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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * RSA padding templates.
4 *
5 * Copyright (c) 2015 Intel Corporation
6 */
7
8#include <crypto/algapi.h>
9#include <crypto/akcipher.h>
10#include <crypto/internal/akcipher.h>
11#include <crypto/internal/rsa.h>
12#include <linux/err.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/random.h>
17#include <linux/scatterlist.h>
18
19struct pkcs1pad_ctx {
20 struct crypto_akcipher *child;
21 unsigned int key_size;
22};
23
24struct pkcs1pad_inst_ctx {
25 struct crypto_akcipher_spawn spawn;
26};
27
28struct pkcs1pad_request {
29 struct scatterlist in_sg[2], out_sg[1];
30 uint8_t *in_buf, *out_buf;
31 struct akcipher_request child_req;
32};
33
34static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
35 unsigned int keylen)
36{
37 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
38
39 return rsa_set_key(ctx->child, &ctx->key_size, RSA_PUB, key, keylen);
40}
41
42static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
43 unsigned int keylen)
44{
45 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
46
47 return rsa_set_key(ctx->child, &ctx->key_size, RSA_PRIV, key, keylen);
48}
49
50static unsigned int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
51{
52 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
53
54 /*
55 * The maximum destination buffer size for the encrypt operation
56 * will be the same as for RSA, even though it's smaller for
57 * decrypt.
58 */
59
60 return ctx->key_size;
61}
62
63static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
64 struct scatterlist *next)
65{
66 int nsegs = next ? 2 : 1;
67
68 sg_init_table(sg, nsegs);
69 sg_set_buf(sg, buf, len);
70
71 if (next)
72 sg_chain(sg, nsegs, next);
73}
74
75static int pkcs1pad_encrypt_complete(struct akcipher_request *req, int err)
76{
77 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
78 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
79 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
80 unsigned int pad_len;
81 unsigned int len;
82 u8 *out_buf;
83
84 if (err)
85 goto out;
86
87 len = req_ctx->child_req.dst_len;
88 pad_len = ctx->key_size - len;
89
90 /* Four billion to one */
91 if (likely(!pad_len))
92 goto out;
93
94 out_buf = kzalloc(ctx->key_size, GFP_ATOMIC);
95 err = -ENOMEM;
96 if (!out_buf)
97 goto out;
98
99 sg_copy_to_buffer(req->dst, sg_nents_for_len(req->dst, len),
100 out_buf + pad_len, len);
101 sg_copy_from_buffer(req->dst,
102 sg_nents_for_len(req->dst, ctx->key_size),
103 out_buf, ctx->key_size);
104 kfree_sensitive(out_buf);
105
106out:
107 req->dst_len = ctx->key_size;
108
109 kfree(req_ctx->in_buf);
110
111 return err;
112}
113
114static void pkcs1pad_encrypt_complete_cb(void *data, int err)
115{
116 struct akcipher_request *req = data;
117
118 if (err == -EINPROGRESS)
119 goto out;
120
121 err = pkcs1pad_encrypt_complete(req, err);
122
123out:
124 akcipher_request_complete(req, err);
125}
126
127static int pkcs1pad_encrypt(struct akcipher_request *req)
128{
129 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
130 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
131 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
132 int err;
133 unsigned int i, ps_end;
134
135 if (!ctx->key_size)
136 return -EINVAL;
137
138 if (req->src_len > ctx->key_size - 11)
139 return -EOVERFLOW;
140
141 if (req->dst_len < ctx->key_size) {
142 req->dst_len = ctx->key_size;
143 return -EOVERFLOW;
144 }
145
146 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
147 GFP_KERNEL);
148 if (!req_ctx->in_buf)
149 return -ENOMEM;
150
151 ps_end = ctx->key_size - req->src_len - 2;
152 req_ctx->in_buf[0] = 0x02;
153 for (i = 1; i < ps_end; i++)
154 req_ctx->in_buf[i] = get_random_u32_inclusive(1, 255);
155 req_ctx->in_buf[ps_end] = 0x00;
156
157 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
158 ctx->key_size - 1 - req->src_len, req->src);
159
160 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
161 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
