| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Copyright (C)2006 USAGI/WIDE Project |
| * |
| * Author: |
| * Kazunori Miyazawa <miyazawa@linux-ipv6.org> |
| */ |
| |
| #include <crypto/internal/hash.h> |
| #include <linux/err.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| |
| static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101, |
| 0x02020202, 0x02020202, 0x02020202, 0x02020202, |
| 0x03030303, 0x03030303, 0x03030303, 0x03030303}; |
| |
| /* |
| * +------------------------ |
| * | <parent tfm> |
| * +------------------------ |
| * | xcbc_tfm_ctx |
| * +------------------------ |
| * | consts (block size * 2) |
| * +------------------------ |
| */ |
| struct xcbc_tfm_ctx { |
| struct crypto_cipher *child; |
| u8 ctx[]; |
| }; |
| |
| /* |
| * +------------------------ |
| * | <shash desc> |
| * +------------------------ |
| * | xcbc_desc_ctx |
| * +------------------------ |
| * | odds (block size) |
| * +------------------------ |
| * | prev (block size) |
| * +------------------------ |
| */ |
| struct xcbc_desc_ctx { |
| unsigned int len; |
| u8 ctx[]; |
| }; |
| |
| #define XCBC_BLOCKSIZE 16 |
| |
| static int crypto_xcbc_digest_setkey(struct crypto_shash *parent, |
| const u8 *inkey, unsigned int keylen) |
| { |
| unsigned long alignmask = crypto_shash_alignmask(parent); |
| struct xcbc_tfm_ctx *ctx = crypto_shash_ctx(parent); |
| u8 *consts = PTR_ALIGN(&ctx->ctx[0], alignmask + 1); |
| int err = 0; |
| u8 key1[XCBC_BLOCKSIZE]; |
| int bs = sizeof(key1); |
| |
| if ((err = crypto_cipher_setkey(ctx->child, inkey, keylen))) |
| return err; |
| |
| crypto_cipher_encrypt_one(ctx->child, consts, (u8 *)ks + bs); |
| crypto_cipher_encrypt_one(ctx->child, consts + bs, (u8 *)ks + bs * 2); |
| crypto_cipher_encrypt_one(ctx->child, key1, (u8 *)ks); |
| |
| return crypto_cipher_setkey(ctx->child, key1, bs); |
| |
| } |
| |
| static int crypto_xcbc_digest_init(struct shash_desc *pdesc) |
| { |
| unsigned long alignmask = crypto_shash_alignmask(pdesc->tfm); |
| struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc); |
| int bs = crypto_shash_blocksize(pdesc->tfm); |
| u8 *prev = PTR_ALIGN(&ctx->ctx[0], alignmask + 1) + bs; |
| |
| ctx->len = 0; |
| memset(prev, 0, bs); |
| |
| return 0; |
| } |
| |
| static int crypto_xcbc_digest_update(struct shash_desc *pdesc, const u8 *p, |
| unsigned int len) |
| { |
| struct crypto_shash *parent = pdesc->tfm; |
| unsigned long alignmask = crypto_shash_alignmask(parent); |
| struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent); |
| struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc); |
| struct crypto_cipher *tfm = tctx->child; |
| int bs = crypto_shash_blocksize(parent); |
| u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1); |
| u8 *prev = odds + bs; |
| |
| /* checking the data can fill the block */ |
| if ((ctx->len + len) <= bs) { |
| memcpy(odds + ctx->len, p, len); |
| ctx->len += len; |
| return 0; |
| } |
| |
| /* filling odds with new data and encrypting it */ |
| memcpy(odds + ctx->len, p, bs - ctx->len); |
| len -= bs - ctx->len; |
| p += bs - ctx->len; |
| |
| crypto_xor(prev, odds, bs); |
| crypto_cipher_encrypt_one(tfm, prev, prev); |
| |
| /* clearing the length */ |
| ctx->len = 0; |
| |
| /* encrypting the rest of data */ |
| while (len > bs) { |
| crypto_xor(prev, p, bs); |
| crypto_cipher_encrypt_one(tfm, prev, prev); |
| p += bs; |
| len -= bs; |
| } |
| |
| /* keeping the surplus of blocksize */ |
| if (len) { |
| memcpy(odds, p, len); |
| ctx->len = len; |
| } |
| |
| return 0; |
| } |
| |
| static int crypto_xcbc_digest_final(struct shash_desc *pdesc, u8 *out) |
| { |
| struct crypto_shash *parent = pdesc->tfm; |
| unsigned long alignmask = crypto_shash_alignmask(parent); |
| struct xcbc_tfm_ctx *tctx = crypto_shash_ctx(parent); |
