[GitHub/moto-9609/android_kernel_motorola_exynos9610.git] / net / sunrpc / auth_gss / gss_krb5_crypto.c

/*
 *  linux/net/sunrpc/gss_krb5_crypto.c
 *
 *  Copyright (c) 2000 The Regents of the University of Michigan.
 *  All rights reserved.
 *
 *  Andy Adamson   <andros@umich.edu>
 *  Bruce Fields   <bfields@umich.edu>
 */

/*
 * Copyright (C) 1998 by the FundsXpress, INC.
 *
 * All rights reserved.
 *
 * Export of this software from the United States of America may require
 * a specific license from the United States Government.  It is the
 * responsibility of any person or organization contemplating export to
 * obtain such a license before exporting.
 *
 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
 * distribute this software and its documentation for any purpose and
 * without fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright notice and
 * this permission notice appear in supporting documentation, and that
 * the name of FundsXpress. not be used in advertising or publicity pertaining
 * to distribution of the software without specific, written prior
 * permission.  FundsXpress makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is" without express
 * or implied warranty.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

#include <linux/err.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/scatterlist.h>
#include <linux/crypto.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/sunrpc/gss_krb5.h>

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY        RPCDBG_AUTH
#endif

u32
krb5_encrypt(
	struct crypto_blkcipher *tfm,
	void * iv,
	void * in,
	void * out,
	int length)
{
	u32 ret = -EINVAL;
        struct scatterlist sg[1];
	u8 local_iv[16] = {0};
	struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };

	dprintk("RPC:      krb5_encrypt: input data:\n");
	print_hexl((u32 *)in, length, 0);

	if (length % crypto_blkcipher_blocksize(tfm) != 0)
		goto out;

	if (crypto_blkcipher_ivsize(tfm) > 16) {
		dprintk("RPC:      gss_k5encrypt: tfm iv size to large %d\n",
		         crypto_blkcipher_ivsize(tfm));
		goto out;
	}

	if (iv)
		memcpy(local_iv, iv, crypto_blkcipher_ivsize(tfm));

	memcpy(out, in, length);
	sg_set_buf(sg, out, length);

	ret = crypto_blkcipher_encrypt_iv(&desc, sg, sg, length);

	dprintk("RPC:      krb5_encrypt: output data:\n");
	print_hexl((u32 *)out, length, 0);
out:
	dprintk("RPC:      krb5_encrypt returns %d\n",ret);
	return(ret);
}

EXPORT_SYMBOL(krb5_encrypt);

u32
krb5_decrypt(
     struct crypto_blkcipher *tfm,
     void * iv,
     void * in,
     void * out,
     int length)
{
	u32 ret = -EINVAL;
	struct scatterlist sg[1];
	u8 local_iv[16] = {0};
	struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };

	dprintk("RPC:      krb5_decrypt: input data:\n");
	print_hexl((u32 *)in, length, 0);

	if (length % crypto_blkcipher_blocksize(tfm) != 0)
		goto out;

	if (crypto_blkcipher_ivsize(tfm) > 16) {
		dprintk("RPC:      gss_k5decrypt: tfm iv size to large %d\n",
			crypto_blkcipher_ivsize(tfm));
		goto out;
	}
	if (iv)
		memcpy(local_iv,iv, crypto_blkcipher_ivsize(tfm));

	memcpy(out, in, length);
	sg_set_buf(sg, out, length);

	ret = crypto_blkcipher_decrypt_iv(&desc, sg, sg, length);

	dprintk("RPC:      krb5_decrypt: output_data:\n");
	print_hexl((u32 *)out, length, 0);
out:
	dprintk("RPC:      gss_k5decrypt returns %d\n",ret);
	return(ret);
}

