1 files changed, 121 insertions, 7 deletions

diff --git a/crypto/crc32c.c b/crypto/crc32c.c
index 0dcf64a..a882d9e 100644
--- a/crypto/crc32c.c
+++ b/crypto/crc32c.c
@@ -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 @@ static void chksum_final(struct crypto_tfm *tfm, u8 *out)
 	*(__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 @@ static int crc32c_cra_init(struct crypto_tfm *tfm)
 	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 @@ static struct crypto_alg alg = {
 	}
 };
 
+/*
+ * 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);