Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* RSA asymmetric public-key algorithm [RFC3447]
3 *
4 * Copyright (c) 2015, Intel Corporation
5 * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
6 */
7
8#include <linux/fips.h>
9#include <linux/module.h>
10#include <linux/mpi.h>
11#include <crypto/internal/rsa.h>
12#include <crypto/internal/akcipher.h>
13#include <crypto/akcipher.h>
14#include <crypto/algapi.h>
15
16struct rsa_mpi_key {
17 MPI n;
18 MPI e;
19 MPI d;
20 MPI p;
21 MPI q;
22 MPI dp;
23 MPI dq;
24 MPI qinv;
25};
26
27/*
28 * RSAEP function [RFC3447 sec 5.1.1]
29 * c = m^e mod n;
30 */
31static int _rsa_enc(const struct rsa_mpi_key *key, MPI c, MPI m)
32{
33 /* (1) Validate 0 <= m < n */
34 if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
35 return -EINVAL;
36
37 /* (2) c = m^e mod n */
38 return mpi_powm(c, m, key->e, key->n);
39}
40
41/*
42 * RSADP function [RFC3447 sec 5.1.2]
43 * m_1 = c^dP mod p;
44 * m_2 = c^dQ mod q;
45 * h = (m_1 - m_2) * qInv mod p;
46 * m = m_2 + q * h;
47 */
48static int _rsa_dec_crt(const struct rsa_mpi_key *key, MPI m_or_m1_or_h, MPI c)
49{
50 MPI m2, m12_or_qh;
51 int ret = -ENOMEM;
52
53 /* (1) Validate 0 <= c < n */
54 if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0)
55 return -EINVAL;
56
57 m2 = mpi_alloc(0);
58 m12_or_qh = mpi_alloc(0);
59 if (!m2 || !m12_or_qh)
60 goto err_free_mpi;
61
62 /* (2i) m_1 = c^dP mod p */
63 ret = mpi_powm(m_or_m1_or_h, c, key->dp, key->p);
64 if (ret)
65 goto err_free_mpi;
66
67 /* (2i) m_2 = c^dQ mod q */
68 ret = mpi_powm(m2, c, key->dq, key->q);
69 if (ret)
70 goto err_free_mpi;
71
72 /* (2iii) h = (m_1 - m_2) * qInv mod p */
73 mpi_sub(m12_or_qh, m_or_m1_or_h, m2);
74 mpi_mulm(m_or_m1_or_h, m12_or_qh, key->qinv, key->p);
75
76 /* (2iv) m = m_2 + q * h */
77 mpi_mul(m12_or_qh, key->q, m_or_m1_or_h);
78 mpi_addm(m_or_m1_or_h, m2, m12_or_qh, key->n);
79
80 ret = 0;
81
82err_free_mpi:
83 mpi_free(m12_or_qh);
84 mpi_free(m2);
85 return ret;
86}
87
88static inline struct rsa_mpi_key *rsa_get_key(struct crypto_akcipher *tfm)
89{
90 return akcipher_tfm_ctx(tfm);
91}
92
93static int rsa_enc(struct akcipher_request *req)
94{
95 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
96 const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
97 MPI m, c = mpi_alloc(0);
98 int ret = 0;
99 int sign;
100
101 if (!c)
102 return -ENOMEM;
103
104 if (unlikely(!pkey->n || !pkey->e)) {
105 ret = -EINVAL;
106 goto err_free_c;
107 }
108
109 ret = -ENOMEM;
110 m = mpi_read_raw_from_sgl(req->src, req->src_len);
111 if (!m)
112 goto err_free_c;
113
114 ret = _rsa_enc(pkey, c, m);
115 if (ret)
116 goto err_free_m;
117
118 ret = mpi_write_to_sgl(c, req->dst, req->dst_len, &sign);
119 if (ret)
120 goto err_free_m;
121
122 if (sign < 0)
123 ret = -EBADMSG;
124
125err_free_m:
126 mpi_free(m);
127err_free_c:
128 mpi_free(c);
129 return ret;
130}
131
132static int rsa_dec(struct akcipher_request *req)
133{
134 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
135 const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
136 MPI c, m = mpi_alloc(0);
137 int ret = 0;
138 int sign;
139
140 if (!m)
141 return -ENOMEM;
142
143 if (unlikely(!pkey->n || !pkey->d)) {
144 ret = -EINVAL;
145 goto err_free_m;
146 }
147
148 ret = -ENOMEM;