EXPORT_SYMBOL(krb5_decrypt);

static int
process_xdr_buf(struct xdr_buf *buf, int offset, int len,
		int (*actor)(struct scatterlist *, void *), void *data)
{
	int i, page_len, thislen, page_offset, ret = 0;
	struct scatterlist	sg[1];

	if (offset >= buf->head[0].iov_len) {
		offset -= buf->head[0].iov_len;
	} else {
		thislen = buf->head[0].iov_len - offset;
		if (thislen > len)
			thislen = len;
		sg_set_buf(sg, buf->head[0].iov_base + offset, thislen);
		ret = actor(sg, data);
		if (ret)
			goto out;
		offset = 0;
		len -= thislen;
	}
	if (len == 0)
		goto out;

	if (offset >= buf->page_len) {
		offset -= buf->page_len;
	} else {
		page_len = buf->page_len - offset;
		if (page_len > len)
			page_len = len;
		len -= page_len;
		page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1);
		i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT;
		thislen = PAGE_CACHE_SIZE - page_offset;
		do {
			if (thislen > page_len)
				thislen = page_len;
			sg->page = buf->pages[i];
			sg->offset = page_offset;
			sg->length = thislen;
			ret = actor(sg, data);
			if (ret)
				goto out;
			page_len -= thislen;
			i++;
			page_offset = 0;
			thislen = PAGE_CACHE_SIZE;
		} while (page_len != 0);
		offset = 0;
	}
	if (len == 0)
		goto out;

	if (offset < buf->tail[0].iov_len) {
		thislen = buf->tail[0].iov_len - offset;
		if (thislen > len)
			thislen = len;
		sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen);
		ret = actor(sg, data);
		len -= thislen;
	}
	if (len != 0)
		ret = -EINVAL;
out:
	return ret;
}

static int
checksummer(struct scatterlist *sg, void *data)
{
	struct hash_desc *desc = data;

	return crypto_hash_update(desc, sg, sg->length);
}

/* checksum the plaintext data and hdrlen bytes of the token header */
s32
make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
		   int body_offset, struct xdr_netobj *cksum)
{
	char                            *cksumname;
	struct hash_desc                desc; /* XXX add to ctx? */
	struct scatterlist              sg[1];
	int err;

	switch (cksumtype) {
		case CKSUMTYPE_RSA_MD5:
			cksumname = "md5";
			break;
		default:
			dprintk("RPC:      krb5_make_checksum:"
				" unsupported checksum %d", cksumtype);
			return GSS_S_FAILURE;
	}
	desc.tfm = crypto_alloc_hash(cksumname, 0, CRYPTO_ALG_ASYNC);
	if (IS_ERR(desc.tfm))
		return GSS_S_FAILURE;
	cksum->len = crypto_hash_digestsize(desc.tfm);
	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;

	err = crypto_hash_init(&desc);
	if (err)
		goto out;
	sg_set_buf(sg, header, hdrlen);
	err = crypto_hash_update(&desc, sg, hdrlen);
	if (err)
		goto out;
	err = process_xdr_buf(body, body_offset, body->len - body_offset,
			      checksummer, &desc);
	if (err)
		goto out;
	err = crypto_hash_final(&desc, cksum->data);

out:
	crypto_free_hash(desc.tfm);
	return err ? GSS_S_FAILURE : 0;
}

EXPORT_SYMBOL(make_checksum);

struct encryptor_desc {
	u8 iv[8]; /* XXX hard-coded blocksize */
	struct blkcipher_desc desc;
	int pos;
	struct xdr_buf *outbuf;
	struct page **pages;
	struct scatterlist infrags[4];
	struct scatterlist outfrags[4];
	int fragno;
	int fraglen;
};

static int
encryptor(struct scatterlist *sg, void *data)
{
	struct encryptor_desc *desc = data;
	struct xdr_buf *outbuf = desc->outbuf;
	struct page *in_page;
	int thislen = desc->fraglen + sg->length;
	int fraglen, ret;
	int page_pos;

