Commit 69affe7f authored by Herbert Xu's avatar Herbert Xu
Browse files

[BLOCK] cryptoloop: Use block ciphers where applicable 



This patch converts cryptoloop to use the new block cipher type where
applicable.  As a result the ECB-specific and CBC-specific transfer
functions have been merged.

Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent cba83564

drivers/block/cryptoloop.c

+54 −106
Original line number Diff line number Diff line
@@ -40,11 +40,13 @@ static int 
cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info)

{

	int err = -EINVAL;

	int cipher_len;

	int mode_len;

	char cms[LO_NAME_SIZE];			/* cipher-mode string */

	char *cipher;

	char *mode;

	char *cmsp = cms;			/* c-m string pointer */

	struct crypto_tfm *tfm = NULL;

	struct crypto_blkcipher *tfm;



	/* encryption breaks for non sector aligned offsets */
@@ -53,19 +55,38 @@ cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info) 


	strncpy(cms, info->lo_crypt_name, LO_NAME_SIZE);

	cms[LO_NAME_SIZE - 1] = 0;

	cipher = strsep(&cmsp, "-");

	mode = strsep(&cmsp, "-");



	if (mode == NULL || strcmp(mode, "cbc") == 0)

		tfm = crypto_alloc_tfm(cipher, CRYPTO_TFM_MODE_CBC |

					       CRYPTO_TFM_REQ_MAY_SLEEP);

	else if (strcmp(mode, "ecb") == 0)

		tfm = crypto_alloc_tfm(cipher, CRYPTO_TFM_MODE_ECB |

					       CRYPTO_TFM_REQ_MAY_SLEEP);

	if (tfm == NULL)



	cipher = cmsp;

	cipher_len = strcspn(cmsp, "-");



	mode = cmsp + cipher_len;

	mode_len = 0;

	if (*mode) {

		mode++;

		mode_len = strcspn(mode, "-");

	}



	if (!mode_len) {

		mode = "cbc";

		mode_len = 3;

	}



	if (cipher_len + mode_len + 3 > LO_NAME_SIZE)

		return -EINVAL;



	err = tfm->crt_u.cipher.cit_setkey(tfm, info->lo_encrypt_key,

	memmove(cms, mode, mode_len);

	cmsp = cms + mode_len;

	*cmsp++ = '(';

	memcpy(cmsp, info->lo_crypt_name, cipher_len);

	cmsp += cipher_len;

	*cmsp++ = ')';

	*cmsp = 0;



	tfm = crypto_alloc_blkcipher(cms, 0, CRYPTO_ALG_ASYNC);

	if (IS_ERR(tfm))

		return PTR_ERR(tfm);



	err = crypto_blkcipher_setkey(tfm, info->lo_encrypt_key,

				      info->lo_encrypt_key_size);

	

	if (err != 0)
@@ -75,99 +96,49 @@ cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info) 
	return 0;



 out_free_tfm:

	crypto_free_tfm(tfm);

	crypto_free_blkcipher(tfm);



 out:

	return err;

}





typedef int (*encdec_ecb_t)(struct crypto_tfm *tfm,

typedef int (*encdec_cbc_t)(struct blkcipher_desc *desc,

			struct scatterlist *sg_out,

			struct scatterlist *sg_in,

			unsigned int nsg);





static int

cryptoloop_transfer_ecb(struct loop_device *lo, int cmd,

			struct page *raw_page, unsigned raw_off,

			struct page *loop_page, unsigned loop_off,

			int size, sector_t IV)

{

	struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;

	struct scatterlist sg_out = { NULL, };

	struct scatterlist sg_in = { NULL, };



	encdec_ecb_t encdecfunc;

	struct page *in_page, *out_page;

	unsigned in_offs, out_offs;



	if (cmd == READ) {

		in_page = raw_page;

		in_offs = raw_off;

		out_page = loop_page;

		out_offs = loop_off;

		encdecfunc = tfm->crt_u.cipher.cit_decrypt;

	} else {

		in_page = loop_page;

		in_offs = loop_off;

		out_page = raw_page;

		out_offs = raw_off;

		encdecfunc = tfm->crt_u.cipher.cit_encrypt;

