lkml.org 
[lkml]   [2013]   [Feb]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/2] ima: use new crypto_shash API instead of old crypto_hash
Date
From: Dmitry Kasatkin <dmitry.kasatkin@intel.com>

Old crypto hash API internally uses shash API.
Using shash API directly is more efficient.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
security/integrity/ima/ima.h | 1 +
security/integrity/ima/ima_crypto.c | 75 ++++++++++++++++++-------------------
security/integrity/ima/ima_init.c | 3 ++
3 files changed, 41 insertions(+), 38 deletions(-)

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index ab68bed..5a94f9c 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -89,6 +89,7 @@ int ima_calc_template_hash(int template_len, void *template, char *digest);
int ima_calc_boot_aggregate(char *digest);
void ima_add_violation(struct inode *inode, const unsigned char *filename,
const char *op, const char *cause);
+int ima_init_crypto(void);

/*
* used to protect h_table and sha_table
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index b21ee5b..920f49c 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -19,24 +19,22 @@
#include <linux/scatterlist.h>
#include <linux/err.h>
#include <linux/slab.h>
+#include <crypto/hash.h>
#include "ima.h"

-static int init_desc(struct hash_desc *desc)
+static struct crypto_shash *ima_shash_tfm;
+
+int ima_init_crypto(void)
{
- int rc;
+ long rc;

- desc->tfm = crypto_alloc_hash(ima_hash, 0, CRYPTO_ALG_ASYNC);
- if (IS_ERR(desc->tfm)) {
- pr_info("IMA: failed to load %s transform: %ld\n",
- ima_hash, PTR_ERR(desc->tfm));
- rc = PTR_ERR(desc->tfm);
+ ima_shash_tfm = crypto_alloc_shash(ima_hash, 0, 0);
+ if (IS_ERR(ima_shash_tfm)) {
+ rc = PTR_ERR(ima_shash_tfm);
+ pr_err("Can not allocate %s (reason: %ld)\n", ima_hash, rc);
return rc;
}
- desc->flags = 0;
- rc = crypto_hash_init(desc);
- if (rc)
- crypto_free_hash(desc->tfm);
- return rc;
+ return 0;
}

/*
@@ -44,13 +42,18 @@ static int init_desc(struct hash_desc *desc)
*/
int ima_calc_hash(struct file *file, char *digest)
{
- struct hash_desc desc;
- struct scatterlist sg[1];
loff_t i_size, offset = 0;
char *rbuf;
int rc, read = 0;
+ struct {
+ struct shash_desc shash;
+ char ctx[crypto_shash_descsize(ima_shash_tfm)];
+ } desc;

- rc = init_desc(&desc);
+ desc.shash.tfm = ima_shash_tfm;
+ desc.shash.flags = 0;
+
+ rc = crypto_shash_init(&desc.shash);
if (rc != 0)
return rc;

@@ -75,19 +78,17 @@ int ima_calc_hash(struct file *file, char *digest)
if (rbuf_len == 0)
break;
offset += rbuf_len;
- sg_init_one(sg, rbuf, rbuf_len);

- rc = crypto_hash_update(&desc, sg, rbuf_len);
+ rc = crypto_shash_update(&desc.shash, rbuf, rbuf_len);
if (rc)
break;
}
kfree(rbuf);
if (!rc)
- rc = crypto_hash_final(&desc, digest);
+ rc = crypto_shash_final(&desc.shash, digest);
if (read)
file->f_mode &= ~FMODE_READ;
out:
- crypto_free_hash(desc.tfm);
return rc;
}

@@ -96,20 +97,15 @@ out:
*/
int ima_calc_template_hash(int template_len, void *template, char *digest)
{
- struct hash_desc desc;
- struct scatterlist sg[1];
- int rc;
+ struct {
+ struct shash_desc shash;
+ char ctx[crypto_shash_descsize(ima_shash_tfm)];
+ } desc;

- rc = init_desc(&desc);
- if (rc != 0)
- return rc;
+ desc.shash.tfm = ima_shash_tfm;
+ desc.shash.flags = 0;

- sg_init_one(sg, template, template_len);
- rc = crypto_hash_update(&desc, sg, template_len);
- if (!rc)
- rc = crypto_hash_final(&desc, digest);
- crypto_free_hash(desc.tfm);
- return rc;
+ return crypto_shash_digest(&desc.shash, template, template_len, digest);
}

static void __init ima_pcrread(int idx, u8 *pcr)
@@ -126,12 +122,17 @@ static void __init ima_pcrread(int idx, u8 *pcr)
*/
int __init ima_calc_boot_aggregate(char *digest)
{
- struct hash_desc desc;
- struct scatterlist sg;
u8 pcr_i[IMA_DIGEST_SIZE];
int rc, i;
+ struct {
+ struct shash_desc shash;
+ char ctx[crypto_shash_descsize(ima_shash_tfm)];
+ } desc;
+
+ desc.shash.tfm = ima_shash_tfm;
+ desc.shash.flags = 0;

- rc = init_desc(&desc);
+ rc = crypto_shash_init(&desc.shash);
if (rc != 0)
return rc;

@@ -139,11 +140,9 @@ int __init ima_calc_boot_aggregate(char *digest)
for (i = TPM_PCR0; i < TPM_PCR8; i++) {
ima_pcrread(i, pcr_i);
/* now accumulate with current aggregate */
- sg_init_one(&sg, pcr_i, IMA_DIGEST_SIZE);
- rc = crypto_hash_update(&desc, &sg, IMA_DIGEST_SIZE);
+ rc = crypto_shash_update(&desc.shash, pcr_i, IMA_DIGEST_SIZE);
}
if (!rc)
- crypto_hash_final(&desc, digest);
- crypto_free_hash(desc.tfm);
+ crypto_shash_final(&desc.shash, digest);
return rc;
}
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index b5dfd53..162ea72 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -85,6 +85,9 @@ int __init ima_init(void)
if (!ima_used_chip)
pr_info("IMA: No TPM chip found, activating TPM-bypass!\n");

+ rc = ima_init_crypto();
+ if (rc)
+ return rc;
ima_add_boot_aggregate(); /* boot aggregate must be first entry */
ima_init_policy();

--
1.8.1.rc3


\
 
 \ /
  Last update: 2013-02-06 20:42    [W:0.078 / U:0.068 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site