Commit | Line | Data |
---|---|---|
3d5b1ecd AZ |
1 | /* |
2 | * RSA padding templates. | |
3 | * | |
4 | * Copyright (c) 2015 Intel Corporation | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the Free | |
8 | * Software Foundation; either version 2 of the License, or (at your option) | |
9 | * any later version. | |
10 | */ | |
11 | ||
12 | #include <crypto/algapi.h> | |
13 | #include <crypto/akcipher.h> | |
14 | #include <crypto/internal/akcipher.h> | |
15 | #include <linux/err.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/kernel.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/random.h> | |
20 | ||
a49de377 TS |
21 | /* |
22 | * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2]. | |
23 | */ | |
24 | static const u8 rsa_digest_info_md5[] = { | |
25 | 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, | |
26 | 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */ | |
27 | 0x05, 0x00, 0x04, 0x10 | |
28 | }; | |
29 | ||
30 | static const u8 rsa_digest_info_sha1[] = { | |
31 | 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, | |
32 | 0x2b, 0x0e, 0x03, 0x02, 0x1a, | |
33 | 0x05, 0x00, 0x04, 0x14 | |
34 | }; | |
35 | ||
36 | static const u8 rsa_digest_info_rmd160[] = { | |
37 | 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, | |
38 | 0x2b, 0x24, 0x03, 0x02, 0x01, | |
39 | 0x05, 0x00, 0x04, 0x14 | |
40 | }; | |
41 | ||
42 | static const u8 rsa_digest_info_sha224[] = { | |
43 | 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09, | |
44 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, | |
45 | 0x05, 0x00, 0x04, 0x1c | |
46 | }; | |
47 | ||
48 | static const u8 rsa_digest_info_sha256[] = { | |
49 | 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, | |
50 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, | |
51 | 0x05, 0x00, 0x04, 0x20 | |
52 | }; | |
53 | ||
54 | static const u8 rsa_digest_info_sha384[] = { | |
55 | 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, | |
56 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, | |
57 | 0x05, 0x00, 0x04, 0x30 | |
58 | }; | |
59 | ||
60 | static const u8 rsa_digest_info_sha512[] = { | |
61 | 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, | |
62 | 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, | |
63 | 0x05, 0x00, 0x04, 0x40 | |
64 | }; | |
65 | ||
66 | static const struct rsa_asn1_template { | |
67 | const char *name; | |
68 | const u8 *data; | |
69 | size_t size; | |
70 | } rsa_asn1_templates[] = { | |
71 | #define _(X) { #X, rsa_digest_info_##X, sizeof(rsa_digest_info_##X) } | |
72 | _(md5), | |
73 | _(sha1), | |
74 | _(rmd160), | |
75 | _(sha256), | |
76 | _(sha384), | |
77 | _(sha512), | |
78 | _(sha224), | |
79 | { NULL } | |
80 | #undef _ | |
81 | }; | |
82 | ||
83 | static const struct rsa_asn1_template *rsa_lookup_asn1(const char *name) | |
84 | { | |
85 | const struct rsa_asn1_template *p; | |
86 | ||
87 | for (p = rsa_asn1_templates; p->name; p++) | |
88 | if (strcmp(name, p->name) == 0) | |
89 | return p; | |
90 | return NULL; | |
91 | } | |
92 | ||
3d5b1ecd AZ |
93 | struct pkcs1pad_ctx { |
94 | struct crypto_akcipher *child; | |
3d5b1ecd AZ |
95 | unsigned int key_size; |
96 | }; | |
97 | ||
a49de377 TS |
98 | struct pkcs1pad_inst_ctx { |
99 | struct crypto_akcipher_spawn spawn; | |
c0d20d22 | 100 | const struct rsa_asn1_template *digest_info; |
a49de377 TS |
101 | }; |
102 | ||
3d5b1ecd | 103 | struct pkcs1pad_request { |
0f2c8319 | 104 | struct scatterlist in_sg[2], out_sg[1]; |
3d5b1ecd | 105 | uint8_t *in_buf, *out_buf; |