149 c = mpi_read_raw_from_sgl(req->src, req->src_len);
150 if (!c)
151 goto err_free_m;
152
153 ret = _rsa_dec_crt(pkey, m, c);
154 if (ret)
155 goto err_free_c;
156
157 ret = mpi_write_to_sgl(m, req->dst, req->dst_len, &sign);
158 if (ret)
159 goto err_free_c;
160
161 if (sign < 0)
162 ret = -EBADMSG;
163err_free_c:
164 mpi_free(c);
165err_free_m:
166 mpi_free(m);
167 return ret;
168}
169
170static void rsa_free_mpi_key(struct rsa_mpi_key *key)
171{
172 mpi_free(key->d);
173 mpi_free(key->e);
174 mpi_free(key->n);
175 mpi_free(key->p);
176 mpi_free(key->q);
177 mpi_free(key->dp);
178 mpi_free(key->dq);
179 mpi_free(key->qinv);
180 key->d = NULL;
181 key->e = NULL;
182 key->n = NULL;
183 key->p = NULL;
184 key->q = NULL;
185 key->dp = NULL;
186 key->dq = NULL;
187 key->qinv = NULL;
188}
189
190static int rsa_check_key_length(unsigned int len)
191{
192 switch (len) {
193 case 512:
194 case 1024:
195 case 1536:
196 if (fips_enabled)
197 return -EINVAL;
198 fallthrough;
199 case 2048:
200 case 3072:
201 case 4096:
202 return 0;
203 }
204
205 return -EINVAL;
206}
207
208static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
209 unsigned int keylen)
210{
211 struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
212 struct rsa_key raw_key = {0};
213 int ret;
214
215 /* Free the old MPI key if any */
216 rsa_free_mpi_key(mpi_key);
217
218 ret = rsa_parse_pub_key(&raw_key, key, keylen);
219 if (ret)
220 return ret;
221
222 mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
223 if (!mpi_key->e)
224 goto err;
225
226 mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
227 if (!mpi_key->n)
228 goto err;
229
230 if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
231 rsa_free_mpi_key(mpi_key);
232 return -EINVAL;
233 }
234
235 return 0;
236
237err:
238 rsa_free_mpi_key(mpi_key);
239 return -ENOMEM;
240}
241
242static int rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
243 unsigned int keylen)
244{
245 struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
246 struct rsa_key raw_key = {0};
247 int ret;
248
249 /* Free the old MPI key if any */
250 rsa_free_mpi_key(mpi_key);
251
252 ret = rsa_parse_priv_key(&raw_key, key, keylen);
253 if (ret)
254 return ret;
255
256 mpi_key->d = mpi_read_raw_data(raw_key.d, raw_key.d_sz);
257 if (!mpi_key->d)
258 goto err;
259
260 mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
261 if (!mpi_key->e)
262 goto err;
263
264 mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
265 if (!mpi_key->n)
266 goto err;
267
268 mpi_key->p = mpi_read_raw_data(raw_key.p, raw_key.p_sz);
269 if (!mpi_key->p)
270 goto err;
271
272 mpi_key->q = mpi_read_raw_data(raw_key.q, raw_key.q_sz);
273 if (!mpi_key->q)
274 goto err;
275
276 mpi_key->dp = mpi_read_raw_data(raw_key.dp, raw_key.dp_sz);
277 if (!mpi_key->dp)
278 goto err;
279
280 mpi_key->dq = mpi_read_raw_data(raw_key.dq, raw_key.dq_sz);
281 if (!mpi_key->dq)
282 goto err;
283
284 mpi_key->qinv = mpi_read_raw_data(raw_key.qinv, raw_key.qinv_sz);
285 if (!mpi_key->qinv)
286 goto err;
287
288 if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
289 rsa_free_mpi_key(mpi_key);
290 return -EINVAL;
291 }
292
293 return 0;
294
295err:
296 rsa_free_mpi_key(mpi_key);
297 return -ENOMEM;
298}
299
