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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 u8 rsa_digest_info_sha3_256[] = {
65 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
66 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x08,
67 0x05, 0x00, 0x04, 0x20
68};
69
70static const u8 rsa_digest_info_sha3_384[] = {
71 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
72 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x09,
73 0x05, 0x00, 0x04, 0x30
74};
75
76static const u8 rsa_digest_info_sha3_512[] = {
77 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
78 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x0A,
79 0x05, 0x00, 0x04, 0x40
80};
81
82static const struct rsa_asn1_template {
83 const char *name;
84 const u8 *data;
85 size_t size;
86} rsa_asn1_templates[] = {
87#define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) }
88 _(md5),
89 _(sha1),
90 _(rmd160),
91 _(sha256),
92 _(sha384),
93 _(sha512),
94 _(sha224),
95#undef _
96#define _(X) { "sha3-" #X, rsa_digest_info_sha3_##X, sizeof(rsa_digest_info_sha3_##X) }
97 _(256),
98 _(384),
99 _(512),
100#undef _
101 { NULL }
102};
103
104static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name)
105{
106 const struct rsa_asn1_template *p;
107
108 for (p = rsa_asn1_templates; p->name; p++)
109 if (strcmp(name, p->name) == 0)
110 return p;
111 return NULL;
112}
113
114struct pkcs1pad_ctx {
115 struct crypto_akcipher *child;
116 unsigned int key_size;
117};
118
119struct pkcs1pad_inst_ctx {
120 struct crypto_akcipher_spawn spawn;
121 const struct rsa_asn1_template *digest_info;
122};
123
124struct pkcs1pad_request {
125 struct scatterlist in_sg[2], out_sg[1];
126 uint8_t *in_buf, *out_buf;
127 struct akcipher_request child_req;
128};
129
130static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key,
131 unsigned int keylen)
132{
133 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
134 int err;
135
136 ctx->key_size = 0;
137
138 err = crypto_akcipher_set_pub_key(ctx->child, key, keylen);
139 if (err)
140 return err;
141
142 /* Find out new modulus size from rsa implementation */
143 err = crypto_akcipher_maxsize(ctx->child);
144 if (err > PAGE_SIZE)
145 return -ENOTSUPP;
146
147 ctx->key_size = err;
148 return 0;
149}
150
151static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key,
152 unsigned int keylen)
153{
154 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
155 int err;
156
157 ctx->key_size = 0;
158
159 err = crypto_akcipher_set_priv_key(ctx->child, key, keylen);
160 if (err)
161 return err;
162
163 /* Find out new modulus size from rsa implementation */
164 err = crypto_akcipher_maxsize(ctx->child);
165 if (err > PAGE_SIZE)
166 return -ENOTSUPP;
167
168 ctx->key_size = err;
169 return 0;
170}
171
172static unsigned int pkcs1pad_get_max_size(struct crypto_akcipher *tfm)
173{
174 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
175
176 /*
177 * The maximum destination buffer size for the encrypt/sign operations
178 * will be the same as for RSA, even though it's smaller for
179 * decrypt/verify.
180 */
181
182 return ctx->key_size;
183}
184
185static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len,
186 struct scatterlist *next)
187{
188 int nsegs = next ? 2 : 1;
189
190 sg_init_table(sg, nsegs);
191 sg_set_buf(sg, buf, len);
192
193 if (next)
194 sg_chain(sg, nsegs, next);
195}
196
197static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err)
198{
199 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
200 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
201 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
202 unsigned int pad_len;
203 unsigned int len;
204 u8 *out_buf;
205
206 if (err)
207 goto out;
208
209 len = req_ctx->child_req.dst_len;
210 pad_len = ctx->key_size - len;
211
212 /* Four billion to one */
213 if (likely(!pad_len))
214 goto out;
215
216 out_buf = kzalloc(ctx->key_size, GFP_ATOMIC);
217 err = -ENOMEM;
218 if (!out_buf)
219 goto out;
220
221 sg_copy_to_buffer(req->dst, sg_nents_for_len(req->dst, len),
222 out_buf + pad_len, len);
223 sg_copy_from_buffer(req->dst,
224 sg_nents_for_len(req->dst, ctx->key_size),
225 out_buf, ctx->key_size);
226 kfree_sensitive(out_buf);
227
228out:
229 req->dst_len = ctx->key_size;
230
231 kfree(req_ctx->in_buf);
232
233 return err;
234}
235