a6d7bfd0 | 106 | struct akcipher_request child_req; |
3d5b1ecd AZ |
107 | }; |
108 | ||
109 | static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key, | |
110 | unsigned int keylen) | |
111 | { | |
112 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
73f79189 HX |
113 | int err; |
114 | ||
115 | ctx->key_size = 0; | |
3d5b1ecd AZ |
116 | |
117 | err = crypto_akcipher_set_pub_key(ctx->child, key, keylen); | |
73f79189 HX |
118 | if (err) |
119 | return err; | |
3d5b1ecd | 120 | |
73f79189 HX |
121 | /* Find out new modulus size from rsa implementation */ |
122 | err = crypto_akcipher_maxsize(ctx->child); | |
123 | if (err < 0) | |
124 | return err; | |
3d5b1ecd | 125 | |
73f79189 HX |
126 | if (err > PAGE_SIZE) |
127 | return -ENOTSUPP; | |
3d5b1ecd | 128 | |
73f79189 HX |
129 | ctx->key_size = err; |
130 | return 0; | |
3d5b1ecd AZ |
131 | } |
132 | ||
133 | static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key, | |
134 | unsigned int keylen) | |
135 | { | |
136 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
73f79189 HX |
137 | int err; |
138 | ||
139 | ctx->key_size = 0; | |
3d5b1ecd AZ |
140 | |
141 | err = crypto_akcipher_set_priv_key(ctx->child, key, keylen); | |
73f79189 HX |
142 | if (err) |
143 | return err; | |
3d5b1ecd | 144 | |
73f79189 HX |
145 | /* Find out new modulus size from rsa implementation */ |
146 | err = crypto_akcipher_maxsize(ctx->child); | |
147 | if (err < 0) | |
148 | return err; | |
3d5b1ecd | 149 | |
73f79189 HX |
150 | if (err > PAGE_SIZE) |
151 | return -ENOTSUPP; | |
3d5b1ecd | 152 | |
73f79189 HX |
153 | ctx->key_size = err; |
154 | return 0; | |
3d5b1ecd AZ |
155 | } |
156 | ||
157 | static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm) | |
158 | { | |
159 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
160 | ||
161 | /* | |
162 | * The maximum destination buffer size for the encrypt/sign operations | |
163 | * will be the same as for RSA, even though it's smaller for | |
164 | * decrypt/verify. | |
165 | */ | |
166 | ||
167 | return ctx->key_size ?: -EINVAL; | |
168 | } | |
169 | ||
170 | static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len, | |
171 | struct scatterlist *next) | |
172 | { | |
0f2c8319 HX |
173 | int nsegs = next ? 2 : 1; |
174 | ||
175 | sg_init_table(sg, nsegs); | |
176 | sg_set_buf(sg, buf, len); | |
3d5b1ecd AZ |
177 | |
178 | if (next) | |
179 | sg_chain(sg, nsegs, next); | |
180 | } | |
181 | ||
182 | static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err) | |
183 | { | |
184 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
185 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
186 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
d858b071 HX |
187 | unsigned int pad_len; |
188 | unsigned int len; | |
189 | u8 *out_buf; | |
190 | ||
191 | if (err) | |
192 | goto out; | |
193 | ||
194 | len = req_ctx->child_req.dst_len; | |
195 | pad_len = ctx->key_size - len; | |
196 | ||
197 | /* Four billion to one */ | |
198 | if (likely(!pad_len)) | |
199 | goto out; | |
200 | ||
201 | out_buf = kzalloc(ctx->key_size, GFP_ATOMIC); | |
202 | err = -ENOMEM; | |
203 | if (!out_buf) | |
204 | goto out; | |
205 | ||
206 | sg_copy_to_buffer(req->dst, sg_nents_for_len(req->dst, len), | |
207 | out_buf + pad_len, len); | |
208 | sg_copy_from_buffer(req->dst, | |
209 | sg_nents_for_len(req->dst, ctx->key_size), | |
210 | out_buf, ctx->key_size); | |
211 | kzfree(out_buf); | |
212 | ||
213 | out: | |
3d5b1ecd AZ |
214 | req->dst_len = ctx->key_size; |
215 | ||
216 | kfree(req_ctx->in_buf); | |
