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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; | |
3d5b1ecd AZ |
95 | unsigned int key_size; |
96 | }; | |
97 | ||
a49de377 TS |
98 | struct pkcs1pad_inst_ctx { |
99 | struct crypto_akcipher_spawn spawn; | |
c0d20d22 | 100 | const struct rsa_asn1_template *digest_info; |
a49de377 TS |
101 | }; |
102 | ||
3d5b1ecd AZ |
103 | struct pkcs1pad_request { |
104 | struct akcipher_request child_req; | |
105 | ||
106 | struct scatterlist in_sg[3], out_sg[2]; | |
107 | uint8_t *in_buf, *out_buf; | |
108 | }; | |
109 | ||
110 | static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key, | |
111 | unsigned int keylen) | |
112 | { | |
113 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
114 | int err, size; | |
115 | ||
116 | err = crypto_akcipher_set_pub_key(ctx->child, key, keylen); | |
117 | ||
118 | if (!err) { | |
119 | /* Find out new modulus size from rsa implementation */ | |
120 | size = crypto_akcipher_maxsize(ctx->child); | |
121 | ||
122 | ctx->key_size = size > 0 ? size : 0; | |
123 | if (size <= 0) | |
124 | err = size; | |
125 | } | |
126 | ||
127 | return err; | |
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, size; | |
135 | ||
136 | err = crypto_akcipher_set_priv_key(ctx->child, key, keylen); | |
137 | ||
138 | if (!err) { | |
139 | /* Find out new modulus size from rsa implementation */ | |
140 | size = crypto_akcipher_maxsize(ctx->child); | |
141 | ||
142 | ctx->key_size = size > 0 ? size : 0; | |
143 | if (size <= 0) | |
144 | err = size; | |
145 | } | |
146 | ||
147 | return err; | |
148 | } | |
149 | ||
150 | static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm) | |
151 | { | |
152 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
153 | ||
154 | /* | |
155 | * The maximum destination buffer size for the encrypt/sign operations | |
156 | * will be the same as for RSA, even though it's smaller for | |
157 | * decrypt/verify. | |
158 | */ | |
159 | ||
160 | return ctx->key_size ?: -EINVAL; | |
161 | } | |
162 | ||
163 | static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len, | |
164 | struct scatterlist *next) | |
165 | { | |
166 | int nsegs = next ? 1 : 0; | |
167 | ||
168 | if (offset_in_page(buf) + len <= PAGE_SIZE) { | |
169 | nsegs += 1; | |
170 | sg_init_table(sg, nsegs); | |
171 | sg_set_buf(sg, buf, len); | |
172 | } else { | |
173 | nsegs += 2; | |
174 | sg_init_table(sg, nsegs); | |
175 | sg_set_buf(sg + 0, buf, PAGE_SIZE - offset_in_page(buf)); | |
176 | sg_set_buf(sg + 1, buf + PAGE_SIZE - offset_in_page(buf), | |
177 | offset_in_page(buf) + len - PAGE_SIZE); | |
178 | } | |
179 | ||
180 | if (next) | |
181 | sg_chain(sg, nsegs, next); | |
182 | } | |
183 | ||
184 | static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err) | |
185 | { | |
186 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
187 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
188 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
5319216d AZ |
189 | size_t pad_len = ctx->key_size - req_ctx->child_req.dst_len; |
190 | size_t chunk_len, pad_left; | |
191 | struct sg_mapping_iter miter; | |
3d5b1ecd AZ |
192 | |
193 | if (!err) { | |
5319216d AZ |
194 | if (pad_len) { |
195 | sg_miter_start(&miter, req->dst, | |
196 | sg_nents_for_len(req->dst, pad_len), | |
197 | SG_MITER_ATOMIC | SG_MITER_TO_SG); | |
198 | ||
199 | pad_left = pad_len; | |
200 | while (pad_left) { | |
201 | sg_miter_next(&miter); | |
202 | ||
203 | chunk_len = min(miter.length, pad_left); | |
204 | memset(miter.addr, 0, chunk_len); | |
205 | pad_left -= chunk_len; | |
206 | } | |
207 | ||
208 | sg_miter_stop(&miter); | |
3d5b1ecd AZ |
209 | } |
210 | ||
211 | sg_pcopy_from_buffer(req->dst, | |
212 | sg_nents_for_len(req->dst, ctx->key_size), | |
213 | req_ctx->out_buf, req_ctx->child_req.dst_len, | |