300static unsigned int rsa_max_size(struct crypto_akcipher *tfm)
301{
302 struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);
303
304 return mpi_get_size(pkey->n);
305}
306
307static void rsa_exit_tfm(struct crypto_akcipher *tfm)
308{
309 struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);
310
311 rsa_free_mpi_key(pkey);
312}
313
314static struct akcipher_alg rsa = {
315 .encrypt = rsa_enc,
316 .decrypt = rsa_dec,
317 .set_priv_key = rsa_set_priv_key,
318 .set_pub_key = rsa_set_pub_key,
319 .max_size = rsa_max_size,
320 .exit = rsa_exit_tfm,
321 .base = {
322 .cra_name = "rsa",
323 .cra_driver_name = "rsa-generic",
324 .cra_priority = 100,
325 .cra_module = THIS_MODULE,
326 .cra_ctxsize = sizeof(struct rsa_mpi_key),
327 },
328};
329
330static int __init rsa_init(void)
331{
332 int err;
333
334 err = crypto_register_akcipher(&rsa);
335 if (err)
336 return err;
337
338 err = crypto_register_template(&rsa_pkcs1pad_tmpl);
339 if (err) {
340 crypto_unregister_akcipher(&rsa);
341 return err;
342 }
343
344 return 0;
345}
346
347static void __exit rsa_exit(void)
348{
349 crypto_unregister_template(&rsa_pkcs1pad_tmpl);
350 crypto_unregister_akcipher(&rsa);
351}
352
353subsys_initcall(rsa_init);
354module_exit(rsa_exit);
355MODULE_ALIAS_CRYPTO("rsa");
356MODULE_LICENSE("GPL");
357MODULE_DESCRIPTION("RSA generic algorithm");
1/* RSA asymmetric public-key algorithm [RFC3447]
2 *
3 * Copyright (c) 2015, Intel Corporation
4 * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11
12#include <linux/module.h>
13#include <linux/mpi.h>
14#include <crypto/internal/rsa.h>
15#include <crypto/internal/akcipher.h>
16#include <crypto/akcipher.h>
17#include <crypto/algapi.h>
18
19struct rsa_mpi_key {
20 MPI n;
21 MPI e;
22 MPI d;
23};
24
25/*
26 * RSAEP function [RFC3447 sec 5.1.1]
27 * c = m^e mod n;
28 */
29static int _rsa_enc(const struct rsa_mpi_key *key, MPI c, MPI m)
30{
31 /* (1) Validate 0 <= m < n */
32 if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
33 return -EINVAL;
34
35 /* (2) c = m^e mod n */
36 return mpi_powm(c, m, key->e, key->n);
37}
38
39/*
40 * RSADP function [RFC3447 sec 5.1.2]
41 * m = c^d mod n;
42 */
43static int _rsa_dec(const struct rsa_mpi_key *key, MPI m, MPI c)
44{
45 /* (1) Validate 0 <= c < n */
46 if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0)
47 return -EINVAL;
48
49 /* (2) m = c^d mod n */
50 return mpi_powm(m, c, key->d, key->n);
51}
52
53/*
54 * RSASP1 function [RFC3447 sec 5.2.1]
55 * s = m^d mod n
56 */
57static int _rsa_sign(const struct rsa_mpi_key *key, MPI s, MPI m)
58{
59 /* (1) Validate 0 <= m < n */
60 if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
61 return -EINVAL;
62
63 /* (2) s = m^d mod n */
64 return mpi_powm(s, m, key->d, key->n);
65}
66
67/*
68 * RSAVP1 function [RFC3447 sec 5.2.2]
69 * m = s^e mod n;
70 */
71static int _rsa_verify(const struct rsa_mpi_key *key, MPI m, MPI s)
72{
73 /* (1) Validate 0 <= s < n */
74 if (mpi_cmp_ui(s, 0) < 0 || mpi_cmp(s, key->n) >= 0)
75 return -EINVAL;
76
77 /* (2) m = s^e mod n */
78 return mpi_powm(m, s, key->e, key->n);
79}
80
81static inline struct rsa_mpi_key *rsa_get_key(struct crypto_akcipher *tfm)
82{
83 return akcipher_tfm_ctx(tfm);
84}
85
86static int rsa_enc(struct akcipher_request *req)
87{