	/* Worst case is 4 fragments: head, end of page 1, start
	 * of page 2, tail.  Anything more is a bug. */
	BUG_ON(desc->fragno > 3);
	desc->infrags[desc->fragno] = *sg;
	desc->outfrags[desc->fragno] = *sg;

	page_pos = desc->pos - outbuf->head[0].iov_len;
	if (page_pos >= 0 && page_pos < outbuf->page_len) {
		/* pages are not in place: */
		int i = (page_pos + outbuf->page_base) >> PAGE_CACHE_SHIFT;
		in_page = desc->pages[i];
	} else {
		in_page = sg->page;
	}
	desc->infrags[desc->fragno].page = in_page;
	desc->fragno++;
	desc->fraglen += sg->length;
	desc->pos += sg->length;

	fraglen = thislen & 7; /* XXX hardcoded blocksize */
	thislen -= fraglen;

	if (thislen == 0)
		return 0;

	ret = crypto_blkcipher_encrypt_iv(&desc->desc, desc->outfrags,
					  desc->infrags, thislen);
	if (ret)
		return ret;
	if (fraglen) {
		desc->outfrags[0].page = sg->page;
		desc->outfrags[0].offset = sg->offset + sg->length - fraglen;
		desc->outfrags[0].length = fraglen;
		desc->infrags[0] = desc->outfrags[0];
		desc->infrags[0].page = in_page;
		desc->fragno = 1;
		desc->fraglen = fraglen;
	} else {
		desc->fragno = 0;
		desc->fraglen = 0;
	}
	return 0;
}

int
gss_encrypt_xdr_buf(struct crypto_blkcipher *tfm, struct xdr_buf *buf,
		    int offset, struct page **pages)
{
	int ret;
	struct encryptor_desc desc;

	BUG_ON((buf->len - offset) % crypto_blkcipher_blocksize(tfm) != 0);

	memset(desc.iv, 0, sizeof(desc.iv));
	desc.desc.tfm = tfm;
	desc.desc.info = desc.iv;
	desc.desc.flags = 0;
	desc.pos = offset;
	desc.outbuf = buf;
	desc.pages = pages;
	desc.fragno = 0;
	desc.fraglen = 0;

	ret = process_xdr_buf(buf, offset, buf->len - offset, encryptor, &desc);
	return ret;
}

EXPORT_SYMBOL(gss_encrypt_xdr_buf);

struct decryptor_desc {
	u8 iv[8]; /* XXX hard-coded blocksize */
	struct blkcipher_desc desc;
	struct scatterlist frags[4];
	int fragno;
	int fraglen;
};

static int
decryptor(struct scatterlist *sg, void *data)
{
	struct decryptor_desc *desc = data;
	int thislen = desc->fraglen + sg->length;
	int fraglen, ret;

	/* Worst case is 4 fragments: head, end of page 1, start
	 * of page 2, tail.  Anything more is a bug. */
	BUG_ON(desc->fragno > 3);
	desc->frags[desc->fragno] = *sg;
	desc->fragno++;
	desc->fraglen += sg->length;

	fraglen = thislen & 7; /* XXX hardcoded blocksize */
	thislen -= fraglen;

	if (thislen == 0)
		return 0;

	ret = crypto_blkcipher_decrypt_iv(&desc->desc, desc->frags,
					  desc->frags, thislen);
	if (ret)
		return ret;
	if (fraglen) {
		desc->frags[0].page = sg->page;
		desc->frags[0].offset = sg->offset + sg->length - fraglen;
		desc->frags[0].length = fraglen;
		desc->fragno = 1;
		desc->fraglen = fraglen;
	} else {
		desc->fragno = 0;
		desc->fraglen = 0;
	}
	return 0;
}

int
gss_decrypt_xdr_buf(struct crypto_blkcipher *tfm, struct xdr_buf *buf,
		    int offset)
{
	struct decryptor_desc desc;

	/* XXXJBF: */
	BUG_ON((buf->len - offset) % crypto_blkcipher_blocksize(tfm) != 0);

	memset(desc.iv, 0, sizeof(desc.iv));
	desc.desc.tfm = tfm;
	desc.desc.info = desc.iv;
	desc.desc.flags = 0;
	desc.fragno = 0;
	desc.fraglen = 0;
	return process_xdr_buf(buf, offset, buf->len - offset, decryptor, &desc);
}

