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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
18/*
19 * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
20 */
21static const u8 rsa_digest_info_md5[] = {
22 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08,
23 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */
24 0x05, 0x00, 0x04, 0x10
25};
26
27static const u8 rsa_digest_info_sha1[] = {
28 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
29 0x2b, 0x0e, 0x03, 0x02, 0x1a,
30 0x05, 0x00, 0x04, 0x14
31};
32
33static const u8 rsa_digest_info_rmd160[] = {
34 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
35 0x2b, 0x24, 0x03, 0x02, 0x01,
36 0x05, 0x00, 0x04, 0x14
37};
38
39static const u8 rsa_digest_info_sha224[] = {
40 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
41 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
42 0x05, 0x00, 0x04, 0x1c
43};
44
45static const u8 rsa_digest_info_sha256[] = {
46 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
47 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
48 0x05, 0x00, 0x04, 0x20
49};
50
51static const u8 rsa_digest_info_sha384[] = {
52 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
53 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
54 0x05, 0x00, 0x04, 0x30
55};
56
57static const u8 rsa_digest_info_sha512[] = {
58 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
59 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
60 0x05, 0x00, 0x04, 0x40
61};
62
63static const struct rsa_asn1_template {
64 const char *name;
65 const u8 *data;
66 size_t size;
67} rsa_asn1_templates[] = {
68#define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
69 _(md5),
70 _(sha1),
71 _(rmd160),
72 _(sha256),
73 _(sha384),
74 _(sha512),
75 _(sha224),
76 { NULL }
77#undef _
78};
79
80static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
81{
82 const struct rsa_asn1_template *p;
83
84 for (p = rsa_asn1_templates; p->name; p++)
85 if (strcmp(name, p->name) == 0)
86 return p;
87 return NULL;
88}
89
90struct pkcs1pad_ctx {
91 struct crypto_akcipher *child;
92 unsigned int key_size;
93};
94
95struct pkcs1pad_inst_ctx {
96 struct crypto_akcipher_spawn spawn;
97 const struct rsa_asn1_template *digest_info;
98};
99
100struct pkcs1pad_request {
101 struct scatterlist in_sg[2], out_sg[1];
102 uint8_t *in_buf, *out_buf;
103 struct akcipher_request child_req;
104};
105
106static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
107 unsigned int keylen)
108{
109 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
110 int err;
111
112 ctx->key_size = 0;
113
114 err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
115 if (err)
116 return err;
117
118 /* Find out new modulus size from rsa implementation */
119 err = crypto_akcipher_maxsize(ctx->child);
120 if (err > PAGE_SIZE)
121 return -ENOTSUPP;
122
123 ctx->key_size = err;
124 return 0;
125}
126
127static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
128 unsigned int keylen)
129{
130 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
131 int err;
132
133 ctx->key_size = 0;
134
135 err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
136 if (err)
137 return err;
138
139 /* Find out new modulus size from rsa implementation */
140 err = crypto_akcipher_maxsize(ctx->child);
141 if (err > PAGE_SIZE)
142 return -ENOTSUPP;
143
144 ctx->key_size = err;
145 return 0;
146}
147
148static unsigned int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
149{
150 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
151
152 /*
153 * The maximum destination buffer size for the encrypt/sign operations
154 * will be the same as for RSA, even though it's smaller for
155 * decrypt/verify.
