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path: root/drivers/md/dm-crypt.c
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Diffstat (limited to 'drivers/md/dm-crypt.c')
-rw-r--r--drivers/md/dm-crypt.c207
1 files changed, 139 insertions, 68 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index e412980763b..a93637223c8 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -1,7 +1,7 @@
/*
* Copyright (C) 2003 Christophe Saout <christophe@saout.de>
* Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
- * Copyright (C) 2006-2008 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved.
*
* This file is released under the GPL.
*/
@@ -71,10 +71,21 @@ struct crypt_iv_operations {
int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
const char *opts);
void (*dtr)(struct crypt_config *cc);
- const char *(*status)(struct crypt_config *cc);
+ int (*init)(struct crypt_config *cc);
+ int (*wipe)(struct crypt_config *cc);
int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector);
};
+struct iv_essiv_private {
+ struct crypto_cipher *tfm;
+ struct crypto_hash *hash_tfm;
+ u8 *salt;
+};
+
+struct iv_benbi_private {
+ int shift;
+};
+
/*
* Crypt: maps a linear range of a block device
* and encrypts / decrypts at the same time.
@@ -102,8 +113,8 @@ struct crypt_config {
struct crypt_iv_operations *iv_gen_ops;
char *iv_mode;
union {
- struct crypto_cipher *essiv_tfm;
- int benbi_shift;
+ struct iv_essiv_private essiv;
+ struct iv_benbi_private benbi;
} iv_gen_private;
sector_t iv_offset;
unsigned int iv_size;
@@ -147,6 +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.
@@ -169,88 +183,123 @@ static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
return 0;
}
-static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
- const char *opts)
+static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
+ sector_t sector)
{
- struct crypto_cipher *essiv_tfm;
- struct crypto_hash *hash_tfm;
+ 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)
+{
+ struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
struct hash_desc desc;
struct scatterlist sg;
- unsigned int saltsize;
- u8 *salt;
int err;
- if (opts == NULL) {
+ sg_init_one(&sg, cc->key, cc->key_size);
+ desc.tfm = essiv->hash_tfm;
+ desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+ err = crypto_hash_digest(&desc, &sg, cc->key_size, essiv->salt);
+ if (err)
+ return err;
+
+ return crypto_cipher_setkey(essiv->tfm, essiv->salt,
+ crypto_hash_digestsize(essiv->hash_tfm));
+}
+
+/* Wipe salt and reset key derived from volume key */
+static int crypt_iv_essiv_wipe(struct crypt_config *cc)
+{
+ struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
+ unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm);
+
+ memset(essiv->salt, 0, salt_size);
+
+ return crypto_cipher_setkey(essiv->tfm, essiv->salt, salt_size);
+}
+
+static void crypt_iv_essiv_dtr(struct crypt_config *cc)
+{
+ struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
+
+ crypto_free_cipher(essiv->tfm);
+ essiv->tfm = NULL;
+
+ crypto_free_hash(essiv->hash_tfm);
+ essiv->hash_tfm = NULL;
+
+ kzfree(essiv->salt);
+ essiv->salt = NULL;
+}
+
+static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
+ const char *opts)
+{
+ struct crypto_cipher *essiv_tfm = NULL;
+ struct crypto_hash *hash_tfm = NULL;
+ u8 *salt = NULL;
+ int err;
+
+ if (!opts) {
ti->error = "Digest algorithm missing for ESSIV mode";
return -EINVAL;
}
- /* Hash the cipher key with the given hash algorithm */
+ /* Allocate hash algorithm */
hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(hash_tfm)) {
ti->error = "Error initializing ESSIV hash";
- return PTR_ERR(hash_tfm);
+ err = PTR_ERR(hash_tfm);
+ goto bad;
}
- saltsize = crypto_hash_digestsize(hash_tfm);
- salt = kmalloc(saltsize, GFP_KERNEL);
- if (salt == NULL) {
+ salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL);
+ if (!salt) {
ti->error = "Error kmallocing salt storage in ESSIV";
- crypto_free_hash(hash_tfm);
- return -ENOMEM;
+ err = -ENOMEM;
+ goto bad;
}
- sg_init_one(&sg, cc->key, cc->key_size);
- desc.tfm = hash_tfm;
- desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
- err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
- crypto_free_hash(hash_tfm);
-
- if (err) {
- ti->error = "Error calculating hash in ESSIV";
- kfree(salt);
- return err;
- }
-
- /* Setup the essiv_tfm with the given salt */
+ /* Allocate essiv_tfm */
essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(essiv_tfm)) {
ti->error = "Error allocating crypto tfm for ESSIV";
- kfree(salt);
- return PTR_ERR(essiv_tfm);
+ err = PTR_ERR(essiv_tfm);
+ goto bad;
}
if (crypto_cipher_blocksize(essiv_tfm) !=