5319216d | 214 | pad_len); |
3d5b1ecd AZ |
215 | } |
216 | req->dst_len = ctx->key_size; | |
217 | ||
218 | kfree(req_ctx->in_buf); | |
219 | kzfree(req_ctx->out_buf); | |
220 | ||
221 | return err; | |
222 | } | |
223 | ||
224 | static void pkcs1pad_encrypt_sign_complete_cb( | |
225 | struct crypto_async_request *child_async_req, int err) | |
226 | { | |
227 | struct akcipher_request *req = child_async_req->data; | |
228 | struct crypto_async_request async_req; | |
229 | ||
230 | if (err == -EINPROGRESS) | |
231 | return; | |
232 | ||
233 | async_req.data = req->base.data; | |
234 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
235 | async_req.flags = child_async_req->flags; | |
236 | req->base.complete(&async_req, | |
237 | pkcs1pad_encrypt_sign_complete(req, err)); | |
238 | } | |
239 | ||
240 | static int pkcs1pad_encrypt(struct akcipher_request *req) | |
241 | { | |
242 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
243 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
244 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
245 | int err; | |
246 | unsigned int i, ps_end; | |
247 | ||
248 | if (!ctx->key_size) | |
249 | return -EINVAL; | |
250 | ||
251 | if (req->src_len > ctx->key_size - 11) | |
252 | return -EOVERFLOW; | |
253 | ||
254 | if (req->dst_len < ctx->key_size) { | |
255 | req->dst_len = ctx->key_size; | |
256 | return -EOVERFLOW; | |
257 | } | |
258 | ||
259 | if (ctx->key_size > PAGE_SIZE) | |
260 | return -ENOTSUPP; | |
261 | ||
262 | /* | |
263 | * Replace both input and output to add the padding in the input and | |
264 | * the potential missing leading zeros in the output. | |
265 | */ | |
266 | req_ctx->child_req.src = req_ctx->in_sg; | |
267 | req_ctx->child_req.src_len = ctx->key_size - 1; | |
268 | req_ctx->child_req.dst = req_ctx->out_sg; | |
269 | req_ctx->child_req.dst_len = ctx->key_size; | |
270 | ||
271 | req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, | |
272 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? | |
273 | GFP_KERNEL : GFP_ATOMIC); | |
274 | if (!req_ctx->in_buf) | |
275 | return -ENOMEM; | |
276 | ||
277 | ps_end = ctx->key_size - req->src_len - 2; | |
278 | req_ctx->in_buf[0] = 0x02; | |
279 | for (i = 1; i < ps_end; i++) | |
280 | req_ctx->in_buf[i] = 1 + prandom_u32_max(255); | |
281 | req_ctx->in_buf[ps_end] = 0x00; | |
282 | ||
283 | pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, | |
284 | ctx->key_size - 1 - req->src_len, req->src); | |
285 | ||
286 | req_ctx->out_buf = kmalloc(ctx->key_size, | |
287 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? | |
288 | GFP_KERNEL : GFP_ATOMIC); | |
289 | if (!req_ctx->out_buf) { | |
290 | kfree(req_ctx->in_buf); | |
291 | return -ENOMEM; | |
292 | } | |
293 | ||
294 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
295 | ctx->key_size, NULL); | |
296 | ||
297 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
298 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
299 | pkcs1pad_encrypt_sign_complete_cb, req); | |
300 | ||
301 | err = crypto_akcipher_encrypt(&req_ctx->child_req); | |
302 | if (err != -EINPROGRESS && | |
303 | (err != -EBUSY || | |
304 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
305 | return pkcs1pad_encrypt_sign_complete(req, err); | |
306 | ||
307 | return err; | |
308 | } | |
309 | ||
310 | static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err) | |
311 | { | |
312 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
313 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
314 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
315 | unsigned int pos; | |
316 | ||
317 | if (err == -EOVERFLOW) | |
318 | /* Decrypted value had no leading 0 byte */ | |
319 | err = -EINVAL; | |
320 | ||
321 | if (err) | |
322 | goto done; | |
323 | ||
324 | if (req_ctx->child_req.dst_len != ctx->key_size - 1) { | |
