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 AZ |
103 | struct pkcs1pad_request { |
104 | struct akcipher_request child_req; | |
105 | ||
0f2c8319 | 106 | struct scatterlist in_sg[2], out_sg[1]; |
3d5b1ecd AZ |
107 | uint8_t *in_buf, *out_buf; |
108 | }; | |
109 | ||
110 | static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key, | |
111 | unsigned int keylen) | |
112 | { | |
113 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
73f79189 HX |
114 | int err; |
115 | ||
116 | ctx->key_size = 0; | |
3d5b1ecd AZ |
117 | |
118 | err = crypto_akcipher_set_pub_key(ctx->child, key, keylen); | |
73f79189 HX |
119 | if (err) |
120 | return err; | |
3d5b1ecd | 121 | |
73f79189 HX |
122 | /* Find out new modulus size from rsa implementation */ |
123 | err = crypto_akcipher_maxsize(ctx->child); | |
124 | if (err < 0) | |
125 | return err; | |
3d5b1ecd | 126 | |
73f79189 HX |
127 | if (err > PAGE_SIZE) |
128 | return -ENOTSUPP; | |
3d5b1ecd | 129 | |
73f79189 HX |
130 | ctx->key_size = err; |
131 | return 0; | |
3d5b1ecd AZ |
132 | } |
133 | ||
134 | static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key, | |
135 | unsigned int keylen) | |
136 | { | |
137 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
73f79189 HX |
138 | int err; |
139 | ||
140 | ctx->key_size = 0; | |
3d5b1ecd AZ |
141 | |
142 | err = crypto_akcipher_set_priv_key(ctx->child, key, keylen); | |
73f79189 HX |
143 | if (err) |
144 | return err; | |
3d5b1ecd | 145 | |
73f79189 HX |
146 | /* Find out new modulus size from rsa implementation */ |
147 | err = crypto_akcipher_maxsize(ctx->child); | |
148 | if (err < 0) | |
149 | return err; | |
3d5b1ecd | 150 | |
73f79189 HX |
151 | if (err > PAGE_SIZE) |
152 | return -ENOTSUPP; | |
3d5b1ecd | 153 | |
73f79189 HX |
154 | ctx->key_size = err; |
155 | return 0; | |
3d5b1ecd AZ |
156 | } |
157 | ||
158 | static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm) | |
159 | { | |
160 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
161 | ||
162 | /* | |
163 | * The maximum destination buffer size for the encrypt/sign operations | |
164 | * will be the same as for RSA, even though it's smaller for | |
165 | * decrypt/verify. | |
166 | */ | |
167 | ||
168 | return ctx->key_size ?: -EINVAL; | |
169 | } | |
170 | ||
171 | static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len, | |
172 | struct scatterlist *next) | |
173 | { | |
0f2c8319 HX |
174 | int nsegs = next ? 2 : 1; |
175 | ||
176 | sg_init_table(sg, nsegs); | |
177 | sg_set_buf(sg, buf, len); | |
3d5b1ecd AZ |
178 | |
179 | if (next) | |
180 | sg_chain(sg, nsegs, next); | |
181 | } | |
182 | ||
183 | static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err) | |
184 | { | |
185 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
186 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
187 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
5319216d AZ |
188 | size_t pad_len = ctx->key_size - req_ctx->child_req.dst_len; |
189 | size_t chunk_len, pad_left; | |
190 | struct sg_mapping_iter miter; | |
3d5b1ecd AZ |
191 | |
192 | if (!err) { | |
5319216d AZ |
193 | if (pad_len) { |
194 | sg_miter_start(&miter, req->dst, | |
195 | sg_nents_for_len(req->dst, pad_len), | |
196 | SG_MITER_ATOMIC | SG_MITER_TO_SG); | |
197 | ||
198 | pad_left = pad_len; | |
199 | while (pad_left) { | |
200 | sg_miter_next(&miter); | |
201 | ||
202 | chunk_len = min(miter.length, pad_left); | |
203 | memset(miter.addr, 0, chunk_len); | |
204 | pad_left -= chunk_len; | |
205 | } | |
206 | ||
207 | sg_miter_stop(&miter); | |
3d5b1ecd AZ |
208 | } |
209 | ||
210 | sg_pcopy_from_buffer(req->dst, | |
211 | sg_nents_for_len(req->dst, ctx->key_size), | |
212 | req_ctx->out_buf, req_ctx->child_req.dst_len, | |
5319216d | 213 | pad_len); |
3d5b1ecd AZ |
214 | } |
215 | req->dst_len = ctx->key_size; | |
216 | ||
217 | kfree(req_ctx->in_buf); | |
218 | kzfree(req_ctx->out_buf); | |
219 | ||
220 | return err; | |
221 | } | |
222 | ||
223 | static void pkcs1pad_encrypt_sign_complete_cb( | |
224 | struct crypto_async_request *child_async_req, int err) | |
