/* GPL HEADER START * * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 only, * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License version 2 for more details (a copy is included * in the LICENSE file that accompanied this code). * * You should have received a copy of the GNU General Public License * version 2 along with this program; If not, see http://www.gnu.org/licenses * * Please visit http://www.xyratex.com/contact if you need additional * information or have any questions. * * GPL HEADER END */ /* * Copyright 2012 Xyratex Technology Limited */ /* * This is crypto api shash wrappers to crc32_le. */ #include <linux/crc32.h> #include <crypto/internal/hash.h> #include <linux/init.h> #include <linux/module.h> #include <linux/string.h> #include <linux/kernel.h> #define CHKSUM_BLOCK_SIZE 1 #define CHKSUM_DIGEST_SIZE 4 static u32 __crc32_le(u32 crc, unsigned char const *p, size_t len) { return crc32_le(crc, p, len); } /** No default init with ~0 */ static int crc32_cra_init(struct crypto_tfm *tfm) { u32 *key = crypto_tfm_ctx(tfm); *key = 0; return 0; } /* * 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 crc32_setkey(struct crypto_shash *hash, const u8 *key, unsigned int keylen) { u32 *mctx = crypto_shash_ctx(hash); if (keylen != sizeof(u32)) { crypto_shash_set_flags(hash, CRYPTO_TFM_RES_BAD_KEY_LEN); return -EINVAL; } *mctx = le32_to_cpup((__le32 *)key); return 0; } static int crc32_init(struct shash_desc *desc) { u32 *mctx = crypto_shash_ctx(desc->tfm); u32 *crcp = shash_desc_ctx(desc); *crcp = *mctx; return 0; } static int crc32_update(struct shash_desc *desc, const u8 *data, unsigned int len) { u32 *crcp = shash_desc_ctx(desc); *crcp = __crc32_le(*crcp, data, len); return 0; } /* No final XOR 0xFFFFFFFF, like crc32_le */ static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len, u8 *out) { *(__le32 *)out = cpu_to_le32(__crc32_le(*crcp, data, len)); return 0; } static int crc32_finup(struct shash_desc *desc, const u8 *data, unsigned int len, u8 *out) { return __crc32_finup(shash_desc_ctx(desc), data, len, out); } static int crc32_final(struct shash_desc *desc, u8 *out) { u32 *crcp = shash_desc_ctx(desc); *(__le32 *)out = cpu_to_le32p(crcp); return 0; } static int crc32_digest(struct shash_desc *desc, const u8 *data, unsigned int len, u8 *out) { return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len, out); } static struct shash_alg alg = { .setkey = crc32_setkey, .init = crc32_init, .update = crc32_update, .final = crc32_final, .finup = crc32_finup, .digest = crc32_digest, .descsize = sizeof(u32), .digestsize = CHKSUM_DIGEST_SIZE, .base = { .cra_name = "crc32", .cra_driver_name = "crc32-generic", .cra_priority = 100, .cra_blocksize = CHKSUM_BLOCK_SIZE, .cra_ctxsize = sizeof(u32), .cra_module = THIS_MODULE, .cra_init = crc32_cra_init, } }; static int __init crc32_mod_init(void) { return crypto_register_shash(&alg); } static void __exit crc32_mod_fini(void) { crypto_unregister_shash(&alg); } module_init(crc32_mod_init); module_exit(crc32_mod_fini); MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>"); MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32"); MODULE_LICENSE("GPL"); MODULE_ALIAS_CRYPTO("crc32"); MODULE_ALIAS_CRYPTO("crc32-generic");