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authorMilan Broz <gmazyland@gmail.com>2017-06-06 09:07:01 +0200
committerMike Snitzer <snitzer@redhat.com>2017-06-19 11:03:50 -0400
commit7e3fd855ad66ffc0dd926911da23dd21e59f9462 (patch)
treeb59aba4462121c5da375aec54fa46755628809ee /drivers/md/dm-crypt.c
parent6e333d0be346372390785ecd9a0ddcf7ea9f82ed (diff)
dm crypt: add big-endian variant of plain64 IV
The big-endian IV (plain64be) is needed to map images from extracted disks that are used in some external (on-chip FDE) disk encryption drives, e.g.: data recovery from external USB/SATA drives that support "internal" encryption. Signed-off-by: Milan Broz <gmazyland@gmail.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Diffstat (limited to 'drivers/md/dm-crypt.c')
-rw-r--r--drivers/md/dm-crypt.c21
1 files changed, 20 insertions, 1 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 9e1b72e8f7ef..cdf6b1e12460 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)
@@ -2987,7 +3006,7 @@ 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,