EXPORT_SYMBOL(gss_decrypt_xdr_buf);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/net/sunrpc/gss_krb5_crypto.c
	3	*
	4	* Copyright (c) 2000 The Regents of the University of Michigan.
	5	* All rights reserved.
	6	*
	7	* Andy Adamson <andros@umich.edu>
	8	* Bruce Fields <bfields@umich.edu>
	9	*/
	10
	11	/*
	12	* Copyright (C) 1998 by the FundsXpress, INC.
	13	*
	14	* All rights reserved.
	15	*
	16	* Export of this software from the United States of America may require
	17	* a specific license from the United States Government. It is the
	18	* responsibility of any person or organization contemplating export to
	19	* obtain such a license before exporting.
	20	*
	21	* WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
	22	* distribute this software and its documentation for any purpose and
	23	* without fee is hereby granted, provided that the above copyright
	24	* notice appear in all copies and that both that copyright notice and
	25	* this permission notice appear in supporting documentation, and that
	26	* the name of FundsXpress. not be used in advertising or publicity pertaining
	27	* to distribution of the software without specific, written prior
	28	* permission. FundsXpress makes no representations about the suitability of
	29	* this software for any purpose. It is provided "as is" without express
	30	* or implied warranty.
	31	*
	32	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
	33	* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
	34	* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
	35	*/
	36
35058687	37	#include <linux/err.h>
1da177e4 LT	38	#include <linux/types.h>
	39	#include <linux/mm.h>
	40	#include <linux/slab.h>
378f058c	41	#include <linux/scatterlist.h>
1da177e4 LT	42	#include <linux/crypto.h>
	43	#include <linux/highmem.h>
	44	#include <linux/pagemap.h>
	45	#include <linux/sunrpc/gss_krb5.h>
	46
	47	#ifdef RPC_DEBUG
	48	# define RPCDBG_FACILITY RPCDBG_AUTH
	49	#endif
	50
	51	u32
	52	krb5_encrypt(
378c6697	53	struct crypto_blkcipher *tfm,
1da177e4 LT	54	void * iv,
	55	void * in,
	56	void * out,
	57	int length)
	58	{
	59	u32 ret = -EINVAL;
	60	struct scatterlist sg[1];
	61	u8 local_iv[16] = {0};
378c6697	62	struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };
1da177e4 LT	63
	64	dprintk("RPC: krb5_encrypt: input data:\n");
	65	print_hexl((u32 *)in, length, 0);
	66
378c6697	67	if (length % crypto_blkcipher_blocksize(tfm) != 0)
1da177e4 LT	68	goto out;
1da177e4 LT	69
378c6697	70	if (crypto_blkcipher_ivsize(tfm) > 16) {
1da177e4	71	dprintk("RPC: gss_k5encrypt: tfm iv size to large %d\n",
378c6697	72	crypto_blkcipher_ivsize(tfm));
1da177e4 LT	73	goto out;
	74	}
	75
	76	if (iv)
378c6697	77	memcpy(local_iv, iv, crypto_blkcipher_ivsize(tfm));
1da177e4 LT	78
1da177e4 LT	79	memcpy(out, in, length);
6df5b9f4	80	sg_set_buf(sg, out, length);
1da177e4	81
378c6697	82	ret = crypto_blkcipher_encrypt_iv(&desc, sg, sg, length);
1da177e4 LT	83
	84	dprintk("RPC: krb5_encrypt: output data:\n");
	85	print_hexl((u32 *)out, length, 0);
	86	out:
	87	dprintk("RPC: krb5_encrypt returns %d\n",ret);
	88	return(ret);
	89	}
