[CRYPTO] xcbc: New algorithm

This is core code of XCBC. XCBC is an algorithm that forms a MAC algorithm out of a cipher algorithm. For example, AES-XCBC-MAC is a MAC algorithm based on the AES cipher algorithm. Signed-off-by: Kazunori MIYAZAWA <miyazawa@linux-ipv6.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

[CRYPTO] xcbc: New algorithm
This is core code of XCBC. XCBC is an algorithm that forms a MAC algorithm out of a cipher algorithm. For example, AES-XCBC-MAC is a MAC algorithm based on the AES cipher algorithm. Signed-off-by: Kazunori MIYAZAWA <miyazawa@linux-ipv6.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Kazunori MIYAZAWA · David S. Miller
1 parent 45789328e5
Showing 3 changed files with 358 additions and 0 deletions Side-by-side Diff
crypto/Kconfig
crypto/Makefile
crypto/xcbc.c
@@ -39,6 +39,17 @@
 	  HMAC: Keyed-Hashing for Message Authentication (RFC2104).
 	  This is required for IPSec.
  
+config CRYPTO_XCBC
+	tristate "XCBC support"
+	depends on EXPERIMENTAL
+	select CRYPTO_HASH
+	select CRYPTO_MANAGER
+	help
+	  XCBC: Keyed-Hashing with encryption algorithm
+		http://www.ietf.org/rfc/rfc3566.txt
+		http://csrc.nist.gov/encryption/modes/proposedmodes/
+		 xcbc-mac/xcbc-mac-spec.pdf
+
 config CRYPTO_NULL
 	tristate "Null algorithms"
 	select CRYPTO_ALGAPI
@@ -15,6 +15,7 @@
  
 obj-$(CONFIG_CRYPTO_MANAGER) += cryptomgr.o
 obj-$(CONFIG_CRYPTO_HMAC) += hmac.o
+obj-$(CONFIG_CRYPTO_XCBC) += xcbc.o
 obj-$(CONFIG_CRYPTO_NULL) += crypto_null.o
 obj-$(CONFIG_CRYPTO_MD4) += md4.o
 obj-$(CONFIG_CRYPTO_MD5) += md5.o
+/*
+ * 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 <linux/crypto.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+#include <linux/scatterlist.h>
+#include "internal.h"
+
+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_tfm *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_hash *parent,
+				      struct crypto_xcbc_ctx *ctx)
+{
+	int bs = crypto_hash_blocksize(parent);
+	int err = 0;
+	u8 key1[bs];
+
+	if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
+	    return err;
+
+	ctx->child->__crt_alg->cra_cipher.cia_encrypt(ctx->child, key1,
+			ctx->consts);
+
+	return crypto_cipher_setkey(ctx->child, key1, bs);
+}
+
+static int crypto_xcbc_digest_setkey(struct crypto_hash *parent,
+				     const u8 *inkey, unsigned int keylen)
+{
+	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
+
+	if (keylen != crypto_tfm_alg_blocksize(ctx->child))
+		return -EINVAL;
+
+	ctx->keylen = keylen;
+	memcpy(ctx->key, inkey, keylen);
+	ctx->consts = (u8*)ks;
+
+	return _crypto_xcbc_digest_setkey(parent, ctx);
+}
+
+int crypto_xcbc_digest_init(struct hash_desc *pdesc)
+{
+	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(pdesc->tfm);
+	int bs = crypto_hash_blocksize(pdesc->tfm);
+
+	ctx->len = 0;
+	memset(ctx->odds, 0, bs);
+	memset(ctx->prev, 0, bs);
+
+	return 0;
+}
+
+int crypto_xcbc_digest_update(struct hash_desc *pdesc, struct scatterlist *sg, unsigned int nbytes)
+{
+	struct crypto_hash *parent = pdesc->tfm;
+	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
+	struct crypto_tfm *tfm = ctx->child;
