[CRYPTO] gcm: Allow block cipher parameter

This patch adds the gcm_base template which takes a block cipher parameter instead of cipher. This allows the user to specify a specific CTR implementation. This also fixes a leak of the cipher algorithm that was previously looked up but never freed. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

[CRYPTO] gcm: Allow block cipher parameter
This patch adds the gcm_base template which takes a block cipher parameter instead of cipher. This allows the user to specify a specific CTR implementation. This also fixes a leak of the cipher algorithm that was previously looked up but never freed. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Herbert Xu
1 parent 9ffde35a8e
Showing 1 changed file with 89 additions and 24 deletions Side-by-side Diff
crypto/gcm.c
@@ -413,61 +413,61 @@
 	crypto_free_ablkcipher(ctx->ctr);
 }
  
-static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
+static struct crypto_instance *crypto_gcm_alloc_common(struct rtattr **tb,
+						       const char *full_name,
+						       const char *ctr_name)
 {
+	struct crypto_attr_type *algt;
 	struct crypto_instance *inst;
 	struct crypto_alg *ctr;
-	struct crypto_alg *cipher;
 	struct gcm_instance_ctx *ctx;
 	int err;
-	char ctr_name[CRYPTO_MAX_ALG_NAME];
  
-	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD);
-	if (err)
+	algt = crypto_get_attr_type(tb);
+	err = PTR_ERR(algt);
+	if (IS_ERR(algt))
 		return ERR_PTR(err);
  
-	cipher = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER,
-			      CRYPTO_ALG_TYPE_MASK);
+	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
+		return ERR_PTR(-EINVAL);
  
-	inst = ERR_PTR(PTR_ERR(cipher));
-	if (IS_ERR(cipher))
-		return inst;
-
-	inst = ERR_PTR(ENAMETOOLONG);
-	if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
-		     cipher->cra_name) >= CRYPTO_MAX_ALG_NAME)
-		return inst;
-
 	ctr = crypto_alg_mod_lookup(ctr_name, CRYPTO_ALG_TYPE_BLKCIPHER,
 				    CRYPTO_ALG_TYPE_MASK);
  
 	if (IS_ERR(ctr))
 		return ERR_PTR(PTR_ERR(ctr));
  
-	if (cipher->cra_blocksize != 16)
+	/* We only support 16-byte blocks. */
+	if ((ctr->cra_type == &crypto_blkcipher_type ?
+	     ctr->cra_blkcipher.ivsize : ctr->cra_ablkcipher.ivsize) != 16)
 		goto out_put_ctr;
  
+	/* Not a stream cipher? */
+	err = -EINVAL;
+	if (ctr->cra_blocksize != 1)
+		goto out_put_ctr;
+
 	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
 	err = -ENOMEM;
 	if (!inst)
 		goto out_put_ctr;
  
 	err = -ENAMETOOLONG;
-	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
-		     "gcm(%s)", cipher->cra_name) >= CRYPTO_MAX_ALG_NAME ||
-	    snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
-		     "gcm(%s)", cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
+	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
+		     "gcm_base(%s)", ctr->cra_driver_name) >=
+	    CRYPTO_MAX_ALG_NAME)
 		goto err_free_inst;
  
-
 	ctx = crypto_instance_ctx(inst);
 	err = crypto_init_spawn(&ctx->ctr, ctr, inst, CRYPTO_ALG_TYPE_MASK);
 	if (err)
 		goto err_free_inst;
  
+	memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
+
 	inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_ASYNC;
 	inst->alg.cra_priority = ctr->cra_priority;
-	inst->alg.cra_blocksize = 16;
+	inst->alg.cra_blocksize = 1;
 	inst->alg.cra_alignmask = ctr->cra_alignmask | (__alignof__(u64) - 1);
 	inst->alg.cra_type = &crypto_aead_type;
 	inst->alg.cra_aead.ivsize = 16;
@@ -489,6 +489,29 @@
 	goto out;
 }
  
+static struct crypto_instance *crypto_gcm_alloc(struct rtattr **tb)
+{
+	int err;
+	const char *cipher_name;
+	char ctr_name[CRYPTO_MAX_ALG_NAME];
+	char full_name[CRYPTO_MAX_ALG_NAME];
+
+	cipher_name = crypto_attr_alg_name(tb[1]);
+	err = PTR_ERR(cipher_name);
+	if (IS_ERR(cipher_name))
+		return ERR_PTR(err);
+
+	if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
+	    CRYPTO_MAX_ALG_NAME)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm(%s)", cipher_name) >=
+	    CRYPTO_MAX_ALG_NAME)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	return crypto_gcm_alloc_common(tb, full_name, ctr_name);
+}
+
 static void crypto_gcm_free(struct crypto_instance *inst)
 {
 	struct gcm_instance_ctx *ctx = crypto_instance_ctx(inst);
  
  
@@ -504,14 +527,55 @@
 	.module = THIS_MODULE,
 };
  