3d5b1ecd AZ |
217 | |
218 | return err; | |
219 | } | |
220 | ||
221 | static void pkcs1pad_encrypt_sign_complete_cb( | |
222 | struct crypto_async_request *child_async_req, int err) | |
223 | { | |
224 | struct akcipher_request *req = child_async_req->data; | |
225 | struct crypto_async_request async_req; | |
226 | ||
227 | if (err == -EINPROGRESS) | |
228 | return; | |
229 | ||
230 | async_req.data = req->base.data; | |
231 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
232 | async_req.flags = child_async_req->flags; | |
233 | req->base.complete(&async_req, | |
234 | pkcs1pad_encrypt_sign_complete(req, err)); | |
235 | } | |
236 | ||
237 | static int pkcs1pad_encrypt(struct akcipher_request *req) | |
238 | { | |
239 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
240 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
241 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
242 | int err; | |
243 | unsigned int i, ps_end; | |
244 | ||
245 | if (!ctx->key_size) | |
246 | return -EINVAL; | |
247 | ||
248 | if (req->src_len > ctx->key_size - 11) | |
249 | return -EOVERFLOW; | |
250 | ||
251 | if (req->dst_len < ctx->key_size) { | |
252 | req->dst_len = ctx->key_size; | |
253 | return -EOVERFLOW; | |
254 | } | |
255 | ||
3d5b1ecd | 256 | req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, |
3a32ce50 | 257 | GFP_KERNEL); |
3d5b1ecd AZ |
258 | if (!req_ctx->in_buf) |
259 | return -ENOMEM; | |
260 | ||
261 | ps_end = ctx->key_size - req->src_len - 2; | |
262 | req_ctx->in_buf[0] = 0x02; | |
263 | for (i = 1; i < ps_end; i++) | |
264 | req_ctx->in_buf[i] = 1 + prandom_u32_max(255); | |
265 | req_ctx->in_buf[ps_end] = 0x00; | |
266 | ||
267 | pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, | |
268 | ctx->key_size - 1 - req->src_len, req->src); | |
269 | ||
3a32ce50 | 270 | req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL); |
3d5b1ecd AZ |
271 | if (!req_ctx->out_buf) { |
272 | kfree(req_ctx->in_buf); | |
273 | return -ENOMEM; | |
274 | } | |
275 | ||
276 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
277 | ctx->key_size, NULL); | |
278 | ||
279 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
280 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
281 | pkcs1pad_encrypt_sign_complete_cb, req); | |
282 | ||
d858b071 HX |
283 | /* Reuse output buffer */ |
284 | akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg, | |
285 | req->dst, ctx->key_size - 1, req->dst_len); | |
286 | ||
3d5b1ecd AZ |
287 | err = crypto_akcipher_encrypt(&req_ctx->child_req); |
288 | if (err != -EINPROGRESS && | |
289 | (err != -EBUSY || | |
290 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
291 | return pkcs1pad_encrypt_sign_complete(req, err); | |
292 | ||
293 | return err; | |
294 | } | |
295 | ||
296 | static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err) | |
297 | { | |
298 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
299 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
300 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
301 | unsigned int pos; | |
302 | ||
303 | if (err == -EOVERFLOW) | |
304 | /* Decrypted value had no leading 0 byte */ | |
305 | err = -EINVAL; | |
306 | ||
307 | if (err) | |
308 | goto done; | |
309 | ||
310 | if (req_ctx->child_req.dst_len != ctx->key_size - 1) { | |
311 | err = -EINVAL; | |
312 | goto done; | |
313 | } | |
314 | ||
315 | if (req_ctx->out_buf[0] != 0x02) { | |
316 | err = -EINVAL; | |
317 | goto done; | |
318 | } | |
319 | for (pos = 1; pos < req_ctx->child_req.dst_len; pos++) | |