236static void pkcs1pad_encrypt_sign_complete_cb(void *data, int err)
237{
238 struct akcipher_request *req = data;
239
240 if (err == -EINPROGRESS)
241 goto out;
242
243 err = pkcs1pad_encrypt_sign_complete(req, err);
244
245out:
246 akcipher_request_complete(req, err);
247}
248
249static int pkcs1pad_encrypt(struct akcipher_request *req)
250{
251 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
252 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
253 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
254 int err;
255 unsigned int i, ps_end;
256
257 if (!ctx->key_size)
258 return -EINVAL;
259
260 if (req->src_len > ctx->key_size - 11)
261 return -EOVERFLOW;
262
263 if (req->dst_len < ctx->key_size) {
264 req->dst_len = ctx->key_size;
265 return -EOVERFLOW;
266 }
267
268 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
269 GFP_KERNEL);
270 if (!req_ctx->in_buf)
271 return -ENOMEM;
272
273 ps_end = ctx->key_size - req->src_len - 2;
274 req_ctx->in_buf[0] = 0x02;
275 for (i = 1; i < ps_end; i++)
276 req_ctx->in_buf[i] = get_random_u32_inclusive(1, 255);
277 req_ctx->in_buf[ps_end] = 0x00;
278
279 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
280 ctx->key_size - 1 - req->src_len, req->src);
281
282 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
283 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
284 pkcs1pad_encrypt_sign_complete_cb, req);
285
286 /* Reuse output buffer */
287 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
288 req->dst, ctx->key_size - 1, req->dst_len);
289
290 err = crypto_akcipher_encrypt(&req_ctx->child_req);
291 if (err != -EINPROGRESS && err != -EBUSY)
292 return pkcs1pad_encrypt_sign_complete(req, err);
293
294 return err;
295}
296
297static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err)
298{
299 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
300 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
301 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
302 unsigned int dst_len;
303 unsigned int pos;
304 u8 *out_buf;
305
306 if (err)
307 goto done;
308
309 err = -EINVAL;
310 dst_len = req_ctx->child_req.dst_len;
311 if (dst_len < ctx->key_size - 1)
312 goto done;
313
314 out_buf = req_ctx->out_buf;
315 if (dst_len == ctx->key_size) {
316 if (out_buf[0] != 0x00)
317 /* Decrypted value had no leading 0 byte */
318 goto done;
319
320 dst_len--;
321 out_buf++;
322 }
323
324 if (out_buf[0] != 0x02)
325 goto done;
326
327 for (pos = 1; pos < dst_len; pos++)
328 if (out_buf[pos] == 0x00)
329 break;
330 if (pos < 9 || pos == dst_len)
331 goto done;
332 pos++;
333
334 err = 0;
335
336 if (req->dst_len < dst_len - pos)
337 err = -EOVERFLOW;
338 req->dst_len = dst_len - pos;
339
340 if (!err)
341 sg_copy_from_buffer(req->dst,
342 sg_nents_for_len(req->dst, req->dst_len),
343 out_buf + pos, req->dst_len);
344
345done:
346 kfree_sensitive(req_ctx->out_buf);
347
348 return err;
349}
350
351static void pkcs1pad_decrypt_complete_cb(void *data, int err)
352{
353 struct akcipher_request *req = data;
354
355 if (err == -EINPROGRESS)
356 goto out;
357
358 err = pkcs1pad_decrypt_complete(req, err);
359
360out:
361 akcipher_request_complete(req, err);
362}
363
364static int pkcs1pad_decrypt(struct akcipher_request *req)
365{
366 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
367 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
368 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
369 int err;
370
371 if (!ctx->key_size || req->src_len != ctx->key_size)
372 return -EINVAL;
373
374 req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL);
375 if (!req_ctx->out_buf)
376 return -ENOMEM;
377
378 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
379 ctx->key_size, NULL);
380
381 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
382 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
383 pkcs1pad_decrypt_complete_cb, req);
384
385 /* Reuse input buffer, output to a new buffer */
386 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
387 req_ctx->out_sg, req->src_len,
388 ctx->key_size);
389
390 err = crypto_akcipher_decrypt(&req_ctx->child_req);
391 if (err != -EINPROGRESS && err != -EBUSY)
392 return pkcs1pad_decrypt_complete(req, err);
393
394 return err;
395}
396
397static int pkcs1pad_sign(struct akcipher_request *req)
398{
399 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
400 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
