crypto/xcbc.c - linux - Git at Google

 /*
  * 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, see <http://www.gnu.org/licenses/>.
  *
  * 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_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 XCBC_BLOCKSIZE:
 		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");
 MODULE_ALIAS_CRYPTO("xcbc");
	/*
	* 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, see <http://www.gnu.org/licenses/>.
	*
	* 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_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 XCBC_BLOCKSIZE:
	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");
	MODULE_ALIAS_CRYPTO("xcbc");