[linux-2.6-block.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>
#include <linux/sunrpc/xdr.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 };

	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);
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 };

	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);
out:
	dprintk("RPC:      gss_k5decrypt returns %d\n",ret);
	return ret;
}

EXPORT_SYMBOL(krb5_decrypt);

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(char *cksumname, char *header, int hdrlen, struct xdr_buf *body,
		   int body_offset, struct xdr_netobj *cksum)
{
	struct hash_desc                desc; /* XXX add to ctx? */
	struct scatterlist              sg[1];
	int err;

	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 = xdr_process_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 = xdr_process_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 xdr_process_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>
37a4e6cb	46	#include <linux/sunrpc/xdr.h>
1da177e4 LT	47
	48	#ifdef RPC_DEBUG
	49	# define RPCDBG_FACILITY RPCDBG_AUTH
	50	#endif
	51
	52	u32
	53	krb5_encrypt(
378c6697	54	struct crypto_blkcipher *tfm,
1da177e4 LT	55	void * iv,
	56	void * in,
	57	void * out,
	58	int length)
	59	{
	60	u32 ret = -EINVAL;
cca5172a	61	struct scatterlist sg[1];
1da177e4	62	u8 local_iv[16] = {0};
378c6697	63	struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };
1da177e4	64
378c6697	65	if (length % crypto_blkcipher_blocksize(tfm) != 0)
1da177e4 LT	66	goto out;
1da177e4 LT	67
378c6697	68	if (crypto_blkcipher_ivsize(tfm) > 16) {
1da177e4	69	dprintk("RPC: gss_k5encrypt: tfm iv size to large %d\n",
cca5172a	70	crypto_blkcipher_ivsize(tfm));
1da177e4 LT	71	goto out;
	72	}
	73
	74	if (iv)
378c6697	75	memcpy(local_iv, iv, crypto_blkcipher_ivsize(tfm));
1da177e4 LT	76
1da177e4 LT	77	memcpy(out, in, length);
6df5b9f4	78	sg_set_buf(sg, out, length);
1da177e4	79
378c6697	80	ret = crypto_blkcipher_encrypt_iv(&desc, sg, sg, length);
1da177e4 LT	81	out:
1da177e4 LT	82	dprintk("RPC: krb5_encrypt returns %d\n",ret);
8fc7500b	83	return ret;
1da177e4 LT	84	}
	85
	86	EXPORT_SYMBOL(krb5_encrypt);
	87
	88	u32
	89	krb5_decrypt(
378c6697	90	struct crypto_blkcipher *tfm,
1da177e4 LT	91	void * iv,
	92	void * in,
	93	void * out,
	94	int length)
	95	{
	96	u32 ret = -EINVAL;
	97	struct scatterlist sg[1];
	98	u8 local_iv[16] = {0};
378c6697	99	struct blkcipher_desc desc = { .tfm = tfm, .info = local_iv };
1da177e4	100
378c6697	101	if (length % crypto_blkcipher_blocksize(tfm) != 0)
1da177e4 LT	102	goto out;
1da177e4 LT	103
378c6697	104	if (crypto_blkcipher_ivsize(tfm) > 16) {
1da177e4	105	dprintk("RPC: gss_k5decrypt: tfm iv size to large %d\n",
378c6697	106	crypto_blkcipher_ivsize(tfm));
1da177e4 LT	107	goto out;
	108	}
	109	if (iv)
378c6697	110	memcpy(local_iv,iv, crypto_blkcipher_ivsize(tfm));
1da177e4 LT	111
1da177e4 LT	112	memcpy(out, in, length);
6df5b9f4	113	sg_set_buf(sg, out, length);
1da177e4	114
378c6697	115	ret = crypto_blkcipher_decrypt_iv(&desc, sg, sg, length);
1da177e4 LT	116	out:
1da177e4 LT	117	dprintk("RPC: gss_k5decrypt returns %d\n",ret);