401 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
402 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
403 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
404 const struct rsa_asn1_template *digest_info = ictx->digest_info;
405 int err;
406 unsigned int ps_end, digest_info_size = 0;
407
408 if (!ctx->key_size)
409 return -EINVAL;
410
411 if (digest_info)
412 digest_info_size = digest_info->size;
413
414 if (req->src_len + digest_info_size > ctx->key_size - 11)
415 return -EOVERFLOW;
416
417 if (req->dst_len < ctx->key_size) {
418 req->dst_len = ctx->key_size;
419 return -EOVERFLOW;
420 }
421
422 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len,
423 GFP_KERNEL);
424 if (!req_ctx->in_buf)
425 return -ENOMEM;
426
427 ps_end = ctx->key_size - digest_info_size - req->src_len - 2;
428 req_ctx->in_buf[0] = 0x01;
429 memset(req_ctx->in_buf + 1, 0xff, ps_end - 1);
430 req_ctx->in_buf[ps_end] = 0x00;
431
432 if (digest_info)
433 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data,
434 digest_info->size);
435
436 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf,
437 ctx->key_size - 1 - req->src_len, req->src);
438
439 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
440 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
441 pkcs1pad_encrypt_sign_complete_cb, req);
442
443 /* Reuse output buffer */
444 akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg,
445 req->dst, ctx->key_size - 1, req->dst_len);
446
447 err = crypto_akcipher_decrypt(&req_ctx->child_req);
448 if (err != -EINPROGRESS && err != -EBUSY)
449 return pkcs1pad_encrypt_sign_complete(req, err);
450
451 return err;
452}
453
454static int pkcs1pad_verify_complete(struct akcipher_request *req, int err)
455{
456 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
457 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
458 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
459 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
460 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
461 const struct rsa_asn1_template *digest_info = ictx->digest_info;
462 const unsigned int sig_size = req->src_len;
463 const unsigned int digest_size = req->dst_len;
464 unsigned int dst_len;
465 unsigned int pos;
466 u8 *out_buf;
467
468 if (err)
469 goto done;
470
471 err = -EINVAL;
472 dst_len = req_ctx->child_req.dst_len;
473 if (dst_len < ctx->key_size - 1)
474 goto done;
475
476 out_buf = req_ctx->out_buf;
477 if (dst_len == ctx->key_size) {
478 if (out_buf[0] != 0x00)
479 /* Decrypted value had no leading 0 byte */
480 goto done;
481
482 dst_len--;
483 out_buf++;
484 }
485
486 err = -EBADMSG;
487 if (out_buf[0] != 0x01)
488 goto done;
489
490 for (pos = 1; pos < dst_len; pos++)
491 if (out_buf[pos] != 0xff)
492 break;
493
494 if (pos < 9 || pos == dst_len || out_buf[pos] != 0x00)
495 goto done;
496 pos++;
497
498 if (digest_info) {
499 if (digest_info->size > dst_len - pos)
500 goto done;
501 if (crypto_memneq(out_buf + pos, digest_info->data,
502 digest_info->size))
503 goto done;
504
505 pos += digest_info->size;
506 }
507
508 err = 0;
509
510 if (digest_size != dst_len - pos) {
511 err = -EKEYREJECTED;
512 req->dst_len = dst_len - pos;
513 goto done;
514 }
515 /* Extract appended digest. */
516 sg_pcopy_to_buffer(req->src,
517 sg_nents_for_len(req->src, sig_size + digest_size),
518 req_ctx->out_buf + ctx->key_size,
519 digest_size, sig_size);
520 /* Do the actual verification step. */
521 if (memcmp(req_ctx->out_buf + ctx->key_size, out_buf + pos,
522 digest_size) != 0)
523 err = -EKEYREJECTED;
524done:
525 kfree_sensitive(req_ctx->out_buf);
526
527 return err;
528}
529
530static void pkcs1pad_verify_complete_cb(void *data, int err)
531{
532 struct akcipher_request *req = data;
533
534 if (err == -EINPROGRESS)
535 goto out;
536
537 err = pkcs1pad_verify_complete(req, err);
538
539out:
540 akcipher_request_complete(req, err);
541}
542
543/*
544 * The verify operation is here for completeness similar to the verification
545 * defined in RFC2313 section 10.2 except that block type 0 is not accepted,
546 * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to
547 * retrieve the DigestInfo from a signature, instead the user is expected
548 * to call the sign operation to generate the expected signature and compare
549 * signatures instead of the message-digests.
