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 /crypto/cipher.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 'crypto/cipher.c')
-rw-r--r-- | crypto/cipher.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/crypto/cipher.c b/crypto/cipher.c new file mode 100644 index 000000000000..f434ce7c2d0b --- /dev/null +++ b/crypto/cipher.c | |||
@@ -0,0 +1,341 @@ | |||
1 | /* | ||
2 | * Cryptographic API. | ||
3 | * | ||
4 | * Cipher operations. | ||
5 | * | ||
6 | * Copyright (c) 2002 James Morris <jmorris@intercode.com.au> | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or modify it | ||
9 | * under the terms of the GNU General Public License as published by the Free | ||
10 | * Software Foundation; either version 2 of the License, or (at your option) | ||
11 | * any later version. | ||
12 | * | ||
13 | */ | ||
14 | #include <linux/compiler.h> | ||
15 | #include <linux/kernel.h> | ||
16 | #include <linux/crypto.h> | ||
17 | #include <linux/errno.h> | ||
18 | #include <linux/mm.h> | ||
19 | #include <linux/slab.h> | ||
20 | #include <linux/string.h> | ||
21 | #include <asm/scatterlist.h> | ||
22 | #include "internal.h" | ||
23 | #include "scatterwalk.h" | ||
24 | |||
25 | typedef void (cryptfn_t)(void *, u8 *, const u8 *); | ||
26 | typedef void (procfn_t)(struct crypto_tfm *, u8 *, | ||
27 | u8*, cryptfn_t, void *); | ||
28 | |||
29 | static inline void xor_64(u8 *a, const u8 *b) | ||
30 | { | ||
31 | ((u32 *)a)[0] ^= ((u32 *)b)[0]; | ||
32 | ((u32 *)a)[1] ^= ((u32 *)b)[1]; | ||
33 | } | ||
34 | |||
35 | static inline void xor_128(u8 *a, const u8 *b) | ||
36 | { | ||
37 | ((u32 *)a)[0] ^= ((u32 *)b)[0]; | ||
38 | ((u32 *)a)[1] ^= ((u32 *)b)[1]; | ||
39 | ((u32 *)a)[2] ^= ((u32 *)b)[2]; | ||
40 | ((u32 *)a)[3] ^= ((u32 *)b)[3]; | ||
41 | } | ||
42 | |||
43 | static inline void *prepare_src(struct scatter_walk *walk, int bsize, | ||
44 | void *tmp, int in_place) | ||
45 | { | ||
46 | void *src = walk->data; | ||
47 | int n = bsize; | ||
48 | |||
49 | if (unlikely(scatterwalk_across_pages(walk, bsize))) { | ||
50 | src = tmp; | ||
51 | n = scatterwalk_copychunks(src, walk, bsize, 0); | ||
52 | } | ||
53 | scatterwalk_advance(walk, n); | ||
54 | return src; | ||
55 | } | ||
56 | |||
57 | static inline void *prepare_dst(struct scatter_walk *walk, int bsize, | ||
58 | void *tmp, int in_place) | ||
59 | { | ||
60 | void *dst = walk->data; | ||
61 | |||
62 | if (unlikely(scatterwalk_across_pages(walk, bsize)) || in_place) | ||
63 | dst = tmp; | ||
64 | return dst; | ||
65 | } | ||
66 | |||
67 | static inline void complete_src(struct scatter_walk *walk, int bsize, | ||
68 | void *src, int in_place) | ||
69 | { | ||
70 | } | ||
71 | |||
72 | static inline void complete_dst(struct scatter_walk *walk, int bsize, | ||
73 | void *dst, int in_place) | ||
74 | { | ||
75 | int n = bsize; | ||
76 | |||