+static struct crypto_instance *crypto_gcm_base_alloc(struct rtattr **tb)
+{
+	int err;
+	const char *ctr_name;
+	char full_name[CRYPTO_MAX_ALG_NAME];
+
+	ctr_name = crypto_attr_alg_name(tb[1]);
+	err = PTR_ERR(ctr_name);
+	if (IS_ERR(ctr_name))
+		return ERR_PTR(err);
+
+	if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s)",
+		     ctr_name) >= CRYPTO_MAX_ALG_NAME)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	return crypto_gcm_alloc_common(tb, full_name, ctr_name);
+}
+
+static struct crypto_template crypto_gcm_base_tmpl = {
+	.name = "gcm_base",
+	.alloc = crypto_gcm_base_alloc,
+	.free = crypto_gcm_free,
+	.module = THIS_MODULE,
+};
+
 static int __init crypto_gcm_module_init(void)
 {
-	return crypto_register_template(&crypto_gcm_tmpl);
+	int err;
+
+	err = crypto_register_template(&crypto_gcm_base_tmpl);
+	if (err)
+		goto out;
+
+	err = crypto_register_template(&crypto_gcm_tmpl);
+	if (err)
+		goto out_undo_base;
+
+out:
+	return err;
+
+out_undo_base:
+	crypto_unregister_template(&crypto_gcm_base_tmpl);
+	goto out;
 }
  
 static void __exit crypto_gcm_module_exit(void)
 {
 	crypto_unregister_template(&crypto_gcm_tmpl);
+	crypto_unregister_template(&crypto_gcm_base_tmpl);
 }
  
