1 files changed, 121 insertions, 7 deletions

diff --git a/crypto/crc32c.c b/crypto/crc32c.c
index 0dcf64a74e68..a882d9e4e63e 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);