156 */
157
158 return ctx->key_size;
159}
160
161static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
162 struct scatterlist *next)
163{
164 int nsegs = next ? 2 : 1;
165
166 sg_init_table(sg, nsegs);
167 sg_set_buf(sg, buf, len);
168
169 if (next)
170 sg_chain(sg, nsegs, next);
171}
172
173static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
174{
175 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
176 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
177 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
178 unsigned int pad_len;
179 unsigned int len;
180 u8 *out_buf;
181
182 if (err)
183 goto out;
184
185 len = req_ctx->child_req.dst_len;
186 pad_len = ctx->key_size - len;
187
188 /* Four billion to one */
189 if (likely(!pad_len))
190 goto out;
191
192 out_buf = kzalloc(ctx->key_size, GFP_KERNEL);
193 err = -ENOMEM;
194 if (!out_buf)
195 goto out;
196
197 sg_copy_to_buffer(req->dst, sg_nents_for_len(req->dst, len),
198 out_buf + pad_len, len);
199 sg_copy_from_buffer(req->dst,
200 sg_nents_for_len(req->dst, ctx->key_size),
201 out_buf, ctx->key_size);
202 kzfree(out_buf);
203
204out:
205 req->dst_len = ctx->key_size;
206
207 kfree(req_ctx->in_buf);
208
209 return err;
210}
211
212static void pkcs1pad_encrypt_sign_complete_cb(
213 struct crypto_async_request *child_async_req, int err)
214{
215 struct akcipher_request *req = child_async_req->data;
216 struct crypto_async_request async_req;
217
218 if (err == -EINPROGRESS)
219 return;
220
221 async_req.data = req->base.data;
222 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
223 async_req.flags = child_async_req->flags;
224 req->base.complete(&async_req,
225 pkcs1pad_encrypt_sign_complete(req, err));
226}
227
228static int pkcs1pad_encrypt(struct akcipher_request *req)
229{
230 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
231 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
232 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
233 int err;
234 unsigned int i, ps_end;
235
236 if (!ctx->key_size)
237 return -EINVAL;
238
239 if (req->src_len > ctx->key_size - 11)
240 return -EOVERFLOW;
241
242 if (req->dst_len < ctx->key_size) {
243 req->dst_len = ctx->key_size;
244 return -EOVERFLOW;
245 }
246
247 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
248 GFP_KERNEL);
249 if (!req_ctx->in_buf)
250 return -ENOMEM;
251
252 ps_end = ctx->key_size - req->src_len - 2;
253 req_ctx->in_buf[0] = 0x02;
254 for (i = 1; i < ps_end; i++)
255 req_ctx->in_buf[i] = 1 + prandom_u32_max(255);
256 req_ctx->in_buf[ps_end] = 0x00;
257
258 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
259 ctx->key_size - 1 - req->src_len, req->src);
260
261 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
262 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
263 pkcs1pad_encrypt_sign_complete_cb, req);
264
265 /* Reuse output buffer */
266 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
267 req->dst, ctx->key_size - 1, req->dst_len);
268
269 err = crypto_akcipher_encrypt(&req_ctx->child_req);
270 if (err != -EINPROGRESS && err != -EBUSY)
271 return pkcs1pad_encrypt_sign_complete(req, err);
272
273 return err;
274}
275
276static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
277{
278 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
279 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
280 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
281 unsigned int dst_len;
282 unsigned int pos;
283 u8 *out_buf;
284
285 if (err)
286 goto done;
287
288 err = -EINVAL;
289 dst_len = req_ctx->child_req.dst_len;
290 if (dst_len < ctx->key_size - 1)
291 goto done;
292
293 out_buf = req_ctx->out_buf;
294 if (dst_len == ctx->key_size) {
295 if (out_buf[0] != 0x00)
296 /* Decrypted value had no leading 0 byte */
297 goto done;
298
299 dst_len--;
300 out_buf++;
301 }
302
303 if (out_buf[0] != 0x02)
304 goto done;
305
306 for (pos = 1; pos < dst_len; pos++)
307 if (out_buf[pos] == 0x00)
308 break;
309 if (pos < 9 || pos == dst_len)
310 goto done;
311 pos++;
312
313 err = 0;
314
315 if (req->dst_len < dst_len - pos)
316 err = -EOVERFLOW;
317 req->dst_len = dst_len - pos;
318
319 if (!err)
320 sg_copy_from_buffer(req->dst,
321 sg_nents_for_len(req->dst, req->dst_len),
322 out_buf + pos, req->dst_len);
323
324done:
325 kzfree(req_ctx->out_buf);
326
327 return err;
328}
329
330static void pkcs1pad_decrypt_complete_cb(
331 struct crypto_async_request *child_async_req, int err)
332{
333 struct akcipher_request *req = child_async_req->data;
334 struct crypto_async_request async_req;
335
336 if (err == -EINPROGRESS)
337 return;
338
339 async_req.data = req->base.data;
340 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
341 async_req.flags = child_async_req->flags;
342 req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err));
343}
344
345static int pkcs1pad_decrypt(struct akcipher_request *req)
346{
347 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
348 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
349 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
350 int err;
351
352 if (!ctx->key_size || req->src_len != ctx->key_size)
353 return -EINVAL;
354
355 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
