blob: 3bc76edb3f8a93b29f6258419053107d990ab47f [file] [log] [blame]
Thomas Gleixner2874c5f2019-05-27 08:55:01 +02001// SPDX-License-Identifier: GPL-2.0-or-later
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +01002/*
3 * RSA padding templates.
4 *
5 * Copyright (c) 2015 Intel Corporation
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +01006 */
7
8#include <crypto/algapi.h>
9#include <crypto/akcipher.h>
10#include <crypto/internal/akcipher.h>
Eric Biggersa1180cf2019-01-10 12:17:53 -080011#include <crypto/internal/rsa.h>
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +010012#include <linux/err.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/random.h>
Herbert Xu0c3dc782020-08-19 21:58:20 +100017#include <linux/scatterlist.h>
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +010018
Tadeusz Struka49de372016-03-03 21:49:26 +000019/*
20 * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
21 */
22static const u8 rsa_digest_info_md5[] = {
23 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08,
24 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */
25 0x05, 0x00, 0x04, 0x10
26};
27
28static const u8 rsa_digest_info_sha1[] = {
29 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
30 0x2b, 0x0e, 0x03, 0x02, 0x1a,
31 0x05, 0x00, 0x04, 0x14
32};
33
34static const u8 rsa_digest_info_rmd160[] = {
35 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
36 0x2b, 0x24, 0x03, 0x02, 0x01,
37 0x05, 0x00, 0x04, 0x14
38};
39
40static const u8 rsa_digest_info_sha224[] = {
41 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
42 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
43 0x05, 0x00, 0x04, 0x1c
44};
45
46static const u8 rsa_digest_info_sha256[] = {
47 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
48 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
49 0x05, 0x00, 0x04, 0x20
50};
51
52static const u8 rsa_digest_info_sha384[] = {
53 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
54 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
55 0x05, 0x00, 0x04, 0x30
56};
57
58static const u8 rsa_digest_info_sha512[] = {
59 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
60 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
61 0x05, 0x00, 0x04, 0x40
62};
63
64static const struct rsa_asn1_template {
65 const char *name;
66 const u8 *data;
67 size_t size;
68} rsa_asn1_templates[] = {
69#define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
70 _(md5),
71 _(sha1),
72 _(rmd160),
73 _(sha256),
74 _(sha384),
75 _(sha512),
76 _(sha224),
77 { NULL }
78#undef _
79};
80
81static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
82{
83 const struct rsa_asn1_template *p;
84
85 for (p = rsa_asn1_templates; p->name; p++)
86 if (strcmp(name, p->name) == 0)
87 return p;
88 return NULL;
89}
90
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +010091struct pkcs1pad_ctx {
92 struct crypto_akcipher *child;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +010093 unsigned int key_size;
94};
95
Tadeusz Struka49de372016-03-03 21:49:26 +000096struct pkcs1pad_inst_ctx {
97 struct crypto_akcipher_spawn spawn;
Herbert Xuc0d20d22016-06-29 19:32:23 +080098 const struct rsa_asn1_template *digest_info;
Tadeusz Struka49de372016-03-03 21:49:26 +000099};
100
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100101struct pkcs1pad_request {
Herbert Xu0f2c8312016-06-29 19:32:24 +0800102 struct scatterlist in_sg[2], out_sg[1];
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100103 uint8_t *in_buf, *out_buf;
Tadeusz Struka6d7bfd2016-07-14 20:39:18 -0700104 struct akcipher_request child_req;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100105};
106
107static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
108 unsigned int keylen)
109{
110 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
Herbert Xu73f791892016-06-29 19:32:27 +0800111 int err;
112
113 ctx->key_size = 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100114
115 err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
Herbert Xu73f791892016-06-29 19:32:27 +0800116 if (err)
117 return err;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100118
Herbert Xu73f791892016-06-29 19:32:27 +0800119 /* Find out new modulus size from rsa implementation */
120 err = crypto_akcipher_maxsize(ctx->child);
Herbert Xu73f791892016-06-29 19:32:27 +0800121 if (err > PAGE_SIZE)
122 return -ENOTSUPP;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100123
Herbert Xu73f791892016-06-29 19:32:27 +0800124 ctx->key_size = err;
125 return 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100126}
127
128static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
129 unsigned int keylen)
130{
131 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
Herbert Xu73f791892016-06-29 19:32:27 +0800132 int err;
133
134 ctx->key_size = 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100135
136 err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
Herbert Xu73f791892016-06-29 19:32:27 +0800137 if (err)
138 return err;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100139
Herbert Xu73f791892016-06-29 19:32:27 +0800140 /* Find out new modulus size from rsa implementation */
141 err = crypto_akcipher_maxsize(ctx->child);
Herbert Xu73f791892016-06-29 19:32:27 +0800142 if (err > PAGE_SIZE)
143 return -ENOTSUPP;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100144
Herbert Xu73f791892016-06-29 19:32:27 +0800145 ctx->key_size = err;
146 return 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100147}
148
Tudor-Dan Ambarus543de102017-05-25 10:18:16 +0300149static unsigned int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100150{
151 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
152
153 /*
154 * The maximum destination buffer size for the encrypt/sign operations
155 * will be the same as for RSA, even though it's smaller for
156 * decrypt/verify.
157 */
158
Tudor-Dan Ambarus543de102017-05-25 10:18:16 +0300159 return ctx->key_size;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100160}
161
162static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
163 struct scatterlist *next)
164{
Herbert Xu0f2c8312016-06-29 19:32:24 +0800165 int nsegs = next ? 2 : 1;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100166
Herbert Xu0f2c8312016-06-29 19:32:24 +0800167 sg_init_table(sg, nsegs);
168 sg_set_buf(sg, buf, len);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100169
170 if (next)
171 sg_chain(sg, nsegs, next);
172}
173
174static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
175{
176 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
177 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
178 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Herbert Xud858b072016-06-29 19:32:28 +0800179 unsigned int pad_len;
180 unsigned int len;
181 u8 *out_buf;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100182
Herbert Xud858b072016-06-29 19:32:28 +0800183 if (err)
184 goto out;
Andrzej Zaborowski53192162015-12-12 00:03:51 -0500185
Herbert Xud858b072016-06-29 19:32:28 +0800186 len = req_ctx->child_req.dst_len;
187 pad_len = ctx->key_size - len;
Andrzej Zaborowski53192162015-12-12 00:03:51 -0500188
Herbert Xud858b072016-06-29 19:32:28 +0800189 /* Four billion to one */
190 if (likely(!pad_len))
191 goto out;
Andrzej Zaborowski53192162015-12-12 00:03:51 -0500192
Jia-Ju Bai1ca28092018-01-25 17:57:54 +0800193 out_buf = kzalloc(ctx->key_size, GFP_KERNEL);
Herbert Xud858b072016-06-29 19:32:28 +0800194 err = -ENOMEM;
195 if (!out_buf)
196 goto out;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100197
Herbert Xud858b072016-06-29 19:32:28 +0800198 sg_copy_to_buffer(req->dst, sg_nents_for_len(req->dst, len),
199 out_buf + pad_len, len);
200 sg_copy_from_buffer(req->dst,
201 sg_nents_for_len(req->dst, ctx->key_size),
202 out_buf, ctx->key_size);
Waiman Long453431a2020-08-06 23:18:13 -0700203 kfree_sensitive(out_buf);
Herbert Xud858b072016-06-29 19:32:28 +0800204
205out:
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100206 req->dst_len = ctx->key_size;
207
208 kfree(req_ctx->in_buf);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100209
210 return err;
211}
212
213static void pkcs1pad_encrypt_sign_complete_cb(
214 struct crypto_async_request *child_async_req, int err)
215{
216 struct akcipher_request *req = child_async_req->data;
217 struct crypto_async_request async_req;
218
219 if (err == -EINPROGRESS)
220 return;
221
222 async_req.data = req->base.data;
223 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
224 async_req.flags = child_async_req->flags;
225 req->base.complete(&async_req,
226 pkcs1pad_encrypt_sign_complete(req, err));
227}
228
229static int pkcs1pad_encrypt(struct akcipher_request *req)
230{
231 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
232 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
233 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
234 int err;
235 unsigned int i, ps_end;
236
237 if (!ctx->key_size)
238 return -EINVAL;
239
240 if (req->src_len > ctx->key_size - 11)
241 return -EOVERFLOW;
242
243 if (req->dst_len < ctx->key_size) {
244 req->dst_len = ctx->key_size;
245 return -EOVERFLOW;
246 }
247
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100248 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
Herbert Xu3a32ce52016-06-29 19:32:26 +0800249 GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100250 if (!req_ctx->in_buf)
251 return -ENOMEM;
252
253 ps_end = ctx->key_size - req->src_len - 2;
254 req_ctx->in_buf[0] = 0x02;
255 for (i = 1; i < ps_end; i++)
256 req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
257 req_ctx->in_buf[ps_end] = 0x00;
258
259 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
260 ctx->key_size - 1 - req->src_len, req->src);
261
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100262 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
263 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
264 pkcs1pad_encrypt_sign_complete_cb, req);
265
Herbert Xud858b072016-06-29 19:32:28 +0800266 /* Reuse output buffer */
267 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
268 req->dst, ctx->key_size - 1, req->dst_len);
269
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100270 err = crypto_akcipher_encrypt(&req_ctx->child_req);
Gilad Ben-Yossef4e5b0ad2017-10-18 08:00:36 +0100271 if (err != -EINPROGRESS && err != -EBUSY)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100272 return pkcs1pad_encrypt_sign_complete(req, err);
273
274 return err;
275}
276
277static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
278{
279 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
280 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
281 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Herbert Xu0cf43f52016-09-22 17:04:57 +0800282 unsigned int dst_len;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100283 unsigned int pos;
Herbert Xu0cf43f52016-09-22 17:04:57 +0800284 u8 *out_buf;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100285
286 if (err)
287 goto done;
288
Herbert Xu0cf43f52016-09-22 17:04:57 +0800289 err = -EINVAL;
290 dst_len = req_ctx->child_req.dst_len;
291 if (dst_len < ctx->key_size - 1)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100292 goto done;
Herbert Xu0cf43f52016-09-22 17:04:57 +0800293
294 out_buf = req_ctx->out_buf;
295 if (dst_len == ctx->key_size) {
296 if (out_buf[0] != 0x00)
297 /* Decrypted value had no leading 0 byte */
298 goto done;
299
300 dst_len--;
301 out_buf++;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100302 }
303
Herbert Xu0cf43f52016-09-22 17:04:57 +0800304 if (out_buf[0] != 0x02)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100305 goto done;
Herbert Xu0cf43f52016-09-22 17:04:57 +0800306
307 for (pos = 1; pos < dst_len; pos++)
308 if (out_buf[pos] == 0x00)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100309 break;
Herbert Xu0cf43f52016-09-22 17:04:57 +0800310 if (pos < 9 || pos == dst_len)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100311 goto done;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100312 pos++;
313
Herbert Xu0cf43f52016-09-22 17:04:57 +0800314 err = 0;
315
316 if (req->dst_len < dst_len - pos)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100317 err = -EOVERFLOW;
Herbert Xu0cf43f52016-09-22 17:04:57 +0800318 req->dst_len = dst_len - pos;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100319
320 if (!err)
321 sg_copy_from_buffer(req->dst,
322 sg_nents_for_len(req->dst, req->dst_len),
Herbert Xu0cf43f52016-09-22 17:04:57 +0800323 out_buf + pos, req->dst_len);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100324
325done:
Waiman Long453431a2020-08-06 23:18:13 -0700326 kfree_sensitive(req_ctx->out_buf);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100327
328 return err;
329}
330
331static void pkcs1pad_decrypt_complete_cb(
332 struct crypto_async_request *child_async_req, int err)
333{
334 struct akcipher_request *req = child_async_req->data;
335 struct crypto_async_request async_req;
336
337 if (err == -EINPROGRESS)
338 return;
339
340 async_req.data = req->base.data;
341 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
342 async_req.flags = child_async_req->flags;
343 req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err));
344}
345
346static int pkcs1pad_decrypt(struct akcipher_request *req)
347{
348 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
349 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
350 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
351 int err;
352
353 if (!ctx->key_size || req->src_len != ctx->key_size)
354 return -EINVAL;
355
Herbert Xu3a32ce52016-06-29 19:32:26 +0800356 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100357 if (!req_ctx->out_buf)
358 return -ENOMEM;
359
360 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700361 ctx->key_size, NULL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100362
363 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
364 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
365 pkcs1pad_decrypt_complete_cb, req);
366
Herbert Xud858b072016-06-29 19:32:28 +0800367 /* Reuse input buffer, output to a new buffer */
368 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
369 req_ctx->out_sg, req->src_len,
370 ctx->key_size);
371
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100372 err = crypto_akcipher_decrypt(&req_ctx->child_req);
Gilad Ben-Yossef4e5b0ad2017-10-18 08:00:36 +0100373 if (err != -EINPROGRESS && err != -EBUSY)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100374 return pkcs1pad_decrypt_complete(req, err);
375
376 return err;
377}
378
379static int pkcs1pad_sign(struct akcipher_request *req)
380{
381 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
382 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
383 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Herbert Xuc0d20d22016-06-29 19:32:23 +0800384 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
385 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
386 const struct rsa_asn1_template *digest_info = ictx->digest_info;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100387 int err;
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800388 unsigned int ps_end, digest_info_size = 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100389
390 if (!ctx->key_size)
391 return -EINVAL;
392
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100393 if (digest_info)
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800394 digest_info_size = digest_info->size;
Tadeusz Struka49de372016-03-03 21:49:26 +0000395
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800396 if (req->src_len + digest_info_size > ctx->key_size - 11)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100397 return -EOVERFLOW;
398
399 if (req->dst_len < ctx->key_size) {
400 req->dst_len = ctx->key_size;
401 return -EOVERFLOW;
402 }
403
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100404 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
Herbert Xu3a32ce52016-06-29 19:32:26 +0800405 GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100406 if (!req_ctx->in_buf)
407 return -ENOMEM;
408
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800409 ps_end = ctx->key_size - digest_info_size - req->src_len - 2;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100410 req_ctx->in_buf[0] = 0x01;
411 memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
412 req_ctx->in_buf[ps_end] = 0x00;
413
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100414 if (digest_info)
415 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
416 digest_info->size);
Tadeusz Struka49de372016-03-03 21:49:26 +0000417
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100418 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
419 ctx->key_size - 1 - req->src_len, req->src);
420
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100421 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
422 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
423 pkcs1pad_encrypt_sign_complete_cb, req);
424
Herbert Xud858b072016-06-29 19:32:28 +0800425 /* Reuse output buffer */
426 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
427 req->dst, ctx->key_size - 1, req->dst_len);
428
Vitaly Chikunov3ecc9722019-04-11 18:51:14 +0300429 err = crypto_akcipher_decrypt(&req_ctx->child_req);
Gilad Ben-Yossef4e5b0ad2017-10-18 08:00:36 +0100430 if (err != -EINPROGRESS && err != -EBUSY)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100431 return pkcs1pad_encrypt_sign_complete(req, err);
432
433 return err;
434}
435
436static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
437{
438 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
439 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
440 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Herbert Xuc0d20d22016-06-29 19:32:23 +0800441 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
442 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
443 const struct rsa_asn1_template *digest_info = ictx->digest_info;
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800444 const unsigned int sig_size = req->src_len;
445 const unsigned int digest_size = req->dst_len;
Herbert Xu27710b82016-07-03 10:46:11 +0800446 unsigned int dst_len;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100447 unsigned int pos;
Herbert Xu27710b82016-07-03 10:46:11 +0800448 u8 *out_buf;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100449
450 if (err)
451 goto done;
452
Herbert Xu27710b82016-07-03 10:46:11 +0800453 err = -EINVAL;
454 dst_len = req_ctx->child_req.dst_len;
455 if (dst_len < ctx->key_size - 1)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100456 goto done;
Herbert Xu27710b82016-07-03 10:46:11 +0800457
458 out_buf = req_ctx->out_buf;
459 if (dst_len == ctx->key_size) {
460 if (out_buf[0] != 0x00)
461 /* Decrypted value had no leading 0 byte */
462 goto done;
463
464 dst_len--;
465 out_buf++;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100466 }
467
Tadeusz Struka49de372016-03-03 21:49:26 +0000468 err = -EBADMSG;
Herbert Xu27710b82016-07-03 10:46:11 +0800469 if (out_buf[0] != 0x01)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100470 goto done;
Tadeusz Struka49de372016-03-03 21:49:26 +0000471
Herbert Xu27710b82016-07-03 10:46:11 +0800472 for (pos = 1; pos < dst_len; pos++)
473 if (out_buf[pos] != 0xff)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100474 break;
Tadeusz Struka49de372016-03-03 21:49:26 +0000475
Herbert Xu27710b82016-07-03 10:46:11 +0800476 if (pos < 9 || pos == dst_len || out_buf[pos] != 0x00)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100477 goto done;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100478 pos++;
479
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100480 if (digest_info) {
Eric Biggersa24611e2022-01-18 16:13:05 -0800481 if (digest_info->size > dst_len - pos)
482 goto done;
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100483 if (crypto_memneq(out_buf + pos, digest_info->data,
484 digest_info->size))
485 goto done;
Tadeusz Struka49de372016-03-03 21:49:26 +0000486
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100487 pos += digest_info->size;
488 }
Tadeusz Struka49de372016-03-03 21:49:26 +0000489
490 err = 0;
491
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800492 if (digest_size != dst_len - pos) {
Vitaly Chikunovc7381b02019-04-11 18:51:15 +0300493 err = -EKEYREJECTED;
494 req->dst_len = dst_len - pos;
495 goto done;
496 }
497 /* Extract appended digest. */
498 sg_pcopy_to_buffer(req->src,
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800499 sg_nents_for_len(req->src, sig_size + digest_size),
Vitaly Chikunovc7381b02019-04-11 18:51:15 +0300500 req_ctx->out_buf + ctx->key_size,
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800501 digest_size, sig_size);
Vitaly Chikunovc7381b02019-04-11 18:51:15 +0300502 /* Do the actual verification step. */
503 if (memcmp(req_ctx->out_buf + ctx->key_size, out_buf + pos,
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800504 digest_size) != 0)
Vitaly Chikunovc7381b02019-04-11 18:51:15 +0300505 err = -EKEYREJECTED;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100506done:
Waiman Long453431a2020-08-06 23:18:13 -0700507 kfree_sensitive(req_ctx->out_buf);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100508
509 return err;
510}
511
512static void pkcs1pad_verify_complete_cb(
513 struct crypto_async_request *child_async_req, int err)
514{
515 struct akcipher_request *req = child_async_req->data;
516 struct crypto_async_request async_req;
517
518 if (err == -EINPROGRESS)
519 return;
520
521 async_req.data = req->base.data;
522 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
523 async_req.flags = child_async_req->flags;
524 req->base.complete(&async_req, pkcs1pad_verify_complete(req, err));
525}
526
527/*
528 * The verify operation is here for completeness similar to the verification
529 * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
530 * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to
531 * retrieve the DigestInfo from a signature, instead the user is expected
532 * to call the sign operation to generate the expected signature and compare
533 * signatures instead of the message-digests.
534 */
535static int pkcs1pad_verify(struct akcipher_request *req)
536{
537 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
538 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
539 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800540 const unsigned int sig_size = req->src_len;
541 const unsigned int digest_size = req->dst_len;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100542 int err;
543
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800544 if (WARN_ON(req->dst) || WARN_ON(!digest_size) ||
545 !ctx->key_size || sig_size != ctx->key_size)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100546 return -EINVAL;
547
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800548 req_ctx->out_buf = kmalloc(ctx->key_size + digest_size, GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100549 if (!req_ctx->out_buf)
550 return -ENOMEM;
551
552 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700553 ctx->key_size, NULL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100554
555 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
556 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
557 pkcs1pad_verify_complete_cb, req);
558
Herbert Xud858b072016-06-29 19:32:28 +0800559 /* Reuse input buffer, output to a new buffer */
560 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800561 req_ctx->out_sg, sig_size, ctx->key_size);
Herbert Xud858b072016-06-29 19:32:28 +0800562
Vitaly Chikunov3ecc9722019-04-11 18:51:14 +0300563 err = crypto_akcipher_encrypt(&req_ctx->child_req);
Gilad Ben-Yossef4e5b0ad2017-10-18 08:00:36 +0100564 if (err != -EINPROGRESS && err != -EBUSY)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100565 return pkcs1pad_verify_complete(req, err);
566
567 return err;
568}
569
570static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
571{
572 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
Tadeusz Struka49de372016-03-03 21:49:26 +0000573 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100574 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
575 struct crypto_akcipher *child_tfm;
576
Herbert Xuc0d20d22016-06-29 19:32:23 +0800577 child_tfm = crypto_spawn_akcipher(&ictx->spawn);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100578 if (IS_ERR(child_tfm))
579 return PTR_ERR(child_tfm);
580
581 ctx->child = child_tfm;
Herbert Xu5b11d1a2022-11-22 13:53:38 +0800582
583 akcipher_set_reqsize(tfm, sizeof(struct pkcs1pad_request) +
584 crypto_akcipher_reqsize(child_tfm));
585
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100586 return 0;
587}
588
589static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
590{
591 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
592
593 crypto_free_akcipher(ctx->child);
594}
595
596static void pkcs1pad_free(struct akcipher_instance *inst)
597{
Tadeusz Struka49de372016-03-03 21:49:26 +0000598 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
599 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100600
601 crypto_drop_akcipher(spawn);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100602 kfree(inst);
603}
604
605static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
606{
Eric Biggers73bed262020-01-02 19:58:47 -0800607 u32 mask;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100608 struct akcipher_instance *inst;
Tadeusz Struka49de372016-03-03 21:49:26 +0000609 struct pkcs1pad_inst_ctx *ctx;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100610 struct akcipher_alg *rsa_alg;
Tadeusz Struka49de372016-03-03 21:49:26 +0000611 const char *hash_name;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100612 int err;
613
Eric Biggers7bcb2c92020-07-09 23:20:38 -0700614 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AKCIPHER, &mask);
615 if (err)
616 return err;
Eric Biggers73bed262020-01-02 19:58:47 -0800617
Tadeusz Struka49de372016-03-03 21:49:26 +0000618 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100619 if (!inst)
620 return -ENOMEM;
621
Tadeusz Struka49de372016-03-03 21:49:26 +0000622 ctx = akcipher_instance_ctx(inst);
Tadeusz Struka49de372016-03-03 21:49:26 +0000623
Eric Biggers0708bb42020-02-25 20:59:23 -0800624 err = crypto_grab_akcipher(&ctx->spawn, akcipher_crypto_instance(inst),
625 crypto_attr_alg_name(tb[1]), 0, mask);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100626 if (err)
Eric Biggers0708bb42020-02-25 20:59:23 -0800627 goto err_free_inst;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100628
Eric Biggers0708bb42020-02-25 20:59:23 -0800629 rsa_alg = crypto_spawn_akcipher_alg(&ctx->spawn);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100630
Eric Biggers9b304302022-01-18 16:13:02 -0800631 if (strcmp(rsa_alg->base.cra_name, "rsa") != 0) {
632 err = -EINVAL;
633 goto err_free_inst;
634 }
635
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100636 err = -ENAMETOOLONG;
Eric Biggers0708bb42020-02-25 20:59:23 -0800637 hash_name = crypto_attr_alg_name(tb[2]);
638 if (IS_ERR(hash_name)) {
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100639 if (snprintf(inst->alg.base.cra_name,
640 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
641 rsa_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
Eric Biggers0708bb42020-02-25 20:59:23 -0800642 goto err_free_inst;
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100643
644 if (snprintf(inst->alg.base.cra_driver_name,
645 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
646 rsa_alg->base.cra_driver_name) >=
647 CRYPTO_MAX_ALG_NAME)
Eric Biggers0708bb42020-02-25 20:59:23 -0800648 goto err_free_inst;
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100649 } else {
Eric Biggers0708bb42020-02-25 20:59:23 -0800650 ctx->digest_info = rsa_lookup_asn1(hash_name);
651 if (!ctx->digest_info) {
652 err = -EINVAL;
653 goto err_free_inst;
654 }
655
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100656 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
657 "pkcs1pad(%s,%s)", rsa_alg->base.cra_name,
658 hash_name) >= CRYPTO_MAX_ALG_NAME)
Eric Biggers0708bb42020-02-25 20:59:23 -0800659 goto err_free_inst;
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100660
661 if (snprintf(inst->alg.base.cra_driver_name,
662 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
663 rsa_alg->base.cra_driver_name,
664 hash_name) >= CRYPTO_MAX_ALG_NAME)
Eric Biggers0708bb42020-02-25 20:59:23 -0800665 goto err_free_inst;
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100666 }
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100667
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100668 inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
669 inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
670
671 inst->alg.init = pkcs1pad_init_tfm;
672 inst->alg.exit = pkcs1pad_exit_tfm;
673
674 inst->alg.encrypt = pkcs1pad_encrypt;
675 inst->alg.decrypt = pkcs1pad_decrypt;
676 inst->alg.sign = pkcs1pad_sign;
677 inst->alg.verify = pkcs1pad_verify;
678 inst->alg.set_pub_key = pkcs1pad_set_pub_key;
679 inst->alg.set_priv_key = pkcs1pad_set_priv_key;
680 inst->alg.max_size = pkcs1pad_get_max_size;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100681
682 inst->free = pkcs1pad_free;
683
684 err = akcipher_register_instance(tmpl, inst);
Eric Biggers0708bb42020-02-25 20:59:23 -0800685 if (err) {
686err_free_inst:
687 pkcs1pad_free(inst);
688 }
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100689 return err;
690}
691
692struct crypto_template rsa_pkcs1pad_tmpl = {
693 .name = "pkcs1pad",
694 .create = pkcs1pad_create,
695 .module = THIS_MODULE,
696};