	90
	91	EXPORT_SYMBOL(krb5_encrypt);
	92
	93	u32
	94	krb5_decrypt(
378c6697	95	struct crypto_blkcipher *tfm,
1da177e4 LT	96	void * iv,
	97	void * in,
	98	void * out,
	99	int length)
	100	{
	101	u32 ret = -EINVAL;
	102	struct scatterlist sg[1];
	103	u8 local_iv[16] = {0};
378c6697	104	struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };
1da177e4 LT	105
	106	dprintk("RPC: krb5_decrypt: input data:\n");
	107	print_hexl((u32 *)in, length, 0);
	108
378c6697	109	if (length % crypto_blkcipher_blocksize(tfm) != 0)
1da177e4 LT	110	goto out;
1da177e4 LT	111
378c6697	112	if (crypto_blkcipher_ivsize(tfm) > 16) {
1da177e4	113	dprintk("RPC: gss_k5decrypt: tfm iv size to large %d\n",
378c6697	114	crypto_blkcipher_ivsize(tfm));
1da177e4 LT	115	goto out;
	116	}
	117	if (iv)
378c6697	118	memcpy(local_iv,iv, crypto_blkcipher_ivsize(tfm));
1da177e4 LT	119
1da177e4 LT	120	memcpy(out, in, length);
6df5b9f4	121	sg_set_buf(sg, out, length);
1da177e4	122
378c6697	123	ret = crypto_blkcipher_decrypt_iv(&desc, sg, sg, length);
1da177e4 LT	124
	125	dprintk("RPC: krb5_decrypt: output_data:\n");
	126	print_hexl((u32 *)out, length, 0);
	127	out:
	128	dprintk("RPC: gss_k5decrypt returns %d\n",ret);
	129	return(ret);
	130	}
	131
	132	EXPORT_SYMBOL(krb5_decrypt);
	133
f7b3af64 BF	134	static int
	135	process_xdr_buf(struct xdr_buf *buf, int offset, int len,
	136	int (actor)(struct scatterlist , void ), void data)
	137	{
	138	int i, page_len, thislen, page_offset, ret = 0;
	139	struct scatterlist sg[1];
	140
	141	if (offset >= buf->head[0].iov_len) {
	142	offset -= buf->head[0].iov_len;
	143	} else {
	144	thislen = buf->head[0].iov_len - offset;
	145	if (thislen > len)
	146	thislen = len;
378f058c	147	sg_set_buf(sg, buf->head[0].iov_base + offset, thislen);
f7b3af64 BF	148	ret = actor(sg, data);
	149	if (ret)
	150	goto out;
	151	offset = 0;
	152	len -= thislen;
	153	}
	154	if (len == 0)
	155	goto out;
	156
	157	if (offset >= buf->page_len) {
	158	offset -= buf->page_len;
	159	} else {
	160	page_len = buf->page_len - offset;
	161	if (page_len > len)
	162	page_len = len;
	163	len -= page_len;
	164	page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1);
	165	i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT;
	166	thislen = PAGE_CACHE_SIZE - page_offset;
	167	do {
	168	if (thislen > page_len)
	169	thislen = page_len;
	170	sg->page = buf->pages[i];
	171	sg->offset = page_offset;
	172	sg->length = thislen;
	173	ret = actor(sg, data);
	174	if (ret)
	175	goto out;
	176	page_len -= thislen;
	177	i++;
	178	page_offset = 0;
	179	thislen = PAGE_CACHE_SIZE;
	180	} while (page_len != 0);
	181	offset = 0;
	182	}
	183	if (len == 0)
	184	goto out;
	185
	186	if (offset < buf->tail[0].iov_len) {
	187	thislen = buf->tail[0].iov_len - offset;
	188	if (thislen > len)
	189	thislen = len;
378f058c	190	sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen);
f7b3af64 BF	191	ret = actor(sg, data);
	192	len -= thislen;
	193	}
	194	if (len != 0)
	195	ret = -EINVAL;
	196	out:
	197	return ret;
	198	}
	199
	200	static int
	201	checksummer(struct scatterlist sg, void data)
	202	{