8fc7500b	118	return ret;
1da177e4 LT	119	}
	120
	121	EXPORT_SYMBOL(krb5_decrypt);
	122
f7b3af64 BF	123	static int
	124	checksummer(struct scatterlist sg, void data)
	125	{
35058687	126	struct hash_desc *desc = data;
f7b3af64	127
35058687	128	return crypto_hash_update(desc, sg, sg->length);
f7b3af64 BF	129	}
f7b3af64 BF	130
1da177e4 LT	131	/* checksum the plaintext data and hdrlen bytes of the token header */
1da177e4 LT	132	s32
ca54f896	133	make_checksum(char cksumname, char header, int hdrlen, struct xdr_buf *body,
14ae162c	134	int body_offset, struct xdr_netobj *cksum)
1da177e4	135	{
35058687	136	struct hash_desc desc; /* XXX add to ctx? */
1da177e4	137	struct scatterlist sg[1];
35058687	138	int err;
1da177e4	139
35058687 HX	140	desc.tfm = crypto_alloc_hash(cksumname, 0, CRYPTO_ALG_ASYNC);
35058687 HX	141	if (IS_ERR(desc.tfm))
d4a30e7e	142	return GSS_S_FAILURE;
35058687 HX	143	cksum->len = crypto_hash_digestsize(desc.tfm);
35058687 HX	144	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
1da177e4	145
35058687 HX	146	err = crypto_hash_init(&desc);
	147	if (err)
	148	goto out;
378f058c	149	sg_set_buf(sg, header, hdrlen);
35058687 HX	150	err = crypto_hash_update(&desc, sg, hdrlen);
	151	if (err)
	152	goto out;
37a4e6cb	153	err = xdr_process_buf(body, body_offset, body->len - body_offset,
35058687 HX	154	checksummer, &desc);
	155	if (err)
	156	goto out;
	157	err = crypto_hash_final(&desc, cksum->data);
	158
	159	out:
	160	crypto_free_hash(desc.tfm);
	161	return err ? GSS_S_FAILURE : 0;
1da177e4 LT	162	}
	163
	164	EXPORT_SYMBOL(make_checksum);
14ae162c BF	165
	166	struct encryptor_desc {
	167	u8 iv[8]; /* XXX hard-coded blocksize */
378c6697	168	struct blkcipher_desc desc;
14ae162c BF	169	int pos;
	170	struct xdr_buf *outbuf;
	171	struct page **pages;
	172	struct scatterlist infrags[4];
	173	struct scatterlist outfrags[4];
	174	int fragno;
	175	int fraglen;
	176	};
	177
	178	static int
	179	encryptor(struct scatterlist sg, void data)
	180	{
	181	struct encryptor_desc *desc = data;
	182	struct xdr_buf *outbuf = desc->outbuf;
	183	struct page *in_page;
	184	int thislen = desc->fraglen + sg->length;
	185	int fraglen, ret;
	186	int page_pos;
	187
	188	/* Worst case is 4 fragments: head, end of page 1, start
	189	* of page 2, tail. Anything more is a bug. */
	190	BUG_ON(desc->fragno > 3);
	191	desc->infrags[desc->fragno] = *sg;
	192	desc->outfrags[desc->fragno] = *sg;
	193
	194	page_pos = desc->pos - outbuf->head[0].iov_len;
	195	if (page_pos >= 0 && page_pos < outbuf->page_len) {
	196	/* pages are not in place: */
	197	int i = (page_pos + outbuf->page_base) >> PAGE_CACHE_SHIFT;
	198	in_page = desc->pages[i];
	199	} else {
	200	in_page = sg->page;
	201	}
	202	desc->infrags[desc->fragno].page = in_page;
	203	desc->fragno++;
	204	desc->fraglen += sg->length;
	205	desc->pos += sg->length;
	206
	207	fraglen = thislen & 7; /* XXX hardcoded blocksize */
	208	thislen -= fraglen;
	209
	210	if (thislen == 0)
	211	return 0;
	212
378c6697 HX	213	ret = crypto_blkcipher_encrypt_iv(&desc->desc, desc->outfrags,
378c6697 HX	214	desc->infrags, thislen);