225 | { | |
226 | struct akcipher_request *req = child_async_req->data; | |
227 | struct crypto_async_request async_req; | |
228 | ||
229 | if (err == -EINPROGRESS) | |
230 | return; | |
231 | ||
232 | async_req.data = req->base.data; | |
233 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
234 | async_req.flags = child_async_req->flags; | |
235 | req->base.complete(&async_req, | |
236 | pkcs1pad_encrypt_sign_complete(req, err)); | |
237 | } | |
238 | ||
239 | static int pkcs1pad_encrypt(struct akcipher_request *req) | |
240 | { | |
241 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
242 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
243 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
244 | int err; | |
245 | unsigned int i, ps_end; | |
246 | ||
247 | if (!ctx->key_size) | |
248 | return -EINVAL; | |
249 | ||
250 | if (req->src_len > ctx->key_size - 11) | |
251 | return -EOVERFLOW; | |
252 | ||
253 | if (req->dst_len < ctx->key_size) { | |
254 | req->dst_len = ctx->key_size; | |
255 | return -EOVERFLOW; | |
256 | } | |
257 | ||
3d5b1ecd AZ |
258 | /* |
259 | * Replace both input and output to add the padding in the input and | |
260 | * the potential missing leading zeros in the output. | |
261 | */ | |
262 | req_ctx->child_req.src = req_ctx->in_sg; | |
263 | req_ctx->child_req.src_len = ctx->key_size - 1; | |
264 | req_ctx->child_req.dst = req_ctx->out_sg; | |
265 | req_ctx->child_req.dst_len = ctx->key_size; | |
266 | ||
267 | req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, | |
3a32ce50 | 268 | GFP_KERNEL); |
3d5b1ecd AZ |
269 | if (!req_ctx->in_buf) |
270 | return -ENOMEM; | |
271 | ||
272 | ps_end = ctx->key_size - req->src_len - 2; | |
273 | req_ctx->in_buf[0] = 0x02; | |
274 | for (i = 1; i < ps_end; i++) | |
275 | req_ctx->in_buf[i] = 1 + prandom_u32_max(255); | |
276 | req_ctx->in_buf[ps_end] = 0x00; | |
277 | ||
278 | pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, | |
279 | ctx->key_size - 1 - req->src_len, req->src); | |
280 | ||
3a32ce50 | 281 | req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL); |
3d5b1ecd AZ |
282 | if (!req_ctx->out_buf) { |
283 | kfree(req_ctx->in_buf); | |
284 | return -ENOMEM; | |
285 | } | |
286 | ||
287 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
288 | ctx->key_size, NULL); | |
289 | ||
290 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
291 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
292 | pkcs1pad_encrypt_sign_complete_cb, req); | |
293 | ||
294 | err = crypto_akcipher_encrypt(&req_ctx->child_req); | |
295 | if (err != -EINPROGRESS && | |
296 | (err != -EBUSY || | |
297 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
298 | return pkcs1pad_encrypt_sign_complete(req, err); | |
299 | ||
300 | return err; | |
301 | } | |
302 | ||
303 | static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err) | |
304 | { | |
305 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
306 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
307 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
308 | unsigned int pos; | |
309 | ||
310 | if (err == -EOVERFLOW) | |
311 | /* Decrypted value had no leading 0 byte */ | |
312 | err = -EINVAL; | |
313 | ||
314 | if (err) | |
315 | goto done; | |
316 | ||
317 | if (req_ctx->child_req.dst_len != ctx->key_size - 1) { | |
318 | err = -EINVAL; | |
319 | goto done; | |
320 | } | |
321 | ||
322 | if (req_ctx->out_buf[0] != 0x02) { | |
323 | err = -EINVAL; | |
324 | goto done; | |
325 | } | |
326 | for (pos = 1; pos < req_ctx->child_req.dst_len; pos++) | |
327 | if (req_ctx->out_buf[pos] == 0x00) | |
328 | break; | |
329 | if (pos < 9 || pos == req_ctx->child_req.dst_len) { | |
330 | err = -EINVAL; | |
331 | goto done; | |
332 | } | |
333 | pos++; | |
334 | ||
335 | if (req->dst_len < req_ctx->child_req.dst_len - pos) | |
336 | err = -EOVERFLOW; | |
337 | req->dst_len = req_ctx->child_req.dst_len - pos; | |
338 | ||
339 | if (!err) | |
340 | sg_copy_from_buffer(req->dst, | |
341 | sg_nents_for_len(req->dst, req->dst_len), | |
342 | req_ctx->out_buf + pos, req->dst_len); | |
343 | ||
