blob: 877019a6d3ea81c3e130deb882e5ceccb1fe62ae [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;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +010095 unsigned int key_size;
96};
97
Tadeusz Struka49de372016-03-03 21:49:26 +000098struct pkcs1pad_inst_ctx {
99 struct crypto_akcipher_spawn spawn;
Herbert Xuc0d20d22016-06-29 19:32:23 +0800100 const struct rsa_asn1_template *digest_info;
Tadeusz Struka49de372016-03-03 21:49:26 +0000101};
102
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100103struct pkcs1pad_request {
Herbert Xu0f2c8312016-06-29 19:32:24 +0800104 struct scatterlist in_sg[2], out_sg[1];
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100105 uint8_t *in_buf, *out_buf;
Tadeusz Struka6d7bfd2016-07-14 20:39:18 -0700106 struct akcipher_request child_req;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100107};
108
109static 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);
Herbert Xu73f79182016-06-29 19:32:27 +0800113 int err;
114
115 ctx->key_size = 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100116
117 err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
Herbert Xu73f79182016-06-29 19:32:27 +0800118 if (err)
119 return err;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100120
Herbert Xu73f79182016-06-29 19:32:27 +0800121 /* Find out new modulus size from rsa implementation */
122 err = crypto_akcipher_maxsize(ctx->child);
123 if (err < 0)
124 return err;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100125
Herbert Xu73f79182016-06-29 19:32:27 +0800126 if (err > PAGE_SIZE)
127 return -ENOTSUPP;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100128
Herbert Xu73f79182016-06-29 19:32:27 +0800129 ctx->key_size = err;
130 return 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100131}
132
133static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
134 unsigned int keylen)
135{
136 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
Herbert Xu73f79182016-06-29 19:32:27 +0800137 int err;
138
139 ctx->key_size = 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100140
141 err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
Herbert Xu73f79182016-06-29 19:32:27 +0800142 if (err)
143 return err;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100144
Herbert Xu73f79182016-06-29 19:32:27 +0800145 /* Find out new modulus size from rsa implementation */
146 err = crypto_akcipher_maxsize(ctx->child);
147 if (err < 0)
148 return err;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100149
Herbert Xu73f79182016-06-29 19:32:27 +0800150 if (err > PAGE_SIZE)
151 return -ENOTSUPP;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100152
Herbert Xu73f79182016-06-29 19:32:27 +0800153 ctx->key_size = err;
154 return 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100155}
156
157static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
158{
159 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
160
161 /*
162 * The maximum destination buffer size for the encrypt/sign operations
163 * will be the same as for RSA, even though it's smaller for
164 * decrypt/verify.
165 */
166
167 return ctx->key_size ?: -EINVAL;
168}
169
170static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
171 struct scatterlist *next)
172{
Herbert Xu0f2c8312016-06-29 19:32:24 +0800173 int nsegs = next ? 2 : 1;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100174
Herbert Xu0f2c8312016-06-29 19:32:24 +0800175 sg_init_table(sg, nsegs);
176 sg_set_buf(sg, buf, len);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100177
178 if (next)
179 sg_chain(sg, nsegs, next);
180}
181
182static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
183{
184 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
185 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
186 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Herbert Xud858b072016-06-29 19:32:28 +0800187 unsigned int pad_len;
188 unsigned int len;
189 u8 *out_buf;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100190
Herbert Xud858b072016-06-29 19:32:28 +0800191 if (err)
192 goto out;
Andrzej Zaborowski53192162015-12-12 00:03:51 -0500193
Herbert Xud858b072016-06-29 19:32:28 +0800194 len = req_ctx->child_req.dst_len;
195 pad_len = ctx->key_size - len;
Andrzej Zaborowski53192162015-12-12 00:03:51 -0500196
Herbert Xud858b072016-06-29 19:32:28 +0800197 /* Four billion to one */
198 if (likely(!pad_len))
199 goto out;
Andrzej Zaborowski53192162015-12-12 00:03:51 -0500200
Herbert Xud858b072016-06-29 19:32:28 +0800201 out_buf = kzalloc(ctx->key_size, GFP_ATOMIC);
202 err = -ENOMEM;
203 if (!out_buf)
204 goto out;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100205