+	int bs = crypto_hash_blocksize(parent);
+	unsigned int i = 0;
+
+	do {
+
+		struct page *pg = sg[i].page;
+		unsigned int offset = sg[i].offset;
+		unsigned int slen = sg[i].length;
+
+		while (slen > 0) {
+			unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
+			char *p = crypto_kmap(pg, 0) + offset;
+
+			/* checking the data can fill the block */
+			if ((ctx->len + len) <= bs) {
+				memcpy(ctx->odds + ctx->len, p, len);
+				ctx->len += len;
+				slen -= len;
+
+				/* checking the rest of the page */
+				if (len + offset >= PAGE_SIZE) {
+					offset = 0;
+					pg++;
+				} else
+					offset += len;
+
+				crypto_kunmap(p, 0);
+				crypto_yield(tfm->crt_flags);
+				continue;
+			}
+
+			/* 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);
+			tfm->__crt_alg->cra_cipher.cia_encrypt(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);
+				tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, ctx->prev, ctx->prev);
+				p += bs;
+				len -= bs;
+			}
+
+			/* keeping the surplus of blocksize */
+			if (len) {
+				memcpy(ctx->odds, p, len);
+				ctx->len = len;
+			}
+			crypto_kunmap(p, 0);
+			crypto_yield(tfm->crt_flags);
+			slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
+			offset = 0;
+			pg++;
+		}
+		nbytes-=sg[i].length;
+		i++;
+	} while (nbytes>0);
+
+	return 0;
+}
+
+int crypto_xcbc_digest_final(struct hash_desc *pdesc, u8 *out)
+{
+	struct crypto_hash *parent = pdesc->tfm;
+	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
+	struct crypto_tfm *tfm = ctx->child;
+	int bs = crypto_hash_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;
+
+		tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key2, (const u8*)(ctx->consts+bs));
+
+		ctx->xor(ctx->prev, ctx->odds, bs);
+		ctx->xor(ctx->prev, key2, bs);
+		_crypto_xcbc_digest_setkey(parent, ctx);
+
+		tfm->__crt_alg->cra_cipher.cia_encrypt(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;
+
+		tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key3, (const u8*)(ctx->consts+bs*2));
+
+		ctx->xor(ctx->prev, ctx->odds, bs);
+		ctx->xor(ctx->prev, key3, bs);
+
+		_crypto_xcbc_digest_setkey(parent, ctx);
+
+		tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, out, ctx->prev);
+	}
+
+	return 0;
+}
+
+static int crypto_xcbc_digest(struct hash_desc *pdesc,
+		  struct scatterlist *sg, unsigned int nbytes, u8 *out)
+{
+	crypto_xcbc_digest_init(pdesc);
+	crypto_xcbc_digest_update(pdesc, sg, nbytes);
+	return crypto_xcbc_digest_final(pdesc, out);
+}
+
+static int xcbc_init_tfm(struct crypto_tfm *tfm)
+{
+	struct crypto_instance *inst = (void *)tfm->__crt_alg;
+	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
+	struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
+	int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm));
+
+	tfm = crypto_spawn_tfm(spawn);
+	if (IS_ERR(tfm))
+		return PTR_ERR(tfm);
+
+	switch(bs) {
+	case 16:
+		ctx->xor = xor_128;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ctx->child = crypto_cipher_cast(tfm);
+	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_hash_ctx_aligned(__crypto_hash_cast(tfm));
+	crypto_free_cipher(ctx->child);
