crypto: adiantum - use crypto_grab_{cipher,shash} and simplify error paths

Make the adiantum template use the new functions crypto_grab_cipher()
and crypto_grab_shash() to initialize its cipher and shash spawns.

This is needed to make all spawns be initialized in a consistent way.

Also simplify the error handling by taking advantage of crypto_drop_*()
now accepting (as a no-op) spawns that haven't been initialized yet, and
by taking advantage of crypto_grab_*() now handling ERR_PTR() names.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/adiantum.c

@@ -39,8 +39,6 @@
 #include <crypto/scatterwalk.h>
 #include <linux/module.h>
 
-#include "internal.h"
-
 /*
  * Size of right-hand part of input data, in bytes; also the size of the block
  * cipher's block size and the hash function's output.
@@ -64,7 +62,7 @@
 
 struct adiantum_instance_ctx {
 	struct crypto_skcipher_spawn streamcipher_spawn;
-	struct crypto_spawn blockcipher_spawn;
+	struct crypto_cipher_spawn blockcipher_spawn;
 	struct crypto_shash_spawn hash_spawn;
 };
 
@@ -410,7 +408,7 @@ static int adiantum_init_tfm(struct crypto_skcipher *tfm)
 	if (IS_ERR(streamcipher))
 		return PTR_ERR(streamcipher);
 
-	blockcipher = crypto_spawn_cipher(&ictx->blockcipher_spawn);
+	blockcipher = crypto_spawn_cipher(&ictx->blockcipher_spawn.base);
 	if (IS_ERR(blockcipher)) {
 		err = PTR_ERR(blockcipher);
 		goto err_free_streamcipher;
@@ -461,7 +459,7 @@ static void adiantum_free_instance(struct skcipher_instance *inst)
 	struct adiantum_instance_ctx *ictx = skcipher_instance_ctx(inst);
 
 	crypto_drop_skcipher(&ictx->streamcipher_spawn);
-	crypto_drop_spawn(&ictx->blockcipher_spawn);
+	crypto_drop_cipher(&ictx->blockcipher_spawn);
 	crypto_drop_shash(&ictx->hash_spawn);
 	kfree(inst);
 }
@@ -494,14 +492,11 @@ static int adiantum_create(struct crypto_template *tmpl, struct rtattr **tb)
 {
 	struct crypto_attr_type *algt;
 	u32 mask;
-	const char *streamcipher_name;
-	const char *blockcipher_name;
 	const char *nhpoly1305_name;
 	struct skcipher_instance *inst;
 	struct adiantum_instance_ctx *ictx;
 	struct skcipher_alg *streamcipher_alg;
 	struct crypto_alg *blockcipher_alg;
-	struct crypto_alg *_hash_alg;
 	struct shash_alg *hash_alg;
 	int err;
 
@@ -514,20 +509,6 @@ static int adiantum_create(struct crypto_template *tmpl, struct rtattr **tb)
 
 	mask = crypto_requires_sync(algt->type, algt->mask);
 
-	streamcipher_name = crypto_attr_alg_name(tb[1]);
-	if (IS_ERR(streamcipher_name))
-		return PTR_ERR(streamcipher_name);
-
-	blockcipher_name = crypto_attr_alg_name(tb[2]);
-	if (IS_ERR(blockcipher_name))
-		return PTR_ERR(blockcipher_name);
-
-	nhpoly1305_name = crypto_attr_alg_name(tb[3]);
-	if (nhpoly1305_name == ERR_PTR(-ENOENT))
-		nhpoly1305_name = "nhpoly1305";
-	if (IS_ERR(nhpoly1305_name))
-		return PTR_ERR(nhpoly1305_name);
-
 	inst = kzalloc(sizeof(*inst) + sizeof(*ictx), GFP_KERNEL);
 	if (!inst)
 		return -ENOMEM;
@@ -536,33 +517,29 @@ static int adiantum_create(struct crypto_template *tmpl, struct rtattr **tb)
 	/* Stream cipher, e.g. "xchacha12" */
 	err = crypto_grab_skcipher(&ictx->streamcipher_spawn,
 				   skcipher_crypto_instance(inst),
-				   streamcipher_name, 0, mask);
+				   crypto_attr_alg_name(tb[1]), 0, mask);
 	if (err)
-		goto out_free_inst;
+		goto err_free_inst;
 	streamcipher_alg = crypto_spawn_skcipher_alg(&ictx->streamcipher_spawn);
 