Herbert Xud858b072016-06-29 19:32:28 +0800206 sg_copy_to_buffer(req->dst, sg_nents_for_len(req->dst, len),
207 out_buf + pad_len, len);
208 sg_copy_from_buffer(req->dst,
209 sg_nents_for_len(req->dst, ctx->key_size),
210 out_buf, ctx->key_size);
211 kzfree(out_buf);
212
213out:
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100214 req->dst_len = ctx->key_size;
215
216 kfree(req_ctx->in_buf);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100217
218 return err;
219}
220
221static void pkcs1pad_encrypt_sign_complete_cb(
222 struct crypto_async_request *child_async_req, int err)
223{
224 struct akcipher_request *req = child_async_req->data;
225 struct crypto_async_request async_req;
226
227 if (err == -EINPROGRESS)
228 return;
229
230 async_req.data = req->base.data;
231 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
232 async_req.flags = child_async_req->flags;
233 req->base.complete(&async_req,
234 pkcs1pad_encrypt_sign_complete(req, err));
235}
236
237static int pkcs1pad_encrypt(struct akcipher_request *req)
238{
239 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
240 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
241 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
242 int err;
243 unsigned int i, ps_end;
244
245 if (!ctx->key_size)
246 return -EINVAL;
247
248 if (req->src_len > ctx->key_size - 11)
249 return -EOVERFLOW;
250
251 if (req->dst_len < ctx->key_size) {
252 req->dst_len = ctx->key_size;
253 return -EOVERFLOW;
254 }
255
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100256 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
Herbert Xu3a32ce52016-06-29 19:32:26 +0800257 GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100258 if (!req_ctx->in_buf)
259 return -ENOMEM;
260
261 ps_end = ctx->key_size - req->src_len - 2;
262 req_ctx->in_buf[0] = 0x02;
263 for (i = 1; i < ps_end; i++)
264 req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
265 req_ctx->in_buf[ps_end] = 0x00;
266
267 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
268 ctx->key_size - 1 - req->src_len, req->src);
269
Herbert Xu3a32ce52016-06-29 19:32:26 +0800270 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100271 if (!req_ctx->out_buf) {
272 kfree(req_ctx->in_buf);
273 return -ENOMEM;
274 }
275
276 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
277 ctx->key_size, NULL);
278
279 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
280 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
281 pkcs1pad_encrypt_sign_complete_cb, req);
282
Herbert Xud858b072016-06-29 19:32:28 +0800283 /* Reuse output buffer */
284 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
285 req->dst, ctx->key_size - 1, req->dst_len);
286
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100287 err = crypto_akcipher_encrypt(&req_ctx->child_req);
288 if (err != -EINPROGRESS &&
289 (err != -EBUSY ||
290 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
291 return pkcs1pad_encrypt_sign_complete(req, err);
292
293 return err;
294}
295
296static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
297{
298 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
299 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
300 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
301 unsigned int pos;
302
303 if (err == -EOVERFLOW)
304 /* Decrypted value had no leading 0 byte */
305 err = -EINVAL;
306
307 if (err)
308 goto done;
309
310 if (req_ctx->child_req.dst_len != ctx->key_size - 1) {
311 err = -EINVAL;
312 goto done;
313 }
314
315 if (req_ctx->out_buf[0] != 0x02) {
316 err = -EINVAL;
317 goto done;
318 }
319 for (pos = 1; pos < req_ctx->child_req.dst_len; pos++)
320 if (req_ctx->out_buf[pos] == 0x00)
321 break;
322 if (pos < 9 || pos == req_ctx->child_req.dst_len) {
323 err = -EINVAL;
324 goto done;
325 }
326 pos++;
327
328 if (req->dst_len < req_ctx->child_req.dst_len - pos)
329 err = -EOVERFLOW;
330 req->dst_len = req_ctx->child_req.dst_len - pos;
331
332 if (!err)
333 sg_copy_from_buffer(req->dst,
334 sg_nents_for_len(req->dst, req->dst_len),
335 req_ctx->out_buf + pos, req->dst_len);
336
337done:
338 kzfree(req_ctx->out_buf);
339
340 return err;
341}
342
343static void pkcs1pad_decrypt_complete_cb(
344 struct crypto_async_request *child_async_req, int err)
345{
346 struct akcipher_request *req = child_async_req->data;
347 struct crypto_async_request async_req;
348
349 if (err == -EINPROGRESS)
350 return;
351
352 async_req.data = req->base.data;
353 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
354 async_req.flags = child_async_req->flags;
355 req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err));
356}
357
358static int pkcs1pad_decrypt(struct akcipher_request *req)