35058687	203	struct hash_desc *desc = data;
f7b3af64	204
35058687	205	return crypto_hash_update(desc, sg, sg->length);
f7b3af64 BF	206	}
f7b3af64 BF	207
1da177e4 LT	208	/* checksum the plaintext data and hdrlen bytes of the token header */
	209	s32
	210	make_checksum(s32 cksumtype, char header, int hdrlen, struct xdr_buf body,
14ae162c	211	int body_offset, struct xdr_netobj *cksum)
1da177e4 LT	212	{
1da177e4 LT	213	char *cksumname;
35058687	214	struct hash_desc desc; /* XXX add to ctx? */
1da177e4	215	struct scatterlist sg[1];
35058687	216	int err;
1da177e4 LT	217
	218	switch (cksumtype) {
	219	case CKSUMTYPE_RSA_MD5:
	220	cksumname = "md5";
	221	break;
	222	default:
	223	dprintk("RPC: krb5_make_checksum:"
	224	" unsupported checksum %d", cksumtype);
d4a30e7e	225	return GSS_S_FAILURE;
1da177e4	226	}
35058687 HX	227	desc.tfm = crypto_alloc_hash(cksumname, 0, CRYPTO_ALG_ASYNC);
35058687 HX	228	if (IS_ERR(desc.tfm))
d4a30e7e	229	return GSS_S_FAILURE;
35058687 HX	230	cksum->len = crypto_hash_digestsize(desc.tfm);
35058687 HX	231	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
1da177e4	232
35058687 HX	233	err = crypto_hash_init(&desc);
	234	if (err)
	235	goto out;
378f058c	236	sg_set_buf(sg, header, hdrlen);
35058687 HX	237	err = crypto_hash_update(&desc, sg, hdrlen);
	238	if (err)
	239	goto out;
	240	err = process_xdr_buf(body, body_offset, body->len - body_offset,
	241	checksummer, &desc);
	242	if (err)
	243	goto out;
	244	err = crypto_hash_final(&desc, cksum->data);
	245
	246	out:
	247	crypto_free_hash(desc.tfm);
	248	return err ? GSS_S_FAILURE : 0;
1da177e4 LT	249	}
	250
	251	EXPORT_SYMBOL(make_checksum);
14ae162c BF	252
	253	struct encryptor_desc {
	254	u8 iv[8]; /* XXX hard-coded blocksize */
378c6697	255	struct blkcipher_desc desc;
14ae162c BF	256	int pos;
	257	struct xdr_buf *outbuf;
	258	struct page **pages;
	259	struct scatterlist infrags[4];
	260	struct scatterlist outfrags[4];
	261	int fragno;
	262	int fraglen;
	263	};
	264
	265	static int
	266	encryptor(struct scatterlist sg, void data)
	267	{
	268	struct encryptor_desc *desc = data;
	269	struct xdr_buf *outbuf = desc->outbuf;
	270	struct page *in_page;
	271	int thislen = desc->fraglen + sg->length;
	272	int fraglen, ret;
	273	int page_pos;
	274
	275	/* Worst case is 4 fragments: head, end of page 1, start
	276	* of page 2, tail. Anything more is a bug. */
	277	BUG_ON(desc->fragno > 3);
	278	desc->infrags[desc->fragno] = *sg;
	279	desc->outfrags[desc->fragno] = *sg;
	280
	281	page_pos = desc->pos - outbuf->head[0].iov_len;
	282	if (page_pos >= 0 && page_pos < outbuf->page_len) {
	283	/* pages are not in place: */
	284	int i = (page_pos + outbuf->page_base) >> PAGE_CACHE_SHIFT;
	285	in_page = desc->pages[i];
	286	} else {
	287	in_page = sg->page;
	288	}
	289	desc->infrags[desc->fragno].page = in_page;
	290	desc->fragno++;
	291	desc->fraglen += sg->length;
	292	desc->pos += sg->length;
	293
	294	fraglen = thislen & 7; /* XXX hardcoded blocksize */
	295	thislen -= fraglen;
	296
	297	if (thislen == 0)
	298	return 0;
	299
378c6697 HX	300	ret = crypto_blkcipher_encrypt_iv(&desc->desc, desc->outfrags,