+}
+
+static struct crypto_instance *xcbc_alloc(void *param, unsigned int len)
+{
+	struct crypto_instance *inst;
+	struct crypto_alg *alg;
+	alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER,
+				  CRYPTO_ALG_TYPE_HASH_MASK | CRYPTO_ALG_ASYNC);
+	if (IS_ERR(alg))
+		return ERR_PTR(PTR_ERR(alg));
+
+	switch(alg->cra_blocksize) {
+	case 16:
+		break;
+	default:
+		return ERR_PTR(PTR_ERR(alg));
+	}
+
+	inst = crypto_alloc_instance("xcbc", alg);
+	if (IS_ERR(inst))
+		goto out_put_alg;
+
+	inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
+	inst->alg.cra_priority = alg->cra_priority;
+	inst->alg.cra_blocksize = alg->cra_blocksize;
+	inst->alg.cra_alignmask = alg->cra_alignmask;
+	inst->alg.cra_type = &crypto_hash_type;
+
+	inst->alg.cra_hash.digestsize =
+		(alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
+		CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize :
+				       alg->cra_blocksize;
+	inst->alg.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
+				ALIGN(inst->alg.cra_blocksize * 3, sizeof(void *));
+	inst->alg.cra_init = xcbc_init_tfm;
+	inst->alg.cra_exit = xcbc_exit_tfm;
+
+	inst->alg.cra_hash.init = crypto_xcbc_digest_init;
+	inst->alg.cra_hash.update = crypto_xcbc_digest_update;
+	inst->alg.cra_hash.final = crypto_xcbc_digest_final;
+	inst->alg.cra_hash.digest = crypto_xcbc_digest;
+	inst->alg.cra_hash.setkey = crypto_xcbc_digest_setkey;
+
+out_put_alg:
+	crypto_mod_put(alg);
+	return inst;
+}
+
+static void xcbc_free(struct crypto_instance *inst)
+{
+	crypto_drop_spawn(crypto_instance_ctx(inst));
+	kfree(inst);
+}
+
+static struct crypto_template crypto_xcbc_tmpl = {
+	.name = "xcbc",
+	.alloc = xcbc_alloc,
+	.free = xcbc_free,
+	.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");
...	...	@@ -39,6 +39,17 @@
39	39	HMAC: Keyed-Hashing for Message Authentication (RFC2104).
40	40	This is required for IPSec.
41	41
	42	+config CRYPTO_XCBC
	43	+ tristate "XCBC support"
	44	+ depends on EXPERIMENTAL
	45	+ select CRYPTO_HASH
	46	+ select CRYPTO_MANAGER
	47	+ help
	48	+ XCBC: Keyed-Hashing with encryption algorithm
	49	+ http://www.ietf.org/rfc/rfc3566.txt
	50	+ http://csrc.nist.gov/encryption/modes/proposedmodes/
	51	+ xcbc-mac/xcbc-mac-spec.pdf
	52	+
42	53	config CRYPTO_NULL
43	54	tristate "Null algorithms"
44	55	select CRYPTO_ALGAPI
...	...	@@ -15,6 +15,7 @@
15	15
16	16	obj-$(CONFIG_CRYPTO_MANAGER) += cryptomgr.o
17	17	obj-$(CONFIG_CRYPTO_HMAC) += hmac.o
	18	+obj-$(CONFIG_CRYPTO_XCBC) += xcbc.o
18	19	obj-$(CONFIG_CRYPTO_NULL) += crypto_null.o
19	20	obj-$(CONFIG_CRYPTO_MD4) += md4.o
20	21	obj-$(CONFIG_CRYPTO_MD5) += md5.o
	1	+/*
	2	+ * Copyright (C)2006 USAGI/WIDE Project
	3	+ *
	4	+ * This program is free software; you can redistribute it and/or modify
	5	+ * it under the terms of the GNU General Public License as published by
	6	+ * the Free Software Foundation; either version 2 of the License, or
	7	+ * (at your option) any later version.
	8	+ *
	9	+ * This program is distributed in the hope that it will be useful,
	10	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	+ * GNU General Public License for more details.
