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Commit b1d1e296 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Mike Snitzer
Browse files

dm crypt: omit parsing of the encapsulated cipher 



Only the ESSIV IV generation mode used to use cc->cipher so it could
instantiate the bare cipher used to encrypt the IV. However, this is
now taken care of by the ESSIV template, and so no users of cc->cipher
remain. So remove it altogether.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: default avatarMilan Broz <gmazyland@gmail.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent a1a262b6

drivers/md/dm-crypt.c

+0 −58
Original line number Diff line number Diff line
@@ -143,7 +143,6 @@ struct crypt_config { 
	struct task_struct *write_thread;

	struct rb_root write_tree;



	char *cipher;

	char *cipher_string;

	char *cipher_auth;

	char *key_string;
@@ -2140,7 +2139,6 @@ static void crypt_dtr(struct dm_target *ti) 
	if (cc->dev)

		dm_put_device(ti, cc->dev);



	kzfree(cc->cipher);

	kzfree(cc->cipher_string);

	kzfree(cc->key_string);

	kzfree(cc->cipher_auth);
@@ -2221,52 +2219,6 @@ static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode) 
	return 0;

}



/*

 * Workaround to parse cipher algorithm from crypto API spec.

 * The cc->cipher is currently used only in ESSIV.

 * This should be probably done by crypto-api calls (once available...)

 */

static int crypt_ctr_blkdev_cipher(struct crypt_config *cc)

{

	const char *alg_name = NULL;

	char *start, *end;



	if (crypt_integrity_aead(cc)) {

		alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc)));

		if (!alg_name)

			return -EINVAL;

		if (crypt_integrity_hmac(cc)) {

			alg_name = strchr(alg_name, ',');

			if (!alg_name)

				return -EINVAL;

		}

		alg_name++;

	} else {

		alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc)));

		if (!alg_name)

			return -EINVAL;

	}



	start = strchr(alg_name, '(');

	end = strchr(alg_name, ')');



	if (!start && !end) {

		cc->cipher = kstrdup(alg_name, GFP_KERNEL);

		return cc->cipher ? 0 : -ENOMEM;

	}



	if (!start || !end || ++start >= end)

		return -EINVAL;



	cc->cipher = kzalloc(end - start + 1, GFP_KERNEL);

	if (!cc->cipher)

		return -ENOMEM;



	strncpy(cc->cipher, start, end - start);



	return 0;

}



/*

 * Workaround to parse HMAC algorithm from AEAD crypto API spec.

 * The HMAC is needed to calculate tag size (HMAC digest size).
@@ -2376,12 +2328,6 @@ static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key 
	else

		cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));



	ret = crypt_ctr_blkdev_cipher(cc);

	if (ret < 0) {

		ti->error = "Cannot allocate cipher string";

		return -ENOMEM;

	}



	return 0;

}
@@ -2416,10 +2362,6 @@ static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key 
	}

	cc->key_parts = cc->tfms_count;



	cc->cipher = kstrdup(cipher, GFP_KERNEL);

	if (!cc->cipher)

		goto bad_mem;



	chainmode = strsep(&tmp, "-");

	*ivmode = strsep(&tmp, ":");

	*ivopts = tmp;