359{
360 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
361 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
362 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
363 int err;
364
365 if (!ctx->key_size || req->src_len != ctx->key_size)
366 return -EINVAL;
367
Herbert Xu3a32ce52016-06-29 19:32:26 +0800368 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100369 if (!req_ctx->out_buf)
370 return -ENOMEM;
371
372 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700373 ctx->key_size, NULL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100374
375 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
376 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
377 pkcs1pad_decrypt_complete_cb, req);
378
Herbert Xud858b072016-06-29 19:32:28 +0800379 /* Reuse input buffer, output to a new buffer */
380 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
381 req_ctx->out_sg, req->src_len,
382 ctx->key_size);
383
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100384 err = crypto_akcipher_decrypt(&req_ctx->child_req);
385 if (err != -EINPROGRESS &&
386 (err != -EBUSY ||
387 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
388 return pkcs1pad_decrypt_complete(req, err);
389
390 return err;
391}
392
393static int pkcs1pad_sign(struct akcipher_request *req)
394{
395 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
396 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
397 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Herbert Xuc0d20d22016-06-29 19:32:23 +0800398 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
399 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
400 const struct rsa_asn1_template *digest_info = ictx->digest_info;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100401 int err;
Tadeusz Struka49de372016-03-03 21:49:26 +0000402 unsigned int ps_end, digest_size = 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100403
404 if (!ctx->key_size)
405 return -EINVAL;
406
Herbert Xuc0d20d22016-06-29 19:32:23 +0800407 digest_size = digest_info->size;
Tadeusz Struka49de372016-03-03 21:49:26 +0000408
409 if (req->src_len + digest_size > ctx->key_size - 11)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100410 return -EOVERFLOW;
411
412 if (req->dst_len < ctx->key_size) {
413 req->dst_len = ctx->key_size;
414 return -EOVERFLOW;
415 }
416
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100417 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
Herbert Xu3a32ce52016-06-29 19:32:26 +0800418 GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100419 if (!req_ctx->in_buf)
420 return -ENOMEM;
421
Tadeusz Struka49de372016-03-03 21:49:26 +0000422 ps_end = ctx->key_size - digest_size - req->src_len - 2;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100423 req_ctx->in_buf[0] = 0x01;
424 memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
425 req_ctx->in_buf[ps_end] = 0x00;
426
Herbert Xuc0d20d22016-06-29 19:32:23 +0800427 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
428 digest_info->size);
Tadeusz Struka49de372016-03-03 21:49:26 +0000429
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100430 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
431 ctx->key_size - 1 - req->src_len, req->src);
432
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100433 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
434 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
435 pkcs1pad_encrypt_sign_complete_cb, req);
436
Herbert Xud858b072016-06-29 19:32:28 +0800437 /* Reuse output buffer */
438 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
439 req->dst, ctx->key_size - 1, req->dst_len);
440
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100441 err = crypto_akcipher_sign(&req_ctx->child_req);
442 if (err != -EINPROGRESS &&
443 (err != -EBUSY ||
444 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
445 return pkcs1pad_encrypt_sign_complete(req, err);
446
447 return err;
448}
449
450static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
451{
452 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
453 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
454 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Herbert Xuc0d20d22016-06-29 19:32:23 +0800455 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
456 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
457 const struct rsa_asn1_template *digest_info = ictx->digest_info;
Herbert Xu27710b82016-07-03 10:46:11 +0800458 unsigned int dst_len;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100459 unsigned int pos;
Herbert Xu27710b82016-07-03 10:46:11 +0800460 u8 *out_buf;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100461