| struct xcbc_desc_ctx *ctx = shash_desc_ctx(pdesc); |
| struct crypto_cipher *tfm = tctx->child; |
| int bs = crypto_shash_blocksize(parent); |
| u8 *consts = PTR_ALIGN(&tctx->ctx[0], alignmask + 1); |
| u8 *odds = PTR_ALIGN(&ctx->ctx[0], alignmask + 1); |
| u8 *prev = odds + bs; |
| unsigned int offset = 0; |
| |
| if (ctx->len != bs) { |
| unsigned int rlen; |
| u8 *p = odds + ctx->len; |
| |
| *p = 0x80; |
| p++; |
| |
| rlen = bs - ctx->len -1; |
| if (rlen) |
| memset(p, 0, rlen); |
| |
| offset += bs; |
| } |
| |
| crypto_xor(prev, odds, bs); |
| crypto_xor(prev, consts + offset, bs); |
| |
| crypto_cipher_encrypt_one(tfm, out, prev); |
| |
| return 0; |
| } |
| |
| static int xcbc_init_tfm(struct crypto_tfm *tfm) |
| { |
| struct crypto_cipher *cipher; |
| struct crypto_instance *inst = (void *)tfm->__crt_alg; |
| struct crypto_cipher_spawn *spawn = crypto_instance_ctx(inst); |
| struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm); |
| |
| cipher = crypto_spawn_cipher(spawn); |
| if (IS_ERR(cipher)) |
| return PTR_ERR(cipher); |
| |
| ctx->child = cipher; |
| |
| return 0; |
| }; |
| |
| static void xcbc_exit_tfm(struct crypto_tfm *tfm) |
| { |
| struct xcbc_tfm_ctx *ctx = crypto_tfm_ctx(tfm); |
| crypto_free_cipher(ctx->child); |
| } |
| |
| static int xcbc_create(struct crypto_template *tmpl, struct rtattr **tb) |
| { |
| struct shash_instance *inst; |
| struct crypto_cipher_spawn *spawn; |
| struct crypto_alg *alg; |
| unsigned long alignmask; |
| u32 mask; |
| int err; |
| |
| err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH, &mask); |
| if (err) |
| return err; |
| |
| inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); |
| if (!inst) |
| return -ENOMEM; |
| spawn = shash_instance_ctx(inst); |
| |
| err = crypto_grab_cipher(spawn, shash_crypto_instance(inst), |
| crypto_attr_alg_name(tb[1]), 0, mask); |
| if (err) |
| goto err_free_inst; |
| alg = crypto_spawn_cipher_alg(spawn); |
| |
| err = -EINVAL; |
| if (alg->cra_blocksize != XCBC_BLOCKSIZE) |
| goto err_free_inst; |
| |
| err = crypto_inst_setname(shash_crypto_instance(inst), tmpl->name, alg); |
| if (err) |
| goto err_free_inst; |
| |
| alignmask = alg->cra_alignmask | 3; |
| inst->alg.base.cra_alignmask = alignmask; |
| inst->alg.base.cra_priority = alg->cra_priority; |
| inst->alg.base.cra_blocksize = alg->cra_blocksize; |
| |
| inst->alg.digestsize = alg->cra_blocksize; |
| inst->alg.descsize = ALIGN(sizeof(struct xcbc_desc_ctx), |
| crypto_tfm_ctx_alignment()) + |
| (alignmask & |
| ~(crypto_tfm_ctx_alignment() - 1)) + |
| alg->cra_blocksize * 2; |
| |
| inst->alg.base.cra_ctxsize = ALIGN(sizeof(struct xcbc_tfm_ctx), |
| alignmask + 1) + |
| alg->cra_blocksize * 2; |
| inst->alg.base.cra_init = xcbc_init_tfm; |
| inst->alg.base.cra_exit = xcbc_exit_tfm; |
| |
| inst->alg.init = crypto_xcbc_digest_init; |
| inst->alg.update = crypto_xcbc_digest_update; |
| inst->alg.final = crypto_xcbc_digest_final; |
| inst->alg.setkey = crypto_xcbc_digest_setkey; |
| |
| inst->free = shash_free_singlespawn_instance; |
| |
| err = shash_register_instance(tmpl, inst); |
| if (err) { |
| err_free_inst: |
| shash_free_singlespawn_instance(inst); |
| } |
| return err; |
| } |
| |
| static struct crypto_template crypto_xcbc_tmpl = { |
| .name = "xcbc", |
| .create = xcbc_create, |
| .module = THIS_MODULE, |
| }; |
| |
| static int __init crypto_xcbc_module_init(void) |
| { |
| return crypto_register_template(&crypto_xcbc_tmpl); |
| } |
| |
| static void __exit crypto_xcbc_module_exit(void) |
| { |
| crypto_unregister_template(&crypto_xcbc_tmpl); |
| } |
| |
| subsys_initcall(crypto_xcbc_module_init); |
| module_exit(crypto_xcbc_module_exit); |
| |
| MODULE_LICENSE("GPL"); |
| MODULE_DESCRIPTION("XCBC keyed hash algorithm"); |
| MODULE_ALIAS_CRYPTO("xcbc"); |