162 pkcs1pad_encrypt_complete_cb, req);
163
164 /* Reuse output buffer */
165 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
166 req->dst, ctx->key_size - 1, req->dst_len);
167
168 err = crypto_akcipher_encrypt(&req_ctx->child_req);
169 if (err != -EINPROGRESS && err != -EBUSY)
170 return pkcs1pad_encrypt_complete(req, err);
171
172 return err;
173}
174
175static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
176{
177 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
178 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
179 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
180 unsigned int dst_len;
181 unsigned int pos;
182 u8 *out_buf;
183
184 if (err)
185 goto done;
186
187 err = -EINVAL;
188 dst_len = req_ctx->child_req.dst_len;
189 if (dst_len < ctx->key_size - 1)
190 goto done;
191
192 out_buf = req_ctx->out_buf;
193 if (dst_len == ctx->key_size) {
194 if (out_buf[0] != 0x00)
195 /* Decrypted value had no leading 0 byte */
196 goto done;
197
198 dst_len--;
199 out_buf++;
200 }
201
202 if (out_buf[0] != 0x02)
203 goto done;
204
205 for (pos = 1; pos < dst_len; pos++)
206 if (out_buf[pos] == 0x00)
207 break;
208 if (pos < 9 || pos == dst_len)
209 goto done;
210 pos++;
211
212 err = 0;
213
214 if (req->dst_len < dst_len - pos)
215 err = -EOVERFLOW;
216 req->dst_len = dst_len - pos;
217
218 if (!err)
219 sg_copy_from_buffer(req->dst,
220 sg_nents_for_len(req->dst, req->dst_len),
221 out_buf + pos, req->dst_len);
222
223done:
224 kfree_sensitive(req_ctx->out_buf);
225
226 return err;
227}
228
229static void pkcs1pad_decrypt_complete_cb(void *data, int err)
230{
231 struct akcipher_request *req = data;
232
233 if (err == -EINPROGRESS)
234 goto out;
235
236 err = pkcs1pad_decrypt_complete(req, err);
237
238out:
239 akcipher_request_complete(req, err);
240}
241
242static int pkcs1pad_decrypt(struct akcipher_request *req)
243{
244 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
245 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
246 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
247 int err;
248
249 if (!ctx->key_size || req->src_len != ctx->key_size)
250 return -EINVAL;
251
252 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
253 if (!req_ctx->out_buf)
254 return -ENOMEM;
255
256 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
257 ctx->key_size, NULL);
258
259 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
260 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
261 pkcs1pad_decrypt_complete_cb, req);
262
263 /* Reuse input buffer, output to a new buffer */
264 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
265 req_ctx->out_sg, req->src_len,
266 ctx->key_size);
267
268 err = crypto_akcipher_decrypt(&req_ctx->child_req);
269 if (err != -EINPROGRESS && err != -EBUSY)
270 return pkcs1pad_decrypt_complete(req, err);
271
272 return err;
273}
274
275static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
276{
277 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
278 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
279 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
280 struct crypto_akcipher *child_tfm;
281
282 child_tfm = crypto_spawn_akcipher(&ictx->spawn);
283 if (IS_ERR(child_tfm))
284 return PTR_ERR(child_tfm);
285
286 ctx->child = child_tfm;
287
288 akcipher_set_reqsize(tfm, sizeof(struct pkcs1pad_request) +
289 crypto_akcipher_reqsize(child_tfm));
290
291 return 0;
292}
293
294static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
295{
296 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
297
298 crypto_free_akcipher(ctx->child);
299}
300
301static void pkcs1pad_free(struct akcipher_instance *inst)
302{
303 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
304 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
305
306 crypto_drop_akcipher(spawn);
307 kfree(inst);
308}
309
310static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
311{
312 u32 mask;
313 struct akcipher_instance *inst;
314 struct pkcs1pad_inst_ctx *ctx;
315 struct akcipher_alg *rsa_alg;
316 int err;
317
