crypto: crc32c - Add ahash implementation

This patch reimplements crc32c using the ahash interface. This allows one tfm to be used by an unlimited number of users provided that they all use the same key (which all current crc32c users do). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto: crc32c - Add ahash implementation
This patch reimplements crc32c using the ahash interface. This allows one tfm to be used by an unlimited number of users provided that they all use the same key (which all current crc32c users do). Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Herbert Xu
1 parent 20036252fc
Showing 2 changed files with 122 additions and 8 deletions Side-by-side Diff
crypto/Kconfig
crypto/crc32c.c
@@ -213,7 +213,7 @@
  
 config CRYPTO_CRC32C
 	tristate "CRC32c CRC algorithm"
-	select CRYPTO_ALGAPI
+	select CRYPTO_HASH
 	select LIBCRC32C
 	help
 	  Castagnoli, et al Cyclic Redundancy-Check Algorithm.  Used
@@ -5,20 +5,23 @@
  *
  * This module file is a wrapper to invoke the lib/crc32c routines.
  *
+ * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
+ *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License as published by the Free
  * Software Foundation; either version 2 of the License, or (at your option) 
  * any later version.
  *
  */
+
+#include <crypto/internal/hash.h>
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/string.h>
-#include <linux/crypto.h>
 #include <linux/crc32c.h>
 #include <linux/kernel.h>
  
-#define CHKSUM_BLOCK_SIZE	32
+#define CHKSUM_BLOCK_SIZE	1
 #define CHKSUM_DIGEST_SIZE	4
  
 struct chksum_ctx {
@@ -71,7 +74,7 @@
 	*(__le32 *)out = ~cpu_to_le32(mctx->crc);
 }
  
-static int crc32c_cra_init(struct crypto_tfm *tfm)
+static int crc32c_cra_init_old(struct crypto_tfm *tfm)
 {
 	struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
  
  
@@ -79,14 +82,14 @@
 	return 0;
 }
  
-static struct crypto_alg alg = {
+static struct crypto_alg old_alg = {
 	.cra_name	=	"crc32c",
 	.cra_flags	=	CRYPTO_ALG_TYPE_DIGEST,
 	.cra_blocksize	=	CHKSUM_BLOCK_SIZE,
 	.cra_ctxsize	=	sizeof(struct chksum_ctx),
 	.cra_module	=	THIS_MODULE,
-	.cra_list	=	LIST_HEAD_INIT(alg.cra_list),
-	.cra_init	=	crc32c_cra_init,
+	.cra_list	=	LIST_HEAD_INIT(old_alg.cra_list),
+	.cra_init	=	crc32c_cra_init_old,
 	.cra_u		=	{
 		.digest = {
 			 .dia_digestsize=	CHKSUM_DIGEST_SIZE,
  
  
@@ -98,14 +101,125 @@
 	}
 };
  
+/*
+ * Setting the seed allows arbitrary accumulators and flexible XOR policy
+ * If your algorithm starts with ~0, then XOR with ~0 before you set
+ * the seed.
+ */
+static int crc32c_setkey(struct crypto_ahash *hash, const u8 *key,
+			 unsigned int keylen)
+{
+	u32 *mctx = crypto_ahash_ctx(hash);
+
+	if (keylen != sizeof(u32)) {
+		crypto_ahash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
+		return -EINVAL;
+	}
+	*mctx = le32_to_cpup((__le32 *)key);
+	return 0;
+}
+
+static int crc32c_init(struct ahash_request *req)
+{
+	u32 *mctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
+	u32 *crcp = ahash_request_ctx(req);
+
+	*crcp = *mctx;
+	return 0;
+}
+
+static int crc32c_update(struct ahash_request *req)
+{
+	struct crypto_hash_walk walk;
+	u32 *crcp = ahash_request_ctx(req);
+	u32 crc = *crcp;
+	int nbytes;
+
+	for (nbytes = crypto_hash_walk_first(req, &walk); nbytes;
+	     nbytes = crypto_hash_walk_done(&walk, 0))
+		crc = crc32c(crc, walk.data, nbytes);
+
+	*crcp = crc;
+	return 0;
+}
+
+static int crc32c_final(struct ahash_request *req)
+{
+	u32 *crcp = ahash_request_ctx(req);
+	
+	*(__le32 *)req->result = ~cpu_to_le32p(crcp);
+	return 0;
+}
+
+static int crc32c_digest(struct ahash_request *req)
+{
+	struct crypto_hash_walk walk;
+	u32 *mctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
+	u32 crc = *mctx;
+	int nbytes;
+
+	for (nbytes = crypto_hash_walk_first(req, &walk); nbytes;
+	     nbytes = crypto_hash_walk_done(&walk, 0))
+		crc = crc32c(crc, walk.data, nbytes);
+
+	*(__le32 *)req->result = ~cpu_to_le32(crc);
+	return 0;
+}
+
+static int crc32c_cra_init(struct crypto_tfm *tfm)
+{
+	u32 *key = crypto_tfm_ctx(tfm);
+
+	*key = ~0;
+
+	tfm->crt_ahash.reqsize = sizeof(u32);
+
+	return 0;
+}
+
+static struct crypto_alg alg = {
+	.cra_name		=	"crc32c",
+	.cra_driver_name	=	"crc32c-generic",
+	.cra_priority		=	100,
+	.cra_flags		=	CRYPTO_ALG_TYPE_AHASH,
+	.cra_blocksize		=	CHKSUM_BLOCK_SIZE,
+	.cra_alignmask		=	3,
+	.cra_ctxsize		=	sizeof(u32),
+	.cra_module		=	THIS_MODULE,
+	.cra_list		=	LIST_HEAD_INIT(alg.cra_list),
+	.cra_init		=	crc32c_cra_init,
+	.cra_type		=	&crypto_ahash_type,
+	.cra_u			=	{
+		.ahash = {
+			 .digestsize	=	CHKSUM_DIGEST_SIZE,
+			 .setkey	=	crc32c_setkey,
+			 .init   	= 	crc32c_init,
+			 .update 	=	crc32c_update,
+			 .final  	=	crc32c_final,
+			 .digest  	=	crc32c_digest,
+		 }
+	}
+};
+
 static int __init crc32c_mod_init(void)
 {
-	return crypto_register_alg(&alg);
+	int err;
+
+	err = crypto_register_alg(&old_alg);
+	if (err)
+		return err;
+
+	err = crypto_register_alg(&alg);
+	if (err)
+		crypto_unregister_alg(&old_alg);
+
+	return err;
 }
  