77 | if (unlikely(scatterwalk_across_pages(walk, bsize))) | ||
78 | n = scatterwalk_copychunks(dst, walk, bsize, 1); | ||
79 | else if (in_place) | ||
80 | memcpy(walk->data, dst, bsize); | ||
81 | scatterwalk_advance(walk, n); | ||
82 | } | ||
83 | |||
84 | /* | ||
85 | * Generic encrypt/decrypt wrapper for ciphers, handles operations across | ||
86 | * multiple page boundaries by using temporary blocks. In user context, | ||
87 | * the kernel is given a chance to schedule us once per block. | ||
88 | */ | ||
89 | static int crypt(struct crypto_tfm *tfm, | ||
90 | struct scatterlist *dst, | ||
91 | struct scatterlist *src, | ||
92 | unsigned int nbytes, cryptfn_t crfn, | ||
93 | procfn_t prfn, void *info) | ||
94 | { | ||
95 | struct scatter_walk walk_in, walk_out; | ||
96 | const unsigned int bsize = crypto_tfm_alg_blocksize(tfm); | ||
97 | u8 tmp_src[bsize]; | ||
98 | u8 tmp_dst[bsize]; | ||
99 | |||
100 | if (!nbytes) | ||
101 | return 0; | ||
102 | |||
103 | if (nbytes % bsize) { | ||
104 | tfm->crt_flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN; | ||
105 | return -EINVAL; | ||
106 | } | ||
107 | |||
108 | scatterwalk_start(&walk_in, src); | ||
109 | scatterwalk_start(&walk_out, dst); | ||
110 | |||
111 | for(;;) { | ||
112 | u8 *src_p, *dst_p; | ||
113 | int in_place; | ||
114 | |||
115 | scatterwalk_map(&walk_in, 0); | ||
116 | scatterwalk_map(&walk_out, 1); | ||
117 | |||
118 | in_place = scatterwalk_samebuf(&walk_in, &walk_out); | ||
119 | |||
120 | do { | ||
121 | src_p = prepare_src(&walk_in, bsize, tmp_src, | ||
122 | in_place); | ||
123 | dst_p = prepare_dst(&walk_out, bsize, tmp_dst, | ||
124 | in_place); | ||
125 | |||
126 | prfn(tfm, dst_p, src_p, crfn, info); | ||
127 | |||
128 | complete_src(&walk_in, bsize, src_p, in_place); | ||
129 | complete_dst(&walk_out, bsize, dst_p, in_place); | ||
130 | |||
131 | nbytes -= bsize; | ||
132 | } while (nbytes && | ||
133 | !scatterwalk_across_pages(&walk_in, bsize) && | ||
134 | !scatterwalk_across_pages(&walk_out, bsize)); | ||
135 | |||
136 | scatterwalk_done(&walk_in, 0, nbytes); | ||
137 | scatterwalk_done(&walk_out, 1, nbytes); | ||
138 | |||
139 | if (!nbytes) | ||
140 | return 0; | ||
141 | |||
142 | crypto_yield(tfm); | ||
143 | } | ||
144 | } | ||
145 | |||
146 | static void cbc_process_encrypt(struct crypto_tfm *tfm, u8 *dst, u8 *src, | ||
147 | cryptfn_t fn, void *info) | ||
148 | { | ||
149 | u8 *iv = info; | ||
150 | |||
151 | tfm->crt_u.cipher.cit_xor_block(iv, src); | ||
152 | fn(crypto_tfm_ctx(tfm), dst, iv); | ||
153 | memcpy(iv, dst, crypto_tfm_alg_blocksize(tfm)); | ||
154 | } | ||
155 | |||
156 | static void cbc_process_decrypt(struct crypto_tfm *tfm, u8 *dst, u8 *src, | ||
157 | cryptfn_t fn, void *info) | ||
158 | { | ||
159 | u8 *iv = info; | ||
160 | |||
161 | fn(crypto_tfm_ctx(tfm), dst, src); | ||
162 | tfm->crt_u.cipher.cit_xor_block(dst, iv); | ||
