blob: ead8dc0d084e749e35733abc164f1e209aca3f6f [file] [log] [blame]
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +01001/*
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
Tadeusz Struka49de372016-03-03 21:49:26 +000021/*
22 * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
23 */
24static 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
30static 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
36static 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
42static 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
48static 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
54static 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
60static 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
66static 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
83static 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
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +010093struct pkcs1pad_ctx {
94 struct crypto_akcipher *child;
Tadeusz Struka49de372016-03-03 21:49:26 +000095 const char *hash_name;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +010096 unsigned int key_size;
97};
98
Tadeusz Struka49de372016-03-03 21:49:26 +000099struct pkcs1pad_inst_ctx {
100 struct crypto_akcipher_spawn spawn;
101 const char *hash_name;
102};
103
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100104struct 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
111static 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
131static 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
151static 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
164static 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
185static 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);
Andrzej Zaborowski53192162015-12-12 00:03:51 -0500190 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;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100193
194 if (!err) {
Andrzej Zaborowski53192162015-12-12 00:03:51 -0500195 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);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100210 }
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,
Andrzej Zaborowski53192162015-12-12 00:03:51 -0500215 pad_len);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100216 }
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
225static 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
241static 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
311static 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
352done:
353 kzfree(req_ctx->out_buf);
354
355 return err;
356}
357
358static 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
373static 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;
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700390 req_ctx->child_req.dst_len = ctx->key_size ;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100391
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700392 req_ctx->out_buf = kmalloc(ctx->key_size,
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100393 (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,
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700399 ctx->key_size, NULL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100400
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
414static 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);
Tadeusz Struka49de372016-03-03 21:49:26 +0000419 const struct rsa_asn1_template *digest_info = NULL;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100420 int err;
Tadeusz Struka49de372016-03-03 21:49:26 +0000421 unsigned int ps_end, digest_size = 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100422
423 if (!ctx->key_size)
424 return -EINVAL;
425
Tadeusz Struka49de372016-03-03 21:49:26 +0000426 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)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100435 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
Tadeusz Struka49de372016-03-03 21:49:26 +0000460 ps_end = ctx->key_size - digest_size - req->src_len - 2;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100461 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
Tadeusz Struka49de372016-03-03 21:49:26 +0000465 if (digest_info) {
466 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
467 digest_info->size);
468 }
469
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100470 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
497static 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);
Tadeusz Struka49de372016-03-03 21:49:26 +0000502 const struct rsa_asn1_template *digest_info;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100503 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
Tadeusz Struka49de372016-03-03 21:49:26 +0000517 err = -EBADMSG;
518 if (req_ctx->out_buf[0] != 0x01)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100519 goto done;
Tadeusz Struka49de372016-03-03 21:49:26 +0000520
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100521 for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
522 if (req_ctx->out_buf[pos] != 0xff)
523 break;
Tadeusz Struka49de372016-03-03 21:49:26 +0000524
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100525 if (pos < 9 || pos == req_ctx->child_req.dst_len ||
Tadeusz Struka49de372016-03-03 21:49:26 +0000526 req_ctx->out_buf[pos] != 0x00)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100527 goto done;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100528 pos++;
529
Tadeusz Struka49de372016-03-03 21:49:26 +0000530 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
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100544 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);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100552done:
553 kzfree(req_ctx->out_buf);
554
555 return err;
556}
557
558static 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 */
581static 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
Tadeusz Struka49de372016-03-03 21:49:26 +0000588 if (!ctx->key_size || req->src_len < ctx->key_size)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100589 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;
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700598 req_ctx->child_req.dst_len = ctx->key_size;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100599
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700600 req_ctx->out_buf = kmalloc(ctx->key_size,
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100601 (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,
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700607 ctx->key_size, NULL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100608
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
622static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
623{
624 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
Tadeusz Struka49de372016-03-03 21:49:26 +0000625 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100626 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;
Tadeusz Struka49de372016-03-03 21:49:26 +0000634 ctx->hash_name = ictx->hash_name;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100635 return 0;
636}
637
638static 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
645static void pkcs1pad_free(struct akcipher_instance *inst)
646{
Tadeusz Struka49de372016-03-03 21:49:26 +0000647 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
648 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100649
650 crypto_drop_akcipher(spawn);
Tadeusz Struka49de372016-03-03 21:49:26 +0000651 kfree(ctx->hash_name);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100652 kfree(inst);
653}
654
655static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
656{
657 struct crypto_attr_type *algt;
658 struct akcipher_instance *inst;
Tadeusz Struka49de372016-03-03 21:49:26 +0000659 struct pkcs1pad_inst_ctx *ctx;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100660 struct crypto_akcipher_spawn *spawn;
661 struct akcipher_alg *rsa_alg;
662 const char *rsa_alg_name;
Tadeusz Struka49de372016-03-03 21:49:26 +0000663 const char *hash_name;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100664 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
Tadeusz Struka49de372016-03-03 21:49:26 +0000677 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);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100682 if (!inst)
683 return -ENOMEM;
684
Tadeusz Struka49de372016-03-03 21:49:26 +0000685 ctx = akcipher_instance_ctx(inst);
686 spawn = &ctx->spawn;
687 ctx->hash_name = hash_name ? kstrdup(hash_name, GFP_KERNEL) : NULL;
688
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100689 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;
Tadeusz Struka49de372016-03-03 21:49:26 +0000698
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)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100708 goto out_drop_alg;
Tadeusz Struka49de372016-03-03 21:49:26 +0000709 } 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 }
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100720
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)
Tadeusz Struka49de372016-03-03 21:49:26 +0000741 goto out_free_hash;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100742
743 return 0;
744
Tadeusz Struka49de372016-03-03 21:49:26 +0000745out_free_hash:
746 kfree(ctx->hash_name);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100747out_drop_alg:
748 crypto_drop_akcipher(spawn);
749out_free_inst:
750 kfree(inst);
751 return err;
752}
753
754struct crypto_template rsa_pkcs1pad_tmpl = {
755 .name = "pkcs1pad",
756 .create = pkcs1pad_create,
757 .module = THIS_MODULE,
758};