diff options
| -rw-r--r-- | crypto/Kconfig | 2 | ||||
| -rw-r--r-- | crypto/crc32c.c | 128 |
2 files changed, 122 insertions, 8 deletions
diff --git a/crypto/Kconfig b/crypto/Kconfig index 43b7473..ea50357 100644 --- a/crypto/Kconfig +++ b/crypto/Kconfig @@ -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 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); |