318 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AKCIPHER, &mask);
319 if (err)
320 return err;
321
322 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
323 if (!inst)
324 return -ENOMEM;
325
326 ctx = akcipher_instance_ctx(inst);
327
328 err = crypto_grab_akcipher(&ctx->spawn, akcipher_crypto_instance(inst),
329 crypto_attr_alg_name(tb[1]), 0, mask);
330 if (err)
331 goto err_free_inst;
332
333 rsa_alg = crypto_spawn_akcipher_alg(&ctx->spawn);
334
335 if (strcmp(rsa_alg->base.cra_name, "rsa") != 0) {
336 err = -EINVAL;
337 goto err_free_inst;
338 }
339
340 err = -ENAMETOOLONG;
341 if (snprintf(inst->alg.base.cra_name,
342 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
343 rsa_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
344 goto err_free_inst;
345
346 if (snprintf(inst->alg.base.cra_driver_name,
347 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
348 rsa_alg->base.cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
349 goto err_free_inst;
350
351 inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
352 inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
353
354 inst->alg.init = pkcs1pad_init_tfm;
355 inst->alg.exit = pkcs1pad_exit_tfm;
356
357 inst->alg.encrypt = pkcs1pad_encrypt;
358 inst->alg.decrypt = pkcs1pad_decrypt;
359 inst->alg.set_pub_key = pkcs1pad_set_pub_key;
360 inst->alg.set_priv_key = pkcs1pad_set_priv_key;
361 inst->alg.max_size = pkcs1pad_get_max_size;
362
363 inst->free = pkcs1pad_free;
364
365 err = akcipher_register_instance(tmpl, inst);
366 if (err) {
367err_free_inst:
368 pkcs1pad_free(inst);
369 }
370 return err;
371}
372
373struct crypto_template rsa_pkcs1pad_tmpl = {
374 .name = "pkcs1pad",
375 .create = pkcs1pad_create,
376 .module = THIS_MODULE,
377};
378
379MODULE_ALIAS_CRYPTO("pkcs1pad");
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * RSA padding templates.
4 *
5 * Copyright (c) 2015 Intel Corporation
6 */
7
8#include <crypto/algapi.h>
9#include <crypto/akcipher.h>
10#include <crypto/internal/akcipher.h>
11#include <crypto/internal/rsa.h>
12#include <linux/err.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/random.h>
17#include <linux/scatterlist.h>
18
19/*
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
91struct pkcs1pad_ctx {
92 struct crypto_akcipher *child;
93 unsigned int key_size;
94};
95
96struct pkcs1pad_inst_ctx {
97 struct crypto_akcipher_spawn spawn;
98 const struct rsa_asn1_template *digest_info;
99};
100
101struct pkcs1pad_request {
102 struct scatterlist in_sg[2], out_sg[1];
103 uint8_t *in_buf, *out_buf;
104 struct akcipher_request child_req;
105};
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);
111 int err;
112
113 ctx->key_size = 0;
114
115 err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
116 if (err)
117 return err;
118
119 /* Find out new modulus size from rsa implementation */
120 err = crypto_akcipher_maxsize(ctx->child);
121 if (err > PAGE_SIZE)
122 return -ENOTSUPP;
123
124 ctx->key_size = err;
125 return 0;
126}
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);
132 int err;
133
134 ctx->key_size = 0;
135
136 err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
137 if (err)
138 return err;
139
140 /* Find out new modulus size from rsa implementation */
141 err = crypto_akcipher_maxsize(ctx->child);
142 if (err > PAGE_SIZE)
143 return -ENOTSUPP;
144
145 ctx->key_size = err;
146 return 0;
147}
148
149static unsigned int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
150{
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
159 return ctx->key_size;
160}
161
162static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
163 struct scatterlist *next)
164{
165 int nsegs = next ? 2 : 1;
166
167 sg_init_table(sg, nsegs);
168 sg_set_buf(sg, buf, len);
169
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);
179 unsigned int pad_len;
180 unsigned int len;
181 u8 *out_buf;
182
183 if (err)
184 goto out;
185
186 len = req_ctx->child_req.dst_len;
187 pad_len = ctx->key_size - len;
188
189 /* Four billion to one */
190 if (likely(!pad_len))
191 goto out;
192
193 out_buf = kzalloc(ctx->key_size, GFP_KERNEL);