325 | err = -EINVAL; | |
326 | goto done; | |
327 | } | |
328 | ||
329 | if (req_ctx->out_buf[0] != 0x02) { | |
330 | err = -EINVAL; | |
331 | goto done; | |
332 | } | |
333 | for (pos = 1; pos < req_ctx->child_req.dst_len; pos++) | |
334 | if (req_ctx->out_buf[pos] == 0x00) | |
335 | break; | |
336 | if (pos < 9 || pos == req_ctx->child_req.dst_len) { | |
337 | err = -EINVAL; | |
338 | goto done; | |
339 | } | |
340 | pos++; | |
341 | ||
342 | if (req->dst_len < req_ctx->child_req.dst_len - pos) | |
343 | err = -EOVERFLOW; | |
344 | req->dst_len = req_ctx->child_req.dst_len - pos; | |
345 | ||
346 | if (!err) | |
347 | sg_copy_from_buffer(req->dst, | |
348 | sg_nents_for_len(req->dst, req->dst_len), | |
349 | req_ctx->out_buf + pos, req->dst_len); | |
350 | ||
351 | done: | |
352 | kzfree(req_ctx->out_buf); | |
353 | ||
354 | return err; | |
355 | } | |
356 | ||
357 | static void pkcs1pad_decrypt_complete_cb( | |
358 | struct crypto_async_request *child_async_req, int err) | |
359 | { | |
360 | struct akcipher_request *req = child_async_req->data; | |
361 | struct crypto_async_request async_req; | |
362 | ||
363 | if (err == -EINPROGRESS) | |
364 | return; | |
365 | ||
366 | async_req.data = req->base.data; | |
367 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
368 | async_req.flags = child_async_req->flags; | |
369 | req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err)); | |
370 | } | |
371 | ||
372 | static int pkcs1pad_decrypt(struct akcipher_request *req) | |
373 | { | |
374 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
375 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
376 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
377 | int err; | |
378 | ||
379 | if (!ctx->key_size || req->src_len != ctx->key_size) | |
380 | return -EINVAL; | |
381 | ||
382 | if (ctx->key_size > PAGE_SIZE) | |
383 | return -ENOTSUPP; | |
384 | ||
385 | /* Reuse input buffer, output to a new buffer */ | |
386 | req_ctx->child_req.src = req->src; | |
387 | req_ctx->child_req.src_len = req->src_len; | |
388 | req_ctx->child_req.dst = req_ctx->out_sg; | |
6f0904ad | 389 | req_ctx->child_req.dst_len = ctx->key_size ; |
3d5b1ecd | 390 | |
6f0904ad | 391 | req_ctx->out_buf = kmalloc(ctx->key_size, |
3d5b1ecd AZ |
392 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? |
393 | GFP_KERNEL : GFP_ATOMIC); | |
394 | if (!req_ctx->out_buf) | |
395 | return -ENOMEM; | |
396 | ||
397 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
6f0904ad | 398 | ctx->key_size, NULL); |
3d5b1ecd AZ |
399 | |
400 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
401 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
402 | pkcs1pad_decrypt_complete_cb, req); | |
403 | ||
404 | err = crypto_akcipher_decrypt(&req_ctx->child_req); | |
405 | if (err != -EINPROGRESS && | |
406 | (err != -EBUSY || | |
407 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
408 | return pkcs1pad_decrypt_complete(req, err); | |
409 | ||
410 | return err; | |
411 | } | |
412 | ||
413 | static int pkcs1pad_sign(struct akcipher_request *req) | |
414 | { | |
415 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
416 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
417 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
c0d20d22 HX |
418 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); |
419 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); | |
420 | const struct rsa_asn1_template *digest_info = ictx->digest_info; | |
3d5b1ecd | 421 | int err; |
a49de377 | 422 | unsigned int ps_end, digest_size = 0; |
3d5b1ecd AZ |
423 | |
424 | if (!ctx->key_size) | |
425 | return -EINVAL; | |
426 | ||
c0d20d22 | 427 | digest_size = digest_info->size; |
a49de377 TS |
428 | |
429 | if (req->src_len + digest_size > ctx->key_size - 11) | |
3d5b1ecd AZ |
430 | return -EOVERFLOW; |
