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authorMilan Broz <mbroz@redhat.com>2009-12-10 23:52:25 +0000
committerAlasdair G Kergon <agk@redhat.com>2009-12-10 23:52:25 +0000
commit61afef614b013ee1b767cdd10325acae1db1f4d2 (patch)
treea0ece8668c2d210b4c57ef6c4bec2d9184437357 /drivers/md/dm-crypt.c
parent6db4ccd6357f28c9ef7058b3bc48904c4b2ac419 (diff)
downloadlinux-61afef614b013ee1b767cdd10325acae1db1f4d2.tar.bz2
dm crypt: add plain64 iv
The default plain IV is 32-bit only. This plain64 IV provides a compatible mode for encrypted devices bigger than 4TB. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/dm-crypt.c')
-rw-r--r--drivers/md/dm-crypt.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 91e1bf91769f..a93637223c8d 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -158,6 +158,9 @@ static void kcryptd_queue_crypt(struct dm_crypt_io *io);
* plain: the initial vector is the 32-bit little-endian version of the sector
* number, padded with zeros if necessary.
*
+ * plain64: the initial vector is the 64-bit little-endian version of the sector
+ * number, padded with zeros if necessary.
+ *
* essiv: "encrypted sector|salt initial vector", the sector number is
* encrypted with the bulk cipher using a salt as key. The salt
* should be derived from the bulk cipher's key via hashing.
@@ -180,6 +183,15 @@ static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
return 0;
}
+static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
+ sector_t sector)
+{
+ memset(iv, 0, cc->iv_size);
+ *(u64 *)iv = cpu_to_le64(sector);
+
+ return 0;
+}
+
/* Initialise ESSIV - compute salt but no local memory allocations */
static int crypt_iv_essiv_init(struct crypt_config *cc)
{
@@ -342,6 +354,10 @@ static struct crypt_iv_operations crypt_iv_plain_ops = {
.generator = crypt_iv_plain_gen
};
+static struct crypt_iv_operations crypt_iv_plain64_ops = {
+ .generator = crypt_iv_plain64_gen
+};
+
static struct crypt_iv_operations crypt_iv_essiv_ops = {
.ctr = crypt_iv_essiv_ctr,
.dtr = crypt_iv_essiv_dtr,
@@ -1063,6 +1079,8 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
cc->iv_gen_ops = NULL;
else if (strcmp(ivmode, "plain") == 0)
cc->iv_gen_ops = &crypt_iv_plain_ops;
+ else if (strcmp(ivmode, "plain64") == 0)
+ cc->iv_gen_ops = &crypt_iv_plain64_ops;
else if (strcmp(ivmode, "essiv") == 0)
cc->iv_gen_ops = &crypt_iv_essiv_ops;
else if (strcmp(ivmode, "benbi") == 0)