The big-endian IV is needed to map images from extracted
disks that are used in some external (on-chip FDE) disk encryption drives.
(For example for data recovery from external USB/SATA drives that
supports "internal" encryption.)
Signed-off-by: Milan Broz <gmazyland@xxxxxxxxx>
---
drivers/md/dm-crypt.c | 21 ++++++++++++++++++++-
1 file changed, 20 insertions(+), 1 deletion(-)
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index ebf9e72d479b..a68f9476c483 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -246,6 +246,9 @@ static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
* plain64: the initial vector is the 64-bit little-endian version of the sector
* number, padded with zeros if necessary.
*
+ * plain64be: the initial vector is the 64-bit big-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.
@@ -302,6 +305,16 @@ static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
return 0;
}
+static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv,
+ struct dm_crypt_request *dmreq)
+{
+ memset(iv, 0, cc->iv_size);
+ /* iv_size is at least of size u64; usually it is 16 bytes */
+ *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector);
+
+ return 0;
+}
+
/* Initialise ESSIV - compute salt but no local memory allocations */
static int crypt_iv_essiv_init(struct crypt_config *cc)
{
@@ -835,6 +848,10 @@ static const struct crypt_iv_operations crypt_iv_plain64_ops = {
.generator = crypt_iv_plain64_gen
};
+static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
+ .generator = crypt_iv_plain64be_gen
+};
+
static const struct crypt_iv_operations crypt_iv_essiv_ops = {
.ctr = crypt_iv_essiv_ctr,
.dtr = crypt_iv_essiv_dtr,
@@ -2208,6 +2225,8 @@ static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
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, "plain64be") == 0)
+ cc->iv_gen_ops = &crypt_iv_plain64be_ops;
else if (strcmp(ivmode, "essiv") == 0)
cc->iv_gen_ops = &crypt_iv_essiv_ops;
else if (strcmp(ivmode, "benbi") == 0)
@@ -2986,7 +3005,7 @@ static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
static struct target_type crypt_target = {
.name = "crypt",
- .version = {1, 17, 0},
+ .version = {1, 18, 0},
.module = THIS_MODULE,
.ctr = crypt_ctr,
.dtr = crypt_dtr,
--
2.11.0
--
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