diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/block/cryptoloop.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/block/cryptoloop.c')
-rw-r--r-- | drivers/block/cryptoloop.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/drivers/block/cryptoloop.c b/drivers/block/cryptoloop.c new file mode 100644 index 000000000000..5be6f998d8c5 --- /dev/null +++ b/drivers/block/cryptoloop.c | |||
@@ -0,0 +1,268 @@ | |||
1 | /* | ||
2 | Linux loop encryption enabling module | ||
3 | |||
4 | Copyright (C) 2002 Herbert Valerio Riedel <hvr@gnu.org> | ||
5 | Copyright (C) 2003 Fruhwirth Clemens <clemens@endorphin.org> | ||
6 | |||
7 | This module is free software; you can redistribute it and/or modify | ||
8 | it under the terms of the GNU General Public License as published by | ||
9 | the Free Software Foundation; either version 2 of the License, or | ||
10 | (at your option) any later version. | ||
11 | |||
12 | This module is distributed in the hope that it will be useful, | ||
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
15 | GNU General Public License for more details. | ||
16 | |||
17 | You should have received a copy of the GNU General Public License | ||
18 | along with this module; if not, write to the Free Software | ||
19 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
20 | */ | ||
21 | |||
22 | #include <linux/module.h> | ||
23 | |||
24 | #include <linux/init.h> | ||
25 | #include <linux/string.h> | ||
26 | #include <linux/crypto.h> | ||
27 | #include <linux/blkdev.h> | ||
28 | #include <linux/loop.h> | ||
29 | #include <asm/semaphore.h> | ||
30 | #include <asm/uaccess.h> | ||
31 | |||
32 | MODULE_LICENSE("GPL"); | ||
33 | MODULE_DESCRIPTION("loop blockdevice transferfunction adaptor / CryptoAPI"); | ||
34 | MODULE_AUTHOR("Herbert Valerio Riedel <hvr@gnu.org>"); | ||
35 | |||
36 | #define LOOP_IV_SECTOR_BITS 9 | ||
37 | #define LOOP_IV_SECTOR_SIZE (1 << LOOP_IV_SECTOR_BITS) | ||
38 | |||
39 | static int | ||
40 | cryptoloop_init(struct loop_device *lo, const struct loop_info64 *info) | ||
41 | { | ||
42 | int err = -EINVAL; | ||
43 | char cms[LO_NAME_SIZE]; /* cipher-mode string */ | ||
44 | char *cipher; | ||
45 | char *mode; | ||
46 | char *cmsp = cms; /* c-m string pointer */ | ||
47 | struct crypto_tfm *tfm = NULL; | ||
48 | |||
49 | /* encryption breaks for non sector aligned offsets */ | ||
50 | |||
51 | if (info->lo_offset % LOOP_IV_SECTOR_SIZE) | ||
52 | goto out; | ||
53 | |||
54 | strncpy(cms, info->lo_crypt_name, LO_NAME_SIZE); | ||
55 | cms[LO_NAME_SIZE - 1] = 0; | ||
56 | cipher = strsep(&cmsp, "-"); | ||
57 | mode = strsep(&cmsp, "-"); | ||
58 | |||
59 | if (mode == NULL || strcmp(mode, "cbc") == 0) | ||
60 | tfm = crypto_alloc_tfm(cipher, CRYPTO_TFM_MODE_CBC); | ||
61 | else if (strcmp(mode, "ecb") == 0) | ||
62 | tfm = crypto_alloc_tfm(cipher, CRYPTO_TFM_MODE_ECB); | ||
63 | if (tfm == NULL) | ||
64 | return -EINVAL; | ||
65 | |||
66 | err = tfm->crt_u.cipher.cit_setkey(tfm, info->lo_encrypt_key, | ||
67 | info->lo_encrypt_key_size); | ||
68 | |||
69 | if (err != 0) | ||
70 | goto out_free_tfm; | ||
71 | |||