431 | ||
432 | if (req->dst_len < ctx->key_size) { | |
433 | req->dst_len = ctx->key_size; | |
434 | return -EOVERFLOW; | |
435 | } | |
436 | ||
437 | if (ctx->key_size > PAGE_SIZE) | |
438 | return -ENOTSUPP; | |
439 | ||
440 | /* | |
441 | * Replace both input and output to add the padding in the input and | |
442 | * the potential missing leading zeros in the output. | |
443 | */ | |
444 | req_ctx->child_req.src = req_ctx->in_sg; | |
445 | req_ctx->child_req.src_len = ctx->key_size - 1; | |
446 | req_ctx->child_req.dst = req_ctx->out_sg; | |
447 | req_ctx->child_req.dst_len = ctx->key_size; | |
448 | ||
449 | req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, | |
450 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? | |
451 | GFP_KERNEL : GFP_ATOMIC); | |
452 | if (!req_ctx->in_buf) | |
453 | return -ENOMEM; | |
454 | ||
a49de377 | 455 | ps_end = ctx->key_size - digest_size - req->src_len - 2; |
3d5b1ecd AZ |
456 | req_ctx->in_buf[0] = 0x01; |
457 | memset(req_ctx->in_buf + 1, 0xff, ps_end - 1); | |
458 | req_ctx->in_buf[ps_end] = 0x00; | |
459 | ||
c0d20d22 HX |
460 | memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data, |
461 | digest_info->size); | |
a49de377 | 462 | |
3d5b1ecd AZ |
463 | pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, |
464 | ctx->key_size - 1 - req->src_len, req->src); | |
465 | ||
466 | req_ctx->out_buf = kmalloc(ctx->key_size, | |
467 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? | |
468 | GFP_KERNEL : GFP_ATOMIC); | |
469 | if (!req_ctx->out_buf) { | |
470 | kfree(req_ctx->in_buf); | |
471 | return -ENOMEM; | |
472 | } | |
473 | ||
474 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
475 | ctx->key_size, NULL); | |
476 | ||
477 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
478 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
479 | pkcs1pad_encrypt_sign_complete_cb, req); | |
480 | ||
481 | err = crypto_akcipher_sign(&req_ctx->child_req); | |
482 | if (err != -EINPROGRESS && | |
483 | (err != -EBUSY || | |
484 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
485 | return pkcs1pad_encrypt_sign_complete(req, err); | |
486 | ||
487 | return err; | |
488 | } | |
489 | ||
490 | static int pkcs1pad_verify_complete(struct akcipher_request *req, int err) | |
491 | { | |
492 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
493 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
494 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
c0d20d22 HX |
495 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); |
496 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); | |
497 | const struct rsa_asn1_template *digest_info = ictx->digest_info; | |
3d5b1ecd AZ |
498 | unsigned int pos; |
499 | ||
500 | if (err == -EOVERFLOW) | |
501 | /* Decrypted value had no leading 0 byte */ | |
502 | err = -EINVAL; | |
503 | ||
504 | if (err) | |
505 | goto done; | |
506 | ||
507 | if (req_ctx->child_req.dst_len != ctx->key_size - 1) { | |
508 | err = -EINVAL; | |
509 | goto done; | |
510 | } | |
511 | ||
a49de377 TS |
512 | err = -EBADMSG; |
513 | if (req_ctx->out_buf[0] != 0x01) | |
3d5b1ecd | 514 | goto done; |
a49de377 | 515 | |
3d5b1ecd AZ |
516 | for (pos = 1; pos < req_ctx->child_req.dst_len; pos++) |
517 | if (req_ctx->out_buf[pos] != 0xff) | |
518 | break; | |
a49de377 | 519 | |
3d5b1ecd | 520 | if (pos < 9 || pos == req_ctx->child_req.dst_len || |
a49de377 | 521 | req_ctx->out_buf[pos] != 0x00) |
3d5b1ecd | 522 | goto done; |
3d5b1ecd AZ |
523 | pos++; |
524 | ||
c0d20d22 HX |
525 | if (memcmp(req_ctx->out_buf + pos, digest_info->data, |
526 | digest_info->size)) | |
527 | goto done; | |
a49de377 | 528 | |
c0d20d22 | 529 | pos += digest_info->size; |
a49de377 TS |
530 | |
531 | err = 0; | |
532 | ||
3d5b1ecd AZ |
533 | if (req->dst_len < req_ctx->child_req.dst_len - pos) |