14ae162c BF	215	if (ret)
	216	return ret;
	217	if (fraglen) {
	218	desc->outfrags[0].page = sg->page;
	219	desc->outfrags[0].offset = sg->offset + sg->length - fraglen;
	220	desc->outfrags[0].length = fraglen;
	221	desc->infrags[0] = desc->outfrags[0];
	222	desc->infrags[0].page = in_page;
	223	desc->fragno = 1;
	224	desc->fraglen = fraglen;
	225	} else {
	226	desc->fragno = 0;
	227	desc->fraglen = 0;
	228	}
	229	return 0;
	230	}
	231
	232	int
378c6697 HX	233	gss_encrypt_xdr_buf(struct crypto_blkcipher tfm, struct xdr_buf buf,
378c6697 HX	234	int offset, struct page **pages)
14ae162c BF	235	{
	236	int ret;
	237	struct encryptor_desc desc;
	238
378c6697	239	BUG_ON((buf->len - offset) % crypto_blkcipher_blocksize(tfm) != 0);
14ae162c BF	240
14ae162c BF	241	memset(desc.iv, 0, sizeof(desc.iv));
378c6697 HX	242	desc.desc.tfm = tfm;
	243	desc.desc.info = desc.iv;
	244	desc.desc.flags = 0;
14ae162c BF	245	desc.pos = offset;
	246	desc.outbuf = buf;
	247	desc.pages = pages;
	248	desc.fragno = 0;
	249	desc.fraglen = 0;
	250
37a4e6cb	251	ret = xdr_process_buf(buf, offset, buf->len - offset, encryptor, &desc);
14ae162c BF	252	return ret;
	253	}
	254
	255	EXPORT_SYMBOL(gss_encrypt_xdr_buf);
	256
	257	struct decryptor_desc {
	258	u8 iv[8]; /* XXX hard-coded blocksize */
378c6697	259	struct blkcipher_desc desc;
14ae162c BF	260	struct scatterlist frags[4];
	261	int fragno;
	262	int fraglen;
	263	};
	264
	265	static int
	266	decryptor(struct scatterlist sg, void data)
	267	{
	268	struct decryptor_desc *desc = data;
	269	int thislen = desc->fraglen + sg->length;
	270	int fraglen, ret;
	271
	272	/* Worst case is 4 fragments: head, end of page 1, start
	273	* of page 2, tail. Anything more is a bug. */
	274	BUG_ON(desc->fragno > 3);
	275	desc->frags[desc->fragno] = *sg;
	276	desc->fragno++;
	277	desc->fraglen += sg->length;
	278
	279	fraglen = thislen & 7; /* XXX hardcoded blocksize */
	280	thislen -= fraglen;
	281
	282	if (thislen == 0)
	283	return 0;
	284
378c6697 HX	285	ret = crypto_blkcipher_decrypt_iv(&desc->desc, desc->frags,
378c6697 HX	286	desc->frags, thislen);
14ae162c BF	287	if (ret)
	288	return ret;
	289	if (fraglen) {
	290	desc->frags[0].page = sg->page;
	291	desc->frags[0].offset = sg->offset + sg->length - fraglen;
	292	desc->frags[0].length = fraglen;
	293	desc->fragno = 1;
	294	desc->fraglen = fraglen;
	295	} else {
	296	desc->fragno = 0;
	297	desc->fraglen = 0;
	298	}
	299	return 0;
	300	}
	301
	302	int
378c6697 HX	303	gss_decrypt_xdr_buf(struct crypto_blkcipher tfm, struct xdr_buf buf,
378c6697 HX	304	int offset)
14ae162c BF	305	{
	306	struct decryptor_desc desc;
	307
	308	/* XXXJBF: */
378c6697	309	BUG_ON((buf->len - offset) % crypto_blkcipher_blocksize(tfm) != 0);
14ae162c BF	310
14ae162c BF	311	memset(desc.iv, 0, sizeof(desc.iv));
378c6697 HX	312	desc.desc.tfm = tfm;
	313	desc.desc.info = desc.iv;
	314	desc.desc.flags = 0;
14ae162c BF	315	desc.fragno = 0;
14ae162c BF	316	desc.fraglen = 0;
37a4e6cb	317	return xdr_process_buf(buf, offset, buf->len - offset, decryptor, &desc);
14ae162c BF	318	}
	319
	320	EXPORT_SYMBOL(gss_decrypt_xdr_buf);