 static void __exit crc32c_mod_fini(void)
 {
 	crypto_unregister_alg(&alg);
+	crypto_unregister_alg(&old_alg);
 }
  
 module_init(crc32c_mod_init);
...	...	@@ -213,7 +213,7 @@
213	213
214	214	config CRYPTO_CRC32C
215	215	tristate "CRC32c CRC algorithm"
216		- select CRYPTO_ALGAPI
	216	+ select CRYPTO_HASH
217	217	select LIBCRC32C
218	218	help
219	219	Castagnoli, et al Cyclic Redundancy-Check Algorithm. Used
...	...	@@ -5,20 +5,23 @@
5	5	*
6	6	* This module file is a wrapper to invoke the lib/crc32c routines.
7	7	*
	8	+ * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
	9	+ *
8	10	* This program is free software; you can redistribute it and/or modify it
9	11	* under the terms of the GNU General Public License as published by the Free
10	12	* Software Foundation; either version 2 of the License, or (at your option)
11	13	* any later version.
12	14	*
13	15	*/
	16	+
	17	+#include <crypto/internal/hash.h>
14	18	#include <linux/init.h>
15	19	#include <linux/module.h>
16	20	#include <linux/string.h>
17		-#include <linux/crypto.h>
18	21	#include <linux/crc32c.h>
19	22	#include <linux/kernel.h>
20	23
21		-#define CHKSUM_BLOCK_SIZE 32
	24	+#define CHKSUM_BLOCK_SIZE 1
22	25	#define CHKSUM_DIGEST_SIZE 4
23	26
24	27	struct chksum_ctx {
...	...	@@ -71,7 +74,7 @@
71	74	(__le32 )out = ~cpu_to_le32(mctx->crc);
72	75	}
73	76
74		-static int crc32c_cra_init(struct crypto_tfm *tfm)
	77	+static int crc32c_cra_init_old(struct crypto_tfm *tfm)
75	78	{
76	79	struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
77	80
78	81
...	...	@@ -79,14 +82,14 @@
79	82	return 0;
80	83	}
81	84
82		-static struct crypto_alg alg = {
	85	+static struct crypto_alg old_alg = {
83	86	.cra_name = "crc32c",
84	87	.cra_flags = CRYPTO_ALG_TYPE_DIGEST,
85	88	.cra_blocksize = CHKSUM_BLOCK_SIZE,
86	89	.cra_ctxsize = sizeof(struct chksum_ctx),
87	90	.cra_module = THIS_MODULE,
88		- .cra_list = LIST_HEAD_INIT(alg.cra_list),
89		- .cra_init = crc32c_cra_init,
	91	+ .cra_list = LIST_HEAD_INIT(old_alg.cra_list),
	92	+ .cra_init = crc32c_cra_init_old,
90	93	.cra_u = {
91	94	.digest = {
92	95	.dia_digestsize= CHKSUM_DIGEST_SIZE,
93	96
94	97
...	...	@@ -98,14 +101,125 @@
98	101	}
99	102	};
100	103
	104	+/*
	105	+ * Setting the seed allows arbitrary accumulators and flexible XOR policy
	106	+ * If your algorithm starts with ~0, then XOR with ~0 before you set
	107	+ * the seed.
	108	+ */
	109	+static int crc32c_setkey(struct crypto_ahash hash, const u8 key,
	110	+ unsigned int keylen)
	111	+{
	112	+ u32 *mctx = crypto_ahash_ctx(hash);
	113	+
	114	+ if (keylen != sizeof(u32)) {
	115	+ crypto_ahash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN);
	116	+ return -EINVAL;
	117	+ }
	118	+ mctx = le32_to_cpup((__le32 )key);
	119	+ return 0;
	120	+}
	121	+
