1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * Copyright (C)2006 USAGI/WIDE Project 4 * 5 * Author: 6 * Kazunori Miyazawa <miyazawa@linux-ipv6.org> 7 */ 8 9#include <crypto/internal/hash.h> 10#include <linux/err.h> 11#include <linux/kernel.h> 12#include <linux/module.h> 13 14static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101, 15 0x02020202, 0x02020202, 0x02020202, 0x02020202, 16 0x03030303, 0x03030303, 0x03030303, 0x03030303}; 17 18/* 19 * +------------------------ 20 * | <parent tfm> 21 * +------------------------ 22 * | xcbc_tfm_ctx 23 * +------------------------ 24 * | consts (block size * 2) 25 * +------------------------ 26 */ 27struct xcbc_tfm_ctx { 28 struct crypto_cipher *child; 29 u8 ctx[]; 30}; 31 32/* 33 * +------------------------ 34 * | <shash desc> 35 * +------------------------ 36 * | xcbc_desc_ctx 37 * +------------------------ 38 * | odds (block size) 39 * +------------------------ 40 * | prev (block size) 41 * +------------------------ 42 */ 43struct xcbc_desc_ctx { 44 unsigned int len; 45 u8 ctx[]; 46}; 47 48#define XCBC_BLOCKSIZE 16 49 50static int crypto_xcbc_digest_setkey(struct crypto_shash *parent, 51 const u8 *inkey, unsigned int keylen) 52{ 53 unsigned long alignmask = crypto_shash_alignmask(parent); 54 struct xcbc_tfm_ctx *ctx = crypto_shash_ctx(parent); 55 u8 *consts = PTR_ALIGN(&ctx->ctx[0], alignmask + 1); 56 int err = 0; 57 u8 key1[XCBC_BLOCKSIZE]; 58 int bs = sizeof(key1); 59 60 if ((err = crypto_cipher_setkey(ctx->child, inkey, keylen))) 61 return err; 62 63 crypto_cipher_encrypt_one(ctx->child, consts, (u8 *)ks + bs); 64 crypto_cipher_encrypt_one(ctx->child, consts + bs, (u8 *)ks + bs * 2); 65 crypto_cipher_encrypt_one(ctx->child, key1, (u8 *)ks); 66 67 return crypto_cipher_setkey(ctx->child, key1, bs); 68 69} 70 71static int crypto_xcbc_digest_init(struct shash_desc *pdesc) 72{ 73 unsigned long alignmask = crypto_shash_alignmask(pdesc->tfm); 74 struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc); 75 int bs = crypto_shash_blocksize(pdesc->tfm); 76 u8 *prev = PTR_ALIGN(&ctx->ctx[0], alignmask + 1) + bs; 77 78 ctx->len = 0; 79 memset(prev, 0, bs); 80 81 return 0; 82} 83 84static int crypto_xcbc_digest_update(struct shash_desc *pdesc, const u8 *p, 85 unsigned int len) 86{ 87 struct crypto_shash *parent = pdesc->tfm; 88 unsigned long alignmask = crypto_shash_alignmask(parent); 89 struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent); 90 struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc); 91 struct crypto_cipher *tfm = tctx->child; 92 int bs = crypto_shash_blocksize(parent); 93 u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1); 94 u8 *prev = odds + bs; 95 96 /* checking the data can fill the block */ 97 if ((ctx->len + len) <= bs) { 98 memcpy(odds + ctx->len, p, len); 99 ctx->len += len; 100 return 0; 101 } 102 103 /* filling odds with new data and encrypting it */ 104 memcpy(odds + ctx->len, p, bs - ctx->len); 105 len -= bs - ctx->len; 106 p += bs - ctx->len; 107 108 crypto_xor(prev, odds, bs); 109 crypto_cipher_encrypt_one(tfm, prev, prev); 110 111 /* clearing the length */ 112 ctx->len = 0; 113 114 /* encrypting the rest of data */ 115 while (len > bs) { 116 crypto_xor(prev, p, bs); 117 crypto_cipher_encrypt_one(tfm, prev, prev); 118 p += bs; 119 len -= bs; 120 } 121 122 /* keeping the surplus of blocksize */ 123 if (len) { 124 memcpy(odds, p, len); 125 ctx->len = len; 126 } 127 128 return 0; 129} 130 131static int crypto_xcbc_digest_final(struct shash_desc *pdesc, u8 *out) 132{ 133 struct crypto_shash *parent = pdesc->tfm; 134 unsigned long alignmask = crypto_shash_alignmask(parent); 135 struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent); 136 struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc); 