ima: ima_calc_boot_agregate must use SHA1

With multiple hash algorithms, ima_hash_tfm is no longer guaranteed to be sha1.
Need to force to use sha1.

Changelog:
- pass ima_digest_data to ima_calc_boot_aggregate() instead of char *
  (Roberto Sassu);
- create an ima_digest_data structure in ima_add_boot_aggregate()
  (Roberto Sassu);
- pass hash->algo to ima_alloc_tfm() (Roberto Sassu, reported by Dmitry).
- "move hash definition in ima_add_boot_aggregate()" commit hunk to here.
- sparse warning fix - Fengguang Wu

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: Roberto Sassu <roberto.sassu@polito.it>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>

3 files changed, 31 insertions, 5 deletions

diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h
index 52393edfbfd9..e0e1cde6e674 100644
--- a/security/integrity/ima/ima.h
+++ b/security/integrity/ima/ima.h
@@ -73,7 +73,7 @@ int ima_add_template_entry(struct ima_template_entry *entry, int violation,
 int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash);
 int ima_calc_buffer_hash(const void *data, int len,
                          struct ima_digest_data *hash);
-int ima_calc_boot_aggregate(char *digest);
+int __init ima_calc_boot_aggregate(struct ima_digest_data *hash);
 void ima_add_violation(struct inode *inode, const unsigned char *filename,
                        const char *op, const char *cause);
 int ima_init_crypto(void);
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index e2be2524a372..22be23f13b3d 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -184,16 +184,17 @@ static void __init ima_pcrread(int idx, u8 *pcr)
 /*
  * Calculate the boot aggregate hash
  */
-int __init ima_calc_boot_aggregate(char *digest)
+static int __init ima_calc_boot_aggregate_tfm(char *digest,
+                                              struct crypto_shash *tfm)
 {
         u8 pcr_i[TPM_DIGEST_SIZE];
         int rc, i;
         struct {
                 struct shash_desc shash;
-                char ctx[crypto_shash_descsize(ima_shash_tfm)];
+                char ctx[crypto_shash_descsize(tfm)];
         } desc;
 
-        desc.shash.tfm = ima_shash_tfm;
+        desc.shash.tfm = tfm;
         desc.shash.flags = 0;
 
         rc = crypto_shash_init(&desc.shash);
@@ -210,3 +211,20 @@ int __init ima_calc_boot_aggregate(char *digest)
                 crypto_shash_final(&desc.shash, digest);
         return rc;
 }
+
+int __init ima_calc_boot_aggregate(struct ima_digest_data *hash)
+{
+        struct crypto_shash *tfm;
+        int rc;
+
+        tfm = ima_alloc_tfm(hash->algo);
+        if (IS_ERR(tfm))
+                return PTR_ERR(tfm);
+
+        hash->length = crypto_shash_digestsize(tfm);
+        rc = ima_calc_boot_aggregate_tfm(hash->digest, tfm);
+
+        ima_free_tfm(tfm);
+
+        return rc;
+}
diff --git a/security/integrity/ima/ima_init.c b/security/integrity/ima/ima_init.c
index 9d0243c10558..77cd5005f2db 100644
--- a/security/integrity/ima/ima_init.c
+++ b/security/integrity/ima/ima_init.c
@@ -18,6 +18,7 @@
 #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 */
@@ -46,6 +47,10 @@ static void __init ima_add_boot_aggregate(void)
         const char *audit_cause = "ENOMEM";
         int result = -ENOMEM;
         int violation = 1;
+        struct {
+                struct ima_digest_data hdr;
+                char digest[TPM_DIGEST_SIZE];
+        } hash;
 
         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
         if (!entry)
@@ -56,12 +61,15 @@ static void __init ima_add_boot_aggregate(void)
                 IMA_EVENT_NAME_LEN_MAX);
         if (ima_used_chip) {
                 violation = 0;
-                result = ima_calc_boot_aggregate(entry->template.digest);
+                hash.hdr.algo = HASH_ALGO_SHA1;
+                result = ima_calc_boot_aggregate(&hash.hdr);
                 if (result < 0) {
                         audit_cause = "hashing_error";
                         kfree(entry);
                         goto err_out;
                 }
+                memcpy(entry->template.digest, hash.hdr.digest,
+                       hash.hdr.length);
         }
         result = ima_store_template(entry, violation, NULL);
         if (result < 0)