194 err = -ENOMEM;
195 if (!out_buf)
196 goto out;
197
198 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);
203 kfree_sensitive(out_buf);
204
205out:
206 req->dst_len = ctx->key_size;
207
208 kfree(req_ctx->in_buf);
209
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
248 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
249 GFP_KERNEL);
250 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] = get_random_u32_inclusive(1, 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
262 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
266 /* 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
270 err = crypto_akcipher_encrypt(&req_ctx->child_req);
271 if (err != -EINPROGRESS && err != -EBUSY)
272 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);
282 unsigned int dst_len;
283 unsigned int pos;
284 u8 *out_buf;
285
286 if (err)
287 goto done;
288
289 err = -EINVAL;
290 dst_len = req_ctx->child_req.dst_len;
291 if (dst_len < ctx->key_size - 1)
292 goto done;
293
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++;
302 }
303
304 if (out_buf[0] != 0x02)
305 goto done;
306
307 for (pos = 1; pos < dst_len; pos++)
308 if (out_buf[pos] == 0x00)
309 break;
310 if (pos < 9 || pos == dst_len)
311 goto done;
312 pos++;
313
314 err = 0;
315
316 if (req->dst_len < dst_len - pos)
317 err = -EOVERFLOW;
318 req->dst_len = dst_len - pos;
319
320 if (!err)
321 sg_copy_from_buffer(req->dst,
322 sg_nents_for_len(req->dst, req->dst_len),
323 out_buf + pos, req->dst_len);
324
325done:
326 kfree_sensitive(req_ctx->out_buf);
327
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
356 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
357 if (!req_ctx->out_buf)
358 return -ENOMEM;
359
360 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
361 ctx->key_size, NULL);
362
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
367 /* 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
372 err = crypto_akcipher_decrypt(&req_ctx->child_req);
373 if (err != -EINPROGRESS && err != -EBUSY)
374 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);
384 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;
387 int err;
388 unsigned int ps_end, digest_info_size = 0;
389
390 if (!ctx->key_size)
391 return -EINVAL;
392
393 if (digest_info)
394 digest_info_size = digest_info->size;
395
396 if (req->src_len + digest_info_size > ctx->key_size - 11)
397 return -EOVERFLOW;
398
399 if (req->dst_len < ctx->key_size) {
400 req->dst_len = ctx->key_size;
401 return -EOVERFLOW;
402 }
403
404 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
405 GFP_KERNEL);
406 if (!req_ctx->in_buf)
407 return -ENOMEM;
408
409 ps_end = ctx->key_size - digest_info_size - req->src_len - 2;
410 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
414 if (digest_info)
415 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
416 digest_info->size);
417
418 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
419 ctx->key_size - 1 - req->src_len, req->src);
420
421 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
425 /* 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
429 err = crypto_akcipher_decrypt(&req_ctx->child_req);
430 if (err != -EINPROGRESS && err != -EBUSY)
431 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);
441 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;
444 const unsigned int sig_size = req->src_len;
445 const unsigned int digest_size = req->dst_len;
446 unsigned int dst_len;
447 unsigned int pos;
448 u8 *out_buf;
449
450 if (err)
451 goto done;
452
453 err = -EINVAL;
454 dst_len = req_ctx->child_req.dst_len;
455 if (dst_len < ctx->key_size - 1)
456 goto done;
457
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++;
466 }
467
468 err = -EBADMSG;
469 if (out_buf[0] != 0x01)
470 goto done;
471
472 for (pos = 1; pos < dst_len; pos++)
473 if (out_buf[pos] != 0xff)
474 break;
475
476 if (pos < 9 || pos == dst_len || out_buf[pos] != 0x00)
477 goto done;
478 pos++;
479
480 if (digest_info) {
481 if (digest_info->size > dst_len - pos)
482 goto done;