378c6697 HX	301	desc->infrags, thislen);
14ae162c BF	302	if (ret)
	303	return ret;
	304	if (fraglen) {
	305	desc->outfrags[0].page = sg->page;
	306	desc->outfrags[0].offset = sg->offset + sg->length - fraglen;
	307	desc->outfrags[0].length = fraglen;
	308	desc->infrags[0] = desc->outfrags[0];
	309	desc->infrags[0].page = in_page;
	310	desc->fragno = 1;
	311	desc->fraglen = fraglen;
	312	} else {
	313	desc->fragno = 0;
	314	desc->fraglen = 0;
	315	}
	316	return 0;
	317	}
	318
	319	int
378c6697 HX	320	gss_encrypt_xdr_buf(struct crypto_blkcipher tfm, struct xdr_buf buf,
378c6697 HX	321	int offset, struct page **pages)
14ae162c BF	322	{
	323	int ret;
	324	struct encryptor_desc desc;
	325
378c6697	326	BUG_ON((buf->len - offset) % crypto_blkcipher_blocksize(tfm) != 0);
14ae162c BF	327
14ae162c BF	328	memset(desc.iv, 0, sizeof(desc.iv));
378c6697 HX	329	desc.desc.tfm = tfm;
	330	desc.desc.info = desc.iv;
	331	desc.desc.flags = 0;
14ae162c BF	332	desc.pos = offset;
	333	desc.outbuf = buf;
	334	desc.pages = pages;
	335	desc.fragno = 0;
	336	desc.fraglen = 0;
	337
	338	ret = process_xdr_buf(buf, offset, buf->len - offset, encryptor, &desc);
	339	return ret;
	340	}
	341
	342	EXPORT_SYMBOL(gss_encrypt_xdr_buf);
	343
	344	struct decryptor_desc {
	345	u8 iv[8]; /* XXX hard-coded blocksize */
378c6697	346	struct blkcipher_desc desc;
14ae162c BF	347	struct scatterlist frags[4];
	348	int fragno;
	349	int fraglen;
	350	};
	351
	352	static int
	353	decryptor(struct scatterlist sg, void data)
	354	{
	355	struct decryptor_desc *desc = data;
	356	int thislen = desc->fraglen + sg->length;
	357	int fraglen, ret;
	358
	359	/* Worst case is 4 fragments: head, end of page 1, start
	360	* of page 2, tail. Anything more is a bug. */
	361	BUG_ON(desc->fragno > 3);
	362	desc->frags[desc->fragno] = *sg;
	363	desc->fragno++;
	364	desc->fraglen += sg->length;
	365
	366	fraglen = thislen & 7; /* XXX hardcoded blocksize */
	367	thislen -= fraglen;
	368
	369	if (thislen == 0)
	370	return 0;
	371
378c6697 HX	372	ret = crypto_blkcipher_decrypt_iv(&desc->desc, desc->frags,
378c6697 HX	373	desc->frags, thislen);
14ae162c BF	374	if (ret)
	375	return ret;
	376	if (fraglen) {
	377	desc->frags[0].page = sg->page;
	378	desc->frags[0].offset = sg->offset + sg->length - fraglen;
	379	desc->frags[0].length = fraglen;
	380	desc->fragno = 1;
	381	desc->fraglen = fraglen;
	382	} else {
	383	desc->fragno = 0;
	384	desc->fraglen = 0;
	385	}
	386	return 0;
	387	}
	388
	389	int
378c6697 HX	390	gss_decrypt_xdr_buf(struct crypto_blkcipher tfm, struct xdr_buf buf,
378c6697 HX	391	int offset)
14ae162c BF	392	{
	393	struct decryptor_desc desc;
	394
	395	/* XXXJBF: */
378c6697	396	BUG_ON((buf->len - offset) % crypto_blkcipher_blocksize(tfm) != 0);
14ae162c BF	397
14ae162c BF	398	memset(desc.iv, 0, sizeof(desc.iv));
378c6697 HX	399	desc.desc.tfm = tfm;
	400	desc.desc.info = desc.iv;
	401	desc.desc.flags = 0;
14ae162c BF	402	desc.fragno = 0;
	403	desc.fraglen = 0;
	404	return process_xdr_buf(buf, offset, buf->len - offset, decryptor, &desc);
	405	}
	406
	407	EXPORT_SYMBOL(gss_decrypt_xdr_buf);