	13	+ *
	14	+ * You should have received a copy of the GNU General Public License
	15	+ * along with this program; if not, write to the Free Software
	16	+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	17	+ *
	18	+ * Author:
	19	+ * Kazunori Miyazawa <miyazawa@linux-ipv6.org>
	20	+ */
	21	+
	22	+#include <linux/crypto.h>
	23	+#include <linux/err.h>
	24	+#include <linux/kernel.h>
	25	+#include <linux/mm.h>
	26	+#include <linux/rtnetlink.h>
	27	+#include <linux/slab.h>
	28	+#include <linux/scatterlist.h>
	29	+#include "internal.h"
	30	+
	31	+u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
	32	+ 0x02020202, 0x02020202, 0x02020202, 0x02020202,
	33	+ 0x03030303, 0x03030303, 0x03030303, 0x03030303};
	34	+/*
	35	+ * +------------------------
	36	+ * \| <parent tfm>
	37	+ * +------------------------
	38	+ * \| crypto_xcbc_ctx
	39	+ * +------------------------
	40	+ * \| odds (block size)
	41	+ * +------------------------
	42	+ * \| prev (block size)
	43	+ * +------------------------
	44	+ * \| key (block size)
	45	+ * +------------------------
	46	+ * \| consts (block size * 3)
	47	+ * +------------------------
	48	+ */
	49	+struct crypto_xcbc_ctx {
	50	+ struct crypto_tfm *child;
	51	+ u8 *odds;
	52	+ u8 *prev;
	53	+ u8 *key;
	54	+ u8 *consts;
	55	+ void (xor)(u8 a, const u8 *b, unsigned int bs);
	56	+ unsigned int keylen;
	57	+ unsigned int len;
	58	+};
	59	+
	60	+static void xor_128(u8 a, const u8 b, unsigned int bs)
	61	+{
	62	+ ((u32 )a)[0] ^= ((u32 )b)[0];
	63	+ ((u32 )a)[1] ^= ((u32 )b)[1];
	64	+ ((u32 )a)[2] ^= ((u32 )b)[2];
	65	+ ((u32 )a)[3] ^= ((u32 )b)[3];
	66	+}
	67	+
	68	+static int _crypto_xcbc_digest_setkey(struct crypto_hash *parent,
	69	+ struct crypto_xcbc_ctx *ctx)
	70	+{
	71	+ int bs = crypto_hash_blocksize(parent);
	72	+ int err = 0;
	73	+ u8 key1[bs];
	74	+
	75	+ if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
	76	+ return err;
	77	+
	78	+ ctx->child->__crt_alg->cra_cipher.cia_encrypt(ctx->child, key1,
	79	+ ctx->consts);
	80	+
	81	+ return crypto_cipher_setkey(ctx->child, key1, bs);
	82	+}
	83	+
	84	+static int crypto_xcbc_digest_setkey(struct crypto_hash *parent,
	85	+ const u8 *inkey, unsigned int keylen)
	86	+{
	87	+ struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
	88	+
	89	+ if (keylen != crypto_tfm_alg_blocksize(ctx->child))
	90	+ return -EINVAL;
	91	+
	92	+ ctx->keylen = keylen;
	93	+ memcpy(ctx->key, inkey, keylen);
	94	+ ctx->consts = (u8*)ks;
	95	+
	96	+ return _crypto_xcbc_digest_setkey(parent, ctx);
	97	+}
	98	+
	99	+int crypto_xcbc_digest_init(struct hash_desc *pdesc)
	100	+{
	101	+ struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(pdesc->tfm);
	102	+ int bs = crypto_hash_blocksize(pdesc->tfm);
	103	+
	104	+ ctx->len = 0;
	105	+ memset(ctx->odds, 0, bs);
	106	+ memset(ctx->prev, 0, bs);
	107	+
	108	+ return 0;
	109	+}
	110	+
	111	+int crypto_xcbc_digest_update(struct hash_desc pdesc, struct scatterlist sg, unsigned int nbytes)
	112	+{
	113	+ struct crypto_hash *parent = pdesc->tfm;
	114	+ struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
	115	+ struct crypto_tfm *tfm = ctx->child;
	116	+ int bs = crypto_hash_blocksize(parent);
	117	+ unsigned int i = 0;
	118	+
	119	+ do {
	120	+
	121	+ struct page *pg = sg[i].page;
	122	+ unsigned int offset = sg[i].offset;
	123	+ unsigned int slen = sg[i].length;
	124	+