88 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
89 const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
90 MPI m, c = mpi_alloc(0);
91 int ret = 0;
92 int sign;
93
94 if (!c)
95 return -ENOMEM;
96
97 if (unlikely(!pkey->n || !pkey->e)) {
98 ret = -EINVAL;
99 goto err_free_c;
100 }
101
102 ret = -ENOMEM;
103 m = mpi_read_raw_from_sgl(req->src, req->src_len);
104 if (!m)
105 goto err_free_c;
106
107 ret = _rsa_enc(pkey, c, m);
108 if (ret)
109 goto err_free_m;
110
111 ret = mpi_write_to_sgl(c, req->dst, req->dst_len, &sign);
112 if (ret)
113 goto err_free_m;
114
115 if (sign < 0)
116 ret = -EBADMSG;
117
118err_free_m:
119 mpi_free(m);
120err_free_c:
121 mpi_free(c);
122 return ret;
123}
124
125static int rsa_dec(struct akcipher_request *req)
126{
127 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
128 const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
129 MPI c, m = mpi_alloc(0);
130 int ret = 0;
131 int sign;
132
133 if (!m)
134 return -ENOMEM;
135
136 if (unlikely(!pkey->n || !pkey->d)) {
137 ret = -EINVAL;
138 goto err_free_m;
139 }
140
141 ret = -ENOMEM;
142 c = mpi_read_raw_from_sgl(req->src, req->src_len);
143 if (!c)
144 goto err_free_m;
145
146 ret = _rsa_dec(pkey, m, c);
147 if (ret)
148 goto err_free_c;
149
150 ret = mpi_write_to_sgl(m, req->dst, req->dst_len, &sign);
151 if (ret)
152 goto err_free_c;
153
154 if (sign < 0)
155 ret = -EBADMSG;
156err_free_c:
157 mpi_free(c);
158err_free_m:
159 mpi_free(m);
160 return ret;
161}
162
163static int rsa_sign(struct akcipher_request *req)
164{
165 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
166 const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
167 MPI m, s = mpi_alloc(0);
168 int ret = 0;
169 int sign;
170
171 if (!s)
172 return -ENOMEM;
173
174 if (unlikely(!pkey->n || !pkey->d)) {
175 ret = -EINVAL;
176 goto err_free_s;
177 }
178
179 ret = -ENOMEM;
180 m = mpi_read_raw_from_sgl(req->src, req->src_len);
181 if (!m)
182 goto err_free_s;
183
184 ret = _rsa_sign(pkey, s, m);
185 if (ret)
186 goto err_free_m;
187
188 ret = mpi_write_to_sgl(s, req->dst, req->dst_len, &sign);
189 if (ret)
190 goto err_free_m;
191
192 if (sign < 0)
193 ret = -EBADMSG;
194
195err_free_m:
196 mpi_free(m);
197err_free_s:
198 mpi_free(s);
199 return ret;
200}
201
202static int rsa_verify(struct akcipher_request *req)
203{
204 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
205 const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
206 MPI s, m = mpi_alloc(0);
207 int ret = 0;
208 int sign;
209
210 if (!m)
211 return -ENOMEM;
212
213 if (unlikely(!pkey->n || !pkey->e)) {
214 ret = -EINVAL;
215 goto err_free_m;
216 }
217
218 ret = -ENOMEM;
219 s = mpi_read_raw_from_sgl(req->src, req->src_len);
220 if (!s) {
221 ret = -ENOMEM;
222 goto err_free_m;
223 }
224
225 ret = _rsa_verify(pkey, m, s);
226 if (ret)
227 goto err_free_s;
228
229 ret = mpi_write_to_sgl(m, req->dst, req->dst_len, &sign);
230 if (ret)
231 goto err_free_s;
232
233 if (sign < 0)
234 ret = -EBADMSG;
235
236err_free_s:
237 mpi_free(s);
238err_free_m:
239 mpi_free(m);
240 return ret;
241}
242
243static void rsa_free_mpi_key(struct rsa_mpi_key *key)
244{
245 mpi_free(key->d);
246 mpi_free(key->e);
247 mpi_free(key->n);
248 key->d = NULL;
249 key->e = NULL;