534 | err = -EOVERFLOW; | |
535 | req->dst_len = req_ctx->child_req.dst_len - pos; | |
536 | ||
537 | if (!err) | |
538 | sg_copy_from_buffer(req->dst, | |
539 | sg_nents_for_len(req->dst, req->dst_len), | |
540 | req_ctx->out_buf + pos, req->dst_len); | |
3d5b1ecd AZ |
541 | done: |
542 | kzfree(req_ctx->out_buf); | |
543 | ||
544 | return err; | |
545 | } | |
546 | ||
547 | static void pkcs1pad_verify_complete_cb( | |
548 | struct crypto_async_request *child_async_req, int err) | |
549 | { | |
550 | struct akcipher_request *req = child_async_req->data; | |
551 | struct crypto_async_request async_req; | |
552 | ||
553 | if (err == -EINPROGRESS) | |
554 | return; | |
555 | ||
556 | async_req.data = req->base.data; | |
557 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
558 | async_req.flags = child_async_req->flags; | |
559 | req->base.complete(&async_req, pkcs1pad_verify_complete(req, err)); | |
560 | } | |
561 | ||
562 | /* | |
563 | * The verify operation is here for completeness similar to the verification | |
564 | * defined in RFC2313 section 10.2 except that block type 0 is not accepted, | |
565 | * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to | |
566 | * retrieve the DigestInfo from a signature, instead the user is expected | |
567 | * to call the sign operation to generate the expected signature and compare | |
568 | * signatures instead of the message-digests. | |
569 | */ | |
570 | static int pkcs1pad_verify(struct akcipher_request *req) | |
571 | { | |
572 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
573 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
574 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
575 | int err; | |
576 | ||
a49de377 | 577 | if (!ctx->key_size || req->src_len < ctx->key_size) |
3d5b1ecd AZ |
578 | return -EINVAL; |
579 | ||
580 | if (ctx->key_size > PAGE_SIZE) | |
581 | return -ENOTSUPP; | |
582 | ||
583 | /* Reuse input buffer, output to a new buffer */ | |
584 | req_ctx->child_req.src = req->src; | |
585 | req_ctx->child_req.src_len = req->src_len; | |
586 | req_ctx->child_req.dst = req_ctx->out_sg; | |
6f0904ad | 587 | req_ctx->child_req.dst_len = ctx->key_size; |
3d5b1ecd | 588 | |
6f0904ad | 589 | req_ctx->out_buf = kmalloc(ctx->key_size, |
3d5b1ecd AZ |
590 | (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? |
591 | GFP_KERNEL : GFP_ATOMIC); | |
592 | if (!req_ctx->out_buf) | |
593 | return -ENOMEM; | |
594 | ||
595 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
6f0904ad | 596 | ctx->key_size, NULL); |
3d5b1ecd AZ |
597 | |
598 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
599 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
600 | pkcs1pad_verify_complete_cb, req); | |
601 | ||
602 | err = crypto_akcipher_verify(&req_ctx->child_req); | |
603 | if (err != -EINPROGRESS && | |
604 | (err != -EBUSY || | |
605 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
606 | return pkcs1pad_verify_complete(req, err); | |
607 | ||
608 | return err; | |
609 | } | |
610 | ||
611 | static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm) | |
612 | { | |
613 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); | |
a49de377 | 614 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); |
3d5b1ecd AZ |
615 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); |
616 | struct crypto_akcipher *child_tfm; | |
617 | ||
c0d20d22 | 618 | child_tfm = crypto_spawn_akcipher(&ictx->spawn); |
3d5b1ecd AZ |
619 | if (IS_ERR(child_tfm)) |
620 | return PTR_ERR(child_tfm); | |
621 | ||
622 | ctx->child = child_tfm; | |
3d5b1ecd AZ |
623 | return 0; |
624 | } | |
625 | ||
626 | static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm) | |
627 | { | |
628 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
629 | ||
630 | crypto_free_akcipher(ctx->child); | |
631 | } | |
632 | ||
