From: Mimi Zohar <zohar@linux.vnet.ibm.com>
To: linux-security-module <linux-security-module@vger.kernel.org>
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>,
"Luis R. Rodriguez" <mcgrof@suse.com>,
kexec@lists.infradead.org, linux-modules@vger.kernel.org,
linux-fsdevel@vger.kernel.org, Kees Cook <keescook@chromium.org>,
Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Subject: [PATCH v4 07/19] ima: calculate the hash of a buffer using aynchronous hash(ahash)
Date: Fri, 12 Feb 2016 13:29:19 -0500 [thread overview]
Message-ID: <1455301771-7703-8-git-send-email-zohar@linux.vnet.ibm.com> (raw)
In-Reply-To: <1455301771-7703-1-git-send-email-zohar@linux.vnet.ibm.com>
Setting up ahash has some overhead. Only use ahash to calculate the
hash of a buffer, if the buffer is larger than ima_ahash_minsize.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
---
security/integrity/ima/ima_crypto.c | 75 ++++++++++++++++++++++++++++++++++++-
1 file changed, 73 insertions(+), 2 deletions(-)
diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index fccb6ce..38f2ed8 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -519,6 +519,63 @@ int ima_calc_field_array_hash(struct ima_field_data *field_data,
return rc;
}
+static int calc_buffer_ahash_atfm(const void *buf, loff_t len,
+ struct ima_digest_data *hash,
+ struct crypto_ahash *tfm)
+{
+ struct ahash_request *req;
+ struct scatterlist sg;
+ struct ahash_completion res;
+ int rc, ahash_rc = 0;
+
+ hash->length = crypto_ahash_digestsize(tfm);
+
+ req = ahash_request_alloc(tfm, GFP_KERNEL);
+ if (!req)
+ return -ENOMEM;
+
+ init_completion(&res.completion);
+ ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
+ CRYPTO_TFM_REQ_MAY_SLEEP,
+ ahash_complete, &res);
+
+ rc = ahash_wait(crypto_ahash_init(req), &res);
+ if (rc)
+ goto out;
+
+ sg_init_one(&sg, buf, len);
+ ahash_request_set_crypt(req, &sg, NULL, len);
+
+ ahash_rc = crypto_ahash_update(req);
+
+ /* wait for the update request to complete */
+ rc = ahash_wait(ahash_rc, &res);
+ if (!rc) {
+ ahash_request_set_crypt(req, NULL, hash->digest, 0);
+ rc = ahash_wait(crypto_ahash_final(req), &res);
+ }
+out:
+ ahash_request_free(req);
+ return rc;
+}
+
+static int calc_buffer_ahash(const void *buf, loff_t len,
+ struct ima_digest_data *hash)
+{
+ struct crypto_ahash *tfm;
+ int rc;
+
+ tfm = ima_alloc_atfm(hash->algo);
+ if (IS_ERR(tfm))
+ return PTR_ERR(tfm);
+
+ rc = calc_buffer_ahash_atfm(buf, len, hash, tfm);
+
+ ima_free_atfm(tfm);
+
+ return rc;
+}
+
static int calc_buffer_shash_tfm(const void *buf, loff_t size,
struct ima_digest_data *hash,
struct crypto_shash *tfm)
@@ -550,8 +607,8 @@ static int calc_buffer_shash_tfm(const void *buf, loff_t size,
return rc;
}
-int ima_calc_buffer_hash(const void *buf, loff_t len,
- struct ima_digest_data *hash)
+static int calc_buffer_shash(const void *buf, loff_t len,
+ struct ima_digest_data *hash)
{
struct crypto_shash *tfm;
int rc;
@@ -566,6 +623,20 @@ int ima_calc_buffer_hash(const void *buf, loff_t len,
return rc;
}
+int ima_calc_buffer_hash(const void *buf, loff_t len,
+ struct ima_digest_data *hash)
+{
+ int rc;
+
+ if (ima_ahash_minsize && len >= ima_ahash_minsize) {
+ rc = calc_buffer_ahash(buf, len, hash);
+ if (!rc)
+ return 0;
+ }
+
+ return calc_buffer_shash(buf, len, hash);
+}
+
static void __init ima_pcrread(int idx, u8 *pcr)
{
if (!ima_used_chip)
--
2.1.0
next prev parent reply other threads:[~2016-02-12 18:32 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-12 18:29 [PATCH v4 00/19] vfs: support for a common kernel file loader Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 01/19] firmware: simplify dev_*() print messages for generic helpers Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 02/19] firmware: move completing fw into a helper Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 03/19] firmware: clean up filesystem load exit path Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 04/19] vfs: define a generic function to read a file from the kernel Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 05/19] vfs: define kernel_read_file_id enumeration Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 06/19] ima: provide buffer hash calculation function Mimi Zohar
2016-02-12 18:29 ` Mimi Zohar [this message]
2016-02-12 18:29 ` [PATCH v4 08/19] ima: define a new hook to measure and appraise a file already in memory Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 09/19] vfs: define kernel_read_file_from_path Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 10/19] firmware: replace call to fw_read_file_contents() with kernel version Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 11/19] security: define kernel_read_file hook Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 12/19] vfs: define kernel_copy_file_from_fd() Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 13/19] module: replace copy_module_from_fd with kernel version Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 14/19] ima: remove firmware and module specific cached status info Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 15/19] kexec: replace call to copy_file_from_fd() with kernel version Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 16/19] ima: support for kexec image and initramfs Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 17/19] ima: load policy using path Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 18/19] ima: measure and appraise the IMA policy itself Mimi Zohar
2016-02-12 18:29 ` [PATCH v4 19/19] ima: require signed IMA policy Mimi Zohar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1455301771-7703-8-git-send-email-zohar@linux.vnet.ibm.com \
--to=zohar@linux.vnet.ibm.com \
--cc=dmitry.kasatkin@gmail.com \
--cc=keescook@chromium.org \
--cc=kexec@lists.infradead.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-modules@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=mcgrof@suse.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).