462 if (err)
463 goto done;
464
Herbert Xu27710b82016-07-03 10:46:11 +0800465 err = -EINVAL;
466 dst_len = req_ctx->child_req.dst_len;
467 if (dst_len < ctx->key_size - 1)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100468 goto done;
Herbert Xu27710b82016-07-03 10:46:11 +0800469
470 out_buf = req_ctx->out_buf;
471 if (dst_len == ctx->key_size) {
472 if (out_buf[0] != 0x00)
473 /* Decrypted value had no leading 0 byte */
474 goto done;
475
476 dst_len--;
477 out_buf++;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100478 }
479
Tadeusz Struka49de372016-03-03 21:49:26 +0000480 err = -EBADMSG;
Herbert Xu27710b82016-07-03 10:46:11 +0800481 if (out_buf[0] != 0x01)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100482 goto done;
Tadeusz Struka49de372016-03-03 21:49:26 +0000483
Herbert Xu27710b82016-07-03 10:46:11 +0800484 for (pos = 1; pos < dst_len; pos++)
485 if (out_buf[pos] != 0xff)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100486 break;
Tadeusz Struka49de372016-03-03 21:49:26 +0000487
Herbert Xu27710b82016-07-03 10:46:11 +0800488 if (pos < 9 || pos == dst_len || out_buf[pos] != 0x00)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100489 goto done;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100490 pos++;
491
Herbert Xu27710b82016-07-03 10:46:11 +0800492 if (memcmp(out_buf + pos, digest_info->data, digest_info->size))
Herbert Xuc0d20d22016-06-29 19:32:23 +0800493 goto done;
Tadeusz Struka49de372016-03-03 21:49:26 +0000494
Herbert Xuc0d20d22016-06-29 19:32:23 +0800495 pos += digest_info->size;
Tadeusz Struka49de372016-03-03 21:49:26 +0000496
497 err = 0;
498
Herbert Xu27710b82016-07-03 10:46:11 +0800499 if (req->dst_len < dst_len - pos)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100500 err = -EOVERFLOW;
Herbert Xu27710b82016-07-03 10:46:11 +0800501 req->dst_len = dst_len - pos;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100502
503 if (!err)
504 sg_copy_from_buffer(req->dst,
505 sg_nents_for_len(req->dst, req->dst_len),
Herbert Xu27710b82016-07-03 10:46:11 +0800506 out_buf + pos, req->dst_len);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100507done:
508 kzfree(req_ctx->out_buf);
509
510 return err;
511}
512
513static void pkcs1pad_verify_complete_cb(
514 struct crypto_async_request *child_async_req, int err)
515{
516 struct akcipher_request *req = child_async_req->data;
517 struct crypto_async_request async_req;
518
519 if (err == -EINPROGRESS)
520 return;
521
522 async_req.data = req->base.data;
523 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
524 async_req.flags = child_async_req->flags;
525 req->base.complete(&async_req, pkcs1pad_verify_complete(req, err));
526}
527
528/*
529 * The verify operation is here for completeness similar to the verification
530 * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
531 * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to
532 * retrieve the DigestInfo from a signature, instead the user is expected
533 * to call the sign operation to generate the expected signature and compare
534 * signatures instead of the message-digests.
535 */
536static int pkcs1pad_verify(struct akcipher_request *req)
537{
538 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
539 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
540 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
541 int err;
542
Tadeusz Struka49de372016-03-03 21:49:26 +0000543 if (!ctx->key_size || req->src_len < ctx->key_size)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100544 return -EINVAL;
545
Herbert Xu3a32ce52016-06-29 19:32:26 +0800546 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100547 if (!req_ctx->out_buf)
548 return -ENOMEM;
549
550 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700551 ctx->key_size, NULL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100552
553 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
554 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
555 pkcs1pad_verify_complete_cb, req);
556
Herbert Xud858b072016-06-29 19:32:28 +0800557 /* Reuse input buffer, output to a new buffer */
558 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
559 req_ctx->out_sg, req->src_len,
560 ctx->key_size);
561
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100562 err = crypto_akcipher_verify(&req_ctx->child_req);
563 if (err != -EINPROGRESS &&
564 (err != -EBUSY ||
565 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG)))
566 return pkcs1pad_verify_complete(req, err);
567
568 return err;
569}
570
571static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
572{
573 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