163 | memcpy(iv, src, crypto_tfm_alg_blocksize(tfm)); | ||
164 | } | ||
165 | |||
166 | static void ecb_process(struct crypto_tfm *tfm, u8 *dst, u8 *src, | ||
167 | cryptfn_t fn, void *info) | ||
168 | { | ||
169 | fn(crypto_tfm_ctx(tfm), dst, src); | ||
170 | } | ||
171 | |||
172 | static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) | ||
173 | { | ||
174 | struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher; | ||
175 | |||
176 | if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) { | ||
177 | tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; | ||
178 | return -EINVAL; | ||
179 | } else | ||
180 | return cia->cia_setkey(crypto_tfm_ctx(tfm), key, keylen, | ||
181 | &tfm->crt_flags); | ||
182 | } | ||
183 | |||
184 | static int ecb_encrypt(struct crypto_tfm *tfm, | ||
185 | struct scatterlist *dst, | ||
186 | struct scatterlist *src, unsigned int nbytes) | ||
187 | { | ||
188 | return crypt(tfm, dst, src, nbytes, | ||
189 | tfm->__crt_alg->cra_cipher.cia_encrypt, | ||
190 | ecb_process, NULL); | ||
191 | } | ||
192 | |||
193 | static int ecb_decrypt(struct crypto_tfm *tfm, | ||
194 | struct scatterlist *dst, | ||
195 | struct scatterlist *src, | ||
196 | unsigned int nbytes) | ||
197 | { | ||
198 | return crypt(tfm, dst, src, nbytes, | ||
199 | tfm->__crt_alg->cra_cipher.cia_decrypt, | ||
200 | ecb_process, NULL); | ||
201 | } | ||
202 | |||
203 | static int cbc_encrypt(struct crypto_tfm *tfm, | ||
204 | struct scatterlist *dst, | ||
205 | struct scatterlist *src, | ||
206 | unsigned int nbytes) | ||
207 | { | ||
208 | return crypt(tfm, dst, src, nbytes, | ||
209 | tfm->__crt_alg->cra_cipher.cia_encrypt, | ||
210 | cbc_process_encrypt, tfm->crt_cipher.cit_iv); | ||
211 | } | ||
212 | |||
213 | static int cbc_encrypt_iv(struct crypto_tfm *tfm, | ||
214 | struct scatterlist *dst, | ||
215 | struct scatterlist *src, | ||
216 | unsigned int nbytes, u8 *iv) | ||
217 | { | ||
218 | return crypt(tfm, dst, src, nbytes, | ||
219 | tfm->__crt_alg->cra_cipher.cia_encrypt, | ||
220 | cbc_process_encrypt, iv); | ||
221 | } | ||
222 | |||
223 | static int cbc_decrypt(struct crypto_tfm *tfm, | ||
224 | struct scatterlist *dst, | ||
225 | struct scatterlist *src, | ||
226 | unsigned int nbytes) | ||
227 | { | ||
228 | return crypt(tfm, dst, src, nbytes, | ||
229 | tfm->__crt_alg->cra_cipher.cia_decrypt, | ||
230 | cbc_process_decrypt, tfm->crt_cipher.cit_iv); | ||
231 | } | ||
232 | |||
233 | static int cbc_decrypt_iv(struct crypto_tfm *tfm, | ||
234 | struct scatterlist *dst, | ||
235 | struct scatterlist *src, | ||
236 | unsigned int nbytes, u8 *iv) | ||
237 | { | ||
238 | return crypt(tfm, dst, src, nbytes, | ||
239 | tfm->__crt_alg->cra_cipher.cia_decrypt, | ||
240 | cbc_process_decrypt, iv); | ||
241 | } | ||
242 | |||
243 | static int nocrypt(struct crypto_tfm *tfm, | ||
244 | struct scatterlist *dst, | ||
