ima: use new crypto_shash API instead of old crypto_hash

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>

3 files changed, 41 insertions, 38 deletions

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index ab68bed8ac36..5a94f9c92605 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 b21ee5b5495a..920f49cfbf13 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 b5dfd534f13d..162ea723db3d 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();