crypto: skcipher - remove crypto_skcipher::keysize

Due to the removal of the blkcipher and ablkcipher algorithm types,
crypto_skcipher::keysize is now redundant since it always equals
crypto_skcipher_alg(tfm)->max_keysize.

Remove it and update crypto_skcipher_default_keysize() accordingly.

Also rename crypto_skcipher_default_keysize() to
crypto_skcipher_max_keysize() to clarify that it specifically returns
the maximum key size, not some unspecified "default".
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/skcipher.c

@@ -585,7 +585,7 @@ static unsigned int crypto_skcipher_extsize(struct crypto_alg *alg)
 
 static void skcipher_set_needkey(struct crypto_skcipher *tfm)
 {
-	if (tfm->keysize)
+	if (crypto_skcipher_max_keysize(tfm) != 0)
 		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
 }
 
@@ -686,7 +686,6 @@ static int crypto_skcipher_init_tfm(struct crypto_tfm *tfm)
 	skcipher->setkey = skcipher_setkey;
 	skcipher->encrypt = alg->encrypt;
 	skcipher->decrypt = alg->decrypt;
-	skcipher->keysize = alg->max_keysize;
 
 	skcipher_set_needkey(skcipher);
 

crypto/testmgr.c

@@ -2647,7 +2647,7 @@ static void generate_random_cipher_testvec(struct skcipher_request *req,
 					   char *name, size_t max_namelen)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
-	const unsigned int maxkeysize = tfm->keysize;
+	const unsigned int maxkeysize = crypto_skcipher_max_keysize(tfm);
 	const unsigned int ivsize = crypto_skcipher_ivsize(tfm);
 	struct scatterlist src, dst;
 	u8 iv[MAX_IVLEN];
@@ -2693,6 +2693,7 @@ static int test_skcipher_vs_generic_impl(const char *driver,
 					 struct cipher_test_sglists *tsgls)
 {
 	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
+	const unsigned int maxkeysize = crypto_skcipher_max_keysize(tfm);
 	const unsigned int ivsize = crypto_skcipher_ivsize(tfm);
 	const unsigned int blocksize = crypto_skcipher_blocksize(tfm);
 	const unsigned int maxdatasize = (2 * PAGE_SIZE) - TESTMGR_POISON_LEN;
@@ -2751,9 +2752,10 @@ static int test_skcipher_vs_generic_impl(const char *driver,
 
 	/* Check the algorithm properties for consistency. */
 
-	if (tfm->keysize != generic_tfm->keysize) {
+	if (maxkeysize != crypto_skcipher_max_keysize(generic_tfm)) {
 		pr_err("alg: skcipher: max keysize for %s (%u) doesn't match generic impl (%u)\n",
-		       driver, tfm->keysize, generic_tfm->keysize);
+		       driver, maxkeysize,
+		       crypto_skcipher_max_keysize(generic_tfm));
 		err = -EINVAL;
 		goto out;
 	}
@@ -2778,7 +2780,7 @@ static int test_skcipher_vs_generic_impl(const char *driver,
 	 * the other implementation against them.
 	 */
 
-	vec.key = kmalloc(tfm->keysize, GFP_KERNEL);
+	vec.key = kmalloc(maxkeysize, GFP_KERNEL);
 	vec.iv = kmalloc(ivsize, GFP_KERNEL);
 	vec.ptext = kmalloc(maxdatasize, GFP_KERNEL);
 	vec.ctext = kmalloc(maxdatasize, GFP_KERNEL);

fs/ecryptfs/crypto.c

@@ -1586,7 +1586,7 @@ ecryptfs_process_key_cipher(struct crypto_skcipher **key_tfm,
 	}
 	crypto_skcipher_set_flags(*key_tfm, CRYPTO_TFM_REQ_FORBID_WEAK_KEYS);
 	if (*key_size == 0)
-		*key_size = crypto_skcipher_default_keysize(*key_tfm);
+		*key_size = crypto_skcipher_max_keysize(*key_tfm);
 	get_random_bytes(dummy_key, *key_size);
 	rc = crypto_skcipher_setkey(*key_tfm, dummy_key, *key_size);
 	if (rc) {

fs/ecryptfs/keystore.c

@@ -2204,9 +2204,9 @@ write_tag_3_packet(char *dest, size_t *remaining_bytes,
 	if (mount_crypt_stat->global_default_cipher_key_size == 0) {
 		printk(KERN_WARNING "No key size specified at mount; "
 		       "defaulting to [%d]\n",
-		       crypto_skcipher_default_keysize(tfm));
+		       crypto_skcipher_max_keysize(tfm));
 		mount_crypt_stat->global_default_cipher_key_size =
-			crypto_skcipher_default_keysize(tfm);
+			crypto_skcipher_max_keysize(tfm);
 	}
 	if (crypt_stat->key_size == 0)
 		crypt_stat->key_size =

include/crypto/skcipher.h

@@ -41,7 +41,6 @@ struct crypto_skcipher {
 	int (*decrypt)(struct skcipher_request *req);
 
 	unsigned int reqsize;
-	unsigned int keysize;
 
 	struct crypto_tfm base;
 };
@@ -377,10 +376,10 @@ static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm,
 	return crypto_skcipher_setkey(&tfm->base, key, keylen);
 }
 
-static inline unsigned int crypto_skcipher_default_keysize(
+static inline unsigned int crypto_skcipher_max_keysize(
 	struct crypto_skcipher *tfm)
 {
-	return tfm->keysize;
+	return crypto_skcipher_alg(tfm)->max_keysize;
 }
 
 /**