diff options
| author | Milan Broz <gmazyland@gmail.com> | 2017-06-06 09:07:01 +0200 |
|---|---|---|
| committer | Mike Snitzer <snitzer@redhat.com> | 2017-06-19 11:03:50 -0400 |
| commit | 7e3fd855ad66ffc0dd926911da23dd21e59f9462 (patch) | |
| tree | b59aba4462121c5da375aec54fa46755628809ee /drivers/md/dm-crypt.c | |
| parent | 6e333d0be346372390785ecd9a0ddcf7ea9f82ed (diff) | |
| download | lwn-7e3fd855ad66ffc0dd926911da23dd21e59f9462.tar.gz lwn-7e3fd855ad66ffc0dd926911da23dd21e59f9462.zip | |
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.c | 21 |
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, |