356 if (!req_ctx->out_buf)
357 return -ENOMEM;
358
359 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
360 ctx->key_size, NULL);
361
362 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
363 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
364 pkcs1pad_decrypt_complete_cb, req);
365
366 /* Reuse input buffer, output to a new buffer */
367 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
368 req_ctx->out_sg, req->src_len,
369 ctx->key_size);
370
371 err = crypto_akcipher_decrypt(&req_ctx->child_req);
372 if (err != -EINPROGRESS && err != -EBUSY)
373 return pkcs1pad_decrypt_complete(req, err);
374
375 return err;
376}
377
378static int pkcs1pad_sign(struct akcipher_request *req)
379{
380 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
381 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
382 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
383 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
384 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
385 const struct rsa_asn1_template *digest_info = ictx->digest_info;
386 int err;
387 unsigned int ps_end, digest_size = 0;
388
389 if (!ctx->key_size)
390 return -EINVAL;
391
392 if (digest_info)
393 digest_size = digest_info->size;
394
395 if (req->src_len + digest_size > ctx->key_size - 11)
396 return -EOVERFLOW;
397
398 if (req->dst_len < ctx->key_size) {
399 req->dst_len = ctx->key_size;
400 return -EOVERFLOW;
401 }
402
403 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
404 GFP_KERNEL);
405 if (!req_ctx->in_buf)
406 return -ENOMEM;
407
408 ps_end = ctx->key_size - digest_size - req->src_len - 2;
409 req_ctx->in_buf[0] = 0x01;
410 memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
411 req_ctx->in_buf[ps_end] = 0x00;
412
413 if (digest_info)
414 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
415 digest_info->size);
416
417 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
418 ctx->key_size - 1 - req->src_len, req->src);
419
420 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
421 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
422 pkcs1pad_encrypt_sign_complete_cb, req);
423
424 /* Reuse output buffer */
425 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
426 req->dst, ctx->key_size - 1, req->dst_len);
427
428 err = crypto_akcipher_decrypt(&req_ctx->child_req);
429 if (err != -EINPROGRESS && err != -EBUSY)
430 return pkcs1pad_encrypt_sign_complete(req, err);
431
432 return err;
433}
434
435static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
436{
437 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
438 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
439 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
440 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
441 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
442 const struct rsa_asn1_template *digest_info = ictx->digest_info;
443 unsigned int dst_len;
444 unsigned int pos;
445 u8 *out_buf;
446
447 if (err)
448 goto done;
449
450 err = -EINVAL;
451 dst_len = req_ctx->child_req.dst_len;
452 if (dst_len < ctx->key_size - 1)
453 goto done;
454
455 out_buf = req_ctx->out_buf;
456 if (dst_len == ctx->key_size) {
457 if (out_buf[0] != 0x00)
458 /* Decrypted value had no leading 0 byte */
459 goto done;
460
461 dst_len--;
462 out_buf++;
463 }
464
465 err = -EBADMSG;
466 if (out_buf[0] != 0x01)
467 goto done;
468
469 for (pos = 1; pos < dst_len; pos++)
470 if (out_buf[pos] != 0xff)
471 break;
472
473 if (pos < 9 || pos == dst_len || out_buf[pos] != 0x00)
474 goto done;
475 pos++;
476
477 if (digest_info) {
478 if (crypto_memneq(out_buf + pos, digest_info->data,
479 digest_info->size))
480 goto done;
481
482 pos += digest_info->size;
483 }
484
485 err = 0;
486
487 if (req->dst_len != dst_len - pos) {
488 err = -EKEYREJECTED;
489 req->dst_len = dst_len - pos;
490 goto done;
491 }
492 /* Extract appended digest. */
493 sg_pcopy_to_buffer(req->src,
494 sg_nents_for_len(req->src,
495 req->src_len + req->dst_len),
496 req_ctx->out_buf + ctx->key_size,
497 req->dst_len, ctx->key_size);
498 /* Do the actual verification step. */
499 if (memcmp(req_ctx->out_buf + ctx->key_size, out_buf + pos,
500 req->dst_len) != 0)
501 err = -EKEYREJECTED;
502done:
503 kzfree(req_ctx->out_buf);
504
505 return err;
506}
507
508static void pkcs1pad_verify_complete_cb(
509 struct crypto_async_request *child_async_req, int err)
510{
511 struct akcipher_request *req = child_async_req->data;
512 struct crypto_async_request async_req;
513
514 if (err == -EINPROGRESS)
515 return;
516
517 async_req.data = req->base.data;
518 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req));
519 async_req.flags = child_async_req->flags;
520 req->base.complete(&async_req, pkcs1pad_verify_complete(req, err));
521}
522
523/*
524 * The verify operation is here for completeness similar to the verification
525 * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
526 * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to
527 * retrieve the DigestInfo from a signature, instead the user is expected
528 * to call the sign operation to generate the expected signature and compare
529 * signatures instead of the message-digests.