633 | static void pkcs1pad_free(struct akcipher_instance *inst) | |
634 | { | |
a49de377 TS |
635 | struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst); |
636 | struct crypto_akcipher_spawn *spawn = &ctx->spawn; | |
3d5b1ecd AZ |
637 | |
638 | crypto_drop_akcipher(spawn); | |
3d5b1ecd AZ |
639 | kfree(inst); |
640 | } | |
641 | ||
642 | static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb) | |
643 | { | |
c0d20d22 | 644 | const struct rsa_asn1_template *digest_info; |
3d5b1ecd AZ |
645 | struct crypto_attr_type *algt; |
646 | struct akcipher_instance *inst; | |
a49de377 | 647 | struct pkcs1pad_inst_ctx *ctx; |
3d5b1ecd AZ |
648 | struct crypto_akcipher_spawn *spawn; |
649 | struct akcipher_alg *rsa_alg; | |
650 | const char *rsa_alg_name; | |
a49de377 | 651 | const char *hash_name; |
3d5b1ecd AZ |
652 | int err; |
653 | ||
654 | algt = crypto_get_attr_type(tb); | |
655 | if (IS_ERR(algt)) | |
656 | return PTR_ERR(algt); | |
657 | ||
658 | if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask) | |
659 | return -EINVAL; | |
660 | ||
661 | rsa_alg_name = crypto_attr_alg_name(tb[1]); | |
662 | if (IS_ERR(rsa_alg_name)) | |
663 | return PTR_ERR(rsa_alg_name); | |
664 | ||
a49de377 TS |
665 | hash_name = crypto_attr_alg_name(tb[2]); |
666 | if (IS_ERR(hash_name)) | |
c0d20d22 HX |
667 | return PTR_ERR(hash_name); |
668 | ||
669 | digest_info = rsa_lookup_asn1(hash_name); | |
670 | if (!digest_info) | |
671 | return -EINVAL; | |
a49de377 TS |
672 | |
673 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); | |
3d5b1ecd AZ |
674 | if (!inst) |
675 | return -ENOMEM; | |
676 | ||
a49de377 TS |
677 | ctx = akcipher_instance_ctx(inst); |
678 | spawn = &ctx->spawn; | |
c0d20d22 | 679 | ctx->digest_info = digest_info; |
a49de377 | 680 | |
3d5b1ecd AZ |
681 | crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst)); |
682 | err = crypto_grab_akcipher(spawn, rsa_alg_name, 0, | |
683 | crypto_requires_sync(algt->type, algt->mask)); | |
684 | if (err) | |
685 | goto out_free_inst; | |
686 | ||
687 | rsa_alg = crypto_spawn_akcipher_alg(spawn); | |
688 | ||
689 | err = -ENAMETOOLONG; | |
a49de377 | 690 | |
c0d20d22 HX |
691 | if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, |
692 | "pkcs1pad(%s,%s)", rsa_alg->base.cra_name, hash_name) >= | |
693 | CRYPTO_MAX_ALG_NAME || | |
694 | snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, | |
695 | "pkcs1pad(%s,%s)", | |
696 | rsa_alg->base.cra_driver_name, hash_name) >= | |
697 | CRYPTO_MAX_ALG_NAME) | |
3d5b1ecd AZ |
698 | goto out_drop_alg; |
699 | ||
700 | inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC; | |
701 | inst->alg.base.cra_priority = rsa_alg->base.cra_priority; | |
702 | inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx); | |
703 | ||
704 | inst->alg.init = pkcs1pad_init_tfm; | |
705 | inst->alg.exit = pkcs1pad_exit_tfm; | |
706 | ||
707 | inst->alg.encrypt = pkcs1pad_encrypt; | |
708 | inst->alg.decrypt = pkcs1pad_decrypt; | |
709 | inst->alg.sign = pkcs1pad_sign; | |
710 | inst->alg.verify = pkcs1pad_verify; | |
711 | inst->alg.set_pub_key = pkcs1pad_set_pub_key; | |
712 | inst->alg.set_priv_key = pkcs1pad_set_priv_key; | |
713 | inst->alg.max_size = pkcs1pad_get_max_size; | |
714 | inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize; | |
715 | ||
716 | inst->free = pkcs1pad_free; | |
717 | ||
718 | err = akcipher_register_instance(tmpl, inst); | |
719 | if (err) | |
c0d20d22 | 720 | goto out_drop_alg; |
3d5b1ecd AZ |
721 | |
722 | return 0; | |
723 | ||
724 | out_drop_alg: | |
725 | crypto_drop_akcipher(spawn); | |
726 | out_free_inst: | |
727 | kfree(inst); | |
728 | return err; | |
729 | } | |
730 | ||
731 | struct crypto_template rsa_pkcs1pad_tmpl = { | |
732 | .name = "pkcs1pad", | |
733 | .create = pkcs1pad_create, | |
734 | .module = THIS_MODULE, | |
735 | }; |