72 | lo->key_data = tfm; | ||
73 | return 0; | ||
74 | |||
75 | out_free_tfm: | ||
76 | crypto_free_tfm(tfm); | ||
77 | |||
78 | out: | ||
79 | return err; | ||
80 | } | ||
81 | |||
82 | |||
83 | typedef int (*encdec_ecb_t)(struct crypto_tfm *tfm, | ||
84 | struct scatterlist *sg_out, | ||
85 | struct scatterlist *sg_in, | ||
86 | unsigned int nsg); | ||
87 | |||
88 | |||
89 | static int | ||
90 | cryptoloop_transfer_ecb(struct loop_device *lo, int cmd, | ||
91 | struct page *raw_page, unsigned raw_off, | ||
92 | struct page *loop_page, unsigned loop_off, | ||
93 | int size, sector_t IV) | ||
94 | { | ||
95 | struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data; | ||
96 | struct scatterlist sg_out = { NULL, }; | ||
97 | struct scatterlist sg_in = { NULL, }; | ||
98 | |||
99 | encdec_ecb_t encdecfunc; | ||
100 | struct page *in_page, *out_page; | ||
101 | unsigned in_offs, out_offs; | ||
102 | |||
103 | if (cmd == READ) { | ||
104 | in_page = raw_page; | ||
105 | in_offs = raw_off; | ||
106 | out_page = loop_page; | ||
107 | out_offs = loop_off; | ||
108 | encdecfunc = tfm->crt_u.cipher.cit_decrypt; | ||
109 | } else { | ||
110 | in_page = loop_page; | ||
111 | in_offs = loop_off; | ||
112 | out_page = raw_page; | ||
113 | out_offs = raw_off; | ||
114 | encdecfunc = tfm->crt_u.cipher.cit_encrypt; | ||
115 | } | ||
116 | |||
117 | while (size > 0) { | ||
118 | const int sz = min(size, LOOP_IV_SECTOR_SIZE); | ||
119 | |||
120 | sg_in.page = in_page; | ||
121 | sg_in.offset = in_offs; | ||
122 | sg_in.length = sz; | ||
123 | |||
124 | sg_out.page = out_page; | ||
125 | sg_out.offset = out_offs; | ||
126 | sg_out.length = sz; | ||
127 | |||
128 | encdecfunc(tfm, &sg_out, &sg_in, sz); | ||
129 | |||
130 | size -= sz; | ||
131 | in_offs += sz; | ||
132 | out_offs += sz; | ||
133 | } | ||
134 | |||
135 | return 0; | ||
136 | } | ||
137 | |||
138 | typedef int (*encdec_cbc_t)(struct crypto_tfm *tfm, | ||
139 | struct scatterlist *sg_out, | ||
140 | struct scatterlist *sg_in, | ||
141 | unsigned int nsg, u8 *iv); | ||
142 | |||
143 | static int | ||
144 | cryptoloop_transfer_cbc(struct loop_device *lo, int cmd, | ||
145 | struct page *raw_page, unsigned raw_off, | ||
146 | struct page *loop_page, unsigned loop_off, | ||
147 | int size, sector_t IV) | ||
148 | { | ||
149 | struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data; | ||
150 | struct scatterlist sg_out = { NULL, }; | ||
151 | struct scatterlist sg_in = { NULL, }; | ||
152 | |||
153 | encdec_cbc_t encdecfunc; | ||
154 | struct page *in_page, *out_page; | ||
155 | unsigned in_offs, out_offs; | ||
156 | |||
157 | if (cmd == READ) { | ||
158 | in_page = raw_page; | ||
159 | in_offs = raw_off; | ||
160 | out_page = loop_page; | ||
161 | out_offs = loop_off; | ||
162 | encdecfunc = tfm->crt_u.cipher.cit_decrypt_iv; | ||
163 | } else { | ||
164 | in_page = loop_page; | ||
165 | in_offs = loop_off; | ||
166 | out_page = raw_page; | ||
167 | out_offs = raw_off; | ||
168 | encdecfunc = tfm->crt_u.cipher.cit_encrypt_iv; | ||
169 | } | ||
170 | |||
171 | while (size > 0) { | ||
172 | const int sz = min(size, LOOP_IV_SECTOR_SIZE); | ||