530 */
531static int pkcs1pad_verify(struct akcipher_request *req)
532{
533 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
534 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
535 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
536 int err;
537
538 if (WARN_ON(req->dst) ||
539 WARN_ON(!req->dst_len) ||
540 !ctx->key_size || req->src_len < ctx->key_size)
541 return -EINVAL;
542
543 req_ctx->out_buf = kmalloc(ctx->key_size + req->dst_len, GFP_KERNEL);
544 if (!req_ctx->out_buf)
545 return -ENOMEM;
546
547 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
548 ctx->key_size, NULL);
549
550 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
551 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
552 pkcs1pad_verify_complete_cb, req);
553
554 /* Reuse input buffer, output to a new buffer */
555 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
556 req_ctx->out_sg, req->src_len,
557 ctx->key_size);
558
559 err = crypto_akcipher_encrypt(&req_ctx->child_req);
560 if (err != -EINPROGRESS && err != -EBUSY)
561 return pkcs1pad_verify_complete(req, err);
562
563 return err;
564}
565
566static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
567{
568 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
569 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
570 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
571 struct crypto_akcipher *child_tfm;
572
573 child_tfm = crypto_spawn_akcipher(&ictx->spawn);
574 if (IS_ERR(child_tfm))
575 return PTR_ERR(child_tfm);
576
577 ctx->child = child_tfm;
578 return 0;
579}
580
581static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
582{
583 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
584
585 crypto_free_akcipher(ctx->child);
586}
587
588static void pkcs1pad_free(struct akcipher_instance *inst)
589{
590 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
591 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
592
593 crypto_drop_akcipher(spawn);
594 kfree(inst);
595}
596
597static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
598{
599 const struct rsa_asn1_template *digest_info;
600 struct crypto_attr_type *algt;
601 struct akcipher_instance *inst;
602 struct pkcs1pad_inst_ctx *ctx;
603 struct crypto_akcipher_spawn *spawn;
604 struct akcipher_alg *rsa_alg;
605 const char *rsa_alg_name;
606 const char *hash_name;
607 int err;
608
609 algt = crypto_get_attr_type(tb);
610 if (IS_ERR(algt))
611 return PTR_ERR(algt);
612
613 if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask)
614 return -EINVAL;
615
616 rsa_alg_name = crypto_attr_alg_name(tb[1]);
617 if (IS_ERR(rsa_alg_name))
618 return PTR_ERR(rsa_alg_name);
619
620 hash_name = crypto_attr_alg_name(tb[2]);
621 if (IS_ERR(hash_name))
622 hash_name = NULL;
623
624 if (hash_name) {
625 digest_info = rsa_lookup_asn1(hash_name);
626 if (!digest_info)
627 return -EINVAL;
628 } else
629 digest_info = NULL;
630
631 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
632 if (!inst)
633 return -ENOMEM;
634
635 ctx = akcipher_instance_ctx(inst);
636 spawn = &ctx->spawn;
637 ctx->digest_info = digest_info;
638
639 crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst));
640 err = crypto_grab_akcipher(spawn, rsa_alg_name, 0,
641 crypto_requires_sync(algt->type, algt->mask));
642 if (err)
643 goto out_free_inst;
644
645 rsa_alg = crypto_spawn_akcipher_alg(spawn);
646
647 err = -ENAMETOOLONG;
648
649 if (!hash_name) {
650 if (snprintf(inst->alg.base.cra_name,
651 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
652 rsa_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
653 goto out_drop_alg;
654
655 if (snprintf(inst->alg.base.cra_driver_name,
656 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
657 rsa_alg->base.cra_driver_name) >=
658 CRYPTO_MAX_ALG_NAME)
659 goto out_drop_alg;
660 } else {
661 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
662 "pkcs1pad(%s,%s)", rsa_alg->base.cra_name,
663 hash_name) >= CRYPTO_MAX_ALG_NAME)
664 goto out_drop_alg;
665
666 if (snprintf(inst->alg.base.cra_driver_name,
667 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
668 rsa_alg->base.cra_driver_name,
669 hash_name) >= CRYPTO_MAX_ALG_NAME)
670 goto out_drop_alg;
671 }
672
673 inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC;
674 inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
675 inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
676
677 inst->alg.init = pkcs1pad_init_tfm;
678 inst->alg.exit = pkcs1pad_exit_tfm;
679
680 inst->alg.encrypt = pkcs1pad_encrypt;
681 inst->alg.decrypt = pkcs1pad_decrypt;
682 inst->alg.sign = pkcs1pad_sign;
683 inst->alg.verify = pkcs1pad_verify;
684 inst->alg.set_pub_key = pkcs1pad_set_pub_key;
685 inst->alg.set_priv_key = pkcs1pad_set_priv_key;
686 inst->alg.max_size = pkcs1pad_get_max_size;
687 inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize;
688
689 inst->free = pkcs1pad_free;
690
691 err = akcipher_register_instance(tmpl, inst);
692 if (err)
693 goto out_drop_alg;
694
695 return 0;
696
697out_drop_alg:
698 crypto_drop_akcipher(spawn);
699out_free_inst:
700 kfree(inst);
701 return err;
702}
703
704struct crypto_template rsa_pkcs1pad_tmpl = {
705 .name = "pkcs1pad",
706 .create = pkcs1pad_create,
707 .module = THIS_MODULE,
708};