Tadeusz Struka49de372016-03-03 21:49:26 +0000574 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100575 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
576 struct crypto_akcipher *child_tfm;
577
Herbert Xuc0d20d22016-06-29 19:32:23 +0800578 child_tfm = crypto_spawn_akcipher(&ictx->spawn);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100579 if (IS_ERR(child_tfm))
580 return PTR_ERR(child_tfm);
581
582 ctx->child = child_tfm;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100583 return 0;
584}
585
586static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
587{
588 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
589
590 crypto_free_akcipher(ctx->child);
591}
592
593static void pkcs1pad_free(struct akcipher_instance *inst)
594{
Tadeusz Struka49de372016-03-03 21:49:26 +0000595 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
596 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100597
598 crypto_drop_akcipher(spawn);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100599 kfree(inst);
600}
601
602static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
603{
Herbert Xuc0d20d22016-06-29 19:32:23 +0800604 const struct rsa_asn1_template *digest_info;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100605 struct crypto_attr_type *algt;
606 struct akcipher_instance *inst;
Tadeusz Struka49de372016-03-03 21:49:26 +0000607 struct pkcs1pad_inst_ctx *ctx;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100608 struct crypto_akcipher_spawn *spawn;
609 struct akcipher_alg *rsa_alg;
610 const char *rsa_alg_name;
Tadeusz Struka49de372016-03-03 21:49:26 +0000611 const char *hash_name;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100612 int err;
613
614 algt = crypto_get_attr_type(tb);
615 if (IS_ERR(algt))
616 return PTR_ERR(algt);
617
618 if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask)
619 return -EINVAL;
620
621 rsa_alg_name = crypto_attr_alg_name(tb[1]);
622 if (IS_ERR(rsa_alg_name))
623 return PTR_ERR(rsa_alg_name);
624
Tadeusz Struka49de372016-03-03 21:49:26 +0000625 hash_name = crypto_attr_alg_name(tb[2]);
626 if (IS_ERR(hash_name))
Herbert Xuc0d20d22016-06-29 19:32:23 +0800627 return PTR_ERR(hash_name);
628
629 digest_info = rsa_lookup_asn1(hash_name);
630 if (!digest_info)
631 return -EINVAL;
Tadeusz Struka49de372016-03-03 21:49:26 +0000632
633 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100634 if (!inst)
635 return -ENOMEM;
636
Tadeusz Struka49de372016-03-03 21:49:26 +0000637 ctx = akcipher_instance_ctx(inst);
638 spawn = &ctx->spawn;
Herbert Xuc0d20d22016-06-29 19:32:23 +0800639 ctx->digest_info = digest_info;
Tadeusz Struka49de372016-03-03 21:49:26 +0000640
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100641 crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst));
642 err = crypto_grab_akcipher(spawn, rsa_alg_name, 0,
643 crypto_requires_sync(algt->type, algt->mask));
644 if (err)
645 goto out_free_inst;
646
647 rsa_alg = crypto_spawn_akcipher_alg(spawn);
648
649 err = -ENAMETOOLONG;
Tadeusz Struka49de372016-03-03 21:49:26 +0000650
Herbert Xuc0d20d22016-06-29 19:32:23 +0800651 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
652 "pkcs1pad(%s,%s)", rsa_alg->base.cra_name, hash_name) >=
653 CRYPTO_MAX_ALG_NAME ||
654 snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
655 "pkcs1pad(%s,%s)",
656 rsa_alg->base.cra_driver_name, hash_name) >=
657 CRYPTO_MAX_ALG_NAME)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100658 goto out_drop_alg;
659
660 inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
661 inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
662 inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
663
664 inst->alg.init = pkcs1pad_init_tfm;
665 inst->alg.exit = pkcs1pad_exit_tfm;
666
667 inst->alg.encrypt = pkcs1pad_encrypt;
668 inst->alg.decrypt = pkcs1pad_decrypt;
669 inst->alg.sign = pkcs1pad_sign;
670 inst->alg.verify = pkcs1pad_verify;
671 inst->alg.set_pub_key = pkcs1pad_set_pub_key;
672 inst->alg.set_priv_key = pkcs1pad_set_priv_key;
673 inst->alg.max_size = pkcs1pad_get_max_size;
674 inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize;
675
676 inst->free = pkcs1pad_free;
677
678 err = akcipher_register_instance(tmpl, inst);
679 if (err)
Herbert Xuc0d20d22016-06-29 19:32:23 +0800680 goto out_drop_alg;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100681
682 return 0;
683
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100684out_drop_alg:
685 crypto_drop_akcipher(spawn);
686out_free_inst:
687 kfree(inst);
688 return err;
689}
690
691struct crypto_template rsa_pkcs1pad_tmpl = {
692 .name = "pkcs1pad",
693 .create = pkcs1pad_create,
694 .module = THIS_MODULE,
695};