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ima: use new crypto_shash API instead of old crypto_hash

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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>
This commit is contained in:
Dmitry Kasatkin 2012-06-08 10:42:30 +03:00 committed by Mimi Zohar
parent 85865c1fa1
commit 76bb28f612
3 changed files with 42 additions and 39 deletions
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1
security/integrity/ima/ima.h
View File

@ -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

77
security/integrity/ima/ima_crypto.c
View File

@ -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)
{
int rc;
static struct crypto_shash *ima_shash_tfm;
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);
int ima_init_crypto(void)
{
long rc;
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;
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;
@ -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;
}

3
security/integrity/ima/ima_init.c
View File

@ -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();