 	/* Block cipher, e.g. "aes" */
-	err = crypto_grab_spawn(&ictx->blockcipher_spawn,
-				skcipher_crypto_instance(inst),
-				blockcipher_name,
-				CRYPTO_ALG_TYPE_CIPHER, CRYPTO_ALG_TYPE_MASK);
+	err = crypto_grab_cipher(&ictx->blockcipher_spawn,
+				 skcipher_crypto_instance(inst),
+				 crypto_attr_alg_name(tb[2]), 0, mask);
 	if (err)
-		goto out_drop_streamcipher;
-	blockcipher_alg = ictx->blockcipher_spawn.alg;
+		goto err_free_inst;
+	blockcipher_alg = crypto_spawn_cipher_alg(&ictx->blockcipher_spawn);
 
 	/* NHPoly1305 ε-∆U hash function */
-	_hash_alg = crypto_alg_mod_lookup(nhpoly1305_name,
-					  CRYPTO_ALG_TYPE_SHASH,
-					  CRYPTO_ALG_TYPE_MASK);
-	if (IS_ERR(_hash_alg)) {
-		err = PTR_ERR(_hash_alg);
-		goto out_drop_blockcipher;
-	}
-	hash_alg = __crypto_shash_alg(_hash_alg);
-	err = crypto_init_shash_spawn(&ictx->hash_spawn, hash_alg,
-				      skcipher_crypto_instance(inst));
+	nhpoly1305_name = crypto_attr_alg_name(tb[3]);
+	if (nhpoly1305_name == ERR_PTR(-ENOENT))
+		nhpoly1305_name = "nhpoly1305";
+	err = crypto_grab_shash(&ictx->hash_spawn,
+				skcipher_crypto_instance(inst),
+				nhpoly1305_name, 0, mask);
 	if (err)
-		goto out_put_hash;
+		goto err_free_inst;
+	hash_alg = crypto_spawn_shash_alg(&ictx->hash_spawn);
 
 	/* Check the set of algorithms */
 	if (!adiantum_supported_algorithms(streamcipher_alg, blockcipher_alg,
@@ -571,7 +548,7 @@ static int adiantum_create(struct crypto_template *tmpl, struct rtattr **tb)
 			streamcipher_alg->base.cra_name,
 			blockcipher_alg->cra_name, hash_alg->base.cra_name);
 		err = -EINVAL;
-		goto out_drop_hash;
+		goto err_free_inst;
 	}
 
 	/* Instance fields */
@@ -580,13 +557,13 @@ static int adiantum_create(struct crypto_template *tmpl, struct rtattr **tb)
 	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 		     "adiantum(%s,%s)", streamcipher_alg->base.cra_name,
 		     blockcipher_alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
-		goto out_drop_hash;
+		goto err_free_inst;
 	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 		     "adiantum(%s,%s,%s)",
 		     streamcipher_alg->base.cra_driver_name,
 		     blockcipher_alg->cra_driver_name,
 		     hash_alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
-		goto out_drop_hash;
+		goto err_free_inst;
 
 	inst->alg.base.cra_flags = streamcipher_alg->base.cra_flags &
 				   CRYPTO_ALG_ASYNC;
@@ -616,22 +593,10 @@ static int adiantum_create(struct crypto_template *tmpl, struct rtattr **tb)
 	inst->free = adiantum_free_instance;
 
 	err = skcipher_register_instance(tmpl, inst);
-	if (err)
-		goto out_drop_hash;
-
-	crypto_mod_put(_hash_alg);
-	return 0;
-
-out_drop_hash:
-	crypto_drop_shash(&ictx->hash_spawn);
-out_put_hash:
-	crypto_mod_put(_hash_alg);
-out_drop_blockcipher:
-	crypto_drop_spawn(&ictx->blockcipher_spawn);
-out_drop_streamcipher:
-	crypto_drop_skcipher(&ictx->streamcipher_spawn);
-out_free_inst:
-	kfree(inst);
+	if (err) {
+err_free_inst:
+		adiantum_free_instance(inst);
+	}
 	return err;
 }