Merge branch 'master'
[linux-2.6] / net / sunrpc / auth_gss / gss_krb5_crypto.c
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
37 #include <linux/types.h>
38 #include <linux/mm.h>
39 #include <linux/slab.h>
40 #include <linux/scatterlist.h>
41 #include <linux/crypto.h>
42 #include <linux/highmem.h>
43 #include <linux/pagemap.h>
44 #include <linux/sunrpc/gss_krb5.h>
45
46 #ifdef RPC_DEBUG
47 # define RPCDBG_FACILITY        RPCDBG_AUTH
48 #endif
49
50 u32
51 krb5_encrypt(
52         struct crypto_tfm *tfm,
53         void * iv,
54         void * in,
55         void * out,
56         int length)
57 {
58         u32 ret = -EINVAL;
59         struct scatterlist sg[1];
60         u8 local_iv[16] = {0};
61
62         dprintk("RPC:      krb5_encrypt: input data:\n");
63         print_hexl((u32 *)in, length, 0);
64
65         if (length % crypto_tfm_alg_blocksize(tfm) != 0)
66                 goto out;
67
68         if (crypto_tfm_alg_ivsize(tfm) > 16) {
69                 dprintk("RPC:      gss_k5encrypt: tfm iv size to large %d\n",
70                          crypto_tfm_alg_ivsize(tfm));
71                 goto out;
72         }
73
74         if (iv)
75                 memcpy(local_iv, iv, crypto_tfm_alg_ivsize(tfm));
76
77         memcpy(out, in, length);
78         sg_set_buf(sg, out, length);
79
80         ret = crypto_cipher_encrypt_iv(tfm, sg, sg, length, local_iv);
81
82         dprintk("RPC:      krb5_encrypt: output data:\n");
83         print_hexl((u32 *)out, length, 0);
84 out:
85         dprintk("RPC:      krb5_encrypt returns %d\n",ret);
86         return(ret);
87 }
88
89 EXPORT_SYMBOL(krb5_encrypt);
90
91 u32
92 krb5_decrypt(
93      struct crypto_tfm *tfm,
94      void * iv,
95      void * in,
96      void * out,
97      int length)
98 {
99         u32 ret = -EINVAL;
100         struct scatterlist sg[1];
101         u8 local_iv[16] = {0};
102
103         dprintk("RPC:      krb5_decrypt: input data:\n");
104         print_hexl((u32 *)in, length, 0);
105
106         if (length % crypto_tfm_alg_blocksize(tfm) != 0)
107                 goto out;
108
109         if (crypto_tfm_alg_ivsize(tfm) > 16) {
110                 dprintk("RPC:      gss_k5decrypt: tfm iv size to large %d\n",
111                         crypto_tfm_alg_ivsize(tfm));
112                 goto out;
113         }
114         if (iv)
115                 memcpy(local_iv,iv, crypto_tfm_alg_ivsize(tfm));
116
117         memcpy(out, in, length);
118         sg_set_buf(sg, out, length);
119
120         ret = crypto_cipher_decrypt_iv(tfm, sg, sg, length, local_iv);
121
122         dprintk("RPC:      krb5_decrypt: output_data:\n");
123         print_hexl((u32 *)out, length, 0);
124 out:
125         dprintk("RPC:      gss_k5decrypt returns %d\n",ret);
126         return(ret);
127 }
128
129 EXPORT_SYMBOL(krb5_decrypt);
130
131 static int
132 process_xdr_buf(struct xdr_buf *buf, int offset, int len,
133                 int (*actor)(struct scatterlist *, void *), void *data)
134 {
135         int i, page_len, thislen, page_offset, ret = 0;
136         struct scatterlist      sg[1];
137
138         if (offset >= buf->head[0].iov_len) {
139                 offset -= buf->head[0].iov_len;
140         } else {
141                 thislen = buf->head[0].iov_len - offset;
142                 if (thislen > len)
143                         thislen = len;
144                 sg_set_buf(sg, buf->head[0].iov_base + offset, thislen);
145                 ret = actor(sg, data);
146                 if (ret)
147                         goto out;
148                 offset = 0;
149                 len -= thislen;
150         }
151         if (len == 0)
152                 goto out;
153
154         if (offset >= buf->page_len) {
155                 offset -= buf->page_len;
156         } else {
157                 page_len = buf->page_len - offset;
158                 if (page_len > len)
159                         page_len = len;
160                 len -= page_len;
161                 page_offset = (offset + buf->page_base) & (PAGE_CACHE_SIZE - 1);
162                 i = (offset + buf->page_base) >> PAGE_CACHE_SHIFT;