 module_init(crypto_gcm_module_init);
@@ -520,4 +584,5 @@
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Galois/Counter Mode");
 MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
+MODULE_ALIAS("gcm_base");
...	...	@@ -413,61 +413,61 @@
413	413	crypto_free_ablkcipher(ctx->ctr);
414	414	}
415	415
416		-static struct crypto_instance crypto_gcm_alloc(struct rtattr *tb)
	416	+static struct crypto_instance crypto_gcm_alloc_common(struct rtattr *tb,
	417	+ const char *full_name,
	418	+ const char *ctr_name)
417	419	{
	420	+ struct crypto_attr_type *algt;
418	421	struct crypto_instance *inst;
419	422	struct crypto_alg *ctr;
420		- struct crypto_alg *cipher;
421	423	struct gcm_instance_ctx *ctx;
422	424	int err;
423		- char ctr_name[CRYPTO_MAX_ALG_NAME];
424	425
425		- err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AEAD);
426		- if (err)
	426	+ algt = crypto_get_attr_type(tb);
	427	+ err = PTR_ERR(algt);
	428	+ if (IS_ERR(algt))
427	429	return ERR_PTR(err);
428	430
429		- cipher = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER,
430		- CRYPTO_ALG_TYPE_MASK);
	431	+ if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
	432	+ return ERR_PTR(-EINVAL);
431	433
432		- inst = ERR_PTR(PTR_ERR(cipher));
433		- if (IS_ERR(cipher))
434		- return inst;
435		-
436		- inst = ERR_PTR(ENAMETOOLONG);
437		- if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)",
438		- cipher->cra_name) >= CRYPTO_MAX_ALG_NAME)
439		- return inst;
440		-
441	434	ctr = crypto_alg_mod_lookup(ctr_name, CRYPTO_ALG_TYPE_BLKCIPHER,
442	435	CRYPTO_ALG_TYPE_MASK);
443	436
444	437	if (IS_ERR(ctr))
445	438	return ERR_PTR(PTR_ERR(ctr));
446	439
447		- if (cipher->cra_blocksize != 16)
	440	+ /* We only support 16-byte blocks. */
	441	+ if ((ctr->cra_type == &crypto_blkcipher_type ?
	442	+ ctr->cra_blkcipher.ivsize : ctr->cra_ablkcipher.ivsize) != 16)
448	443	goto out_put_ctr;
449	444
	445	+ /* Not a stream cipher? */
	446	+ err = -EINVAL;
	447	+ if (ctr->cra_blocksize != 1)
	448	+ goto out_put_ctr;
	449	+
450	450	inst = kzalloc(sizeof(inst) + sizeof(ctx), GFP_KERNEL);
451	451	err = -ENOMEM;
452	452	if (!inst)
453	453	goto out_put_ctr;
454	454
455	455	err = -ENAMETOOLONG;
456		- if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
457		- "gcm(%s)", cipher->cra_name) >= CRYPTO_MAX_ALG_NAME \|\|
458		- snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
459		- "gcm(%s)", cipher->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
	456	+ if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
	457	+ "gcm_base(%s)", ctr->cra_driver_name) >=
	458	+ CRYPTO_MAX_ALG_NAME)
460	459	goto err_free_inst;
461	460
462		-
463	461	ctx = crypto_instance_ctx(inst);
464	462	err = crypto_init_spawn(&ctx->ctr, ctr, inst, CRYPTO_ALG_TYPE_MASK);
465	463	if (err)
466	464	goto err_free_inst;
467	465
	466	+ memcpy(inst->alg.cra_name, full_name, CRYPTO_MAX_ALG_NAME);
	467	+
468	468	inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD \| CRYPTO_ALG_ASYNC;
469	469	inst->alg.cra_priority = ctr->cra_priority;
470		- inst->alg.cra_blocksize = 16;
	470	+ inst->alg.cra_blocksize = 1;
471	471	inst->alg.cra_alignmask = ctr->cra_alignmask \| (__alignof__(u64) - 1);
472	472	inst->alg.cra_type = &crypto_aead_type;
473	473	inst->alg.cra_aead.ivsize = 16;
...	...	@@ -489,6 +489,29 @@
489	489	goto out;
490	490	}
491	491
	492	+static struct crypto_instance crypto_gcm_alloc(struct rtattr *tb)
	493	+{
	494	+ int err;
	495	+ const char *cipher_name;
	496	+ char ctr_name[CRYPTO_MAX_ALG_NAME];
	497	+ char full_name[CRYPTO_MAX_ALG_NAME];
	498	+
	499	+ cipher_name = crypto_attr_alg_name(tb[1]);
	500	+ err = PTR_ERR(cipher_name);
	501	+ if (IS_ERR(cipher_name))
	502	+ return ERR_PTR(err);
	503	+
	504	+ if (snprintf(ctr_name, CRYPTO_MAX_ALG_NAME, "ctr(%s)", cipher_name) >=
	505	+ CRYPTO_MAX_ALG_NAME)
	506	+ return ERR_PTR(-ENAMETOOLONG);
	507	+
	508	+ if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm(%s)", cipher_name) >=
	509	+ CRYPTO_MAX_ALG_NAME)
	510	+ return ERR_PTR(-ENAMETOOLONG);
	511	+
	512	+ return crypto_gcm_alloc_common(tb, full_name, ctr_name);
	513	+}
	514	+
492	515	static void crypto_gcm_free(struct crypto_instance *inst)
493	516	{
494	517	struct gcm_instance_ctx *ctx = crypto_instance_ctx(inst);
495	518
496	519
...	...	@@ -504,14 +527,55 @@
504	527	.module = THIS_MODULE,
505	528	};
506	529
	530	+static struct crypto_instance crypto_gcm_base_alloc(struct rtattr *tb)
	531	+{
	532	+ int err;
	533	+ const char *ctr_name;
	534	+ char full_name[CRYPTO_MAX_ALG_NAME];
	535	+
	536	+ ctr_name = crypto_attr_alg_name(tb[1]);
	537	+ err = PTR_ERR(ctr_name);
	538	+ if (IS_ERR(ctr_name))
	539	+ return ERR_PTR(err);
	540	+
	541	+ if (snprintf(full_name, CRYPTO_MAX_ALG_NAME, "gcm_base(%s)",
	542	+ ctr_name) >= CRYPTO_MAX_ALG_NAME)
	543	+ return ERR_PTR(-ENAMETOOLONG);
	544	+
	545	+ return crypto_gcm_alloc_common(tb, full_name, ctr_name);
	546	+}
	547	+
	548	+static struct crypto_template crypto_gcm_base_tmpl = {
	549	+ .name = "gcm_base",
	550	+ .alloc = crypto_gcm_base_alloc,
	551	+ .free = crypto_gcm_free,
	552	+ .module = THIS_MODULE,
	553	+};
	554	+
507	555	static int __init crypto_gcm_module_init(void)
508	556	{
509		- return crypto_register_template(&crypto_gcm_tmpl);
	557	+ int err;
	558	+
	559	+ err = crypto_register_template(&crypto_gcm_base_tmpl);
	560	+ if (err)
	561	+ goto out;
	562	+
	563	+ err = crypto_register_template(&crypto_gcm_tmpl);
	564	+ if (err)
	565	+ goto out_undo_base;
	566	+
	567	+out:
	568	+ return err;
	569	+
	570	+out_undo_base:
	571	+ crypto_unregister_template(&crypto_gcm_base_tmpl);
	572	+ goto out;
510	573	}
511	574
512	575	static void __exit crypto_gcm_module_exit(void)
513	576	{
514	577	crypto_unregister_template(&crypto_gcm_tmpl);
	578	+ crypto_unregister_template(&crypto_gcm_base_tmpl);
515	579	}
516	580
517	581	module_init(crypto_gcm_module_init);
...	...	@@ -520,4 +584,5 @@
520	584	MODULE_LICENSE("GPL");
521	585	MODULE_DESCRIPTION("Galois/Counter Mode");
522	586	MODULE_AUTHOR("Mikko Herranen <mh1@iki.fi>");
	587	+MODULE_ALIAS("gcm_base");