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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C)2006 USAGI/WIDE Project4 *5 * Author:6 * Kazunori Miyazawa <miyazawa@linux-ipv6.org>7 */8 9#include <crypto/internal/cipher.h>10#include <crypto/internal/hash.h>11#include <linux/err.h>12#include <linux/kernel.h>13#include <linux/module.h>14 15static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,16 0x02020202, 0x02020202, 0x02020202, 0x02020202,17 0x03030303, 0x03030303, 0x03030303, 0x03030303};18 19/*20 * +------------------------21 * | <parent tfm>22 * +------------------------23 * | xcbc_tfm_ctx24 * +------------------------25 * | consts (block size * 2)26 * +------------------------27 */28struct xcbc_tfm_ctx {29 struct crypto_cipher *child;30 u8 consts[];31};32 33/*34 * +------------------------35 * | <shash desc>36 * +------------------------37 * | xcbc_desc_ctx38 * +------------------------39 * | odds (block size)40 * +------------------------41 * | prev (block size)42 * +------------------------43 */44struct xcbc_desc_ctx {45 unsigned int len;46 u8 odds[];47};48 49#define XCBC_BLOCKSIZE 1650 51static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,52 const u8 *inkey, unsigned int keylen)53{54 struct xcbc_tfm_ctx *ctx = crypto_shash_ctx(parent);55 u8 *consts = ctx->consts;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 struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);74 int bs = crypto_shash_blocksize(pdesc->tfm);75 u8 *prev = &ctx->odds[bs];76 77 ctx->len = 0;78 memset(prev, 0, bs);79 80 return 0;81}82 83static int crypto_xcbc_digest_update(struct shash_desc *pdesc, const u8 *p,84 unsigned int len)85{86 struct crypto_shash *parent = pdesc->tfm;87 struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);88 struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);89 struct crypto_cipher *tfm = tctx->child;90 int bs = crypto_shash_blocksize(parent);91 u8 *odds = ctx->odds;92 u8 *prev = odds + bs;93 94 /* checking the data can fill the block */95 if ((ctx->len + len) <= bs) {96 memcpy(odds + ctx->len, p, len);97 ctx->len += len;98 return 0;99 }100 101 /* filling odds with new data and encrypting it */102 memcpy(odds + ctx->len, p, bs - ctx->len);103 len -= bs - ctx->len;104 p += bs - ctx->len;105 106 crypto_xor(prev, odds, bs);107 crypto_cipher_encrypt_one(tfm, prev, prev);108 109 /* clearing the length */110 ctx->len = 0;111 112 /* encrypting the rest of data */113 while (len > bs) {114 crypto_xor(prev, p, bs);115 crypto_cipher_encrypt_one(tfm, prev, prev);116 p += bs;117 len -= bs;118 }119 120 /* keeping the surplus of blocksize */121 if (len) {122 memcpy(odds, p, len);123 ctx->len = len;124 }125 126 return 0;127}128 129static int crypto_xcbc_digest_final(struct shash_desc *pdesc, u8 *out)130{131 struct crypto_shash *parent = pdesc->tfm;132 struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent);133 struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc);134 struct crypto_cipher *tfm = tctx->child;135 int bs = crypto_shash_blocksize(parent);136 u8 *odds = ctx->odds;137 u8 *prev = odds + bs;138 unsigned int offset = 0;139 140 if (ctx->len != bs) {141 unsigned int rlen;142 u8 *p = odds + ctx->len;143 144 *p = 0x80;145 p++;146 147 rlen = bs - ctx->len -1;148 if (rlen)149 memset(p, 0, rlen);150 151 offset += bs;152 }153 154 crypto_xor(prev, odds, bs);155 crypto_xor(prev, &tctx->consts[offset], bs);156 157 crypto_cipher_encrypt_one(tfm, out, prev);158 159 return 0;160}161 162static int xcbc_init_tfm(struct crypto_tfm *tfm)163{164 struct crypto_cipher *cipher;165 struct crypto_instance *inst = (void *)tfm->__crt_alg;166 struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst);167 struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);168 169 cipher = crypto_spawn_cipher(spawn);170 if (IS_ERR(cipher))171 return PTR_ERR(cipher);172 173 ctx->child = cipher;174 175 return 0;176};177 178static void xcbc_exit_tfm(struct crypto_tfm *tfm)179{180 struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm);181 crypto_free_cipher(ctx->child);182}183 184static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb)185{186 struct shash_instance *inst;187 struct crypto_cipher_spawn *spawn;188 struct crypto_alg *alg;189 u32 mask;190 int err;191 192 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask);193 if (err)194 return err;195 196 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);197 if (!inst)198 return -ENOMEM;199 spawn = shash_instance_ctx(inst);200 201 err = crypto_grab_cipher(spawn, shash_crypto_instance(inst),202 crypto_attr_alg_name(tb[1]), 0, mask);203 if (err)204 goto err_free_inst;205 alg = crypto_spawn_cipher_alg(spawn);206 207 err = -EINVAL;208 if (alg->cra_blocksize != XCBC_BLOCKSIZE)209 goto err_free_inst;210 211 err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg);212 if (err)213 goto err_free_inst;214 215 inst->alg.base.cra_priority = alg->cra_priority;216 inst->alg.base.cra_blocksize = alg->cra_blocksize;217 inst->alg.base.cra_ctxsize = sizeof(struct xcbc_tfm_ctx) +218 alg->cra_blocksize * 2;219 220 inst->alg.digestsize = alg->cra_blocksize;221 inst->alg.descsize = sizeof(struct xcbc_desc_ctx) +222 alg->cra_blocksize * 2;223 224 inst->alg.base.cra_init = xcbc_init_tfm;225 inst->alg.base.cra_exit = xcbc_exit_tfm;226 227 inst->alg.init = crypto_xcbc_digest_init;228 inst->alg.update = crypto_xcbc_digest_update;229 inst->alg.final = crypto_xcbc_digest_final;230 inst->alg.setkey = crypto_xcbc_digest_setkey;231 232 inst->free = shash_free_singlespawn_instance;233 234 err = shash_register_instance(tmpl, inst);235 if (err) {236err_free_inst:237 shash_free_singlespawn_instance(inst);238 }239 return err;240}241 242static struct crypto_template crypto_xcbc_tmpl = {243 .name = "xcbc",244 .create = xcbc_create,245 .module = THIS_MODULE,246};247 248static int __init crypto_xcbc_module_init(void)249{250 return crypto_register_template(&crypto_xcbc_tmpl);251}252 253static void __exit crypto_xcbc_module_exit(void)254{255 crypto_unregister_template(&crypto_xcbc_tmpl);256}257 258subsys_initcall(crypto_xcbc_module_init);259module_exit(crypto_xcbc_module_exit);260 261MODULE_LICENSE("GPL");262MODULE_DESCRIPTION("XCBC keyed hash algorithm");263MODULE_ALIAS_CRYPTO("xcbc");264MODULE_IMPORT_NS(CRYPTO_INTERNAL);265