320 | if (req_ctx->out_buf[pos] == 0x00) | |
321 | break; | |
322 | if (pos < 9 || pos == req_ctx->child_req.dst_len) { | |
323 | err = -EINVAL; | |
324 | goto done; | |
325 | } | |
326 | pos++; | |
327 | ||
328 | if (req->dst_len < req_ctx->child_req.dst_len - pos) | |
329 | err = -EOVERFLOW; | |
330 | req->dst_len = req_ctx->child_req.dst_len - pos; | |
331 | ||
332 | if (!err) | |
333 | sg_copy_from_buffer(req->dst, | |
334 | sg_nents_for_len(req->dst, req->dst_len), | |
335 | req_ctx->out_buf + pos, req->dst_len); | |
336 | ||
337 | done: | |
338 | kzfree(req_ctx->out_buf); | |
339 | ||
340 | return err; | |
341 | } | |
342 | ||
343 | static void pkcs1pad_decrypt_complete_cb( | |
344 | struct crypto_async_request *child_async_req, int err) | |
345 | { | |
346 | struct akcipher_request *req = child_async_req->data; | |
347 | struct crypto_async_request async_req; | |
348 | ||
349 | if (err == -EINPROGRESS) | |
350 | return; | |
351 | ||
352 | async_req.data = req->base.data; | |
353 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
354 | async_req.flags = child_async_req->flags; | |
355 | req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err)); | |
356 | } | |
357 | ||
358 | static int pkcs1pad_decrypt(struct akcipher_request *req) | |
359 | { | |
360 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
361 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
362 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
363 | int err; | |
364 | ||
365 | if (!ctx->key_size || req->src_len != ctx->key_size) | |
366 | return -EINVAL; | |
367 | ||
3a32ce50 | 368 | req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL); |
3d5b1ecd AZ |
369 | if (!req_ctx->out_buf) |
370 | return -ENOMEM; | |
371 | ||
372 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
6f0904ad | 373 | ctx->key_size, NULL); |
3d5b1ecd AZ |
374 | |
375 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
376 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
377 | pkcs1pad_decrypt_complete_cb, req); | |
378 | ||
d858b071 HX |
379 | /* Reuse input buffer, output to a new buffer */ |
380 | akcipher_request_set_crypt(&req_ctx->child_req, req->src, | |
381 | req_ctx->out_sg, req->src_len, | |
382 | ctx->key_size); | |
383 | ||
3d5b1ecd AZ |
384 | err = crypto_akcipher_decrypt(&req_ctx->child_req); |
385 | if (err != -EINPROGRESS && | |
386 | (err != -EBUSY || | |
387 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
388 | return pkcs1pad_decrypt_complete(req, err); | |
389 | ||
390 | return err; | |
391 | } | |
392 | ||
393 | static int pkcs1pad_sign(struct akcipher_request *req) | |
394 | { | |
395 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
396 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
397 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
c0d20d22 HX |
398 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); |
399 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); | |
400 | const struct rsa_asn1_template *digest_info = ictx->digest_info; | |
3d5b1ecd | 401 | int err; |
a49de377 | 402 | unsigned int ps_end, digest_size = 0; |
3d5b1ecd AZ |
403 | |
404 | if (!ctx->key_size) | |
405 | return -EINVAL; | |
406 | ||
c0d20d22 | 407 | digest_size = digest_info->size; |
a49de377 TS |
408 | |
409 | if (req->src_len + digest_size > ctx->key_size - 11) | |
3d5b1ecd AZ |
410 | return -EOVERFLOW; |
411 | ||
412 | if (req->dst_len < ctx->key_size) { | |
413 | req->dst_len = ctx->key_size; | |
414 | return -EOVERFLOW; | |
415 | } | |
416 | ||
