blob: d2e5e104f8cfe386d0380f5dc469c373bca425ec [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
Herbert Xud52b0c72023-01-23 18:08:56 +0800193 out_buf = kzalloc(ctx->key_size, GFP_ATOMIC);
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
Herbert Xu255e48e2023-02-08 13:58:44 +0800213static void pkcs1pad_encrypt_sign_complete_cb(void *data, int err)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100214{
Herbert Xu255e48e2023-02-08 13:58:44 +0800215 struct akcipher_request *req = data;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100216
217 if (err == -EINPROGRESS)
Herbert Xu564cabc2023-01-31 16:02:04 +0800218 goto out;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100219
Herbert Xu564cabc2023-01-31 16:02:04 +0800220 err = pkcs1pad_encrypt_sign_complete(req, err);
221
222out:
223 akcipher_request_complete(req, err);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100224}
225
226static int pkcs1pad_encrypt(struct akcipher_request *req)
227{
228 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
229 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
230 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
231 int err;
232 unsigned int i, ps_end;
233
234 if (!ctx->key_size)
235 return -EINVAL;
236
237 if (req->src_len > ctx->key_size - 11)
238 return -EOVERFLOW;
239
240 if (req->dst_len < ctx->key_size) {
241 req->dst_len = ctx->key_size;
242 return -EOVERFLOW;
243 }
244
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100245 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
Herbert Xu3a32ce52016-06-29 19:32:26 +0800246 GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100247 if (!req_ctx->in_buf)
248 return -ENOMEM;
249
250 ps_end = ctx->key_size - req->src_len - 2;
251 req_ctx->in_buf[0] = 0x02;
252 for (i = 1; i < ps_end; i++)
Jason A. Donenfelde8a533c2022-10-09 20:44:02 -0600253 req_ctx->in_buf[i] = get_random_u32_inclusive(1, 255);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100254 req_ctx->in_buf[ps_end] = 0x00;
255
256 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
257 ctx->key_size - 1 - req->src_len, req->src);
258
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100259 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
260 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
261 pkcs1pad_encrypt_sign_complete_cb, req);
262
Herbert Xud858b072016-06-29 19:32:28 +0800263 /* Reuse output buffer */
264 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
265 req->dst, ctx->key_size - 1, req->dst_len);
266
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100267 err = crypto_akcipher_encrypt(&req_ctx->child_req);
Gilad Ben-Yossef4e5b0ad2017-10-18 08:00:36 +0100268 if (err != -EINPROGRESS && err != -EBUSY)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100269 return pkcs1pad_encrypt_sign_complete(req, err);
270
271 return err;
272}
273
274static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
275{
276 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
277 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
278 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Herbert Xu0cf43f52016-09-22 17:04:57 +0800279 unsigned int dst_len;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100280 unsigned int pos;
Herbert Xu0cf43f52016-09-22 17:04:57 +0800281 u8 *out_buf;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100282
283 if (err)
284 goto done;
285
Herbert Xu0cf43f52016-09-22 17:04:57 +0800286 err = -EINVAL;
287 dst_len = req_ctx->child_req.dst_len;
288 if (dst_len < ctx->key_size - 1)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100289 goto done;
Herbert Xu0cf43f52016-09-22 17:04:57 +0800290
291 out_buf = req_ctx->out_buf;
292 if (dst_len == ctx->key_size) {
293 if (out_buf[0] != 0x00)
294 /* Decrypted value had no leading 0 byte */
295 goto done;
296
297 dst_len--;
298 out_buf++;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100299 }
300
Herbert Xu0cf43f52016-09-22 17:04:57 +0800301 if (out_buf[0] != 0x02)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100302 goto done;
Herbert Xu0cf43f52016-09-22 17:04:57 +0800303
304 for (pos = 1; pos < dst_len; pos++)
305 if (out_buf[pos] == 0x00)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100306 break;
Herbert Xu0cf43f52016-09-22 17:04:57 +0800307 if (pos < 9 || pos == dst_len)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100308 goto done;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100309 pos++;