	}



	while (size > 0) {

		const int sz = min(size, LOOP_IV_SECTOR_SIZE);



		sg_in.page = in_page;

		sg_in.offset = in_offs;

		sg_in.length = sz;



		sg_out.page = out_page;

		sg_out.offset = out_offs;

		sg_out.length = sz;



		encdecfunc(tfm, &sg_out, &sg_in, sz);



		size -= sz;

		in_offs += sz;

		out_offs += sz;

	}



	return 0;

}



typedef int (*encdec_cbc_t)(struct crypto_tfm *tfm,

			struct scatterlist *sg_out,

			struct scatterlist *sg_in,

			unsigned int nsg, u8 *iv);



static int

cryptoloop_transfer_cbc(struct loop_device *lo, int cmd,

cryptoloop_transfer(struct loop_device *lo, int cmd,

		    struct page *raw_page, unsigned raw_off,

		    struct page *loop_page, unsigned loop_off,

		    int size, sector_t IV)

{

	struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;

	struct crypto_blkcipher *tfm = lo->key_data;

	struct blkcipher_desc desc = {

		.tfm = tfm,

		.flags = CRYPTO_TFM_REQ_MAY_SLEEP,

	};

	struct scatterlist sg_out = { NULL, };

	struct scatterlist sg_in = { NULL, };



	encdec_cbc_t encdecfunc;

	struct page *in_page, *out_page;

	unsigned in_offs, out_offs;

	int err;



	if (cmd == READ) {

		in_page = raw_page;

		in_offs = raw_off;

		out_page = loop_page;

		out_offs = loop_off;

		encdecfunc = tfm->crt_u.cipher.cit_decrypt_iv;

		encdecfunc = crypto_blkcipher_crt(tfm)->decrypt;

	} else {

		in_page = loop_page;

		in_offs = loop_off;

		out_page = raw_page;

		out_offs = raw_off;

		encdecfunc = tfm->crt_u.cipher.cit_encrypt_iv;

		encdecfunc = crypto_blkcipher_crt(tfm)->encrypt;

	}



	while (size > 0) {
@@ -183,7 +154,10 @@ cryptoloop_transfer_cbc(struct loop_device *lo, int cmd, 
		sg_out.offset = out_offs;

		sg_out.length = sz;



		encdecfunc(tfm, &sg_out, &sg_in, sz, (u8 *)iv);

		desc.info = iv;

		err = encdecfunc(&desc, &sg_out, &sg_in, sz);

		if (err)

			return err;



		IV++;

		size -= sz;
@@ -194,32 +168,6 @@ cryptoloop_transfer_cbc(struct loop_device *lo, int cmd, 
	return 0;

}



static int

cryptoloop_transfer(struct loop_device *lo, int cmd,

		    struct page *raw_page, unsigned raw_off,

		    struct page *loop_page, unsigned loop_off,

		    int size, sector_t IV)

{

	struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;

	if(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB)

	{

		lo->transfer = cryptoloop_transfer_ecb;

		return cryptoloop_transfer_ecb(lo, cmd, raw_page, raw_off,

					       loop_page, loop_off, size, IV);

	}	

	if(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_CBC)

	{	

		lo->transfer = cryptoloop_transfer_cbc;

		return cryptoloop_transfer_cbc(lo, cmd, raw_page, raw_off,

					       loop_page, loop_off, size, IV);

	}

	

	/*  This is not supposed to happen */



	printk( KERN_ERR "cryptoloop: unsupported cipher mode in cryptoloop_transfer!\n");

	return -EINVAL;

}



static int

cryptoloop_ioctl(struct loop_device *lo, int cmd, unsigned long arg)

{
@@ -229,9 +177,9 @@ cryptoloop_ioctl(struct loop_device *lo, int cmd, unsigned long arg) 
static int

cryptoloop_release(struct loop_device *lo)

{

	struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data;

	struct crypto_blkcipher *tfm = lo->key_data;

	if (tfm != NULL) {

		crypto_free_tfm(tfm);

		crypto_free_blkcipher(tfm);

		lo->key_data = NULL;

		return 0;

	}

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