From 61afef614b013ee1b767cdd10325acae1db1f4d2 Mon Sep 17 00:00:00 2001 From: Milan Broz Date: Thu, 10 Dec 2009 23:52:25 +0000 Subject: [PATCH] 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 Signed-off-by: Alasdair G Kergon --- drivers/md/dm-crypt.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index 91e1bf91769..a93637223c8 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)