344 | done: | |
345 | kzfree(req_ctx->out_buf); | |
346 | ||
347 | return err; | |
348 | } | |
349 | ||
350 | static void pkcs1pad_decrypt_complete_cb( | |
351 | struct crypto_async_request *child_async_req, int err) | |
352 | { | |
353 | struct akcipher_request *req = child_async_req->data; | |
354 | struct crypto_async_request async_req; | |
355 | ||
356 | if (err == -EINPROGRESS) | |
357 | return; | |
358 | ||
359 | async_req.data = req->base.data; | |
360 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
361 | async_req.flags = child_async_req->flags; | |
362 | req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err)); | |
363 | } | |
364 | ||
365 | static int pkcs1pad_decrypt(struct akcipher_request *req) | |
366 | { | |
367 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
368 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
369 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
370 | int err; | |
371 | ||
372 | if (!ctx->key_size || req->src_len != ctx->key_size) | |
373 | return -EINVAL; | |
374 | ||
3d5b1ecd AZ |
375 | /* Reuse input buffer, output to a new buffer */ |
376 | req_ctx->child_req.src = req->src; | |
377 | req_ctx->child_req.src_len = req->src_len; | |
378 | req_ctx->child_req.dst = req_ctx->out_sg; | |
6f0904ad | 379 | req_ctx->child_req.dst_len = ctx->key_size ; |
3d5b1ecd | 380 | |
3a32ce50 | 381 | req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL); |
3d5b1ecd AZ |
382 | if (!req_ctx->out_buf) |
383 | return -ENOMEM; | |
384 | ||
385 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
6f0904ad | 386 | ctx->key_size, NULL); |
3d5b1ecd AZ |
387 | |
388 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
389 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
390 | pkcs1pad_decrypt_complete_cb, req); | |
391 | ||
392 | err = crypto_akcipher_decrypt(&req_ctx->child_req); | |
393 | if (err != -EINPROGRESS && | |
394 | (err != -EBUSY || | |
395 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
396 | return pkcs1pad_decrypt_complete(req, err); | |
397 | ||
398 | return err; | |
399 | } | |
400 | ||
401 | static int pkcs1pad_sign(struct akcipher_request *req) | |
402 | { | |
403 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
404 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
405 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
c0d20d22 HX |
406 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); |
407 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); | |
408 | const struct rsa_asn1_template *digest_info = ictx->digest_info; | |
3d5b1ecd | 409 | int err; |
a49de377 | 410 | unsigned int ps_end, digest_size = 0; |
3d5b1ecd AZ |
411 | |
412 | if (!ctx->key_size) | |
413 | return -EINVAL; | |
414 | ||
c0d20d22 | 415 | digest_size = digest_info->size; |
a49de377 TS |
416 | |
417 | if (req->src_len + digest_size > ctx->key_size - 11) | |
3d5b1ecd AZ |
418 | return -EOVERFLOW; |
419 | ||
420 | if (req->dst_len < ctx->key_size) { | |
421 | req->dst_len = ctx->key_size; | |
422 | return -EOVERFLOW; | |
423 | } | |
424 | ||
3d5b1ecd AZ |
425 | /* |
426 | * Replace both input and output to add the padding in the input and | |
427 | * the potential missing leading zeros in the output. | |
428 | */ | |
429 | req_ctx->child_req.src = req_ctx->in_sg; | |
430 | req_ctx->child_req.src_len = ctx->key_size - 1; | |
431 | req_ctx->child_req.dst = req_ctx->out_sg; | |
432 | req_ctx->child_req.dst_len = ctx->key_size; | |
433 | ||
434 | req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, | |
3a32ce50 | 435 | GFP_KERNEL); |
3d5b1ecd AZ |
436 | if (!req_ctx->in_buf) |
437 | return -ENOMEM; | |
438 | ||
a49de377 | 439 | ps_end = ctx->key_size - digest_size - req->src_len - 2; |
3d5b1ecd AZ |
440 | req_ctx->in_buf[0] = 0x01; |
441 | memset(req_ctx->in_buf + 1, 0xff, ps_end - 1); | |
442 | req_ctx->in_buf[ps_end] = 0x00; | |
443 | ||
c0d20d22 HX |
444 | memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data, |
445 | digest_info->size); | |
a49de377 | 446 | |
3d5b1ecd AZ |
447 | pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, |
