1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2012 Xyratex Technology Limited 4 */ 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 1 19 #define CHKSUM_DIGEST_SIZE 4 20 21 /** No default init with ~0 */ 22 static 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 policy 33 * If your algorithm starts with ~0, then XOR with ~0 before you set 34 * the seed. 35 */ 36 static 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 47 static 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 57 static 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_base(*crcp, data, len); 63 return 0; 64 } 65 66 static int crc32_update_arch(struct shash_desc *desc, const u8 *data, 67 unsigned int len) 68 { 69 u32 *crcp = shash_desc_ctx(desc); 70 71 *crcp = crc32_le(*crcp, data, len); 72 return 0; 73 } 74 75 /* No final XOR 0xFFFFFFFF, like crc32_le */ 76 static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len, 77 u8 *out) 78 { 79 put_unaligned_le32(crc32_le_base(*crcp, data, len), out); 80 return 0; 81 } 82 83 static int __crc32_finup_arch(u32 *crcp, const u8 *data, unsigned int len, 84 u8 *out) 85 { 86 put_unaligned_le32(crc32_le(*crcp, data, len), out); 87 return 0; 88 } 89 90 static int crc32_finup(struct shash_desc *desc, const u8 *data, 91 unsigned int len, u8 *out) 92 { 93 return __crc32_finup(shash_desc_ctx(desc), data, len, out); 94 } 95 96 static int crc32_finup_arch(struct shash_desc *desc, const u8 *data, 97 unsigned int len, u8 *out) 98 { 99 return __crc32_finup_arch(shash_desc_ctx(desc), data, len, out); 100 } 101 102 static int crc32_final(struct shash_desc *desc, u8 *out) 103 { 104 u32 *crcp = shash_desc_ctx(desc); 105 106 put_unaligned_le32(*crcp, out); 107 return 0; 108 } 109 110 static int crc32_digest(struct shash_desc *desc, const u8 *data, 111 unsigned int len, u8 *out) 112 { 113 return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len, out); 114 } 115 116 static int crc32_digest_arch(struct shash_desc *desc, const u8 *data, 117 unsigned int len, u8 *out) 118 { 119 return __crc32_finup_arch(crypto_shash_ctx(desc->tfm), data, len, out); 120 } 121 122 static struct shash_alg algs[] = {{ 123 .setkey = crc32_setkey, 124 .init = crc32_init, 125 .update = crc32_update, 126 .final = crc32_final, 127 .finup = crc32_finup, 128 .digest = crc32_digest, 129 .descsize = sizeof(u32), 130 .digestsize = CHKSUM_DIGEST_SIZE, 131 132 .base.cra_name = "crc32", 133 .base.cra_driver_name = "crc32-generic", 134 .base.cra_priority = 100, 135 .base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY, 136 .base.cra_blocksize = CHKSUM_BLOCK_SIZE, 137 .base.cra_ctxsize = sizeof(u32), 138 .base.cra_module = THIS_MODULE, 139 .base.cra_init = crc32_cra_init, 140 }, { 141 .setkey = crc32_setkey, 142 .init = crc32_init, 143 .update = crc32_update_arch, 144 .final = crc32_final, 145 .finup = crc32_finup_arch, 146 .digest = crc32_digest_arch, 147 .descsize = sizeof(u32), 148 .digestsize = CHKSUM_DIGEST_SIZE, 149 150 .base.cra_name = "crc32", 151 .base.cra_driver_name = "crc32-" __stringify(ARCH), 152 .base.cra_priority = 150, 153 .base.cra_flags = CRYPTO_ALG_OPTIONAL_KEY, 154 .base.cra_blocksize = CHKSUM_BLOCK_SIZE, 155 .base.cra_ctxsize = sizeof(u32), 156 .base.cra_module = THIS_MODULE, 157 .base.cra_init = crc32_cra_init, 158 }}; 159 160 static int __init crc32_mod_init(void) 161 { 162 /* register the arch flavor only if it differs from the generic one */ 163 return crypto_register_shashes(algs, 1 + (&crc32_le != &crc32_le_base)); 164 } 165 166 static void __exit crc32_mod_fini(void) 167 { 168 crypto_unregister_shashes(algs, 1 + (&crc32_le != &crc32_le_base)); 169 } 170 171 subsys_initcall(crc32_mod_init); 172 module_exit(crc32_mod_fini); 173 174 MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>"); 175 MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32"); 176 MODULE_LICENSE("GPL"); 177 MODULE_ALIAS_CRYPTO("crc32"); 178 MODULE_ALIAS_CRYPTO("crc32-generic"); 179