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, 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>

 static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
 			   0x02020202, 0x02020202, 0x02020202, 0x02020202,
 			   0x03030303, 0x03030303, 0x03030303, 0x03030303};
 /*
  * +------------------------
  * | <parent tfm>
  * +------------------------
  * | crypto_xcbc_ctx
  * +------------------------
  * | odds (block size)
  * +------------------------
  * | prev (block size)
  * +------------------------
  * | key (block size)
  * +------------------------
  * | consts (block size * 3)
  * +------------------------
  */
 struct crypto_xcbc_ctx {
 	struct crypto_cipher *child;
 	u8 *odds;
 	u8 *prev;
 	u8 *key;
 	u8 *consts;
 	void (*xor)(u8 *a, const u8 *b, unsigned int bs);
 	unsigned int keylen;
 	unsigned int len;
 };

 static void xor_128(u8 *a, const u8 *b, unsigned int bs)
 {
 	((u32 *)a)[0] ^= ((u32 *)b)[0];
 	((u32 *)a)[1] ^= ((u32 *)b)[1];
 	((u32 *)a)[2] ^= ((u32 *)b)[2];
 	((u32 *)a)[3] ^= ((u32 *)b)[3];
 }

 static int _crypto_xcbc_digest_setkey(struct crypto_shash *parent,
 				      struct crypto_xcbc_ctx *ctx)
 {
 	int bs = crypto_shash_blocksize(parent);
 	int err = 0;
 	u8 key1[bs];

 	if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
 	    return err;

 	crypto_cipher_encrypt_one(ctx->child, key1, ctx->consts);

 	return crypto_cipher_setkey(ctx->child, key1, bs);
 }

 static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
 				     const u8 *inkey, unsigned int keylen)
 {
 	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);

 	if (keylen != crypto_cipher_blocksize(ctx->child))
 		return -EINVAL;

 	ctx->keylen = keylen;
 	memcpy(ctx->key, inkey, keylen);
 	ctx->consts = (u8*)ks;

 	return _crypto_xcbc_digest_setkey(parent, ctx);
 }

 static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
 {
 	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(pdesc->tfm);
 	int bs = crypto_shash_blocksize(pdesc->tfm);

 	ctx->len = 0;
 	memset(ctx->odds, 0, bs);
 	memset(ctx->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;
 	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
 	struct crypto_cipher *tfm = ctx->child;
 	int bs = crypto_shash_blocksize(parent);

 	/* checking the data can fill the block */
 	if ((ctx->len + len) <= bs) {
 		memcpy(ctx->odds + ctx->len, p, len);
 		ctx->len += len;
 		return 0;
 	}

 	/* filling odds with new data and encrypting it */
 	memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
 	len -= bs - ctx->len;
 	p += bs - ctx->len;

 	ctx->xor(ctx->prev, ctx->odds, bs);
 	crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);

 	/* clearing the length */
 	ctx->len = 0;

 	/* encrypting the rest of data */
 	while (len > bs) {
 		ctx->xor(ctx->prev, p, bs);
 		crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
 		p += bs;
 		len -= bs;
 	}

 	/* keeping the surplus of blocksize */
 	if (len) {
 		memcpy(ctx->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;
 	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
 	struct crypto_cipher *tfm = ctx->child;
 	int bs = crypto_shash_blocksize(parent);
 	int err = 0;

 	if (ctx->len == bs) {
 		u8 key2[bs];

 		if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
 			return err;

 		crypto_cipher_encrypt_one(tfm, key2,
 					  (u8 *)(ctx->consts + bs));

 		ctx->xor(ctx->prev, ctx->odds, bs);
 		ctx->xor(ctx->prev, key2, bs);
 		_crypto_xcbc_digest_setkey(parent, ctx);

 		crypto_cipher_encrypt_one(tfm, out, ctx->prev);
 	} else {
 		u8 key3[bs];
 		unsigned int rlen;
 		u8 *p = ctx->odds + ctx->len;
 		*p = 0x80;
 		p++;

 		rlen = bs - ctx->len -1;
 		if (rlen)
 			memset(p, 0, rlen);

 		if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
 			return err;

 		crypto_cipher_encrypt_one(tfm, key3,
 					  (u8 *)(ctx->consts + bs * 2));

 		ctx->xor(ctx->prev, ctx->odds, bs);
 		ctx->xor(ctx->prev, key3, bs);

 		_crypto_xcbc_digest_setkey(parent, ctx);

 		crypto_cipher_encrypt_one(tfm, out, ctx->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 crypto_xcbc_ctx *ctx = crypto_tfm_ctx(tfm);
 	int bs = crypto_tfm_alg_blocksize(tfm);

 	cipher = crypto_spawn_cipher(spawn);
 	if (IS_ERR(cipher))
 		return PTR_ERR(cipher);

 	switch(bs) {
 	case 16:
 		ctx->xor = xor_128;
 		break;
 	default:
 		return -EINVAL;
 	}

 	ctx->child = cipher;
 	ctx->odds = (u8*)(ctx+1);
 	ctx->prev = ctx->odds + bs;
 	ctx->key = ctx->prev + bs;

 	return 0;
 };

 static void xcbc_exit_tfm(struct crypto_tfm *tfm)
 {
 	struct crypto_xcbc_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;
 	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);
 	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;

 	inst->alg.base.cra_priority = alg->cra_priority;
 	inst->alg.base.cra_blocksize = alg->cra_blocksize;
 	inst->alg.base.cra_alignmask = alg->cra_alignmask;

 	inst->alg.digestsize = alg->cra_blocksize;
 	inst->alg.base.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
 				     ALIGN(alg->cra_blocksize * 3,
 					   sizeof(void *));
 	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");
	/*
	* 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>