550 */
551static int pkcs1pad_verify(struct akcipher_request *req)
552{
553 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
554 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
555 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req);
556 const unsigned int sig_size = req->src_len;
557 const unsigned int digest_size = req->dst_len;
558 int err;
559
560 if (WARN_ON(req->dst) || WARN_ON(!digest_size) ||
561 !ctx->key_size || sig_size != ctx->key_size)
562 return -EINVAL;
563
564 req_ctx->out_buf = kmalloc(ctx->key_size + digest_size, GFP_KERNEL);
565 if (!req_ctx->out_buf)
566 return -ENOMEM;
567
568 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf,
569 ctx->key_size, NULL);
570
571 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child);
572 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags,
573 pkcs1pad_verify_complete_cb, req);
574
575 /* Reuse input buffer, output to a new buffer */
576 akcipher_request_set_crypt(&req_ctx->child_req, req->src,
577 req_ctx->out_sg, sig_size, ctx->key_size);
578
579 err = crypto_akcipher_encrypt(&req_ctx->child_req);
580 if (err != -EINPROGRESS && err != -EBUSY)
581 return pkcs1pad_verify_complete(req, err);
582
583 return err;
584}
585
586static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm)
587{
588 struct akcipher_instance *inst = akcipher_alg_instance(tfm);
589 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst);
590 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
591 struct crypto_akcipher *child_tfm;
592
593 child_tfm = crypto_spawn_akcipher(&ictx->spawn);
594 if (IS_ERR(child_tfm))
595 return PTR_ERR(child_tfm);
596
597 ctx->child = child_tfm;
598
599 akcipher_set_reqsize(tfm, sizeof(struct pkcs1pad_request) +
600 crypto_akcipher_reqsize(child_tfm));
601
602 return 0;
603}
604
605static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm)
606{
607 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm);
608
609 crypto_free_akcipher(ctx->child);
610}
611
612static void pkcs1pad_free(struct akcipher_instance *inst)
613{
614 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst);
615 struct crypto_akcipher_spawn *spawn = &ctx->spawn;
616
617 crypto_drop_akcipher(spawn);
618 kfree(inst);
619}
620
621static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb)
622{
623 u32 mask;
624 struct akcipher_instance *inst;
625 struct pkcs1pad_inst_ctx *ctx;
626 struct akcipher_alg *rsa_alg;
627 const char *hash_name;
628 int err;
629
630 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_AKCIPHER, &mask);
631 if (err)
632 return err;
633
634 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
635 if (!inst)
636 return -ENOMEM;
637
638 ctx = akcipher_instance_ctx(inst);
639
640 err = crypto_grab_akcipher(&ctx->spawn, akcipher_crypto_instance(inst),
641 crypto_attr_alg_name(tb[1]), 0, mask);
642 if (err)
643 goto err_free_inst;
644
645 rsa_alg = crypto_spawn_akcipher_alg(&ctx->spawn);
646
647 if (strcmp(rsa_alg->base.cra_name, "rsa") != 0) {
648 err = -EINVAL;
649 goto err_free_inst;
650 }
651
652 err = -ENAMETOOLONG;
653 hash_name = crypto_attr_alg_name(tb[2]);
654 if (IS_ERR(hash_name)) {
655 if (snprintf(inst->alg.base.cra_name,
656 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
657 rsa_alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
658 goto err_free_inst;
659
660 if (snprintf(inst->alg.base.cra_driver_name,
661 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)",
662 rsa_alg->base.cra_driver_name) >=
663 CRYPTO_MAX_ALG_NAME)
664 goto err_free_inst;
665 } else {
666 ctx->digest_info = rsa_lookup_asn1(hash_name);
667 if (!ctx->digest_info) {
668 err = -EINVAL;
669 goto err_free_inst;
670 }
671
672 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
673 "pkcs1pad(%s,%s)", rsa_alg->base.cra_name,
674 hash_name) >= CRYPTO_MAX_ALG_NAME)
675 goto err_free_inst;
676
677 if (snprintf(inst->alg.base.cra_driver_name,
678 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)",
679 rsa_alg->base.cra_driver_name,
680 hash_name) >= CRYPTO_MAX_ALG_NAME)
681 goto err_free_inst;
682 }
683
684 inst->alg.base.cra_priority = rsa_alg->base.cra_priority;
685 inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx);
686
687 inst->alg.init = pkcs1pad_init_tfm;
688 inst->alg.exit = pkcs1pad_exit_tfm;
689
690 inst->alg.encrypt = pkcs1pad_encrypt;
691 inst->alg.decrypt = pkcs1pad_decrypt;
692 inst->alg.sign = pkcs1pad_sign;
693 inst->alg.verify = pkcs1pad_verify;
694 inst->alg.set_pub_key = pkcs1pad_set_pub_key;
695 inst->alg.set_priv_key = pkcs1pad_set_priv_key;
696 inst->alg.max_size = pkcs1pad_get_max_size;
697
698 inst->free = pkcs1pad_free;
699
700 err = akcipher_register_instance(tmpl, inst);
701 if (err) {
702err_free_inst:
703 pkcs1pad_free(inst);
704 }
705 return err;
706}
707
708struct crypto_template rsa_pkcs1pad_tmpl = {
709 .name = "pkcs1pad",
710 .create = pkcs1pad_create,
711 .module = THIS_MODULE,
712};
713
714MODULE_ALIAS_CRYPTO("pkcs1pad");