[BLOCK] dm-crypt: Use block ciphers where applicable

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>

drivers/md/dm-crypt.c

@@ -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>
@@ -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];
 };
@@ -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";
@@ -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;
 }
 
@@ -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) {
@@ -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;
@@ -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;
 
@@ -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;
 
 	/*
@@ -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)
@@ -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;
 	}
@@ -675,7 +670,7 @@ bad3:
 	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));
@@ -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 */
@@ -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);