dm crypt: add null iv
Add a new IV generation method 'null' to read old filesystem images created
with SuSE's loop_fish2 module.
Signed-off-by: Ludwig Nussel <ludwig.nussel@suse.de>
Acked-By: Christophe Saout <christophe@saout.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 1ecee5e..7b0fcfc 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -121,6 +121,9 @@
* benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
* (needed for LRW-32-AES and possible other narrow block modes)
*
+ * null: the initial vector is always zero. Provides compatibility with
+ * obsolete loop_fish2 devices. Do not use for new devices.
+ *
* plumb: unimplemented, see:
* http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
*/
@@ -257,6 +260,13 @@
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
};
@@ -273,6 +283,10 @@
.generator = crypt_iv_benbi_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,
struct scatterlist *in, unsigned int length,
@@ -803,6 +817,8 @@
cc->iv_gen_ops = &crypt_iv_essiv_ops;
else if (strcmp(ivmode, "benbi") == 0)
cc->iv_gen_ops = &crypt_iv_benbi_ops;
+ else if (strcmp(ivmode, "null") == 0)
+ cc->iv_gen_ops = &crypt_iv_null_ops;
else {
ti->error = "Invalid IV mode";
goto bad2;
@@ -1030,7 +1046,7 @@
static struct target_type crypt_target = {
.name = "crypt",
- .version= {1, 3, 0},
+ .version= {1, 5, 0},
.module = THIS_MODULE,
.ctr = crypt_ctr,
.dtr = crypt_dtr,