3d5b1ecd | 417 | req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, |
3a32ce50 | 418 | GFP_KERNEL); |
3d5b1ecd AZ |
419 | if (!req_ctx->in_buf) |
420 | return -ENOMEM; | |
421 | ||
a49de377 | 422 | ps_end = ctx->key_size - digest_size - req->src_len - 2; |
3d5b1ecd AZ |
423 | req_ctx->in_buf[0] = 0x01; |
424 | memset(req_ctx->in_buf + 1, 0xff, ps_end - 1); | |
425 | req_ctx->in_buf[ps_end] = 0x00; | |
426 | ||
c0d20d22 HX |
427 | memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data, |
428 | digest_info->size); | |
a49de377 | 429 | |
3d5b1ecd AZ |
430 | pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, |
431 | ctx->key_size - 1 - req->src_len, req->src); | |
432 | ||
3d5b1ecd AZ |
433 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); |
434 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
435 | pkcs1pad_encrypt_sign_complete_cb, req); | |
436 | ||
d858b071 HX |
437 | /* Reuse output buffer */ |
438 | akcipher_request_set_crypt(&req_ctx->child_req, req_ctx->in_sg, | |
439 | req->dst, ctx->key_size - 1, req->dst_len); | |
440 | ||
3d5b1ecd AZ |
441 | err = crypto_akcipher_sign(&req_ctx->child_req); |
442 | if (err != -EINPROGRESS && | |
443 | (err != -EBUSY || | |
444 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
445 | return pkcs1pad_encrypt_sign_complete(req, err); | |
446 | ||
447 | return err; | |
448 | } | |
449 | ||
450 | static int pkcs1pad_verify_complete(struct akcipher_request *req, int err) | |
451 | { | |
452 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
453 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
454 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
c0d20d22 HX |
455 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); |
456 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); | |
457 | const struct rsa_asn1_template *digest_info = ictx->digest_info; | |
27710b8e | 458 | unsigned int dst_len; |
3d5b1ecd | 459 | unsigned int pos; |
27710b8e | 460 | u8 *out_buf; |
3d5b1ecd AZ |
461 | |
462 | if (err) | |
463 | goto done; | |
464 | ||
27710b8e HX |
465 | err = -EINVAL; |
466 | dst_len = req_ctx->child_req.dst_len; | |
467 | if (dst_len < ctx->key_size - 1) | |
3d5b1ecd | 468 | goto done; |
27710b8e HX |
469 | |
470 | out_buf = req_ctx->out_buf; | |
471 | if (dst_len == ctx->key_size) { | |
472 | if (out_buf[0] != 0x00) | |
473 | /* Decrypted value had no leading 0 byte */ | |
474 | goto done; | |
475 | ||
476 | dst_len--; | |
477 | out_buf++; | |
3d5b1ecd AZ |
478 | } |
479 | ||
a49de377 | 480 | err = -EBADMSG; |
27710b8e | 481 | if (out_buf[0] != 0x01) |
3d5b1ecd | 482 | goto done; |
a49de377 | 483 | |
27710b8e HX |
484 | for (pos = 1; pos < dst_len; pos++) |
485 | if (out_buf[pos] != 0xff) | |
3d5b1ecd | 486 | break; |
a49de377 | 487 | |
27710b8e | 488 | if (pos < 9 || pos == dst_len || out_buf[pos] != 0x00) |
3d5b1ecd | 489 | goto done; |
3d5b1ecd AZ |
490 | pos++; |
491 | ||
27710b8e | 492 | if (memcmp(out_buf + pos, digest_info->data, digest_info->size)) |
c0d20d22 | 493 | goto done; |
a49de377 | 494 | |
c0d20d22 | 495 | pos += digest_info->size; |
a49de377 TS |
496 | |
497 | err = 0; | |
498 | ||
27710b8e | 499 | if (req->dst_len < dst_len - pos) |
3d5b1ecd | 500 | err = -EOVERFLOW; |
27710b8e | 501 | req->dst_len = dst_len - pos; |
3d5b1ecd AZ |
502 | |
503 | if (!err) | |
504 | sg_copy_from_buffer(req->dst, | |
505 | sg_nents_for_len(req->dst, req->dst_len), | |
27710b8e | 506 | out_buf + pos, req->dst_len); |
3d5b1ecd AZ |
507 | done: |
508 | kzfree(req_ctx->out_buf); | |
509 | ||
510 | return err; | |
511 | } | |