	125	+ while (slen > 0) {
	126	+ unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
	127	+ char *p = crypto_kmap(pg, 0) + offset;
	128	+
	129	+ /* checking the data can fill the block */
	130	+ if ((ctx->len + len) <= bs) {
	131	+ memcpy(ctx->odds + ctx->len, p, len);
	132	+ ctx->len += len;
	133	+ slen -= len;
	134	+
	135	+ /* checking the rest of the page */
	136	+ if (len + offset >= PAGE_SIZE) {
	137	+ offset = 0;
	138	+ pg++;
	139	+ } else
	140	+ offset += len;
	141	+
	142	+ crypto_kunmap(p, 0);
	143	+ crypto_yield(tfm->crt_flags);
	144	+ continue;
	145	+ }
	146	+
	147	+ /* filling odds with new data and encrypting it */
	148	+ memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
	149	+ len -= bs - ctx->len;
	150	+ p += bs - ctx->len;
	151	+
	152	+ ctx->xor(ctx->prev, ctx->odds, bs);
	153	+ tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, ctx->prev, ctx->prev);
	154	+
	155	+ /* clearing the length */
	156	+ ctx->len = 0;
	157	+
	158	+ /* encrypting the rest of data */
	159	+ while (len > bs) {
	160	+ ctx->xor(ctx->prev, p, bs);
	161	+ tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, ctx->prev, ctx->prev);
	162	+ p += bs;
	163	+ len -= bs;
	164	+ }
	165	+
	166	+ /* keeping the surplus of blocksize */
	167	+ if (len) {
	168	+ memcpy(ctx->odds, p, len);
	169	+ ctx->len = len;
	170	+ }
	171	+ crypto_kunmap(p, 0);
	172	+ crypto_yield(tfm->crt_flags);
	173	+ slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
	174	+ offset = 0;
	175	+ pg++;
	176	+ }
	177	+ nbytes-=sg[i].length;
	178	+ i++;
	179	+ } while (nbytes>0);
	180	+
	181	+ return 0;
	182	+}
	183	+
	184	+int crypto_xcbc_digest_final(struct hash_desc pdesc, u8 out)
	185	+{
	186	+ struct crypto_hash *parent = pdesc->tfm;
	187	+ struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
	188	+ struct crypto_tfm *tfm = ctx->child;
	189	+ int bs = crypto_hash_blocksize(parent);
	190	+ int err = 0;
	191	+
	192	+ if (ctx->len == bs) {
	193	+ u8 key2[bs];
	194	+
	195	+ if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	196	+ return err;
	197	+
	198	+ tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key2, (const u8*)(ctx->consts+bs));
	199	+
	200	+ ctx->xor(ctx->prev, ctx->odds, bs);
	201	+ ctx->xor(ctx->prev, key2, bs);
	202	+ _crypto_xcbc_digest_setkey(parent, ctx);
	203	+
	204	+ tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, out, ctx->prev);
	205	+ } else {
	206	+ u8 key3[bs];
	207	+ unsigned int rlen;
	208	+ u8 *p = ctx->odds + ctx->len;
	209	+ *p = 0x80;
	210	+ p++;
	211	+
	212	+ rlen = bs - ctx->len -1;
	213	+ if (rlen)
	214	+ memset(p, 0, rlen);
	215	+
	216	+ if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
	217	+ return err;
	218	+
	219	+ tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key3, (const u8)(ctx->consts+bs2));
	220	+
	221	+ ctx->xor(ctx->prev, ctx->odds, bs);
	222	+ ctx->xor(ctx->prev, key3, bs);
	223	+
	224	+ _crypto_xcbc_digest_setkey(parent, ctx);
	225	+
	226	+ tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, out, ctx->prev);
	227	+ }
	228	+
	229	+ return 0;
	230	+}
	231	+
	232	+static int crypto_xcbc_digest(struct hash_desc *pdesc,
	233	+ struct scatterlist sg, unsigned int nbytes, u8 out)
	234	+{
	235	+ crypto_xcbc_digest_init(pdesc);
	236	+ crypto_xcbc_digest_update(pdesc, sg, nbytes);
	237	+ return crypto_xcbc_digest_final(pdesc, out);
	238	+}
	239	+