	122	+static int crc32c_init(struct ahash_request *req)
	123	+{
	124	+ u32 *mctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
	125	+ u32 *crcp = ahash_request_ctx(req);
	126	+
	127	+ crcp = mctx;
	128	+ return 0;
	129	+}
	130	+
	131	+static int crc32c_update(struct ahash_request *req)
	132	+{
	133	+ struct crypto_hash_walk walk;
	134	+ u32 *crcp = ahash_request_ctx(req);
	135	+ u32 crc = *crcp;
	136	+ int nbytes;
	137	+
	138	+ for (nbytes = crypto_hash_walk_first(req, &walk); nbytes;
	139	+ nbytes = crypto_hash_walk_done(&walk, 0))
	140	+ crc = crc32c(crc, walk.data, nbytes);
	141	+
	142	+ *crcp = crc;
	143	+ return 0;
	144	+}
	145	+
	146	+static int crc32c_final(struct ahash_request *req)
	147	+{
	148	+ u32 *crcp = ahash_request_ctx(req);
	149	+
	150	+ (__le32 )req->result = ~cpu_to_le32p(crcp);
	151	+ return 0;
	152	+}
	153	+
	154	+static int crc32c_digest(struct ahash_request *req)
	155	+{
	156	+ struct crypto_hash_walk walk;
	157	+ u32 *mctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
	158	+ u32 crc = *mctx;
	159	+ int nbytes;
	160	+
	161	+ for (nbytes = crypto_hash_walk_first(req, &walk); nbytes;
	162	+ nbytes = crypto_hash_walk_done(&walk, 0))
	163	+ crc = crc32c(crc, walk.data, nbytes);
	164	+
	165	+ (__le32 )req->result = ~cpu_to_le32(crc);
	166	+ return 0;
	167	+}
	168	+
	169	+static int crc32c_cra_init(struct crypto_tfm *tfm)
	170	+{
	171	+ u32 *key = crypto_tfm_ctx(tfm);
	172	+
	173	+ *key = ~0;
	174	+
	175	+ tfm->crt_ahash.reqsize = sizeof(u32);
	176	+
	177	+ return 0;
	178	+}
	179	+
	180	+static struct crypto_alg alg = {
	181	+ .cra_name = "crc32c",
	182	+ .cra_driver_name = "crc32c-generic",
	183	+ .cra_priority = 100,
	184	+ .cra_flags = CRYPTO_ALG_TYPE_AHASH,
	185	+ .cra_blocksize = CHKSUM_BLOCK_SIZE,
	186	+ .cra_alignmask = 3,
	187	+ .cra_ctxsize = sizeof(u32),
	188	+ .cra_module = THIS_MODULE,
	189	+ .cra_list = LIST_HEAD_INIT(alg.cra_list),
	190	+ .cra_init = crc32c_cra_init,
	191	+ .cra_type = &crypto_ahash_type,
	192	+ .cra_u = {
	193	+ .ahash = {
	194	+ .digestsize = CHKSUM_DIGEST_SIZE,
	195	+ .setkey = crc32c_setkey,
	196	+ .init = crc32c_init,
	197	+ .update = crc32c_update,
	198	+ .final = crc32c_final,
	199	+ .digest = crc32c_digest,
	200	+ }
	201	+ }
	202	+};
	203	+
101	204	static int __init crc32c_mod_init(void)
102	205	{
103		- return crypto_register_alg(&alg);
	206	+ int err;
	207	+
	208	+ err = crypto_register_alg(&old_alg);
	209	+ if (err)
	210	+ return err;
	211	+
	212	+ err = crypto_register_alg(&alg);
	213	+ if (err)
	214	+ crypto_unregister_alg(&old_alg);
	215	+
	216	+ return err;
104	217	}
105	218
106	219	static void __exit crc32c_mod_fini(void)
107	220	{
108	221	crypto_unregister_alg(&alg);
	222	+ crypto_unregister_alg(&old_alg);
109	223	}
110	224
111	225	module_init(crc32c_mod_init);