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yaml
---
r: 99301
b: refs/heads/master
c: 5773a3e
h: refs/heads/master
i:
  99299: 251c666
v: v3
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Herbert Xu committed Jul 10, 2008
1 parent 94fb2b5 commit ca91596
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Showing 3 changed files with 123 additions and 9 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 20036252fc61c624a49770fb89684ea5cfdfa05e
refs/heads/master: 5773a3e6e396d5fd9de58372abe6a86b7e258e3e
2 changes: 1 addition & 1 deletion trunk/crypto/Kconfig
Original file line number Diff line number Diff line change
Expand Up @@ -213,7 +213,7 @@ comment "Digest"

config CRYPTO_CRC32C
tristate "CRC32c CRC algorithm"
select CRYPTO_ALGAPI
select CRYPTO_HASH
select LIBCRC32C
help
Castagnoli, et al Cyclic Redundancy-Check Algorithm. Used
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128 changes: 121 additions & 7 deletions trunk/crypto/crc32c.c
Original file line number Diff line number Diff line change
Expand Up @@ -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 {
Expand Down Expand Up @@ -71,22 +74,22 @@ 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);

mctx->key = ~0;
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,
Expand All @@ -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);
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