	240	+static int xcbc_init_tfm(struct crypto_tfm *tfm)
	241	+{
	242	+ struct crypto_instance inst = (void )tfm->__crt_alg;
	243	+ struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	244	+ struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
	245	+ int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm));
	246	+
	247	+ tfm = crypto_spawn_tfm(spawn);
	248	+ if (IS_ERR(tfm))
	249	+ return PTR_ERR(tfm);
	250	+
	251	+ switch(bs) {
	252	+ case 16:
	253	+ ctx->xor = xor_128;
	254	+ break;
	255	+ default:
	256	+ return -EINVAL;
	257	+ }
	258	+
	259	+ ctx->child = crypto_cipher_cast(tfm);
	260	+ ctx->odds = (u8*)(ctx+1);
	261	+ ctx->prev = ctx->odds + bs;
	262	+ ctx->key = ctx->prev + bs;
	263	+
	264	+ return 0;
	265	+};
	266	+
	267	+static void xcbc_exit_tfm(struct crypto_tfm *tfm)
	268	+{
	269	+ struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
	270	+ crypto_free_cipher(ctx->child);
	271	+}
	272	+
	273	+static struct crypto_instance xcbc_alloc(void param, unsigned int len)
	274	+{
	275	+ struct crypto_instance *inst;
	276	+ struct crypto_alg *alg;
	277	+ alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER,
	278	+ CRYPTO_ALG_TYPE_HASH_MASK \| CRYPTO_ALG_ASYNC);
	279	+ if (IS_ERR(alg))
	280	+ return ERR_PTR(PTR_ERR(alg));
	281	+
	282	+ switch(alg->cra_blocksize) {
	283	+ case 16:
	284	+ break;
	285	+ default:
	286	+ return ERR_PTR(PTR_ERR(alg));
	287	+ }
	288	+
	289	+ inst = crypto_alloc_instance("xcbc", alg);
	290	+ if (IS_ERR(inst))
	291	+ goto out_put_alg;
	292	+
	293	+ inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
	294	+ inst->alg.cra_priority = alg->cra_priority;
	295	+ inst->alg.cra_blocksize = alg->cra_blocksize;
	296	+ inst->alg.cra_alignmask = alg->cra_alignmask;
	297	+ inst->alg.cra_type = &crypto_hash_type;
	298	+
	299	+ inst->alg.cra_hash.digestsize =
	300	+ (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	301	+ CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize :
	302	+ alg->cra_blocksize;
	303	+ inst->alg.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
	304	+ ALIGN(inst->alg.cra_blocksize * 3, sizeof(void *));
	305	+ inst->alg.cra_init = xcbc_init_tfm;
	306	+ inst->alg.cra_exit = xcbc_exit_tfm;
	307	+
	308	+ inst->alg.cra_hash.init = crypto_xcbc_digest_init;
	309	+ inst->alg.cra_hash.update = crypto_xcbc_digest_update;
	310	+ inst->alg.cra_hash.final = crypto_xcbc_digest_final;
	311	+ inst->alg.cra_hash.digest = crypto_xcbc_digest;
	312	+ inst->alg.cra_hash.setkey = crypto_xcbc_digest_setkey;
	313	+
	314	+out_put_alg:
	315	+ crypto_mod_put(alg);
	316	+ return inst;
	317	+}
	318	+
	319	+static void xcbc_free(struct crypto_instance *inst)
	320	+{
	321	+ crypto_drop_spawn(crypto_instance_ctx(inst));
	322	+ kfree(inst);
	323	+}
	324	+
	325	+static struct crypto_template crypto_xcbc_tmpl = {
	326	+ .name = "xcbc",
	327	+ .alloc = xcbc_alloc,
	328	+ .free = xcbc_free,
	329	+ .module = THIS_MODULE,
	330	+};
	331	+
	332	+static int __init crypto_xcbc_module_init(void)
	333	+{
	334	+ return crypto_register_template(&crypto_xcbc_tmpl);
	335	+}
	336	+
	337	+static void __exit crypto_xcbc_module_exit(void)
	338	+{
	339	+ crypto_unregister_template(&crypto_xcbc_tmpl);
	340	+}
	341	+
	342	+module_init(crypto_xcbc_module_init);
	343	+module_exit(crypto_xcbc_module_exit);
	344	+
	345	+MODULE_LICENSE("GPL");
	346	+MODULE_DESCRIPTION("XCBC keyed hash algorithm");