483 if (crypto_memneq(out_buf + pos, digest_info->data,
484 digest_info->size))
485 goto done;
486
487 pos += digest_info->size;
488 }
489
490 err = 0;
491
492 if (digest_size != dst_len - pos) {
493 err = -EKEYREJECTED;
494 req->dst_len = dst_len - pos;
495 goto done;
496 }
497 /* Extract appended digest. */
498 sg_pcopy_to_buffer(req->src,
499 sg_nents_for_len(req->src, sig_size + digest_size),
500 req_ctx->out_buf + ctx->key_size,
501 digest_size, sig_size);
502 /* Do the actual verification step. */
503 if (memcmp(req_ctx->out_buf + ctx->key_size, out_buf + pos,
504 digest_size) != 0)
505 err = -EKEYREJECTED;
506done:
507 kfree_sensitive(req_ctx->out_buf);
508
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);
540 const unsigned int sig_size = req->src_len;
541 const unsigned int digest_size = req->dst_len;
542 int err;
543
544 if (WARN_ON(req->dst) || WARN_ON(!digest_size) ||
545 !ctx->key_size || sig_size != ctx->key_size)
546 return -EINVAL;
547
548 req_ctx->out_buf = kmalloc(ctx->key_size + digest_size, GFP_KERNEL);
549 if (!req_ctx->out_buf)
550 return -ENOMEM;
551
552 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
553 ctx->key_size, NULL);
554
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
559 /* Reuse input buffer, output to a new buffer */
560 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
561 req_ctx->out_sg, sig_size, ctx->key_size);
562
563 err = crypto_akcipher_encrypt(&req_ctx->child_req);
564 if (err != -EINPROGRESS && err != -EBUSY)
565 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);
573 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
574 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
575 struct crypto_akcipher *child_tfm;
576
577 child_tfm = crypto_spawn_akcipher(&ictx->spawn);
578 if (IS_ERR(child_tfm))
579 return PTR_ERR(child_tfm);
580
581 ctx->child = child_tfm;
582
583 akcipher_set_reqsize(tfm, sizeof(struct pkcs1pad_request) +
584 crypto_akcipher_reqsize(child_tfm));
585
586 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{
598 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
599 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
600
601 crypto_drop_akcipher(spawn);
602 kfree(inst);
603}
604
605static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
606{
607 u32 mask;
608 struct akcipher_instance *inst;
609 struct pkcs1pad_inst_ctx *ctx;
610 struct akcipher_alg *rsa_alg;
611 const char *hash_name;
612 int err;
613
614 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AKCIPHER, &mask);
615 if (err)
616 return err;
617
618 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
619 if (!inst)
620 return -ENOMEM;
621
622 ctx = akcipher_instance_ctx(inst);
623
624 err = crypto_grab_akcipher(&ctx->spawn, akcipher_crypto_instance(inst),
625 crypto_attr_alg_name(tb[1]), 0, mask);
626 if (err)
627 goto err_free_inst;
628
629 rsa_alg = crypto_spawn_akcipher_alg(&ctx->spawn);
630
631 if (strcmp(rsa_alg->base.cra_name, "rsa") != 0) {
632 err = -EINVAL;
633 goto err_free_inst;
634 }
635
636 err = -ENAMETOOLONG;
637 hash_name = crypto_attr_alg_name(tb[2]);
638 if (IS_ERR(hash_name)) {
639 if (snprintf(inst->alg.base.cra_name,
640 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
641 rsa_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
642 goto err_free_inst;
643
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)
648 goto err_free_inst;
649 } else {
650 ctx->digest_info = rsa_lookup_asn1(hash_name);
651 if (!ctx->digest_info) {
652 err = -EINVAL;
653 goto err_free_inst;
654 }
655
656 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)
659 goto err_free_inst;
660
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)
665 goto err_free_inst;
666 }
667
668 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;
681
682 inst->free = pkcs1pad_free;
683
684 err = akcipher_register_instance(tmpl, inst);
685 if (err) {
686err_free_inst:
687 pkcs1pad_free(inst);
688 }
689 return err;
690}
691
692struct crypto_template rsa_pkcs1pad_tmpl = {
693 .name = "pkcs1pad",
694 .create = pkcs1pad_create,
695 .module = THIS_MODULE,
696};