448 | ctx->key_size - 1 - req->src_len, req->src); | |
449 | ||
3a32ce50 | 450 | req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL); |
3d5b1ecd AZ |
451 | if (!req_ctx->out_buf) { |
452 | kfree(req_ctx->in_buf); | |
453 | return -ENOMEM; | |
454 | } | |
455 | ||
456 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
457 | ctx->key_size, NULL); | |
458 | ||
459 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
460 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
461 | pkcs1pad_encrypt_sign_complete_cb, req); | |
462 | ||
463 | err = crypto_akcipher_sign(&req_ctx->child_req); | |
464 | if (err != -EINPROGRESS && | |
465 | (err != -EBUSY || | |
466 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
467 | return pkcs1pad_encrypt_sign_complete(req, err); | |
468 | ||
469 | return err; | |
470 | } | |
471 | ||
472 | static int pkcs1pad_verify_complete(struct akcipher_request *req, int err) | |
473 | { | |
474 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
475 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
476 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
c0d20d22 HX |
477 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); |
478 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); | |
479 | const struct rsa_asn1_template *digest_info = ictx->digest_info; | |
3d5b1ecd AZ |
480 | unsigned int pos; |
481 | ||
482 | if (err == -EOVERFLOW) | |
483 | /* Decrypted value had no leading 0 byte */ | |
484 | err = -EINVAL; | |
485 | ||
486 | if (err) | |
487 | goto done; | |
488 | ||
489 | if (req_ctx->child_req.dst_len != ctx->key_size - 1) { | |
490 | err = -EINVAL; | |
491 | goto done; | |
492 | } | |
493 | ||
a49de377 TS |
494 | err = -EBADMSG; |
495 | if (req_ctx->out_buf[0] != 0x01) | |
3d5b1ecd | 496 | goto done; |
a49de377 | 497 | |
3d5b1ecd AZ |
498 | for (pos = 1; pos < req_ctx->child_req.dst_len; pos++) |
499 | if (req_ctx->out_buf[pos] != 0xff) | |
500 | break; | |
a49de377 | 501 | |
3d5b1ecd | 502 | if (pos < 9 || pos == req_ctx->child_req.dst_len || |
a49de377 | 503 | req_ctx->out_buf[pos] != 0x00) |
3d5b1ecd | 504 | goto done; |
3d5b1ecd AZ |
505 | pos++; |
506 | ||
c0d20d22 HX |
507 | if (memcmp(req_ctx->out_buf + pos, digest_info->data, |
508 | digest_info->size)) | |
509 | goto done; | |
a49de377 | 510 | |
c0d20d22 | 511 | pos += digest_info->size; |
a49de377 TS |
512 | |
513 | err = 0; | |
514 | ||
3d5b1ecd AZ |
515 | if (req->dst_len < req_ctx->child_req.dst_len - pos) |
516 | err = -EOVERFLOW; | |
517 | req->dst_len = req_ctx->child_req.dst_len - pos; | |
518 | ||
519 | if (!err) | |
520 | sg_copy_from_buffer(req->dst, | |
521 | sg_nents_for_len(req->dst, req->dst_len), | |
522 | req_ctx->out_buf + pos, req->dst_len); | |
3d5b1ecd AZ |
523 | done: |
524 | kzfree(req_ctx->out_buf); | |
525 | ||
526 | return err; | |
527 | } | |
528 | ||
529 | static void pkcs1pad_verify_complete_cb( | |
530 | struct crypto_async_request *child_async_req, int err) | |
531 | { | |
532 | struct akcipher_request *req = child_async_req->data; | |
533 | struct crypto_async_request async_req; | |
534 | ||
535 | if (err == -EINPROGRESS) | |
536 | return; | |
537 | ||
538 | async_req.data = req->base.data; | |
539 | async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); | |
540 | async_req.flags = child_async_req->flags; | |
541 | req->base.complete(&async_req, pkcs1pad_verify_complete(req, err)); | |
542 | } | |
543 | ||
544 | /* | |
545 | * The verify operation is here for completeness similar to the verification | |
546 | * defined in RFC2313 section 10.2 except that block type 0 is not accepted, | |
547 | * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to | |
548 | * retrieve the DigestInfo from a signature, instead the user is expected | |
549 | * to call the sign operation to generate the expected signature and compare | |
550 | * signatures instead of the message-digests. | |
551 | */ | |
552 | static int pkcs1pad_verify(struct akcipher_request *req) | |
553 | { | |
554 | struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); | |
555 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
