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[BLOCK] dm-crypt: Use block ciphers where applicable
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This patch converts dm-crypt to use the new block cipher type where
applicable.  It also changes simple cipher operations to use the new
encrypt_one/decrypt_one interface.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Herbert Xu committed Sep 21, 2006
1 parent 69affe7 commit d1806f6
Showing 1 changed file with 47 additions and 61 deletions.
108 changes: 47 additions & 61 deletions drivers/md/dm-crypt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@
* This file is released under the GPL.
*/

#include <linux/err.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
Expand Down Expand Up @@ -78,11 +79,13 @@ struct crypt_config {
*/
struct crypt_iv_operations *iv_gen_ops;
char *iv_mode;
void *iv_gen_private;
struct crypto_cipher *iv_gen_private;
sector_t iv_offset;
unsigned int iv_size;

struct crypto_tfm *tfm;
char cipher[CRYPTO_MAX_ALG_NAME];
char chainmode[CRYPTO_MAX_ALG_NAME];
struct crypto_blkcipher *tfm;
unsigned int key_size;
u8 key[0];
};
Expand Down Expand Up @@ -118,11 +121,12 @@ static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
const char *opts)
{
struct crypto_tfm *essiv_tfm;
struct crypto_cipher *essiv_tfm;
struct crypto_tfm *hash_tfm;
struct scatterlist sg;
unsigned int saltsize;
u8 *salt;
int err;

if (opts == NULL) {
ti->error = "Digest algorithm missing for ESSIV mode";
Expand Down Expand Up @@ -155,51 +159,44 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
crypto_free_tfm(hash_tfm);

/* Setup the essiv_tfm with the given salt */
essiv_tfm = crypto_alloc_tfm(crypto_tfm_alg_name(cc->tfm),
CRYPTO_TFM_MODE_ECB |
CRYPTO_TFM_REQ_MAY_SLEEP);
if (essiv_tfm == NULL) {
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 -EINVAL;
return PTR_ERR(essiv_tfm);
}
if (crypto_tfm_alg_blocksize(essiv_tfm)
!= crypto_tfm_alg_ivsize(cc->tfm)) {
if (crypto_cipher_blocksize(essiv_tfm) !=
crypto_blkcipher_ivsize(cc->tfm)) {
ti->error = "Block size of ESSIV cipher does "
"not match IV size of block cipher";
crypto_free_tfm(essiv_tfm);
crypto_free_cipher(essiv_tfm);
kfree(salt);
return -EINVAL;
}
if (crypto_cipher_setkey(essiv_tfm, salt, saltsize) < 0) {
err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
if (err) {
ti->error = "Failed to set key for ESSIV cipher";
crypto_free_tfm(essiv_tfm);
crypto_free_cipher(essiv_tfm);
kfree(salt);
return -EINVAL;
return err;
}
kfree(salt);

cc->iv_gen_private = (void *)essiv_tfm;
cc->iv_gen_private = essiv_tfm;
return 0;
}

static void crypt_iv_essiv_dtr(struct crypt_config *cc)
{
crypto_free_tfm((struct crypto_tfm *)cc->iv_gen_private);
crypto_free_cipher(cc->iv_gen_private);
cc->iv_gen_private = NULL;
}

static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
{
struct scatterlist sg;

memset(iv, 0, cc->iv_size);
*(u64 *)iv = cpu_to_le64(sector);

sg_set_buf(&sg, iv, cc->iv_size);
crypto_cipher_encrypt((struct crypto_tfm *)cc->iv_gen_private,
&sg, &sg, cc->iv_size);

crypto_cipher_encrypt_one(cc->iv_gen_private, iv, iv);
return 0;
}

Expand All @@ -220,6 +217,11 @@ crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
int write, sector_t sector)
{
u8 iv[cc->iv_size];
struct blkcipher_desc desc = {
.tfm = cc->tfm,
.info = iv,
.flags = CRYPTO_TFM_REQ_MAY_SLEEP,
};
int r;

if (cc->iv_gen_ops) {
Expand All @@ -228,14 +230,14 @@ crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
return r;