310
Herbert Xu0cf43f52016-09-22 17:04:57 +0800311 err = 0;
312
313 if (req->dst_len < dst_len - pos)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100314 err = -EOVERFLOW;
Herbert Xu0cf43f52016-09-22 17:04:57 +0800315 req->dst_len = dst_len - pos;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100316
317 if (!err)
318 sg_copy_from_buffer(req->dst,
319 sg_nents_for_len(req->dst, req->dst_len),
Herbert Xu0cf43f52016-09-22 17:04:57 +0800320 out_buf + pos, req->dst_len);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100321
322done:
Waiman Long453431a2020-08-06 23:18:13 -0700323 kfree_sensitive(req_ctx->out_buf);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100324
325 return err;
326}
327
Herbert Xu255e48e2023-02-08 13:58:44 +0800328static void pkcs1pad_decrypt_complete_cb(void *data, int err)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100329{
Herbert Xu255e48e2023-02-08 13:58:44 +0800330 struct akcipher_request *req = data;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100331
332 if (err == -EINPROGRESS)
Herbert Xu564cabc2023-01-31 16:02:04 +0800333 goto out;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100334
Herbert Xu564cabc2023-01-31 16:02:04 +0800335 err = pkcs1pad_decrypt_complete(req, err);
336
337out:
338 akcipher_request_complete(req, err);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100339}
340
341static int pkcs1pad_decrypt(struct akcipher_request *req)
342{
343 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
344 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
345 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
346 int err;
347
348 if (!ctx->key_size || req->src_len != ctx->key_size)
349 return -EINVAL;
350
Herbert Xu3a32ce52016-06-29 19:32:26 +0800351 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100352 if (!req_ctx->out_buf)
353 return -ENOMEM;
354
355 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700356 ctx->key_size, NULL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100357
358 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
359 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
360 pkcs1pad_decrypt_complete_cb, req);
361
Herbert Xud858b072016-06-29 19:32:28 +0800362 /* Reuse input buffer, output to a new buffer */
363 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
364 req_ctx->out_sg, req->src_len,
365 ctx->key_size);
366
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100367 err = crypto_akcipher_decrypt(&req_ctx->child_req);
Gilad Ben-Yossef4e5b0ad2017-10-18 08:00:36 +0100368 if (err != -EINPROGRESS && err != -EBUSY)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100369 return pkcs1pad_decrypt_complete(req, err);
370
371 return err;
372}
373
374static int pkcs1pad_sign(struct akcipher_request *req)
375{
376 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
377 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
378 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Herbert Xuc0d20d22016-06-29 19:32:23 +0800379 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
380 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
381 const struct rsa_asn1_template *digest_info = ictx->digest_info;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100382 int err;
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800383 unsigned int ps_end, digest_info_size = 0;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100384
385 if (!ctx->key_size)
386 return -EINVAL;
387
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100388 if (digest_info)
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800389 digest_info_size = digest_info->size;
Tadeusz Struka49de372016-03-03 21:49:26 +0000390
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800391 if (req->src_len + digest_info_size > ctx->key_size - 11)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100392 return -EOVERFLOW;
393
394 if (req->dst_len < ctx->key_size) {
395 req->dst_len = ctx->key_size;
396 return -EOVERFLOW;
397 }
398
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100399 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
Herbert Xu3a32ce52016-06-29 19:32:26 +0800400 GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100401 if (!req_ctx->in_buf)
402 return -ENOMEM;
403
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800404 ps_end = ctx->key_size - digest_info_size - req->src_len - 2;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100405 req_ctx->in_buf[0] = 0x01;