512 | ||
513 | static void pkcs1pad_verify_complete_cb( | |
514 | struct crypto_async_request *child_async_req, int err) | |
515 | { | |
516 | struct akcipher_request *req = child_async_req->data; | |
517 | struct crypto_async_request async_req; | |
518 | ||
519 | if (err == -EINPROGRESS) | |
520 | return; | |
521 | ||
522 | async_req.data = req->base.data; | |
523 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
524 | async_req.flags = child_async_req->flags; | |
525 | req->base.complete(&async_req, pkcs1pad_verify_complete(req, err)); | |
526 | } | |
527 | ||
528 | /* | |
529 | * The verify operation is here for completeness similar to the verification | |
530 | * defined in RFC2313 section 10.2 except that block type 0 is not accepted, | |
531 | * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to | |
532 | * retrieve the DigestInfo from a signature, instead the user is expected | |
533 | * to call the sign operation to generate the expected signature and compare | |
534 | * signatures instead of the message-digests. | |
535 | */ | |
536 | static int pkcs1pad_verify(struct akcipher_request *req) | |
537 | { | |
538 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
539 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
540 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
541 | int err; | |
542 | ||
a49de377 | 543 | if (!ctx->key_size || req->src_len < ctx->key_size) |
3d5b1ecd AZ |
544 | return -EINVAL; |
545 | ||
3a32ce50 | 546 | req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL); |
3d5b1ecd AZ |
547 | if (!req_ctx->out_buf) |
548 | return -ENOMEM; | |
549 | ||
550 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
6f0904ad | 551 | ctx->key_size, NULL); |
3d5b1ecd AZ |
552 | |
553 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
554 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
555 | pkcs1pad_verify_complete_cb, req); | |
556 | ||
d858b071 HX |
557 | /* Reuse input buffer, output to a new buffer */ |
558 | akcipher_request_set_crypt(&req_ctx->child_req, req->src, | |
559 | req_ctx->out_sg, req->src_len, | |
560 | ctx->key_size); | |
561 | ||
3d5b1ecd AZ |
562 | err = crypto_akcipher_verify(&req_ctx->child_req); |
563 | if (err != -EINPROGRESS && | |
564 | (err != -EBUSY || | |
565 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
566 | return pkcs1pad_verify_complete(req, err); | |
567 | ||
568 | return err; | |
569 | } | |
570 | ||
571 | static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm) | |
572 | { | |
573 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); | |
a49de377 | 574 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); |
3d5b1ecd AZ |
575 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); |
576 | struct crypto_akcipher *child_tfm; | |
577 | ||
c0d20d22 | 578 | child_tfm = crypto_spawn_akcipher(&ictx->spawn); |
3d5b1ecd AZ |
579 | if (IS_ERR(child_tfm)) |
580 | return PTR_ERR(child_tfm); | |
581 | ||
582 | ctx->child = child_tfm; | |
3d5b1ecd AZ |
583 | return 0; |
584 | } | |
585 | ||
586 | static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm) | |
587 | { | |
588 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
589 | ||
590 | crypto_free_akcipher(ctx->child); | |
591 | } | |
592 | ||
593 | static void pkcs1pad_free(struct akcipher_instance *inst) | |
594 | { | |
a49de377 TS |
595 | struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst); |
596 | struct crypto_akcipher_spawn *spawn = &ctx->spawn; | |
3d5b1ecd AZ |
597 | |
598 | crypto_drop_akcipher(spawn); | |
3d5b1ecd AZ |
