattr_noperm(dentry, XATTR_NAME_IMA, (u8 *)&iint->ima_xattr,
+ sizeof iint->ima_xattr, 0);
}

/*
@@ -63,7 +63,7 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint,
{
struct dentry *dentry = file->f_dentry;
struct inode *inode = dentry->d_inode;
- u8 xattr_value[IMA_DIGEST_SIZE];
+ struct evm_ima_xattr_data xattr_value;
enum integrity_status status = INTEGRITY_UNKNOWN;
const char *op = "appraise_data";
char *cause = "unknown";
@@ -74,8 +74,8 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint,
if (iint->flags & IMA_APPRAISED)
return iint->ima_status;

- rc = inode->i_op->getxattr(dentry, XATTR_NAME_IMA, xattr_value,
- IMA_DIGEST_SIZE);
+ rc = inode->i_op->getxattr(dentry, XATTR_NAME_IMA, (u8 *)&xattr_value,
+ sizeof xattr_value);
if (rc <= 0) {
if (rc && rc != -ENODATA)
goto out;
@@ -86,7 +86,8 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint,
goto out;
}

- status = evm_verifyxattr(dentry, XATTR_NAME_IMA, xattr_value, rc, iint);
+ status = evm_verifyxattr(dentry, XATTR_NAME_IMA, (u8 *)&xattr_value,
+ rc, iint);
if ((status != INTEGRITY_PASS) && (status != INTEGRITY_UNKNOWN)) {
if ((status == INTEGRITY_NOLABEL)
|| (status == INTEGRITY_NOXATTRS))
@@ -96,14 +97,16 @@ int ima_appraise_measurement(struct integrity_iint_cache *iint,
goto out;
}

- rc = memcmp(xattr_value, iint->digest, IMA_DIGEST_SIZE);
+ rc = memcmp(xattr_value.digest, iint->ima_xattr.digest,
+ IMA_DIGEST_SIZE);
if (rc) {
status = INTEGRITY_FAIL;
cause = "invalid-hash";
print_hex_dump_bytes("security.ima: ", DUMP_PREFIX_NONE,
- xattr_value, IMA_DIGEST_SIZE);
+ &xattr_value, sizeof xattr_value);
print_hex_dump_bytes("collected: ", DUMP_PREFIX_NONE,
- iint->digest, IMA_DIGEST_SIZE);
+ (u8 *)&iint->ima_xattr,
+ sizeof iint->ima_xattr);
goto out;
}
status = INTEGRITY_PASS;
diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
index 295702d..c145331 100644
--- a/security/integrity/integrity.h
+++ b/security/integrity/integrity.h
@@ -39,7 +39,7 @@ struct integrity_iint_cache {
struct inode *inode; /* back pointer to inode in question */
u64 version; /* track inode changes */
unsigned char flags;
- u8 digest[SHA1_DIGEST_SIZE];
+ struct evm_ima_xattr_data ima_xattr;
enum integrity_status ima_status;
enum integrity_status evm_status;
};
--
1.7.6.5


\
 
 \ /
  Last update: 2012-03-01 20:21    [from the cache]
©2003-2011 Jasper Spaans