[dm-devel] add IV generation method null
Ludwig Nussel
ludwig.nussel at suse.de
Fri Feb 16 14:21:12 UTC 2007
Hi,
Following patch (against SUSE's 2.6.18) adds the IV generation
method 'null' to be able to read old filesystem images created with
SuSE's loop_fish2 module.
Signed-off-by: Ludwig Nussel <ludwig.nussel at suse.de>
Acked-By: Christophe Saout <christophe at saout.de>
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -103,6 +103,8 @@ static kmem_cache_t *_crypt_io_pool;
* encrypted with the bulk cipher using a salt as key. The salt
* should be derived from the bulk cipher's key via hashing.
*
+ * null: For mounting legacy images only.
+ *
* plumb: unimplemented, see:
* http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
*/
@@ -203,6 +205,13 @@ static int crypt_iv_essiv_gen(struct cry
return 0;
}
+static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
+{
+ memset(iv, 0, cc->iv_size);
+
+ return 0;
+}
+
static struct crypt_iv_operations crypt_iv_plain_ops = {
.generator = crypt_iv_plain_gen
};
@@ -213,6 +222,9 @@ static struct crypt_iv_operations crypt_
.generator = crypt_iv_essiv_gen
};
+static struct crypt_iv_operations crypt_iv_null_ops = {
+ .generator = crypt_iv_null_gen
+};
static int
crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
@@ -594,6 +606,8 @@ static int crypt_ctr(struct dm_target *t
cc->iv_gen_ops = &crypt_iv_plain_ops;
else if (strcmp(ivmode, "essiv") == 0)
cc->iv_gen_ops = &crypt_iv_essiv_ops;
+ else if (strcmp(ivmode, "null") == 0)
+ cc->iv_gen_ops = &crypt_iv_null_ops;
else {
ti->error = "Invalid IV mode";
goto bad2;
cu
Ludwig
--
(o_ Ludwig Nussel
//\ SUSE Labs
V_/_ http://www.suse.de/
SUSE LINUX Products GmbH, GF: Markus Rex, HRB 16746 (AG Nuernberg)
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