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3d5b1ecd AZ |
1 | /* |
2 | * RSA padding templates. | |
3 | * | |
4 | * Copyright (c) 2015 Intel Corporation | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the Free | |
8 | * Software Foundation; either version 2 of the License, or (at your option) | |
9 | * any later version. | |
10 | */ | |
11 | ||
12 | #include <crypto/algapi.h> | |
13 | #include <crypto/akcipher.h> | |
14 | #include <crypto/internal/akcipher.h> | |
15 | #include <linux/err.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/random.h> | |
20 | ||
a49de377 TS |
21 | /* |
22 | * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2]. | |
23 | */ | |
24 | static const u8 rsa_digest_info_md5[] = { | |
25 | 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, | |
26 | 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */ | |
27 | 0x05, 0x00, 0x04, 0x10 | |
28 | }; | |
29 | ||
30 | static const u8 rsa_digest_info_sha1[] = { | |
31 | 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, | |
32 | 0x2b, 0x0e, 0x03, 0x02, 0x1a, | |
33 | 0x05, 0x00, 0x04, 0x14 | |
34 | }; | |
35 | ||
36 | static const u8 rsa_digest_info_rmd160[] = { | |
37 | 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, | |
38 | 0x2b, 0x24, 0x03, 0x02, 0x01, | |
39 | 0x05, 0x00, 0x04, 0x14 | |
40 | }; | |
41 | ||
42 | static const u8 rsa_digest_info_sha224[] = { | |
43 | 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, | |
44 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, | |
45 | 0x05, 0x00, 0x04, 0x1c | |
46 | }; | |
47 | ||
48 | static const u8 rsa_digest_info_sha256[] = { | |
49 | 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, | |
50 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, | |
51 | 0x05, 0x00, 0x04, 0x20 | |
52 | }; | |
53 | ||
54 | static const u8 rsa_digest_info_sha384[] = { | |
55 | 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, | |
56 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, | |
57 | 0x05, 0x00, 0x04, 0x30 | |
58 | }; | |
59 | ||
60 | static const u8 rsa_digest_info_sha512[] = { | |
61 | 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, | |
62 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, | |
63 | 0x05, 0x00, 0x04, 0x40 | |
64 | }; | |
65 | ||
66 | static const struct rsa_asn1_template { | |
67 | const char *name; | |
68 | const u8 *data; | |
69 | size_t size; | |
70 | } rsa_asn1_templates[] = { | |
71 | #define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) } | |
72 | _(md5), | |
73 | _(sha1), | |
74 | _(rmd160), | |
75 | _(sha256), | |
76 | _(sha384), | |
77 | _(sha512), | |
78 | _(sha224), | |
79 | { NULL } | |
80 | #undef _ | |
81 | }; | |
82 | ||
83 | static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name) | |
84 | { | |
85 | const struct rsa_asn1_template *p; | |
86 | ||
87 | for (p = rsa_asn1_templates; p->name; p++) | |
88 | if (strcmp(name, p->name) == 0) | |
89 | return p; | |
90 | return NULL; | |
91 | } | |
92 | ||
3d5b1ecd AZ |
93 | struct pkcs1pad_ctx { |
94 | struct crypto_akcipher *child; | |
a49de377 | 95 | const char *hash_name; |
3d5b1ecd AZ |
96 | unsigned int key_size; |
97 | }; | |
98 | ||
a49de377 TS |
99 | struct pkcs1pad_inst_ctx { |
100 | struct crypto_akcipher_spawn spawn; | |
101 | const char *hash_name; | |
102 | }; | |
103 | ||
3d5b1ecd AZ |
104 | struct pkcs1pad_request { |
105 | struct akcipher_request child_req; | |
106 | ||
107 | struct scatterlist in_sg[3], out_sg[2]; | |
108 | uint8_t *in_buf, *out_buf; | |
109 | }; | |
110 | ||
111 | static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key, | |
112 | unsigned int keylen) | |
113 | { | |
114 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
115 | int err, size; | |
116 | ||
117 | err = crypto_akcipher_set_pub_key(ctx->child, key, keylen); | |
118 | ||
119 | if (!err) { | |
120 | /* Find out new modulus size from rsa implementation */ | |
121 | size = crypto_akcipher_maxsize(ctx->child); | |
122 | ||
123 | ctx->key_size = size > 0 ? size : 0; | |
124 | if (size <= 0) | |
125 | err = size; | |
126 | } | |
127 | ||
128 | return err; | |
129 | } | |
130 | ||
131 | static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key, | |
132 | unsigned int keylen) | |
133 | { | |
134 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
135 | int err, size; | |
136 | ||
137 | err = crypto_akcipher_set_priv_key(ctx->child, key, keylen); | |
138 | ||
139 | if (!err) { | |
140 | /* Find out new modulus size from rsa implementation */ | |
141 | size = crypto_akcipher_maxsize(ctx->child); | |
142 | ||
143 | ctx->key_size = size > 0 ? size : 0; | |
144 | if (size <= 0) | |
145 | err = size; | |
146 | } | |
147 | ||
148 | return err; | |
149 | } | |
150 | ||
151 | static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm) | |
152 | { | |
153 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
154 | ||
155 | /* | |
156 | * The maximum destination buffer size for the encrypt/sign operations | |
157 | * will be the same as for RSA, even though it's smaller for | |
158 | * decrypt/verify. | |
159 | */ | |
160 | ||
161 | return ctx->key_size ?: -EINVAL; | |
162 | } | |
163 | ||
164 | static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len, | |
165 | struct scatterlist *next) | |
166 | { | |
167 | int nsegs = next ? 1 : 0; | |
168 | ||
169 | if (offset_in_page(buf) + len <= PAGE_SIZE) { | |
170 | nsegs += 1; | |
171 | sg_init_table(sg, nsegs); | |
172 | sg_set_buf(sg, buf, len); | |
173 | } else { | |
174 | nsegs += 2; | |
175 | sg_init_table(sg, nsegs); | |
176 | sg_set_buf(sg + 0, buf, PAGE_SIZE - offset_in_page(buf)); | |
177 | sg_set_buf(sg + 1, buf + PAGE_SIZE - offset_in_page(buf), | |
178 | offset_in_page(buf) + len - PAGE_SIZE); | |
179 | } | |
180 | ||
181 | if (next) | |
182 | sg_chain(sg, nsegs, next); | |
183 | } | |
184 | ||
185 | static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err) | |
186 | { | |
187 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
188 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
189 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
5319216d AZ |
190 | size_t pad_len = ctx->key_size - req_ctx->child_req.dst_len; |
191 | size_t chunk_len, pad_left; | |
192 | struct sg_mapping_iter miter; | |
3d5b1ecd AZ |
193 | |
194 | if (!err) { | |
5319216d AZ |
195 | if (pad_len) { |
196 | sg_miter_start(&miter, req->dst, | |
197 | sg_nents_for_len(req->dst, pad_len), | |
198 | SG_MITER_ATOMIC | SG_MITER_TO_SG); | |
199 | ||
200 | pad_left = pad_len; | |
201 | while (pad_left) { | |
202 | sg_miter_next(&miter); | |
203 | ||
204 | chunk_len = min(miter.length, pad_left); | |
205 | memset(miter.addr, 0, chunk_len); | |
206 | pad_left -= chunk_len; | |
207 | } | |
208 | ||
209 | sg_miter_stop(&miter); | |
3d5b1ecd AZ |
210 | } |
211 | ||
212 | sg_pcopy_from_buffer(req->dst, | |
213 | sg_nents_for_len(req->dst, ctx->key_size), | |
214 | req_ctx->out_buf, req_ctx->child_req.dst_len, | |
5319216d | 215 | pad_len); |
3d5b1ecd AZ |
216 | } |
217 | req->dst_len = ctx->key_size; | |
218 | ||
219 | kfree(req_ctx->in_buf); | |
220 | kzfree(req_ctx->out_buf); | |
221 | ||
222 | return err; | |
223 | } | |
224 | ||
225 | static void pkcs1pad_encrypt_sign_complete_cb( | |
226 | struct crypto_async_request *child_async_req, int err) | |
227 | { | |
228 | struct akcipher_request *req = child_async_req->data; | |
229 | struct crypto_async_request async_req; | |
230 | ||
231 | if (err == -EINPROGRESS) | |
232 | return; | |
233 | ||
234 | async_req.data = req->base.data; | |
235 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
236 | async_req.flags = child_async_req->flags; | |
237 | req->base.complete(&async_req, | |
238 | pkcs1pad_encrypt_sign_complete(req, err)); | |
239 | } | |
240 | ||
241 | static int pkcs1pad_encrypt(struct akcipher_request *req) | |
242 | { | |
243 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
244 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
245 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
246 | int err; | |
247 | unsigned int i, ps_end; | |
248 | ||
249 | if (!ctx->key_size) | |
250 | return -EINVAL; | |
251 | ||
252 | if (req->src_len > ctx->key_size - 11) | |
253 | return -EOVERFLOW; | |
254 | ||
255 | if (req->dst_len < ctx->key_size) { | |
256 | req->dst_len = ctx->key_size; | |
257 | return -EOVERFLOW; | |
258 | } | |
259 | ||
260 | if (ctx->key_size > PAGE_SIZE) | |
261 | return -ENOTSUPP; | |
262 | ||
263 | /* | |
264 | * Replace both input and output to add the padding in the input and | |
265 | * the potential missing leading zeros in the output. | |
266 | */ | |
267 | req_ctx->child_req.src = req_ctx->in_sg; | |
268 | req_ctx->child_req.src_len = ctx->key_size - 1; | |
269 | req_ctx->child_req.dst = req_ctx->out_sg; | |
270 | req_ctx->child_req.dst_len = ctx->key_size; | |
271 | ||
272 | req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, | |
273 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? | |
274 | GFP_KERNEL : GFP_ATOMIC); | |
275 | if (!req_ctx->in_buf) | |
276 | return -ENOMEM; | |
277 | ||
278 | ps_end = ctx->key_size - req->src_len - 2; | |
279 | req_ctx->in_buf[0] = 0x02; | |
280 | for (i = 1; i < ps_end; i++) | |
281 | req_ctx->in_buf[i] = 1 + prandom_u32_max(255); | |
282 | req_ctx->in_buf[ps_end] = 0x00; | |
283 | ||
284 | pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, | |
285 | ctx->key_size - 1 - req->src_len, req->src); | |
286 | ||
287 | req_ctx->out_buf = kmalloc(ctx->key_size, | |
288 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? | |
289 | GFP_KERNEL : GFP_ATOMIC); | |
290 | if (!req_ctx->out_buf) { | |
291 | kfree(req_ctx->in_buf); | |
292 | return -ENOMEM; | |
293 | } | |
294 | ||
295 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
296 | ctx->key_size, NULL); | |
297 | ||
298 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
299 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
300 | pkcs1pad_encrypt_sign_complete_cb, req); | |
301 | ||
302 | err = crypto_akcipher_encrypt(&req_ctx->child_req); | |
303 | if (err != -EINPROGRESS && | |
304 | (err != -EBUSY || | |
305 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
306 | return pkcs1pad_encrypt_sign_complete(req, err); | |
307 | ||
308 | return err; | |
309 | } | |
310 | ||
311 | static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err) | |
312 | { | |
313 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
314 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
315 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
316 | unsigned int pos; | |
317 | ||
318 | if (err == -EOVERFLOW) | |
319 | /* Decrypted value had no leading 0 byte */ | |
320 | err = -EINVAL; | |
321 | ||
322 | if (err) | |
323 | goto done; | |
324 | ||
325 | if (req_ctx->child_req.dst_len != ctx->key_size - 1) { | |
326 | err = -EINVAL; | |
327 | goto done; | |
328 | } | |
329 | ||
330 | if (req_ctx->out_buf[0] != 0x02) { | |
331 | err = -EINVAL; | |
332 | goto done; | |
333 | } | |
334 | for (pos = 1; pos < req_ctx->child_req.dst_len; pos++) | |
335 | if (req_ctx->out_buf[pos] == 0x00) | |
336 | break; | |
337 | if (pos < 9 || pos == req_ctx->child_req.dst_len) { | |
338 | err = -EINVAL; | |
339 | goto done; | |
340 | } | |
341 | pos++; | |
342 | ||
343 | if (req->dst_len < req_ctx->child_req.dst_len - pos) | |
344 | err = -EOVERFLOW; | |
345 | req->dst_len = req_ctx->child_req.dst_len - pos; | |
346 | ||
347 | if (!err) | |
348 | sg_copy_from_buffer(req->dst, | |
349 | sg_nents_for_len(req->dst, req->dst_len), | |
350 | req_ctx->out_buf + pos, req->dst_len); | |
351 | ||
352 | done: | |
353 | kzfree(req_ctx->out_buf); | |
354 | ||
355 | return err; | |
356 | } | |
357 | ||
358 | static void pkcs1pad_decrypt_complete_cb( | |
359 | struct crypto_async_request *child_async_req, int err) | |
360 | { | |
361 | struct akcipher_request *req = child_async_req->data; | |
362 | struct crypto_async_request async_req; | |
363 | ||
364 | if (err == -EINPROGRESS) | |
365 | return; | |
366 | ||
367 | async_req.data = req->base.data; | |
368 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
369 | async_req.flags = child_async_req->flags; | |
370 | req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err)); | |
371 | } | |
372 | ||
373 | static int pkcs1pad_decrypt(struct akcipher_request *req) | |
374 | { | |
375 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
376 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
377 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
378 | int err; | |
379 | ||
380 | if (!ctx->key_size || req->src_len != ctx->key_size) | |
381 | return -EINVAL; | |
382 | ||
383 | if (ctx->key_size > PAGE_SIZE) | |
384 | return -ENOTSUPP; | |
385 | ||
386 | /* Reuse input buffer, output to a new buffer */ | |
387 | req_ctx->child_req.src = req->src; | |
388 | req_ctx->child_req.src_len = req->src_len; | |
389 | req_ctx->child_req.dst = req_ctx->out_sg; | |
390 | req_ctx->child_req.dst_len = ctx->key_size - 1; | |
391 | ||
392 | req_ctx->out_buf = kmalloc(ctx->key_size - 1, | |
393 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? | |
394 | GFP_KERNEL : GFP_ATOMIC); | |
395 | if (!req_ctx->out_buf) | |
396 | return -ENOMEM; | |
397 | ||
398 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
399 | ctx->key_size - 1, NULL); | |
400 | ||
401 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
402 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
403 | pkcs1pad_decrypt_complete_cb, req); | |
404 | ||
405 | err = crypto_akcipher_decrypt(&req_ctx->child_req); | |
406 | if (err != -EINPROGRESS && | |
407 | (err != -EBUSY || | |
408 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
409 | return pkcs1pad_decrypt_complete(req, err); | |
410 | ||
411 | return err; | |
412 | } | |
413 | ||
414 | static int pkcs1pad_sign(struct akcipher_request *req) | |
415 | { | |
416 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
417 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
418 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
a49de377 | 419 | const struct rsa_asn1_template *digest_info = NULL; |
3d5b1ecd | 420 | int err; |
a49de377 | 421 | unsigned int ps_end, digest_size = 0; |
3d5b1ecd AZ |
422 | |
423 | if (!ctx->key_size) | |
424 | return -EINVAL; | |
425 | ||
a49de377 TS |
426 | if (ctx->hash_name) { |
427 | digest_info = rsa_lookup_asn1(ctx->hash_name); | |
428 | if (!digest_info) | |
429 | return -EINVAL; | |
430 | ||
431 | digest_size = digest_info->size; | |
432 | } | |
433 | ||
434 | if (req->src_len + digest_size > ctx->key_size - 11) | |
3d5b1ecd AZ |
435 | return -EOVERFLOW; |
436 | ||
437 | if (req->dst_len < ctx->key_size) { | |
438 | req->dst_len = ctx->key_size; | |
439 | return -EOVERFLOW; | |
440 | } | |
441 | ||
442 | if (ctx->key_size > PAGE_SIZE) | |
443 | return -ENOTSUPP; | |
444 | ||
445 | /* | |
446 | * Replace both input and output to add the padding in the input and | |
447 | * the potential missing leading zeros in the output. | |
448 | */ | |
449 | req_ctx->child_req.src = req_ctx->in_sg; | |
450 | req_ctx->child_req.src_len = ctx->key_size - 1; | |
451 | req_ctx->child_req.dst = req_ctx->out_sg; | |