250 key->n = NULL;
251}
252
253static int rsa_check_key_length(unsigned int len)
254{
255 switch (len) {
256 case 512:
257 case 1024:
258 case 1536:
259 case 2048:
260 case 3072:
261 case 4096:
262 return 0;
263 }
264
265 return -EINVAL;
266}
267
268static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
269 unsigned int keylen)
270{
271 struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
272 struct rsa_key raw_key = {0};
273 int ret;
274
275 /* Free the old MPI key if any */
276 rsa_free_mpi_key(mpi_key);
277
278 ret = rsa_parse_pub_key(&raw_key, key, keylen);
279 if (ret)
280 return ret;
281
282 mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
283 if (!mpi_key->e)
284 goto err;
285
286 mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
287 if (!mpi_key->n)
288 goto err;
289
290 if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
291 rsa_free_mpi_key(mpi_key);
292 return -EINVAL;
293 }
294
295 return 0;
296
297err:
298 rsa_free_mpi_key(mpi_key);
299 return -ENOMEM;
300}
301
302static int rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
303 unsigned int keylen)
304{
305 struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
306 struct rsa_key raw_key = {0};
307 int ret;
308
309 /* Free the old MPI key if any */
310 rsa_free_mpi_key(mpi_key);
311
312 ret = rsa_parse_priv_key(&raw_key, key, keylen);
313 if (ret)
314 return ret;
315
316 mpi_key->d = mpi_read_raw_data(raw_key.d, raw_key.d_sz);
317 if (!mpi_key->d)
318 goto err;
319
320 mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
321 if (!mpi_key->e)
322 goto err;
323
324 mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
325 if (!mpi_key->n)
326 goto err;
327
328 if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
329 rsa_free_mpi_key(mpi_key);
330 return -EINVAL;
331 }
332
333 return 0;
334
335err:
336 rsa_free_mpi_key(mpi_key);
337 return -ENOMEM;
338}
339
340static unsigned int rsa_max_size(struct crypto_akcipher *tfm)
341{
342 struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);
343
344 return mpi_get_size(pkey->n);
345}
346
347static void rsa_exit_tfm(struct crypto_akcipher *tfm)
348{
349 struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);
350
351 rsa_free_mpi_key(pkey);
352}
353
354static struct akcipher_alg rsa = {
355 .encrypt = rsa_enc,
356 .decrypt = rsa_dec,
357 .sign = rsa_sign,
358 .verify = rsa_verify,
359 .set_priv_key = rsa_set_priv_key,
360 .set_pub_key = rsa_set_pub_key,
361 .max_size = rsa_max_size,
362 .exit = rsa_exit_tfm,
363 .base = {
364 .cra_name = "rsa",
365 .cra_driver_name = "rsa-generic",
366 .cra_priority = 100,
367 .cra_module = THIS_MODULE,
368 .cra_ctxsize = sizeof(struct rsa_mpi_key),
369 },
370};
371
372static int rsa_init(void)
373{
374 int err;
375
376 err = crypto_register_akcipher(&rsa);
377 if (err)
378 return err;
379
380 err = crypto_register_template(&rsa_pkcs1pad_tmpl);
381 if (err) {
382 crypto_unregister_akcipher(&rsa);
383 return err;
384 }
385
386 return 0;
387}
388
389static void rsa_exit(void)
390{
391 crypto_unregister_template(&rsa_pkcs1pad_tmpl);
392 crypto_unregister_akcipher(&rsa);
393}
394
395module_init(rsa_init);
396module_exit(rsa_exit);
397MODULE_ALIAS_CRYPTO("rsa");
398MODULE_LICENSE("GPL");
399MODULE_DESCRIPTION("RSA generic algorithm");