Commit 61afef61 authored by Milan Broz's avatar Milan Broz Committed by Alasdair G Kergon
Browse files

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: default avatarMilan Broz <mbroz@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 6db4ccd6

drivers/md/dm-crypt.c

+18 −0
Original line number Diff line number Diff line
@@ -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)