137 struct crypto_cipher *tfm = tctx->child; 138 int bs = crypto_shash_blocksize(parent); 139 u8 *consts = PTR_ALIGN(&tctx->ctx[0], alignmask + 1); 140 u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1); 141 u8 *prev = odds + bs; 142 unsigned int offset = 0; 143 144 if (ctx->len != bs) { 145 unsigned int rlen; 146 u8 *p = odds + ctx->len; 147 148 *p = 0x80; 149 p++; 150 151 rlen = bs - ctx->len -1; 152 if (rlen) 153 memset(p, 0, rlen); 154 155 offset += bs; 156 } 157 158 crypto_xor(prev, odds, bs); 159 crypto_xor(prev, consts + offset, bs); 160 161 crypto_cipher_encrypt_one(tfm, out, prev); 162 163 return 0; 164} 165 166static int xcbc_init_tfm(struct crypto_tfm *tfm) 167{ 168 struct crypto_cipher *cipher; 169 struct crypto_instance *inst = (void *)tfm->__crt_alg; 170 struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst); 171 struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm); 172 173 cipher = crypto_spawn_cipher(spawn); 174 if (IS_ERR(cipher)) 175 return PTR_ERR(cipher); 176 177 ctx->child = cipher; 178 179 return 0; 180}; 181 182static void xcbc_exit_tfm(struct crypto_tfm *tfm) 183{ 184 struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm); 185 crypto_free_cipher(ctx->child); 186} 187 188static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb) 189{ 190 struct shash_instance *inst; 191 struct crypto_cipher_spawn *spawn; 192 struct crypto_alg *alg; 193 unsigned long alignmask; 194 u32 mask; 195 int err; 196 197 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask); 198 if (err) 199 return err; 200 201 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 202 if (!inst) 203 return -ENOMEM; 204 spawn = shash_instance_ctx(inst); 205 206 err = crypto_grab_cipher(spawn, shash_crypto_instance(inst), 207 crypto_attr_alg_name(tb[1]), 0, mask); 208 if (err) 209 goto err_free_inst; 210 alg = crypto_spawn_cipher_alg(spawn); 211 212 err = -EINVAL; 213 if (alg->cra_blocksize != XCBC_BLOCKSIZE) 214 goto err_free_inst; 215 216 err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg); 217 if (err) 218 goto err_free_inst; 219 220 alignmask = alg->cra_alignmask | 3; 221 inst->alg.base.cra_alignmask = alignmask; 222 inst->alg.base.cra_priority = alg->cra_priority; 223 inst->alg.base.cra_blocksize = alg->cra_blocksize; 224 225 inst->alg.digestsize = alg->cra_blocksize; 226 inst->alg.descsize = ALIGN(sizeof(struct xcbc_desc_ctx), 227 crypto_tfm_ctx_alignment()) + 228 (alignmask & 229 ~(crypto_tfm_ctx_alignment() - 1)) + 230 alg->cra_blocksize * 2; 231 232 inst->alg.base.cra_ctxsize = ALIGN(sizeof(struct xcbc_tfm_ctx), 233 alignmask + 1) + 234 alg->cra_blocksize * 2; 235 inst->alg.base.cra_init = xcbc_init_tfm; 236 inst->alg.base.cra_exit = xcbc_exit_tfm; 237 238 inst->alg.init = crypto_xcbc_digest_init; 239 inst->alg.update = crypto_xcbc_digest_update; 240 inst->alg.final = crypto_xcbc_digest_final; 241 inst->alg.setkey = crypto_xcbc_digest_setkey; 242 243 inst->free = shash_free_singlespawn_instance; 244 245 err = shash_register_instance(tmpl, inst); 246 if (err) { 247err_free_inst: 248 shash_free_singlespawn_instance(inst); 249 } 250 return err; 251} 252 253static struct crypto_template crypto_xcbc_tmpl = { 254 .name = "xcbc", 255 .create = xcbc_create, 256 .module = THIS_MODULE, 257}; 258 259static int __init crypto_xcbc_module_init(void) 260{ 261 return crypto_register_template(&crypto_xcbc_tmpl); 262} 263 264static void __exit crypto_xcbc_module_exit(void) 265{ 266 crypto_unregister_template(&crypto_xcbc_tmpl); 267} 268 269subsys_initcall(crypto_xcbc_module_init); 270module_exit(crypto_xcbc_module_exit); 271 272MODULE_LICENSE("GPL"); 273MODULE_DESCRIPTION("XCBC keyed hash algorithm"); 274MODULE_ALIAS_CRYPTO("xcbc"); 275