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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 | // SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2012 Xyratex Technology Limited */ /* * This is crypto api shash wrappers to crc32_le. */ #include <asm/unaligned.h> #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 /** 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)) return -EINVAL; *mctx = get_unaligned_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) { put_unaligned_le32(crc32_le(*crcp, data, len), out); 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); put_unaligned_le32(*crcp, out); 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_flags = CRYPTO_ALG_OPTIONAL_KEY, .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); } subsys_initcall(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"); |