245 | struct scatterlist *src, | ||
246 | unsigned int nbytes) | ||
247 | { | ||
248 | return -ENOSYS; | ||
249 | } | ||
250 | |||
251 | static int nocrypt_iv(struct crypto_tfm *tfm, | ||
252 | struct scatterlist *dst, | ||
253 | struct scatterlist *src, | ||
254 | unsigned int nbytes, u8 *iv) | ||
255 | { | ||
256 | return -ENOSYS; | ||
257 | } | ||
258 | |||
259 | int crypto_init_cipher_flags(struct crypto_tfm *tfm, u32 flags) | ||
260 | { | ||
261 | u32 mode = flags & CRYPTO_TFM_MODE_MASK; | ||
262 | |||
263 | tfm->crt_cipher.cit_mode = mode ? mode : CRYPTO_TFM_MODE_ECB; | ||
264 | if (flags & CRYPTO_TFM_REQ_WEAK_KEY) | ||
265 | tfm->crt_flags = CRYPTO_TFM_REQ_WEAK_KEY; | ||
266 | |||
267 | return 0; | ||
268 | } | ||
269 | |||
270 | int crypto_init_cipher_ops(struct crypto_tfm *tfm) | ||
271 | { | ||
272 | int ret = 0; | ||
273 | struct cipher_tfm *ops = &tfm->crt_cipher; | ||
274 | |||
275 | ops->cit_setkey = setkey; | ||
276 | |||
277 | switch (tfm->crt_cipher.cit_mode) { | ||
278 | case CRYPTO_TFM_MODE_ECB: | ||
279 | ops->cit_encrypt = ecb_encrypt; | ||
280 | ops->cit_decrypt = ecb_decrypt; | ||
281 | break; | ||
282 | |||
283 | case CRYPTO_TFM_MODE_CBC: | ||
284 | ops->cit_encrypt = cbc_encrypt; | ||
285 | ops->cit_decrypt = cbc_decrypt; | ||
286 | ops->cit_encrypt_iv = cbc_encrypt_iv; | ||
287 | ops->cit_decrypt_iv = cbc_decrypt_iv; | ||
288 | break; | ||
289 | |||
290 | case CRYPTO_TFM_MODE_CFB: | ||
291 | ops->cit_encrypt = nocrypt; | ||
292 | ops->cit_decrypt = nocrypt; | ||
293 | ops->cit_encrypt_iv = nocrypt_iv; | ||
294 | ops->cit_decrypt_iv = nocrypt_iv; | ||
295 | break; | ||
296 | |||
297 | case CRYPTO_TFM_MODE_CTR: | ||
298 | ops->cit_encrypt = nocrypt; | ||
299 | ops->cit_decrypt = nocrypt; | ||
300 | ops->cit_encrypt_iv = nocrypt_iv; | ||
301 | ops->cit_decrypt_iv = nocrypt_iv; | ||
302 | break; | ||
303 | |||
304 | default: | ||
305 | BUG(); | ||
306 | } | ||
307 | |||
308 | if (ops->cit_mode == CRYPTO_TFM_MODE_CBC) { | ||
309 | |||
310 | switch (crypto_tfm_alg_blocksize(tfm)) { | ||
311 | case 8: | ||
312 | ops->cit_xor_block = xor_64; | ||
313 | break; | ||
314 | |||
315 | case 16: | ||
316 | ops->cit_xor_block = xor_128; | ||
317 | break; | ||
318 | |||
319 | default: | ||
320 | printk(KERN_WARNING "%s: block size %u not supported\n", | ||
321 | crypto_tfm_alg_name(tfm), | ||
322 | crypto_tfm_alg_blocksize(tfm)); | ||
323 | ret = -EINVAL; | ||
324 | goto out; | ||
325 | } | ||
326 | |||
327 | ops->cit_ivsize = crypto_tfm_alg_blocksize(tfm); | ||
328 | ops->cit_iv = kmalloc(ops->cit_ivsize, GFP_KERNEL); | ||
329 | if (ops->cit_iv == NULL) | ||
330 | ret = -ENOMEM; | ||
331 | } | ||
332 | |||
333 | out: | ||
334 | return ret; | ||
335 | } | ||
336 | |||
337 | void crypto_exit_cipher_ops(struct crypto_tfm *tfm) | ||
338 | { | ||
339 | if (tfm->crt_cipher.cit_iv) | ||
340 | kfree(tfm->crt_cipher.cit_iv); | ||
341 | } | ||