crypto_ablkcipher_ivsize(cc->tfm)) {
ti->error = "Block size of ESSIV cipher does "
"not match IV size of block cipher";
- crypto_free_cipher(essiv_tfm);
- kfree(salt);
- return -EINVAL;
+ err = -EINVAL;
+ goto bad;
}
- err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
- if (err) {
- ti->error = "Failed to set key for ESSIV cipher";
- crypto_free_cipher(essiv_tfm);
- kfree(salt);
- return err;
- }
- kfree(salt);
- cc->iv_gen_private.essiv_tfm = essiv_tfm;
+ cc->iv_gen_private.essiv.salt = salt;
+ cc->iv_gen_private.essiv.tfm = essiv_tfm;
+ cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
+
return 0;
-}
-static void crypt_iv_essiv_dtr(struct crypt_config *cc)
-{
- crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
- cc->iv_gen_private.essiv_tfm = NULL;
+bad:
+ if (essiv_tfm && !IS_ERR(essiv_tfm))
+ crypto_free_cipher(essiv_tfm);
+ if (hash_tfm && !IS_ERR(hash_tfm))
+ crypto_free_hash(hash_tfm);
+ kfree(salt);
+ return err;
}
static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
{
memset(iv, 0, cc->iv_size);
*(u64 *)iv = cpu_to_le64(sector);
- crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
+ crypto_cipher_encrypt_one(cc->iv_gen_private.essiv.tfm, iv, iv);
return 0;
}
@@ -273,7 +322,7 @@ static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
return -EINVAL;
}
- cc->iv_gen_private.benbi_shift = 9 - log;
+ cc->iv_gen_private.benbi.shift = 9 - log;
return 0;
}
@@ -288,7 +337,7 @@ static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
- val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
+ val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi.shift) + 1);
put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
return 0;
@@ -305,9 +354,15 @@ 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,
+ .init = crypt_iv_essiv_init,
+ .wipe = crypt_iv_essiv_wipe,
.generator = crypt_iv_essiv_gen
};
@@ -934,14 +989,14 @@ static int crypt_set_key(struct crypt_config *cc, char *key)
set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
- return 0;
+ return crypto_ablkcipher_setkey(cc->tfm, cc->key, cc->key_size);
}
static int crypt_wipe_key(struct crypt_config *cc)
{
clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
memset(&cc->key, 0, cc->key_size * sizeof(u8));
- return 0;
+ return crypto_ablkcipher_setkey(cc->tfm, cc->key, cc->key_size);
}
/*
@@ -983,11 +1038,6 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
return -ENOMEM;
}
- if (crypt_set_key(cc, argv[1])) {
- ti->error = "Error decoding key";
- goto bad_cipher;
- }
-
/* Compatibility mode for old dm-crypt cipher strings */
if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
chainmode = "cbc";
@@ -1015,6 +1065,11 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
strcpy(cc->chainmode, chainmode);
cc->tfm = tfm;
+ if (crypt_set_key(cc, argv[1]) < 0) {
+ ti->error = "Error decoding and setting key";
+ goto bad_ivmode;
+ }
+
/*
* Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
* See comments at iv code
@@ -1024,6 +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)
@@ -1039,6 +1096,12 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
goto bad_ivmode;
+ if (cc->iv_gen_ops && cc->iv_gen_ops->init &&
+ cc->iv_gen_ops->init(cc) < 0) {
+ ti->error = "Error initialising IV";
+ goto bad_slab_pool;
+ }
+
cc->iv_size = crypto_ablkcipher_ivsize(tfm);
if (cc->iv_size)
/* at least a 64 bit sector number should fit in our buffer */
@@ -1085,11 +1148,6 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad_bs;
}
- if (crypto_ablkcipher_setkey(tfm, cc->key, key_size) < 0) {
- ti->error = "Error setting key";
- goto bad_device;
- }
-
if (sscanf(argv[2], "%llu", &tmpll) != 1) {
ti->error = "Invalid iv_offset sector";
goto bad_device;
@@ -1278,6 +1336,7 @@ static void crypt_resume(struct dm_target *ti)
static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
{
struct crypt_config *cc = ti->private;
+ int ret = -EINVAL;
if (argc < 2)
goto error;
@@ -1287,10 +1346,22 @@ static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
DMWARN("not suspended during key manipulation.");
return -EINVAL;
}
- if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
- return crypt_set_key(cc, argv[2]);
- if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
+ if (argc == 3 && !strnicmp(argv[1], MESG_STR("set"))) {
+ ret = crypt_set_key(cc, argv[2]);
+ if (ret)
+ return ret;
+ if (cc->iv_gen_ops && cc->iv_gen_ops->init)
+ ret = cc->iv_gen_ops->init(cc);
+ return ret;
+ }
+ if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe"))) {
+ if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
+ ret = cc->iv_gen_ops->wipe(cc);
+ if (ret)
+ return ret;
+ }
return crypt_wipe_key(cc);
+ }
}
error: