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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 | ||
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 | ||
93 | struct pkcs1pad_ctx { | |
94 | struct crypto_akcipher *child; | |
95 | unsigned int key_size; | |
96 | }; | |
97 | ||
98 | struct pkcs1pad_inst_ctx { | |
99 | struct crypto_akcipher_spawn spawn; | |
100 | const struct rsa_asn1_template *digest_info; | |
101 | }; | |
102 | ||
103 | struct pkcs1pad_request { | |
104 | struct scatterlist in_sg[2], out_sg[1]; | |
105 | uint8_t *in_buf, *out_buf; | |
106 | struct akcipher_request child_req; | |
107 | }; | |
108 | ||
109 | static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key, | |
110 | unsigned int keylen) | |
111 | { | |
112 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
113 | int err; | |
114 | ||
115 | ctx->key_size = 0; | |
116 | ||
117 | err = crypto_akcipher_set_pub_key(ctx->child, key, keylen); | |
118 | if (err) | |
119 | return err; | |
120 | ||
121 | /* Find out new modulus size from rsa implementation */ | |
122 | err = crypto_akcipher_maxsize(ctx->child); | |
123 | if (err > PAGE_SIZE) | |
124 | return -ENOTSUPP; | |
125 | ||
126 | ctx->key_size = err; | |
127 | return 0; | |
128 | } | |
129 | ||
130 | static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key, | |
131 | unsigned int keylen) | |
132 | { | |
133 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
134 | int err; | |
135 | ||
136 | ctx->key_size = 0; | |
137 | ||
138 | err = crypto_akcipher_set_priv_key(ctx->child, key, keylen); | |
139 | if (err) | |
140 | return err; | |
141 | ||
142 | /* Find out new modulus size from rsa implementation */ | |
143 | err = crypto_akcipher_maxsize(ctx->child); | |
144 | if (err > PAGE_SIZE) | |
145 | return -ENOTSUPP; | |
146 | ||
147 | ctx->key_size = err; | |
148 | return 0; | |
149 | } | |
150 | ||
151 | static unsigned 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; | |
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 ? 2 : 1; | |
168 | ||
169 | sg_init_table(sg, nsegs); | |
170 | sg_set_buf(sg, buf, len); | |
171 | ||
172 | if (next) | |
173 | sg_chain(sg, nsegs, next); | |
174 | } | |
175 | ||
176 | static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err) | |
177 | { | |
178 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
179 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
180 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
181 | unsigned int pad_len; | |
182 | unsigned int len; | |
183 | u8 *out_buf; | |
184 | ||
185 | if (err) | |
186 | goto out; | |
187 | ||
188 | len = req_ctx->child_req.dst_len; | |
189 | pad_len = ctx->key_size - len; | |
190 | ||
191 | /* Four billion to one */ | |
192 | if (likely(!pad_len)) | |
193 | goto out; | |
194 | ||
195 | out_buf = kzalloc(ctx->key_size, GFP_ATOMIC); | |
196 | err = -ENOMEM; | |
197 | if (!out_buf) | |
198 | goto out; | |
199 | ||
200 | sg_copy_to_buffer(req->dst, sg_nents_for_len(req->dst, len), | |
201 | out_buf + pad_len, len); | |
202 | sg_copy_from_buffer(req->dst, | |
203 | sg_nents_for_len(req->dst, ctx->key_size), | |
204 | out_buf, ctx->key_size); | |
205 | kzfree(out_buf); | |
206 | ||
207 | out: | |
208 | req->dst_len = ctx->key_size; | |
209 | ||
210 | kfree(req_ctx->in_buf); | |
211 | ||
212 | return err; | |
213 | } | |
214 | ||
215 | static void pkcs1pad_encrypt_sign_complete_cb( | |
216 | struct crypto_async_request *child_async_req, int err) | |
217 | { | |
218 | struct akcipher_request *req = child_async_req->data; | |
219 | struct crypto_async_request async_req; | |
220 | ||
221 | if (err == -EINPROGRESS) | |
222 | return; | |
223 | ||
224 | async_req.data = req->base.data; | |
225 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
226 | async_req.flags = child_async_req->flags; | |
227 | req->base.complete(&async_req, | |
228 | pkcs1pad_encrypt_sign_complete(req, err)); | |
229 | } | |
230 | ||
231 | static int pkcs1pad_encrypt(struct akcipher_request *req) | |
232 | { | |
233 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
234 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
235 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
236 | int err; | |
237 | unsigned int i, ps_end; | |
238 | ||
239 | if (!ctx->key_size) | |
240 | return -EINVAL; | |
241 | ||
242 | if (req->src_len > ctx->key_size - 11) | |
243 | return -EOVERFLOW; | |
244 | ||
245 | if (req->dst_len < ctx->key_size) { | |
246 | req->dst_len = ctx->key_size; | |
247 | return -EOVERFLOW; | |
248 | } | |
249 | ||
250 | req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, | |
251 | GFP_KERNEL); | |
252 | if (!req_ctx->in_buf) | |
253 | return -ENOMEM; | |
254 | ||
255 | ps_end = ctx->key_size - req->src_len - 2; | |
256 | req_ctx->in_buf[0] = 0x02; | |
257 | for (i = 1; i < ps_end; i++) | |
258 | req_ctx->in_buf[i] = 1 + prandom_u32_max(255); | |
259 | req_ctx->in_buf[ps_end] = 0x00; | |
260 | ||
261 | pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, | |
262 | ctx->key_size - 1 - req->src_len, req->src); | |
263 | ||
264 | req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL); | |
265 | if (!req_ctx->out_buf) { | |
266 | kfree(req_ctx->in_buf); | |
267 | return -ENOMEM; | |
268 | } | |
269 | ||
270 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
271 | ctx->key_size, NULL); | |
272 | ||
273 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
274 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
275 | pkcs1pad_encrypt_sign_complete_cb, req); | |
276 | ||
277 | /* Reuse output buffer */ | |
278 | akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg, | |
279 | req->dst, ctx->key_size - 1, req->dst_len); | |
280 | ||
281 | err = crypto_akcipher_encrypt(&req_ctx->child_req); | |
282 | if (err != -EINPROGRESS && | |
283 | (err != -EBUSY || | |
284 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
285 | return pkcs1pad_encrypt_sign_complete(req, err); | |
286 | ||
287 | return err; | |
288 | } | |
289 | ||
290 | static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err) | |
291 | { | |
292 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
293 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
294 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
295 | unsigned int dst_len; | |
296 | unsigned int pos; | |
297 | u8 *out_buf; | |
298 | ||
299 | if (err) | |
300 | goto done; | |
301 | ||
302 | err = -EINVAL; | |
303 | dst_len = req_ctx->child_req.dst_len; | |
304 | if (dst_len < ctx->key_size - 1) | |
305 | goto done; | |
306 | ||
307 | out_buf = req_ctx->out_buf; | |
308 | if (dst_len == ctx->key_size) { | |
309 | if (out_buf[0] != 0x00) | |
310 | /* Decrypted value had no leading 0 byte */ | |
311 | goto done; | |
312 | ||
313 | dst_len--; | |
314 | out_buf++; | |
315 | } | |
316 | ||
317 | if (out_buf[0] != 0x02) | |
318 | goto done; | |
319 | ||
320 | for (pos = 1; pos < dst_len; pos++) | |
321 | if (out_buf[pos] == 0x00) | |
322 | break; | |
323 | if (pos < 9 || pos == dst_len) | |
324 | goto done; | |
325 | pos++; | |
326 | ||
327 | err = 0; | |
328 | ||
329 | if (req->dst_len < dst_len - pos) | |
330 | err = -EOVERFLOW; | |
331 | req->dst_len = dst_len - pos; | |
332 | ||
333 | if (!err) | |
334 | sg_copy_from_buffer(req->dst, | |
335 | sg_nents_for_len(req->dst, req->dst_len), | |
336 | out_buf + pos, req->dst_len); | |
337 | ||
338 | done: | |
339 | kzfree(req_ctx->out_buf); | |
340 | ||
341 | return err; | |
342 | } | |
343 | ||
344 | static void pkcs1pad_decrypt_complete_cb( | |
345 | struct crypto_async_request *child_async_req, int err) | |
346 | { | |
347 | struct akcipher_request *req = child_async_req->data; | |
348 | struct crypto_async_request async_req; | |
349 | ||
350 | if (err == -EINPROGRESS) | |
351 | return; | |
352 | ||
353 | async_req.data = req->base.data; | |
354 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
355 | async_req.flags = child_async_req->flags; | |
356 | req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err)); | |
357 | } | |
358 | ||
359 | static int pkcs1pad_decrypt(struct akcipher_request *req) | |
360 | { | |
361 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
362 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
363 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
364 | int err; | |
365 | ||
366 | if (!ctx->key_size || req->src_len != ctx->key_size) | |
367 | return -EINVAL; | |
368 | ||
369 | req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL); | |
370 | if (!req_ctx->out_buf) | |
371 | return -ENOMEM; | |
372 | ||
373 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
374 | ctx->key_size, NULL); | |
375 | ||
376 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
377 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
378 | pkcs1pad_decrypt_complete_cb, req); | |
379 | ||
380 | /* Reuse input buffer, output to a new buffer */ | |
381 | akcipher_request_set_crypt(&req_ctx->child_req, req->src, | |
382 | req_ctx->out_sg, req->src_len, | |
383 | ctx->key_size); | |
384 | ||
385 | err = crypto_akcipher_decrypt(&req_ctx->child_req); | |
386 | if (err != -EINPROGRESS && | |
387 | (err != -EBUSY || | |
388 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
389 | return pkcs1pad_decrypt_complete(req, err); | |
390 | ||
391 | return err; | |
392 | } | |
393 | ||
394 | static int pkcs1pad_sign(struct akcipher_request *req) | |
395 | { | |
396 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
397 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
398 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
399 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); | |
400 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); | |
401 | const struct rsa_asn1_template *digest_info = ictx->digest_info; | |
402 | int err; | |
403 | unsigned int ps_end, digest_size = 0; | |
404 | ||
405 | if (!ctx->key_size) | |
406 | return -EINVAL; | |
407 | ||
408 | digest_size = digest_info->size; | |
409 | ||
410 | if (req->src_len + digest_size > ctx->key_size - 11) | |
411 | return -EOVERFLOW; | |
412 | ||
413 | if (req->dst_len < ctx->key_size) { | |
414 | req->dst_len = ctx->key_size; | |
415 | return -EOVERFLOW; | |
416 | } | |
417 | ||
418 | req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, | |
419 | GFP_KERNEL); | |
420 | if (!req_ctx->in_buf) | |
421 | return -ENOMEM; | |
422 | ||
423 | ps_end = ctx->key_size - digest_size - req->src_len - 2; | |
424 | req_ctx->in_buf[0] = 0x01; | |
425 | memset(req_ctx->in_buf + 1, 0xff, ps_end - 1); | |
426 | req_ctx->in_buf[ps_end] = 0x00; | |
427 | ||
428 | memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data, | |
429 | digest_info->size); | |
430 | ||
431 | pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, | |
432 | ctx->key_size - 1 - req->src_len, req->src); | |
433 | ||
434 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
435 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
436 | pkcs1pad_encrypt_sign_complete_cb, req); | |
437 | ||
438 | /* Reuse output buffer */ | |
439 | akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg, | |
440 | req->dst, ctx->key_size - 1, req->dst_len); | |
441 | ||
442 | err = crypto_akcipher_sign(&req_ctx->child_req); | |
443 | if (err != -EINPROGRESS && | |
444 | (err != -EBUSY || | |
445 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
446 | return pkcs1pad_encrypt_sign_complete(req, err); | |
447 | ||
448 | return err; | |
449 | } | |
450 | ||
451 | static int pkcs1pad_verify_complete(struct akcipher_request *req, int err) | |
452 | { | |
453 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
454 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
455 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
456 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); | |
457 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); | |
458 | const struct rsa_asn1_template *digest_info = ictx->digest_info; | |
459 | unsigned int dst_len; | |
460 | unsigned int pos; | |
461 | u8 *out_buf; | |
462 | ||
463 | if (err) | |
464 | goto done; | |
465 | ||
466 | err = -EINVAL; | |
467 | dst_len = req_ctx->child_req.dst_len; | |
468 | if (dst_len < ctx->key_size - 1) | |
469 | goto done; | |
470 | ||
471 | out_buf = req_ctx->out_buf; | |
472 | if (dst_len == ctx->key_size) { | |
473 | if (out_buf[0] != 0x00) | |
474 | /* Decrypted value had no leading 0 byte */ | |
475 | goto done; | |
476 | ||
477 | dst_len--; | |
478 | out_buf++; | |
479 | } | |
480 | ||
481 | err = -EBADMSG; | |
482 | if (out_buf[0] != 0x01) | |
483 | goto done; | |
484 | ||
485 | for (pos = 1; pos < dst_len; pos++) | |
486 | if (out_buf[pos] != 0xff) | |
487 | break; | |
488 | ||
489 | if (pos < 9 || pos == dst_len || out_buf[pos] != 0x00) | |
490 | goto done; | |
491 | pos++; | |
492 | ||
493 | if (crypto_memneq(out_buf + pos, digest_info->data, digest_info->size)) | |
494 | goto done; | |
495 | ||
496 | pos += digest_info->size; | |
497 | ||
498 | err = 0; | |
499 | ||
500 | if (req->dst_len < dst_len - pos) | |
501 | err = -EOVERFLOW; | |
502 | req->dst_len = dst_len - pos; | |
503 | ||
504 | if (!err) | |
505 | sg_copy_from_buffer(req->dst, | |
506 | sg_nents_for_len(req->dst, req->dst_len), | |
507 | out_buf + pos, req->dst_len); | |
508 | done: | |
509 | kzfree(req_ctx->out_buf); | |
510 | ||
511 | return err; | |
512 | } | |
513 | ||
514 | static void pkcs1pad_verify_complete_cb( | |
515 | struct crypto_async_request *child_async_req, int err) | |
516 | { | |
517 | struct akcipher_request *req = child_async_req->data; | |
518 | struct crypto_async_request async_req; | |
519 | ||
520 | if (err == -EINPROGRESS) | |
521 | return; | |
522 | ||
523 | async_req.data = req->base.data; | |
524 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
525 | async_req.flags = child_async_req->flags; | |
526 | req->base.complete(&async_req, pkcs1pad_verify_complete(req, err)); | |
527 | } | |
528 | ||
529 | /* | |
530 | * The verify operation is here for completeness similar to the verification | |
531 | * defined in RFC2313 section 10.2 except that block type 0 is not accepted, | |
532 | * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to | |
533 | * retrieve the DigestInfo from a signature, instead the user is expected | |
534 | * to call the sign operation to generate the expected signature and compare | |
535 | * signatures instead of the message-digests. | |
536 | */ | |
537 | static int pkcs1pad_verify(struct akcipher_request *req) | |
538 | { | |
539 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
540 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
541 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
542 | int err; | |
543 | ||
544 | if (!ctx->key_size || req->src_len < ctx->key_size) | |
545 | return -EINVAL; | |
546 | ||
547 | req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL); | |
548 | if (!req_ctx->out_buf) | |
549 | return -ENOMEM; | |
550 | ||
551 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
552 | ctx->key_size, NULL); | |
553 | ||
554 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
555 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
556 | pkcs1pad_verify_complete_cb, req); | |
557 | ||
558 | /* Reuse input buffer, output to a new buffer */ | |
559 | akcipher_request_set_crypt(&req_ctx->child_req, req->src, | |
560 | req_ctx->out_sg, req->src_len, | |
561 | ctx->key_size); | |
562 | ||
563 | err = crypto_akcipher_verify(&req_ctx->child_req); | |
564 | if (err != -EINPROGRESS && | |
565 | (err != -EBUSY || | |
566 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
567 | return pkcs1pad_verify_complete(req, err); | |
568 | ||
569 | return err; | |
570 | } | |
571 | ||
572 | static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm) | |
573 | { | |
574 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); | |
575 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); | |
576 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
577 | struct crypto_akcipher *child_tfm; | |
578 | ||
579 | child_tfm = crypto_spawn_akcipher(&ictx->spawn); | |
580 | if (IS_ERR(child_tfm)) | |
581 | return PTR_ERR(child_tfm); | |
582 | ||
583 | ctx->child = child_tfm; | |
584 | return 0; | |
585 | } | |
586 | ||
587 | static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm) | |
588 | { | |
589 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
590 | ||
591 | crypto_free_akcipher(ctx->child); | |
592 | } | |
593 | ||
594 | static void pkcs1pad_free(struct akcipher_instance *inst) | |
595 | { | |
596 | struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst); | |
597 | struct crypto_akcipher_spawn *spawn = &ctx->spawn; | |
598 | ||
599 | crypto_drop_akcipher(spawn); | |
600 | kfree(inst); | |
601 | } | |
602 | ||
603 | static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb) | |
604 | { | |
605 | const struct rsa_asn1_template *digest_info; | |
606 | struct crypto_attr_type *algt; | |
607 | struct akcipher_instance *inst; | |
608 | struct pkcs1pad_inst_ctx *ctx; | |
609 | struct crypto_akcipher_spawn *spawn; | |
610 | struct akcipher_alg *rsa_alg; | |
611 | const char *rsa_alg_name; | |
612 | const char *hash_name; | |
613 | int err; | |
614 | ||
615 | algt = crypto_get_attr_type(tb); | |
616 | if (IS_ERR(algt)) | |
617 | return PTR_ERR(algt); | |
618 | ||
619 | if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask) | |
620 | return -EINVAL; | |
621 | ||
622 | rsa_alg_name = crypto_attr_alg_name(tb[1]); | |
623 | if (IS_ERR(rsa_alg_name)) | |
624 | return PTR_ERR(rsa_alg_name); | |
625 | ||
626 | hash_name = crypto_attr_alg_name(tb[2]); | |
627 | if (IS_ERR(hash_name)) | |
628 | return PTR_ERR(hash_name); | |
629 | ||
630 | digest_info = rsa_lookup_asn1(hash_name); | |
631 | if (!digest_info) | |
632 | return -EINVAL; | |
633 | ||
634 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); | |
635 | if (!inst) | |
636 | return -ENOMEM; | |
637 | ||
638 | ctx = akcipher_instance_ctx(inst); | |
639 | spawn = &ctx->spawn; | |
640 | ctx->digest_info = digest_info; | |
641 | ||
642 | crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst)); | |
643 | err = crypto_grab_akcipher(spawn, rsa_alg_name, 0, | |
644 | crypto_requires_sync(algt->type, algt->mask)); | |
645 | if (err) | |
646 | goto out_free_inst; | |
647 | ||
648 | rsa_alg = crypto_spawn_akcipher_alg(spawn); | |
649 | ||
650 | err = -ENAMETOOLONG; | |
651 | ||
652 | if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, | |
653 | "pkcs1pad(%s,%s)", rsa_alg->base.cra_name, hash_name) >= | |
654 | CRYPTO_MAX_ALG_NAME || | |
655 | snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, | |
656 | "pkcs1pad(%s,%s)", | |
657 | rsa_alg->base.cra_driver_name, hash_name) >= | |
658 | CRYPTO_MAX_ALG_NAME) | |
659 | goto out_drop_alg; | |
660 | ||
661 | inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC; | |
662 | inst->alg.base.cra_priority = rsa_alg->base.cra_priority; | |
663 | inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx); | |
664 | ||
665 | inst->alg.init = pkcs1pad_init_tfm; | |
666 | inst->alg.exit = pkcs1pad_exit_tfm; | |
667 | ||
668 | inst->alg.encrypt = pkcs1pad_encrypt; | |
669 | inst->alg.decrypt = pkcs1pad_decrypt; | |
670 | inst->alg.sign = pkcs1pad_sign; | |
671 | inst->alg.verify = pkcs1pad_verify; | |
672 | inst->alg.set_pub_key = pkcs1pad_set_pub_key; | |
673 | inst->alg.set_priv_key = pkcs1pad_set_priv_key; | |
674 | inst->alg.max_size = pkcs1pad_get_max_size; | |
675 | inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize; | |
676 | ||
677 | inst->free = pkcs1pad_free; | |
678 | ||
679 | err = akcipher_register_instance(tmpl, inst); | |
680 | if (err) | |
681 | goto out_drop_alg; | |
682 | ||
683 | return 0; | |
684 | ||
685 | out_drop_alg: | |
686 | crypto_drop_akcipher(spawn); | |
687 | out_free_inst: | |
688 | kfree(inst); | |
689 | return err; | |
690 | } | |
691 | ||
692 | struct crypto_template rsa_pkcs1pad_tmpl = { | |
693 | .name = "pkcs1pad", | |
694 | .create = pkcs1pad_create, | |
695 | .module = THIS_MODULE, | |
696 | }; |