599 | kfree(inst); |
600 | } | |
601 | ||
602 | static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb) | |
603 | { | |
c0d20d22 | 604 | const struct rsa_asn1_template *digest_info; |
3d5b1ecd AZ |
605 | struct crypto_attr_type *algt; |
606 | struct akcipher_instance *inst; | |
a49de377 | 607 | struct pkcs1pad_inst_ctx *ctx; |
3d5b1ecd AZ |
608 | struct crypto_akcipher_spawn *spawn; |
609 | struct akcipher_alg *rsa_alg; | |
610 | const char *rsa_alg_name; | |
a49de377 | 611 | const char *hash_name; |
3d5b1ecd AZ |
612 | int err; |
613 | ||
614 | algt = crypto_get_attr_type(tb); | |
615 | if (IS_ERR(algt)) | |
616 | return PTR_ERR(algt); | |
617 | ||
618 | if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask) | |
619 | return -EINVAL; | |
620 | ||
621 | rsa_alg_name = crypto_attr_alg_name(tb[1]); | |
622 | if (IS_ERR(rsa_alg_name)) | |
623 | return PTR_ERR(rsa_alg_name); | |
624 | ||
a49de377 TS |
625 | hash_name = crypto_attr_alg_name(tb[2]); |
626 | if (IS_ERR(hash_name)) | |
c0d20d22 HX |
627 | return PTR_ERR(hash_name); |
628 | ||
629 | digest_info = rsa_lookup_asn1(hash_name); | |
630 | if (!digest_info) | |
631 | return -EINVAL; | |
a49de377 TS |
632 | |
633 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); | |
3d5b1ecd AZ |
634 | if (!inst) |
635 | return -ENOMEM; | |
636 | ||
a49de377 TS |
637 | ctx = akcipher_instance_ctx(inst); |
638 | spawn = &ctx->spawn; | |
c0d20d22 | 639 | ctx->digest_info = digest_info; |
a49de377 | 640 | |
3d5b1ecd AZ |
641 | crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst)); |
642 | err = crypto_grab_akcipher(spawn, rsa_alg_name, 0, | |
643 | crypto_requires_sync(algt->type, algt->mask)); | |
644 | if (err) | |
645 | goto out_free_inst; | |
646 | ||
647 | rsa_alg = crypto_spawn_akcipher_alg(spawn); | |
648 | ||
649 | err = -ENAMETOOLONG; | |
a49de377 | 650 | |
c0d20d22 HX |
651 | if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, |
652 | "pkcs1pad(%s,%s)", rsa_alg->base.cra_name, hash_name) >= | |
653 | CRYPTO_MAX_ALG_NAME || | |
654 | snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, | |
655 | "pkcs1pad(%s,%s)", | |
656 | rsa_alg->base.cra_driver_name, hash_name) >= | |
657 | CRYPTO_MAX_ALG_NAME) | |
3d5b1ecd AZ |
658 | goto out_drop_alg; |
659 | ||
660 | inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC; | |
661 | inst->alg.base.cra_priority = rsa_alg->base.cra_priority; | |
662 | inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx); | |
663 | ||
664 | inst->alg.init = pkcs1pad_init_tfm; | |
665 | inst->alg.exit = pkcs1pad_exit_tfm; | |
666 | ||
667 | inst->alg.encrypt = pkcs1pad_encrypt; | |
668 | inst->alg.decrypt = pkcs1pad_decrypt; | |
669 | inst->alg.sign = pkcs1pad_sign; | |
670 | inst->alg.verify = pkcs1pad_verify; | |
671 | inst->alg.set_pub_key = pkcs1pad_set_pub_key; | |
672 | inst->alg.set_priv_key = pkcs1pad_set_priv_key; | |
673 | inst->alg.max_size = pkcs1pad_get_max_size; | |
674 | inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize; | |
675 | ||
676 | inst->free = pkcs1pad_free; | |
677 | ||
678 | err = akcipher_register_instance(tmpl, inst); | |
679 | if (err) | |
c0d20d22 | 680 | goto out_drop_alg; |
3d5b1ecd AZ |
681 | |
682 | return 0; | |
683 | ||
684 | out_drop_alg: | |
685 | crypto_drop_akcipher(spawn); | |
686 | out_free_inst: | |
687 | kfree(inst); | |
688 | return err; | |
689 | } | |
690 | ||
691 | struct crypto_template rsa_pkcs1pad_tmpl = { | |
692 | .name = "pkcs1pad", | |
693 | .create = pkcs1pad_create, | |
694 | .module = THIS_MODULE, | |
695 | }; |