406 memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
407 req_ctx->in_buf[ps_end] = 0x00;
408
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100409 if (digest_info)
410 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
411 digest_info->size);
Tadeusz Struka49de372016-03-03 21:49:26 +0000412
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100413 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
414 ctx->key_size - 1 - req->src_len, req->src);
415
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100416 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
417 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
418 pkcs1pad_encrypt_sign_complete_cb, req);
419
Herbert Xud858b072016-06-29 19:32:28 +0800420 /* Reuse output buffer */
421 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
422 req->dst, ctx->key_size - 1, req->dst_len);
423
Vitaly Chikunov3ecc9722019-04-11 18:51:14 +0300424 err = crypto_akcipher_decrypt(&req_ctx->child_req);
Gilad Ben-Yossef4e5b0ad2017-10-18 08:00:36 +0100425 if (err != -EINPROGRESS && err != -EBUSY)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100426 return pkcs1pad_encrypt_sign_complete(req, err);
427
428 return err;
429}
430
431static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
432{
433 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
434 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
435 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Herbert Xuc0d20d22016-06-29 19:32:23 +0800436 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
437 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
438 const struct rsa_asn1_template *digest_info = ictx->digest_info;
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800439 const unsigned int sig_size = req->src_len;
440 const unsigned int digest_size = req->dst_len;
Herbert Xu27710b82016-07-03 10:46:11 +0800441 unsigned int dst_len;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100442 unsigned int pos;
Herbert Xu27710b82016-07-03 10:46:11 +0800443 u8 *out_buf;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100444
445 if (err)
446 goto done;
447
Herbert Xu27710b82016-07-03 10:46:11 +0800448 err = -EINVAL;
449 dst_len = req_ctx->child_req.dst_len;
450 if (dst_len < ctx->key_size - 1)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100451 goto done;
Herbert Xu27710b82016-07-03 10:46:11 +0800452
453 out_buf = req_ctx->out_buf;
454 if (dst_len == ctx->key_size) {
455 if (out_buf[0] != 0x00)
456 /* Decrypted value had no leading 0 byte */
457 goto done;
458
459 dst_len--;
460 out_buf++;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100461 }
462
Tadeusz Struka49de372016-03-03 21:49:26 +0000463 err = -EBADMSG;
Herbert Xu27710b82016-07-03 10:46:11 +0800464 if (out_buf[0] != 0x01)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100465 goto done;
Tadeusz Struka49de372016-03-03 21:49:26 +0000466
Herbert Xu27710b82016-07-03 10:46:11 +0800467 for (pos = 1; pos < dst_len; pos++)
468 if (out_buf[pos] != 0xff)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100469 break;
Tadeusz Struka49de372016-03-03 21:49:26 +0000470
Herbert Xu27710b82016-07-03 10:46:11 +0800471 if (pos < 9 || pos == dst_len || out_buf[pos] != 0x00)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100472 goto done;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100473 pos++;
474
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100475 if (digest_info) {
Eric Biggersa24611e2022-01-18 16:13:05 -0800476 if (digest_info->size > dst_len - pos)
477 goto done;
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100478 if (crypto_memneq(out_buf + pos, digest_info->data,
479 digest_info->size))
480 goto done;
Tadeusz Struka49de372016-03-03 21:49:26 +0000481
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100482 pos += digest_info->size;
483 }
Tadeusz Struka49de372016-03-03 21:49:26 +0000484
485 err = 0;
486
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800487 if (digest_size != dst_len - pos) {
Vitaly Chikunovc7381b02019-04-11 18:51:15 +0300488 err = -EKEYREJECTED;
489 req->dst_len = dst_len - pos;
490 goto done;
491 }
492 /* Extract appended digest. */
493 sg_pcopy_to_buffer(req->src,
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800494 sg_nents_for_len(req->src, sig_size + digest_size),
Vitaly Chikunovc7381b02019-04-11 18:51:15 +0300495 req_ctx->out_buf + ctx->key_size,
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800496 digest_size, sig_size);
Vitaly Chikunovc7381b02019-04-11 18:51:15 +0300497 /* Do the actual verification step. */
498 if (memcmp(req_ctx->out_buf + ctx->key_size, out_buf + pos,
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800499 digest_size) != 0)
Vitaly Chikunovc7381b02019-04-11 18:51:15 +0300500 err = -EKEYREJECTED;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100501done:
Waiman Long453431a2020-08-06 23:18:13 -0700502 kfree_sensitive(req_ctx->out_buf);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100503
504 return err;
505}
506
Herbert Xu255e48e2023-02-08 13:58:44 +0800507static void pkcs1pad_verify_complete_cb(void *data, int err)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100508{
Herbert Xu255e48e2023-02-08 13:58:44 +0800509 struct akcipher_request *req = data;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100510
511 if (err == -EINPROGRESS)
Herbert Xu564cabc2023-01-31 16:02:04 +0800512 goto out;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100513
Herbert Xu564cabc2023-01-31 16:02:04 +0800514 err = pkcs1pad_verify_complete(req, err);
515
516out:
517 akcipher_request_complete(req, err);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100518}
519
520/*
521 * The verify operation is here for completeness similar to the verification
522 * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
523 * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to
524 * retrieve the DigestInfo from a signature, instead the user is expected
525 * to call the sign operation to generate the expected signature and compare
526 * signatures instead of the message-digests.
527 */
528static int pkcs1pad_verify(struct akcipher_request *req)
529{
530 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
531 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
532 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800533 const unsigned int sig_size = req->src_len;
534 const unsigned int digest_size = req->dst_len;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100535 int err;
536
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800537 if (WARN_ON(req->dst) || WARN_ON(!digest_size) ||
538 !ctx->key_size || sig_size != ctx->key_size)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100539 return -EINVAL;
540
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800541 req_ctx->out_buf = kmalloc(ctx->key_size + digest_size, GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100542 if (!req_ctx->out_buf)
543 return -ENOMEM;
544
545 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
Tadeusz Struk6f0904a2016-04-06 14:42:32 -0700546 ctx->key_size, NULL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100547
548 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
549 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
550 pkcs1pad_verify_complete_cb, req);
551
Herbert Xud858b072016-06-29 19:32:28 +0800552 /* Reuse input buffer, output to a new buffer */
553 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
Eric Biggersc2a28fd2022-01-18 16:13:06 -0800554 req_ctx->out_sg, sig_size, ctx->key_size);
Herbert Xud858b072016-06-29 19:32:28 +0800555
Vitaly Chikunov3ecc9722019-04-11 18:51:14 +0300556 err = crypto_akcipher_encrypt(&req_ctx->child_req);
Gilad Ben-Yossef4e5b0ad2017-10-18 08:00:36 +0100557 if (err != -EINPROGRESS && err != -EBUSY)
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100558 return pkcs1pad_verify_complete(req, err);
559
560 return err;
561}
562
563static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
564{
565 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
Tadeusz Struka49de372016-03-03 21:49:26 +0000566 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100567 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
568 struct crypto_akcipher *child_tfm;
569
Herbert Xuc0d20d22016-06-29 19:32:23 +0800570 child_tfm = crypto_spawn_akcipher(&ictx->spawn);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100571 if (IS_ERR(child_tfm))
572 return PTR_ERR(child_tfm);
573
574 ctx->child = child_tfm;
Herbert Xu5b11d1a2022-11-22 13:53:38 +0800575
576 akcipher_set_reqsize(tfm, sizeof(struct pkcs1pad_request) +
577 crypto_akcipher_reqsize(child_tfm));
578
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100579 return 0;
580}
581
582static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
583{
584 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
585
586 crypto_free_akcipher(ctx->child);
587}
588
589static void pkcs1pad_free(struct akcipher_instance *inst)
590{
Tadeusz Struka49de372016-03-03 21:49:26 +0000591 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
592 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100593
594 crypto_drop_akcipher(spawn);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100595 kfree(inst);
596}
597
598static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
599{
Eric Biggers73bed262020-01-02 19:58:47 -0800600 u32 mask;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100601 struct akcipher_instance *inst;
Tadeusz Struka49de372016-03-03 21:49:26 +0000602 struct pkcs1pad_inst_ctx *ctx;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100603 struct akcipher_alg *rsa_alg;
Tadeusz Struka49de372016-03-03 21:49:26 +0000604 const char *hash_name;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100605 int err;
606
Eric Biggers7bcb2c92020-07-09 23:20:38 -0700607 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AKCIPHER, &mask);
608 if (err)
609 return err;
Eric Biggers73bed262020-01-02 19:58:47 -0800610
Tadeusz Struka49de372016-03-03 21:49:26 +0000611 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100612 if (!inst)
613 return -ENOMEM;
614
Tadeusz Struka49de372016-03-03 21:49:26 +0000615 ctx = akcipher_instance_ctx(inst);
Tadeusz Struka49de372016-03-03 21:49:26 +0000616
Eric Biggers0708bb42020-02-25 20:59:23 -0800617 err = crypto_grab_akcipher(&ctx->spawn, akcipher_crypto_instance(inst),
618 crypto_attr_alg_name(tb[1]), 0, mask);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100619 if (err)
Eric Biggers0708bb42020-02-25 20:59:23 -0800620 goto err_free_inst;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100621
Eric Biggers0708bb42020-02-25 20:59:23 -0800622 rsa_alg = crypto_spawn_akcipher_alg(&ctx->spawn);
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100623
Eric Biggers9b304302022-01-18 16:13:02 -0800624 if (strcmp(rsa_alg->base.cra_name, "rsa") != 0) {
625 err = -EINVAL;
626 goto err_free_inst;
627 }
628
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100629 err = -ENAMETOOLONG;
Eric Biggers0708bb42020-02-25 20:59:23 -0800630 hash_name = crypto_attr_alg_name(tb[2]);
631 if (IS_ERR(hash_name)) {
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100632 if (snprintf(inst->alg.base.cra_name,
633 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
634 rsa_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
Eric Biggers0708bb42020-02-25 20:59:23 -0800635 goto err_free_inst;
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100636
637 if (snprintf(inst->alg.base.cra_driver_name,
638 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
639 rsa_alg->base.cra_driver_name) >=
640 CRYPTO_MAX_ALG_NAME)
Eric Biggers0708bb42020-02-25 20:59:23 -0800641 goto err_free_inst;
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100642 } else {
Eric Biggers0708bb42020-02-25 20:59:23 -0800643 ctx->digest_info = rsa_lookup_asn1(hash_name);
644 if (!ctx->digest_info) {
645 err = -EINVAL;
646 goto err_free_inst;
647 }
648
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100649 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
650 "pkcs1pad(%s,%s)", rsa_alg->base.cra_name,
651 hash_name) >= CRYPTO_MAX_ALG_NAME)
Eric Biggers0708bb42020-02-25 20:59:23 -0800652 goto err_free_inst;
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100653
654 if (snprintf(inst->alg.base.cra_driver_name,
655 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
656 rsa_alg->base.cra_driver_name,
657 hash_name) >= CRYPTO_MAX_ALG_NAME)
Eric Biggers0708bb42020-02-25 20:59:23 -0800658 goto err_free_inst;
Denis Kenziorb3a8c8a2018-10-09 17:47:53 +0100659 }
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100660
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100661 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;
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100674
675 inst->free = pkcs1pad_free;
676
677 err = akcipher_register_instance(tmpl, inst);
Eric Biggers0708bb42020-02-25 20:59:23 -0800678 if (err) {
679err_free_inst:
680 pkcs1pad_free(inst);
681 }
Andrzej Zaborowski3d5b1ec2015-12-05 17:09:34 +0100682 return err;
683}
684
685struct crypto_template rsa_pkcs1pad_tmpl = {
686 .name = "pkcs1pad",
687 .create = pkcs1pad_create,
688 .module = THIS_MODULE,
689};