163                 thislen = PAGE_CACHE_SIZE - page_offset;
164                 do {
165                         if (thislen > page_len)
166                                 thislen = page_len;
167                         sg->page = buf->pages[i];
168                         sg->offset = page_offset;
169                         sg->length = thislen;
170                         ret = actor(sg, data);
171                         if (ret)
172                                 goto out;
173                         page_len -= thislen;
174                         i++;
175                         page_offset = 0;
176                         thislen = PAGE_CACHE_SIZE;
177                 } while (page_len != 0);
178                 offset = 0;
179         }
180         if (len == 0)
181                 goto out;
182
183         if (offset < buf->tail[0].iov_len) {
184                 thislen = buf->tail[0].iov_len - offset;
185                 if (thislen > len)
186                         thislen = len;
187                 sg_set_buf(sg, buf->tail[0].iov_base + offset, thislen);
188                 ret = actor(sg, data);
189                 len -= thislen;
190         }
191         if (len != 0)
192                 ret = -EINVAL;
193 out:
194         return ret;
195 }
196
197 static int
198 checksummer(struct scatterlist *sg, void *data)
199 {
200         struct crypto_tfm *tfm = (struct crypto_tfm *)data;
201
202         crypto_digest_update(tfm, sg, 1);
203
204         return 0;
205 }
206
207 /* checksum the plaintext data and hdrlen bytes of the token header */
208 s32
209 make_checksum(s32 cksumtype, char *header, int hdrlen, struct xdr_buf *body,
210                    int body_offset, struct xdr_netobj *cksum)
211 {
212         char                            *cksumname;
213         struct crypto_tfm               *tfm = NULL; /* XXX add to ctx? */
214         struct scatterlist              sg[1];
215         u32                             code = GSS_S_FAILURE;
216
217         switch (cksumtype) {
218                 case CKSUMTYPE_RSA_MD5:
219                         cksumname = "md5";
220                         break;
221                 default:
222                         dprintk("RPC:      krb5_make_checksum:"
223                                 " unsupported checksum %d", cksumtype);
224                         goto out;
225         }
226         if (!(tfm = crypto_alloc_tfm(cksumname, CRYPTO_TFM_REQ_MAY_SLEEP)))
227                 goto out;
228         cksum->len = crypto_tfm_alg_digestsize(tfm);
229         if ((cksum->data = kmalloc(cksum->len, GFP_KERNEL)) == NULL)
230                 goto out;
231
232         crypto_digest_init(tfm);
233         sg_set_buf(sg, header, hdrlen);
234         crypto_digest_update(tfm, sg, 1);
235         process_xdr_buf(body, body_offset, body->len - body_offset,
236                         checksummer, tfm);
237         crypto_digest_final(tfm, cksum->data);
238         code = 0;
239 out:
240         crypto_free_tfm(tfm);
241         return code;
242 }
243
244 EXPORT_SYMBOL(make_checksum);
245
246 struct encryptor_desc {
247         u8 iv[8]; /* XXX hard-coded blocksize */
248         struct crypto_tfm *tfm;
249         int pos;
250         struct xdr_buf *outbuf;
251         struct page **pages;
252         struct scatterlist infrags[4];
253         struct scatterlist outfrags[4];
254         int fragno;
255         int fraglen;
256 };
257
258 static int
259 encryptor(struct scatterlist *sg, void *data)
260 {
261         struct encryptor_desc *desc = data;
262         struct xdr_buf *outbuf = desc->outbuf;
263         struct page *in_page;
264         int thislen = desc->fraglen + sg->length;
265         int fraglen, ret;
266         int page_pos;
267
268         /* Worst case is 4 fragments: head, end of page 1, start
269          * of page 2, tail.  Anything more is a bug. */
270         BUG_ON(desc->fragno > 3);
271         desc->infrags[desc->fragno] = *sg;
272         desc->outfrags[desc->fragno] = *sg;
273
274         page_pos = desc->pos - outbuf->head[0].iov_len;