173 | u32 iv[4] = { 0, }; | ||
174 | iv[0] = cpu_to_le32(IV & 0xffffffff); | ||
175 | |||
176 | sg_in.page = in_page; | ||
177 | sg_in.offset = in_offs; | ||
178 | sg_in.length = sz; | ||
179 | |||
180 | sg_out.page = out_page; | ||
181 | sg_out.offset = out_offs; | ||
182 | sg_out.length = sz; | ||
183 | |||
184 | encdecfunc(tfm, &sg_out, &sg_in, sz, (u8 *)iv); | ||
185 | |||
186 | IV++; | ||
187 | size -= sz; | ||
188 | in_offs += sz; | ||
189 | out_offs += sz; | ||
190 | } | ||
191 | |||
192 | return 0; | ||
193 | } | ||
194 | |||
195 | static int | ||
196 | cryptoloop_transfer(struct loop_device *lo, int cmd, | ||
197 | struct page *raw_page, unsigned raw_off, | ||
198 | struct page *loop_page, unsigned loop_off, | ||
199 | int size, sector_t IV) | ||
200 | { | ||
201 | struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data; | ||
202 | if(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_ECB) | ||
203 | { | ||
204 | lo->transfer = cryptoloop_transfer_ecb; | ||
205 | return cryptoloop_transfer_ecb(lo, cmd, raw_page, raw_off, | ||
206 | loop_page, loop_off, size, IV); | ||
207 | } | ||
208 | if(tfm->crt_cipher.cit_mode == CRYPTO_TFM_MODE_CBC) | ||
209 | { | ||
210 | lo->transfer = cryptoloop_transfer_cbc; | ||
211 | return cryptoloop_transfer_cbc(lo, cmd, raw_page, raw_off, | ||
212 | loop_page, loop_off, size, IV); | ||
213 | } | ||
214 | |||
215 | /* This is not supposed to happen */ | ||
216 | |||
217 | printk( KERN_ERR "cryptoloop: unsupported cipher mode in cryptoloop_transfer!\n"); | ||
218 | return -EINVAL; | ||
219 | } | ||
220 | |||
221 | static int | ||
222 | cryptoloop_ioctl(struct loop_device *lo, int cmd, unsigned long arg) | ||
223 | { | ||
224 | return -EINVAL; | ||
225 | } | ||
226 | |||
227 | static int | ||
228 | cryptoloop_release(struct loop_device *lo) | ||
229 | { | ||
230 | struct crypto_tfm *tfm = (struct crypto_tfm *) lo->key_data; | ||
231 | if (tfm != NULL) { | ||
232 | crypto_free_tfm(tfm); | ||
233 | lo->key_data = NULL; | ||
234 | return 0; | ||
235 | } | ||
236 | printk(KERN_ERR "cryptoloop_release(): tfm == NULL?\n"); | ||
237 | return -EINVAL; | ||
238 | } | ||
239 | |||
240 | static struct loop_func_table cryptoloop_funcs = { | ||
241 | .number = LO_CRYPT_CRYPTOAPI, | ||
242 | .init = cryptoloop_init, | ||
243 | .ioctl = cryptoloop_ioctl, | ||
244 | .transfer = cryptoloop_transfer, | ||
245 | .release = cryptoloop_release, | ||
246 | .owner = THIS_MODULE | ||
247 | }; | ||
248 | |||
249 | static int __init | ||
250 | init_cryptoloop(void) | ||
251 | { | ||
252 | int rc = loop_register_transfer(&cryptoloop_funcs); | ||
253 | |||
254 | if (rc) | ||
255 | printk(KERN_ERR "cryptoloop: loop_register_transfer failed\n"); | ||
256 | return rc; | ||
257 | } | ||
258 | |||
259 | static void __exit | ||
260 | cleanup_cryptoloop(void) | ||
261 | { | ||
262 | if (loop_unregister_transfer(LO_CRYPT_CRYPTOAPI)) | ||
263 | printk(KERN_ERR | ||
264 | "cryptoloop: loop_unregister_transfer failed\n"); | ||
265 | } | ||
266 | |||
267 | module_init(init_cryptoloop); | ||
268 | module_exit(cleanup_cryptoloop); | ||