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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// 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/module.h>
9#include <linux/mpi.h>
10#include <crypto/internal/rsa.h>
11#include <crypto/internal/akcipher.h>
12#include <crypto/akcipher.h>
13#include <crypto/algapi.h>
14
15struct rsa_mpi_key {
16 MPI n;
17 MPI e;
18 MPI d;
19};
20
21/*
22 * RSAEP function [RFC3447 sec 5.1.1]
23 * c = m^e mod n;
24 */
25static int _rsa_enc(const struct rsa_mpi_key *key, MPI c, MPI m)
26{
27 /* (1) Validate 0 <= m < n */
28 if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
29 return -EINVAL;
30
31 /* (2) c = m^e mod n */
32 return mpi_powm(c, m, key->e, key->n);
33}
34
35/*
36 * RSADP function [RFC3447 sec 5.1.2]
37 * m = c^d mod n;
38 */
39static int _rsa_dec(const struct rsa_mpi_key *key, MPI m, MPI c)
40{
41 /* (1) Validate 0 <= c < n */
42 if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0)
43 return -EINVAL;
44
45 /* (2) m = c^d mod n */
46 return mpi_powm(m, c, key->d, key->n);
47}
48
49static inline struct rsa_mpi_key *rsa_get_key(struct crypto_akcipher *tfm)
50{
51 return akcipher_tfm_ctx(tfm);
52}
53
54static int rsa_enc(struct akcipher_request *req)
55{
56 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
57 const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
58 MPI m, c = mpi_alloc(0);
59 int ret = 0;
60 int sign;
61
62 if (!c)
63 return -ENOMEM;
64
65 if (unlikely(!pkey->n || !pkey->e)) {
66 ret = -EINVAL;
67 goto err_free_c;
68 }
69
70 ret = -ENOMEM;
71 m = mpi_read_raw_from_sgl(req->src, req->src_len);
72 if (!m)
73 goto err_free_c;
74
75 ret = _rsa_enc(pkey, c, m);
76 if (ret)
77 goto err_free_m;
78
79 ret = mpi_write_to_sgl(c, req->dst, req->dst_len, &sign);
80 if (ret)
81 goto err_free_m;
82
83 if (sign < 0)
84 ret = -EBADMSG;
85
86err_free_m:
87 mpi_free(m);
88err_free_c:
89 mpi_free(c);
90 return ret;
91}
92
93static int rsa_dec(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 c, m = mpi_alloc(0);
98 int ret = 0;
99 int sign;
100
101 if (!m)
102 return -ENOMEM;
103
104 if (unlikely(!pkey->n || !pkey->d)) {
105 ret = -EINVAL;
106 goto err_free_m;
107 }
108
109 ret = -ENOMEM;
110 c = mpi_read_raw_from_sgl(req->src, req->src_len);
111 if (!c)
112 goto err_free_m;
113
114 ret = _rsa_dec(pkey, m, c);
115 if (ret)
116 goto err_free_c;
117
118 ret = mpi_write_to_sgl(m, req->dst, req->dst_len, &sign);
119 if (ret)
120 goto err_free_c;
121
122 if (sign < 0)
123 ret = -EBADMSG;
124err_free_c:
125 mpi_free(c);
126err_free_m:
127 mpi_free(m);
128 return ret;
129}
130
131static void rsa_free_mpi_key(struct rsa_mpi_key *key)
132{
133 mpi_free(key->d);
134 mpi_free(key->e);
135 mpi_free(key->n);
136 key->d = NULL;
137 key->e = NULL;
138 key->n = NULL;
139}
140
141static int rsa_check_key_length(unsigned int len)
142{
143 switch (len) {
144 case 512:
145 case 1024:
146 case 1536:
147 case 2048:
148 case 3072:
149 case 4096:
150 return 0;
151 }
152
153 return -EINVAL;
154}
155
156static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
157 unsigned int keylen)
158{
159 struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
160 struct rsa_key raw_key = {0};
161 int ret;
162
163 /* Free the old MPI key if any */
164 rsa_free_mpi_key(mpi_key);
165
166 ret = rsa_parse_pub_key(&raw_key, key, keylen);
167 if (ret)
168 return ret;
169
170 mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
171 if (!mpi_key->e)
172 goto err;
173
174 mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
175 if (!mpi_key->n)
176 goto err;
177
178 if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
179 rsa_free_mpi_key(mpi_key);
180 return -EINVAL;
181 }
182
183 return 0;
184
185err:
186 rsa_free_mpi_key(mpi_key);
187 return -ENOMEM;
188}
189
190static int rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
191 unsigned int keylen)
192{
193 struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
194 struct rsa_key raw_key = {0};
195 int ret;
196
197 /* Free the old MPI key if any */
198 rsa_free_mpi_key(mpi_key);
199
200 ret = rsa_parse_priv_key(&raw_key, key, keylen);
201 if (ret)
202 return ret;
203
204 mpi_key->d = mpi_read_raw_data(raw_key.d, raw_key.d_sz);
205 if (!mpi_key->d)
206 goto err;
207
208 mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
209 if (!mpi_key->e)
210 goto err;
211
212 mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
213 if (!mpi_key->n)
214 goto err;
215
216 if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
217 rsa_free_mpi_key(mpi_key);
218 return -EINVAL;
219 }
220
221 return 0;
222
223err:
224 rsa_free_mpi_key(mpi_key);
225 return -ENOMEM;
226}
227
228static unsigned int rsa_max_size(struct crypto_akcipher *tfm)
229{
230 struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);
231
232 return mpi_get_size(pkey->n);
233}
234
235static void rsa_exit_tfm(struct crypto_akcipher *tfm)
236{
237 struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);
238
239 rsa_free_mpi_key(pkey);
240}
241
242static struct akcipher_alg rsa = {
243 .encrypt = rsa_enc,
244 .decrypt = rsa_dec,
245 .set_priv_key = rsa_set_priv_key,
246 .set_pub_key = rsa_set_pub_key,
247 .max_size = rsa_max_size,
248 .exit = rsa_exit_tfm,
249 .base = {
250 .cra_name = "rsa",
251 .cra_driver_name = "rsa-generic",
252 .cra_priority = 100,
253 .cra_module = THIS_MODULE,
254 .cra_ctxsize = sizeof(struct rsa_mpi_key),
255 },
256};
257
258static int rsa_init(void)
259{
260 int err;
261
262 err = crypto_register_akcipher(&rsa);
263 if (err)
264 return err;
265
266 err = crypto_register_template(&rsa_pkcs1pad_tmpl);
267 if (err) {
268 crypto_unregister_akcipher(&rsa);
269 return err;
270 }
271
272 return 0;
273}
274
275static void rsa_exit(void)
276{
277 crypto_unregister_template(&rsa_pkcs1pad_tmpl);
278 crypto_unregister_akcipher(&rsa);
279}
280
281subsys_initcall(rsa_init);
282module_exit(rsa_exit);
283MODULE_ALIAS_CRYPTO("rsa");
284MODULE_LICENSE("GPL");
285MODULE_DESCRIPTION("RSA generic algorithm");