/* * Copyright (C)2006 USAGI/WIDE Project * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA * * 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[];}; 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);	int bs = crypto_shash_blocksize(parent);	u8 *consts = PTR_ALIGN(&ctx->ctx[0], alignmask + 1);	int err = 0;	u8 key1[bs]; 	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_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_alg *alg;	unsigned long alignmask;	int err; 	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);	if (err)		return err; 	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,				  CRYPTO_ALG_TYPE_MASK);	if (IS_ERR(alg))		return PTR_ERR(alg); 	switch(alg->cra_blocksize) {	case 16:		break;	default:		goto out_put_alg;	} 	inst = shash_alloc_instance("xcbc", alg);	err = PTR_ERR(inst);	if (IS_ERR(inst))		goto out_put_alg; 	err = crypto_init_spawn(shash_instance_ctx(inst), alg,				shash_crypto_instance(inst),				CRYPTO_ALG_TYPE_MASK);	if (err)		goto out_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; 	err = shash_register_instance(tmpl, inst);	if (err) {out_free_inst:		shash_free_instance(shash_crypto_instance(inst));	} out_put_alg:	crypto_mod_put(alg);	return err;} static struct crypto_template crypto_xcbc_tmpl = {	.name = "xcbc",	.create = xcbc_create,	.free = shash_free_instance,	.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);} module_init(crypto_xcbc_module_init);module_exit(crypto_xcbc_module_exit); MODULE_LICENSE("GPL");MODULE_DESCRIPTION("XCBC keyed hash algorithm");