452 | req_ctx->child_req.dst_len = ctx->key_size; | |
453 | ||
454 | req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, | |
455 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? | |
456 | GFP_KERNEL : GFP_ATOMIC); | |
457 | if (!req_ctx->in_buf) | |
458 | return -ENOMEM; | |
459 | ||
a49de377 | 460 | ps_end = ctx->key_size - digest_size - req->src_len - 2; |
3d5b1ecd AZ |
461 | req_ctx->in_buf[0] = 0x01; |
462 | memset(req_ctx->in_buf + 1, 0xff, ps_end - 1); | |
463 | req_ctx->in_buf[ps_end] = 0x00; | |
464 | ||
a49de377 TS |
465 | if (digest_info) { |
466 | memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data, | |
467 | digest_info->size); | |
468 | } | |
469 | ||
3d5b1ecd AZ |
470 | pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, |
471 | ctx->key_size - 1 - req->src_len, req->src); | |
472 | ||
473 | req_ctx->out_buf = kmalloc(ctx->key_size, | |
474 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? | |
475 | GFP_KERNEL : GFP_ATOMIC); | |
476 | if (!req_ctx->out_buf) { | |
477 | kfree(req_ctx->in_buf); | |
478 | return -ENOMEM; | |
479 | } | |
480 | ||
481 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
482 | ctx->key_size, NULL); | |
483 | ||
484 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
485 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
486 | pkcs1pad_encrypt_sign_complete_cb, req); | |
487 | ||
488 | err = crypto_akcipher_sign(&req_ctx->child_req); | |
489 | if (err != -EINPROGRESS && | |
490 | (err != -EBUSY || | |
491 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
492 | return pkcs1pad_encrypt_sign_complete(req, err); | |
493 | ||
494 | return err; | |
495 | } | |
496 | ||
497 | static int pkcs1pad_verify_complete(struct akcipher_request *req, int err) | |
498 | { | |
499 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
500 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
501 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
a49de377 | 502 | const struct rsa_asn1_template *digest_info; |
3d5b1ecd AZ |
503 | unsigned int pos; |
504 | ||
505 | if (err == -EOVERFLOW) | |
506 | /* Decrypted value had no leading 0 byte */ | |
507 | err = -EINVAL; | |
508 | ||
509 | if (err) | |
510 | goto done; | |
511 | ||
512 | if (req_ctx->child_req.dst_len != ctx->key_size - 1) { | |
513 | err = -EINVAL; | |
514 | goto done; | |
515 | } | |
516 | ||
a49de377 TS |
517 | err = -EBADMSG; |
518 | if (req_ctx->out_buf[0] != 0x01) | |
3d5b1ecd | 519 | goto done; |
a49de377 | 520 | |
3d5b1ecd AZ |
521 | for (pos = 1; pos < req_ctx->child_req.dst_len; pos++) |
522 | if (req_ctx->out_buf[pos] != 0xff) | |
523 | break; | |
a49de377 | 524 | |
3d5b1ecd | 525 | if (pos < 9 || pos == req_ctx->child_req.dst_len || |
a49de377 | 526 | req_ctx->out_buf[pos] != 0x00) |
3d5b1ecd | 527 | goto done; |
3d5b1ecd AZ |
528 | pos++; |
529 | ||
a49de377 TS |
530 | if (ctx->hash_name) { |
531 | digest_info = rsa_lookup_asn1(ctx->hash_name); | |
532 | if (!digest_info) | |
533 | goto done; | |
534 | ||
535 | if (memcmp(req_ctx->out_buf + pos, digest_info->data, | |
536 | digest_info->size)) | |
537 | goto done; | |
538 | ||
539 | pos += digest_info->size; | |
540 | } | |
541 | ||
542 | err = 0; | |
543 | ||
3d5b1ecd AZ |
544 | if (req->dst_len < req_ctx->child_req.dst_len - pos) |
545 | err = -EOVERFLOW; | |
546 | req->dst_len = req_ctx->child_req.dst_len - pos; | |
547 | ||
548 | if (!err) | |
549 | sg_copy_from_buffer(req->dst, | |
550 | sg_nents_for_len(req->dst, req->dst_len), | |
551 | req_ctx->out_buf + pos, req->dst_len); | |
3d5b1ecd AZ |
552 | done: |
553 | kzfree(req_ctx->out_buf); | |
554 | ||
555 | return err; | |
556 | } | |
557 | ||
558 | static void pkcs1pad_verify_complete_cb( | |
559 | struct crypto_async_request *child_async_req, int err) | |
560 | { | |
561 | struct akcipher_request *req = child_async_req->data; | |
562 | struct crypto_async_request async_req; | |
563 | ||
564 | if (err == -EINPROGRESS) | |
565 | return; | |
566 | ||
567 | async_req.data = req->base.data; | |
568 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
569 | async_req.flags = child_async_req->flags; | |
570 | req->base.complete(&async_req, pkcs1pad_verify_complete(req, err)); | |
571 | } | |
572 | ||
573 | /* | |
574 | * The verify operation is here for completeness similar to the verification | |
575 | * defined in RFC2313 section 10.2 except that block type 0 is not accepted, | |
576 | * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to | |
577 | * retrieve the DigestInfo from a signature, instead the user is expected | |
578 | * to call the sign operation to generate the expected signature and compare | |
579 | * signatures instead of the message-digests. | |
580 | */ | |
581 | static int pkcs1pad_verify(struct akcipher_request *req) | |
582 | { | |
583 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
584 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
585 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
586 | int err; | |
587 | ||
a49de377 | 588 | if (!ctx->key_size || req->src_len < ctx->key_size) |
3d5b1ecd AZ |
589 | return -EINVAL; |
590 | ||
591 | if (ctx->key_size > PAGE_SIZE) | |
592 | return -ENOTSUPP; | |
593 | ||
594 | /* Reuse input buffer, output to a new buffer */ | |
595 | req_ctx->child_req.src = req->src; | |
596 | req_ctx->child_req.src_len = req->src_len; | |
597 | req_ctx->child_req.dst = req_ctx->out_sg; | |
598 | req_ctx->child_req.dst_len = ctx->key_size - 1; | |
599 | ||
600 | req_ctx->out_buf = kmalloc(ctx->key_size - 1, | |
601 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? | |
602 | GFP_KERNEL : GFP_ATOMIC); | |
603 | if (!req_ctx->out_buf) | |
604 | return -ENOMEM; | |
605 | ||
606 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
607 | ctx->key_size - 1, NULL); | |
608 | ||
609 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
610 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
611 | pkcs1pad_verify_complete_cb, req); | |
612 | ||
613 | err = crypto_akcipher_verify(&req_ctx->child_req); | |
614 | if (err != -EINPROGRESS && | |
615 | (err != -EBUSY || | |
616 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
617 | return pkcs1pad_verify_complete(req, err); | |
618 | ||
619 | return err; | |
620 | } | |
621 | ||
622 | static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm) | |
623 | { | |
624 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); | |
a49de377 | 625 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); |
3d5b1ecd AZ |
626 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); |
627 | struct crypto_akcipher *child_tfm; | |
628 | ||
629 | child_tfm = crypto_spawn_akcipher(akcipher_instance_ctx(inst)); | |
630 | if (IS_ERR(child_tfm)) | |
631 | return PTR_ERR(child_tfm); | |
632 | ||
633 | ctx->child = child_tfm; | |
a49de377 | 634 | ctx->hash_name = ictx->hash_name; |
3d5b1ecd AZ |
635 | return 0; |
636 | } | |
637 | ||
638 | static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm) | |
639 | { | |
640 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
641 | ||
642 | crypto_free_akcipher(ctx->child); | |
643 | } | |
644 | ||
645 | static void pkcs1pad_free(struct akcipher_instance *inst) | |
646 | { | |
a49de377 TS |
647 | struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst); |
648 | struct crypto_akcipher_spawn *spawn = &ctx->spawn; | |
3d5b1ecd AZ |
649 | |
650 | crypto_drop_akcipher(spawn); | |
a49de377 | 651 | kfree(ctx->hash_name); |
3d5b1ecd AZ |
652 | kfree(inst); |
653 | } | |
654 | ||
655 | static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb) | |
656 | { | |
657 | struct crypto_attr_type *algt; | |
658 | struct akcipher_instance *inst; | |
a49de377 | 659 | struct pkcs1pad_inst_ctx *ctx; |
3d5b1ecd AZ |
660 | struct crypto_akcipher_spawn *spawn; |
661 | struct akcipher_alg *rsa_alg; | |
662 | const char *rsa_alg_name; | |
a49de377 | 663 | const char *hash_name; |
3d5b1ecd AZ |
664 | int err; |
665 | ||
666 | algt = crypto_get_attr_type(tb); | |
667 | if (IS_ERR(algt)) | |
668 | return PTR_ERR(algt); | |
669 | ||
670 | if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask) | |
671 | return -EINVAL; | |
672 | ||
673 | rsa_alg_name = crypto_attr_alg_name(tb[1]); | |
674 | if (IS_ERR(rsa_alg_name)) | |
675 | return PTR_ERR(rsa_alg_name); | |
676 | ||
a49de377 TS |
677 | hash_name = crypto_attr_alg_name(tb[2]); |
678 | if (IS_ERR(hash_name)) | |
679 | hash_name = NULL; | |
680 | ||
681 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); | |
3d5b1ecd AZ |
682 | if (!inst) |
683 | return -ENOMEM; | |
684 | ||
a49de377 TS |
685 | ctx = akcipher_instance_ctx(inst); |
686 | spawn = &ctx->spawn; | |
687 | ctx->hash_name = hash_name ? kstrdup(hash_name, GFP_KERNEL) : NULL; | |
688 | ||
3d5b1ecd AZ |
689 | crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst)); |
690 | err = crypto_grab_akcipher(spawn, rsa_alg_name, 0, | |
691 | crypto_requires_sync(algt->type, algt->mask)); | |
692 | if (err) | |
693 | goto out_free_inst; | |
694 | ||
695 | rsa_alg = crypto_spawn_akcipher_alg(spawn); | |
696 | ||
697 | err = -ENAMETOOLONG; | |
a49de377 TS |
698 | |
699 | if (!hash_name) { | |
700 | if (snprintf(inst->alg.base.cra_name, | |
701 | CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)", | |
702 | rsa_alg->base.cra_name) >= | |
703 | CRYPTO_MAX_ALG_NAME || | |
704 | snprintf(inst->alg.base.cra_driver_name, | |
705 | CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)", | |
706 | rsa_alg->base.cra_driver_name) >= | |
707 | CRYPTO_MAX_ALG_NAME) | |
3d5b1ecd | 708 | goto out_drop_alg; |
a49de377 TS |
709 | } else { |
710 | if (snprintf(inst->alg.base.cra_name, | |
711 | CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)", | |
712 | rsa_alg->base.cra_name, hash_name) >= | |
713 | CRYPTO_MAX_ALG_NAME || | |
714 | snprintf(inst->alg.base.cra_driver_name, | |
715 | CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)", | |
716 | rsa_alg->base.cra_driver_name, hash_name) >= | |
717 | CRYPTO_MAX_ALG_NAME) | |
718 | goto out_free_hash; | |
719 | } | |
3d5b1ecd AZ |
720 | |
721 | inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC; | |
722 | inst->alg.base.cra_priority = rsa_alg->base.cra_priority; | |
723 | inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx); | |
724 | ||
725 | inst->alg.init = pkcs1pad_init_tfm; | |
726 | inst->alg.exit = pkcs1pad_exit_tfm; | |
727 | ||
728 | inst->alg.encrypt = pkcs1pad_encrypt; | |
729 | inst->alg.decrypt = pkcs1pad_decrypt; | |
730 | inst->alg.sign = pkcs1pad_sign; | |
731 | inst->alg.verify = pkcs1pad_verify; | |
732 | inst->alg.set_pub_key = pkcs1pad_set_pub_key; | |
733 | inst->alg.set_priv_key = pkcs1pad_set_priv_key; | |
734 | inst->alg.max_size = pkcs1pad_get_max_size; | |
735 | inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize; | |
736 | ||
737 | inst->free = pkcs1pad_free; | |
738 | ||
739 | err = akcipher_register_instance(tmpl, inst); | |
740 | if (err) | |
a49de377 | 741 | goto out_free_hash; |
3d5b1ecd AZ |
742 | |
743 | return 0; | |
744 | ||
a49de377 TS |
745 | out_free_hash: |
746 | kfree(ctx->hash_name); | |
3d5b1ecd AZ |
747 | out_drop_alg: |
748 | crypto_drop_akcipher(spawn); | |
749 | out_free_inst: | |
750 | kfree(inst); | |
751 | return err; | |
752 | } | |
753 | ||
754 | struct crypto_template rsa_pkcs1pad_tmpl = { | |
755 | .name = "pkcs1pad", | |
756 | .create = pkcs1pad_create, | |
757 | .module = THIS_MODULE, | |
758 | }; |