	static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
	0x02020202, 0x02020202, 0x02020202, 0x02020202,
	0x03030303, 0x03030303, 0x03030303, 0x03030303};
	/*
	* +------------------------
	* \| <parent tfm>
	* +------------------------
	* \| crypto_xcbc_ctx
	* +------------------------
	* \| odds (block size)
	* +------------------------
	* \| prev (block size)
	* +------------------------
	* \| key (block size)
	* +------------------------
	* \| consts (block size * 3)
	* +------------------------
	*/
	struct crypto_xcbc_ctx {
	struct crypto_cipher *child;
	u8 *odds;
	u8 *prev;
	u8 *key;
	u8 *consts;
	void (xor)(u8 a, const u8 *b, unsigned int bs);
	unsigned int keylen;
	unsigned int len;
	};

	static void xor_128(u8 a, const u8 b, unsigned int bs)
	{
	((u32 )a)[0] ^= ((u32 )b)[0];
	((u32 )a)[1] ^= ((u32 )b)[1];
	((u32 )a)[2] ^= ((u32 )b)[2];
	((u32 )a)[3] ^= ((u32 )b)[3];
	}

	static int _crypto_xcbc_digest_setkey(struct crypto_shash *parent,
	struct crypto_xcbc_ctx *ctx)
	{
	int bs = crypto_shash_blocksize(parent);
	int err = 0;
	u8 key1[bs];

	if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
	return err;

	crypto_cipher_encrypt_one(ctx->child, key1, ctx->consts);

	return crypto_cipher_setkey(ctx->child, key1, bs);
	}

	static int crypto_xcbc_digest_setkey(struct crypto_shash *parent,
	const u8 *inkey, unsigned int keylen)
	{
	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);

	if (keylen != crypto_cipher_blocksize(ctx->child))
	return -EINVAL;

	ctx->keylen = keylen;
	memcpy(ctx->key, inkey, keylen);
	ctx->consts = (u8*)ks;

	return _crypto_xcbc_digest_setkey(parent, ctx);
	}

	static int crypto_xcbc_digest_init(struct shash_desc *pdesc)
	{
	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(pdesc->tfm);
	int bs = crypto_shash_blocksize(pdesc->tfm);

	ctx->len = 0;
	memset(ctx->odds, 0, bs);
	memset(ctx->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;
	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
	struct crypto_cipher *tfm = ctx->child;
	int bs = crypto_shash_blocksize(parent);

	/* checking the data can fill the block */
	if ((ctx->len + len) <= bs) {
	memcpy(ctx->odds + ctx->len, p, len);
	ctx->len += len;
	return 0;
	}

	/* filling odds with new data and encrypting it */
	memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
	len -= bs - ctx->len;
	p += bs - ctx->len;

	ctx->xor(ctx->prev, ctx->odds, bs);
	crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);

	/* clearing the length */
	ctx->len = 0;

	/* encrypting the rest of data */
	while (len > bs) {
	ctx->xor(ctx->prev, p, bs);
	crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
	p += bs;
	len -= bs;
	}

	/* keeping the surplus of blocksize */
	if (len) {
	memcpy(ctx->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;
	struct crypto_xcbc_ctx *ctx = crypto_shash_ctx(parent);
	struct crypto_cipher *tfm = ctx->child;
	int bs = crypto_shash_blocksize(parent);
	int err = 0;

	if (ctx->len == bs) {
	u8 key2[bs];

	if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	return err;

	crypto_cipher_encrypt_one(tfm, key2,
	(u8 *)(ctx->consts + bs));

	ctx->xor(ctx->prev, ctx->odds, bs);
	ctx->xor(ctx->prev, key2, bs);
	_crypto_xcbc_digest_setkey(parent, ctx);

	crypto_cipher_encrypt_one(tfm, out, ctx->prev);
	} else {
	u8 key3[bs];
	unsigned int rlen;
	u8 *p = ctx->odds + ctx->len;
	*p = 0x80;
	p++;

	rlen = bs - ctx->len -1;
	if (rlen)
	memset(p, 0, rlen);

	if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	return err;

	crypto_cipher_encrypt_one(tfm, key3,
	(u8 )(ctx->consts + bs 2));

	ctx->xor(ctx->prev, ctx->odds, bs);
	ctx->xor(ctx->prev, key3, bs);

	_crypto_xcbc_digest_setkey(parent, ctx);

	crypto_cipher_encrypt_one(tfm, out, ctx->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 crypto_xcbc_ctx *ctx = crypto_tfm_ctx(tfm);
	int bs = crypto_tfm_alg_blocksize(tfm);

	cipher = crypto_spawn_cipher(spawn);
	if (IS_ERR(cipher))
	return PTR_ERR(cipher);

	switch(bs) {
	case 16:
	ctx->xor = xor_128;
	break;
	default:
	return -EINVAL;
	}

	ctx->child = cipher;
	ctx->odds = (u8*)(ctx+1);
	ctx->prev = ctx->odds + bs;
	ctx->key = ctx->prev + bs;

	return 0;
	};

	static void xcbc_exit_tfm(struct crypto_tfm *tfm)
	{
	struct crypto_xcbc_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;
	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);
	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;

	inst->alg.base.cra_priority = alg->cra_priority;
	inst->alg.base.cra_blocksize = alg->cra_blocksize;
	inst->alg.base.cra_alignmask = alg->cra_alignmask;

	inst->alg.digestsize = alg->cra_blocksize;
	inst->alg.base.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
	ALIGN(alg->cra_blocksize * 3,
	sizeof(void *));
	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");