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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright 2012 Xyratex Technology Limited4 */5 6/*7 * This is crypto api shash wrappers to crc32_le.8 */9 10#include <linux/unaligned.h>11#include <linux/crc32.h>12#include <crypto/internal/hash.h>13#include <linux/init.h>14#include <linux/module.h>15#include <linux/string.h>16#include <linux/kernel.h>17 18#define CHKSUM_BLOCK_SIZE 119#define CHKSUM_DIGEST_SIZE 420 21/** No default init with ~0 */22static int crc32_cra_init(struct crypto_tfm *tfm)23{24 u32 *key = crypto_tfm_ctx(tfm);25 26 *key = 0;27 28 return 0;29}30 31/*32 * Setting the seed allows arbitrary accumulators and flexible XOR policy33 * If your algorithm starts with ~0, then XOR with ~0 before you set34 * the seed.35 */36static int crc32_setkey(struct crypto_shash *hash, const u8 *key,37 unsigned int keylen)38{39 u32 *mctx = crypto_shash_ctx(hash);40 41 if (keylen != sizeof(u32))42 return -EINVAL;43 *mctx = get_unaligned_le32(key);44 return 0;45}46 47static int crc32_init(struct shash_desc *desc)48{49 u32 *mctx = crypto_shash_ctx(desc->tfm);50 u32 *crcp = shash_desc_ctx(desc);51 52 *crcp = *mctx;53 54 return 0;55}56 57static int crc32_update(struct shash_desc *desc, const u8 *data,58 unsigned int len)59{60 u32 *crcp = shash_desc_ctx(desc);61 62 *crcp = crc32_le(*crcp, data, len);63 return 0;64}65 66/* No final XOR 0xFFFFFFFF, like crc32_le */67static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len,68 u8 *out)69{70 put_unaligned_le32(crc32_le(*crcp, data, len), out);71 return 0;72}73 74static int crc32_finup(struct shash_desc *desc, const u8 *data,75 unsigned int len, u8 *out)76{77 return __crc32_finup(shash_desc_ctx(desc), data, len, out);78}79 80static int crc32_final(struct shash_desc *desc, u8 *out)81{82 u32 *crcp = shash_desc_ctx(desc);83 84 put_unaligned_le32(*crcp, out);85 return 0;86}87 88static int crc32_digest(struct shash_desc *desc, const u8 *data,89 unsigned int len, u8 *out)90{91 return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len,92 out);93}94static struct shash_alg alg = {95 .setkey = crc32_setkey,96 .init = crc32_init,97 .update = crc32_update,98 .final = crc32_final,99 .finup = crc32_finup,100 .digest = crc32_digest,101 .descsize = sizeof(u32),102 .digestsize = CHKSUM_DIGEST_SIZE,103 .base = {104 .cra_name = "crc32",105 .cra_driver_name = "crc32-generic",106 .cra_priority = 100,107 .cra_flags = CRYPTO_ALG_OPTIONAL_KEY,108 .cra_blocksize = CHKSUM_BLOCK_SIZE,109 .cra_ctxsize = sizeof(u32),110 .cra_module = THIS_MODULE,111 .cra_init = crc32_cra_init,112 }113};114 115static int __init crc32_mod_init(void)116{117 return crypto_register_shash(&alg);118}119 120static void __exit crc32_mod_fini(void)121{122 crypto_unregister_shash(&alg);123}124 125subsys_initcall(crc32_mod_init);126module_exit(crc32_mod_fini);127 128MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>");129MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32");130MODULE_LICENSE("GPL");131MODULE_ALIAS_CRYPTO("crc32");132MODULE_ALIAS_CRYPTO("crc32-generic");133