if (write)
r = crypto_cipher_encrypt_iv(cc->tfm, out, in, length, iv);
r = crypto_blkcipher_encrypt_iv(&desc, out, in, length);
else
r = crypto_cipher_decrypt_iv(cc->tfm, out, in, length, iv);
r = crypto_blkcipher_decrypt_iv(&desc, out, in, length);
} else {
if (write)
r = crypto_cipher_encrypt(cc->tfm, out, in, length);
r = crypto_blkcipher_encrypt(&desc, out, in, length);
else
r = crypto_cipher_decrypt(cc->tfm, out, in, length);
r = crypto_blkcipher_decrypt(&desc, out, in, length);
}

return r;
Expand Down Expand Up @@ -510,13 +512,12 @@ static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
struct crypt_config *cc;
struct crypto_tfm *tfm;
struct crypto_blkcipher *tfm;
char *tmp;
char *cipher;
char *chainmode;
char *ivmode;
char *ivopts;
unsigned int crypto_flags;
unsigned int key_size;
unsigned long long tmpll;

Expand Down Expand Up @@ -556,31 +557,25 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
ivmode = "plain";
}

/* Choose crypto_flags according to chainmode */
if (strcmp(chainmode, "cbc") == 0)
crypto_flags = CRYPTO_TFM_MODE_CBC;
else if (strcmp(chainmode, "ecb") == 0)
crypto_flags = CRYPTO_TFM_MODE_ECB;
else {
ti->error = "Unknown chaining mode";
if (strcmp(chainmode, "ecb") && !ivmode) {
ti->error = "This chaining mode requires an IV mechanism";
goto bad1;
}

if (crypto_flags != CRYPTO_TFM_MODE_ECB && !ivmode) {
ti->error = "This chaining mode requires an IV mechanism";
if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)", chainmode,
cipher) >= CRYPTO_MAX_ALG_NAME) {
ti->error = "Chain mode + cipher name is too long";
goto bad1;
}

tfm = crypto_alloc_tfm(cipher, crypto_flags | CRYPTO_TFM_REQ_MAY_SLEEP);
if (!tfm) {
tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(tfm)) {
ti->error = "Error allocating crypto tfm";
goto bad1;
}
if (crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER) {
ti->error = "Expected cipher algorithm";
goto bad2;
}

strcpy(cc->cipher, cipher);
strcpy(cc->chainmode, chainmode);
cc->tfm = tfm;

/*
Expand All @@ -603,12 +598,12 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
goto bad2;

if (tfm->crt_cipher.cit_decrypt_iv && tfm->crt_cipher.cit_encrypt_iv)
cc->iv_size = crypto_blkcipher_ivsize(tfm);
if (cc->iv_size)
/* at least a 64 bit sector number should fit in our buffer */
cc->iv_size = max(crypto_tfm_alg_ivsize(tfm),
cc->iv_size = max(cc->iv_size,
(unsigned int)(sizeof(u64) / sizeof(u8)));
else {
cc->iv_size = 0;
if (cc->iv_gen_ops) {
DMWARN("Selected cipher does not support IVs");
if (cc->iv_gen_ops->dtr)
Expand All @@ -629,7 +624,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
goto bad4;
}

if (tfm->crt_cipher.cit_setkey(tfm, cc->key, key_size) < 0) {
if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
ti->error = "Error setting key";
goto bad5;
}
Expand Down Expand Up @@ -675,7 +670,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
cc->iv_gen_ops->dtr(cc);
bad2:
crypto_free_tfm(tfm);
crypto_free_blkcipher(tfm);
bad1:
/* Must zero key material before freeing */
memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
Expand All @@ -693,7 +688,7 @@ static void crypt_dtr(struct dm_target *ti)
kfree(cc->iv_mode);
if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
cc->iv_gen_ops->dtr(cc);
crypto_free_tfm(cc->tfm);
crypto_free_blkcipher(cc->tfm);
dm_put_device(ti, cc->dev);

/* Must zero key material before freeing */
Expand Down Expand Up @@ -858,18 +853,9 @@ static int crypt_status(struct dm_target *ti, status_type_t type,
break;

case STATUSTYPE_TABLE:
cipher = crypto_tfm_alg_name(cc->tfm);
cipher = crypto_blkcipher_name(cc->tfm);

switch(cc->tfm->crt_cipher.cit_mode) {
case CRYPTO_TFM_MODE_CBC:
chainmode = "cbc";
break;
case CRYPTO_TFM_MODE_ECB:
chainmode = "ecb";
break;
default:
BUG();
}
chainmode = cc->chainmode;

if (cc->iv_mode)
DMEMIT("%s-%s-%s ", cipher, chainmode, cc->iv_mode);
Expand Down

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