275         if (page_pos >= 0 && page_pos < outbuf->page_len) {
276                 /* pages are not in place: */
277                 int i = (page_pos + outbuf->page_base) >> PAGE_CACHE_SHIFT;
278                 in_page = desc->pages[i];
279         } else {
280                 in_page = sg->page;
281         }
282         desc->infrags[desc->fragno].page = in_page;
283         desc->fragno++;
284         desc->fraglen += sg->length;
285         desc->pos += sg->length;
286
287         fraglen = thislen & 7; /* XXX hardcoded blocksize */
288         thislen -= fraglen;
289
290         if (thislen == 0)
291                 return 0;
292
293         ret = crypto_cipher_encrypt_iv(desc->tfm, desc->outfrags, desc->infrags,
294                                         thislen, desc->iv);
295         if (ret)
296                 return ret;
297         if (fraglen) {
298                 desc->outfrags[0].page = sg->page;
299                 desc->outfrags[0].offset = sg->offset + sg->length - fraglen;
300                 desc->outfrags[0].length = fraglen;
301                 desc->infrags[0] = desc->outfrags[0];
302                 desc->infrags[0].page = in_page;
303                 desc->fragno = 1;
304                 desc->fraglen = fraglen;
305         } else {
306                 desc->fragno = 0;
307                 desc->fraglen = 0;
308         }
309         return 0;
310 }
311
312 int
313 gss_encrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *buf, int offset,
314                 struct page **pages)
315 {
316         int ret;
317         struct encryptor_desc desc;
318
319         BUG_ON((buf->len - offset) % crypto_tfm_alg_blocksize(tfm) != 0);
320
321         memset(desc.iv, 0, sizeof(desc.iv));
322         desc.tfm = tfm;
323         desc.pos = offset;
324         desc.outbuf = buf;
325         desc.pages = pages;
326         desc.fragno = 0;
327         desc.fraglen = 0;
328
329         ret = process_xdr_buf(buf, offset, buf->len - offset, encryptor, &desc);
330         return ret;
331 }
332
333 EXPORT_SYMBOL(gss_encrypt_xdr_buf);
334
335 struct decryptor_desc {
336         u8 iv[8]; /* XXX hard-coded blocksize */
337         struct crypto_tfm *tfm;
338         struct scatterlist frags[4];
339         int fragno;
340         int fraglen;
341 };
342
343 static int
344 decryptor(struct scatterlist *sg, void *data)
345 {
346         struct decryptor_desc *desc = data;
347         int thislen = desc->fraglen + sg->length;
348         int fraglen, ret;
349
350         /* Worst case is 4 fragments: head, end of page 1, start
351          * of page 2, tail.  Anything more is a bug. */
352         BUG_ON(desc->fragno > 3);
353         desc->frags[desc->fragno] = *sg;
354         desc->fragno++;
355         desc->fraglen += sg->length;
356
357         fraglen = thislen & 7; /* XXX hardcoded blocksize */
358         thislen -= fraglen;
359
360         if (thislen == 0)
361                 return 0;
362
363         ret = crypto_cipher_decrypt_iv(desc->tfm, desc->frags, desc->frags,
364                                         thislen, desc->iv);
365         if (ret)
366                 return ret;
367         if (fraglen) {
368                 desc->frags[0].page = sg->page;
369                 desc->frags[0].offset = sg->offset + sg->length - fraglen;
370                 desc->frags[0].length = fraglen;
371                 desc->fragno = 1;
372                 desc->fraglen = fraglen;
373         } else {
374                 desc->fragno = 0;
375                 desc->fraglen = 0;
376         }
377         return 0;
378 }
379
380 int
381 gss_decrypt_xdr_buf(struct crypto_tfm *tfm, struct xdr_buf *buf, int offset)
382 {
383         struct decryptor_desc desc;
384
385         /* XXXJBF: */
386         BUG_ON((buf->len - offset) % crypto_tfm_alg_blocksize(tfm) != 0);
387
388         memset(desc.iv, 0, sizeof(desc.iv));
389         desc.tfm = tfm;
390         desc.fragno = 0;
391         desc.fraglen = 0;
392         return process_xdr_buf(buf, offset, buf->len - offset, decryptor, &desc);
393 }
394
395 EXPORT_SYMBOL(gss_decrypt_xdr_buf);