556 | struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); | |
557 | int err; | |
558 | ||
a49de377 | 559 | if (!ctx->key_size || req->src_len < ctx->key_size) |
3d5b1ecd AZ |
560 | return -EINVAL; |
561 | ||
3d5b1ecd AZ |
562 | /* Reuse input buffer, output to a new buffer */ |
563 | req_ctx->child_req.src = req->src; | |
564 | req_ctx->child_req.src_len = req->src_len; | |
565 | req_ctx->child_req.dst = req_ctx->out_sg; | |
6f0904ad | 566 | req_ctx->child_req.dst_len = ctx->key_size; |
3d5b1ecd | 567 | |
3a32ce50 | 568 | req_ctx->out_buf = kmalloc(ctx->key_size, GFP_KERNEL); |
3d5b1ecd AZ |
569 | if (!req_ctx->out_buf) |
570 | return -ENOMEM; | |
571 | ||
572 | pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, | |
6f0904ad | 573 | ctx->key_size, NULL); |
3d5b1ecd AZ |
574 | |
575 | akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); | |
576 | akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, | |
577 | pkcs1pad_verify_complete_cb, req); | |
578 | ||
579 | err = crypto_akcipher_verify(&req_ctx->child_req); | |
580 | if (err != -EINPROGRESS && | |
581 | (err != -EBUSY || | |
582 | !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) | |
583 | return pkcs1pad_verify_complete(req, err); | |
584 | ||
585 | return err; | |
586 | } | |
587 | ||
588 | static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm) | |
589 | { | |
590 | struct akcipher_instance *inst = akcipher_alg_instance(tfm); | |
a49de377 | 591 | struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); |
3d5b1ecd AZ |
592 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); |
593 | struct crypto_akcipher *child_tfm; | |
594 | ||
c0d20d22 | 595 | child_tfm = crypto_spawn_akcipher(&ictx->spawn); |
3d5b1ecd AZ |
596 | if (IS_ERR(child_tfm)) |
597 | return PTR_ERR(child_tfm); | |
598 | ||
599 | ctx->child = child_tfm; | |
3d5b1ecd AZ |
600 | return 0; |
601 | } | |
602 | ||
603 | static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm) | |
604 | { | |
605 | struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); | |
606 | ||
607 | crypto_free_akcipher(ctx->child); | |
608 | } | |
609 | ||
610 | static void pkcs1pad_free(struct akcipher_instance *inst) | |
611 | { | |
a49de377 TS |
612 | struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst); |
613 | struct crypto_akcipher_spawn *spawn = &ctx->spawn; | |
3d5b1ecd AZ |
614 | |
615 | crypto_drop_akcipher(spawn); | |
3d5b1ecd AZ |
616 | kfree(inst); |
617 | } | |
618 | ||
619 | static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb) | |
620 | { | |
c0d20d22 | 621 | const struct rsa_asn1_template *digest_info; |
3d5b1ecd AZ |
622 | struct crypto_attr_type *algt; |
623 | struct akcipher_instance *inst; | |
a49de377 | 624 | struct pkcs1pad_inst_ctx *ctx; |
3d5b1ecd AZ |
625 | struct crypto_akcipher_spawn *spawn; |
626 | struct akcipher_alg *rsa_alg; | |
627 | const char *rsa_alg_name; | |
a49de377 | 628 | const char *hash_name; |
3d5b1ecd AZ |
629 | int err; |
630 | ||
631 | algt = crypto_get_attr_type(tb); | |
632 | if (IS_ERR(algt)) | |
633 | return PTR_ERR(algt); | |
634 | ||
635 | if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask) | |
636 | return -EINVAL; | |
637 | ||
638 | rsa_alg_name = crypto_attr_alg_name(tb[1]); | |
639 | if (IS_ERR(rsa_alg_name)) | |
640 | return PTR_ERR(rsa_alg_name); | |
641 | ||
a49de377 TS |
642 | hash_name = crypto_attr_alg_name(tb[2]); |
643 | if (IS_ERR(hash_name)) | |
c0d20d22 HX |
644 | return PTR_ERR(hash_name); |
645 | ||
646 | digest_info = rsa_lookup_asn1(hash_name); | |
647 | if (!digest_info) | |
648 | return -EINVAL; | |
a49de377 TS |
649 | |
650 | inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); | |
3d5b1ecd AZ |
651 | if (!inst) |
652 | return -ENOMEM; | |
653 | ||
a49de377 TS |
654 | ctx = akcipher_instance_ctx(inst); |
655 | spawn = &ctx->spawn; | |
c0d20d22 | 656 | ctx->digest_info = digest_info; |
a49de377 | 657 | |
3d5b1ecd AZ |
658 | crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst)); |
659 | err = crypto_grab_akcipher(spawn, rsa_alg_name, 0, | |
660 | crypto_requires_sync(algt->type, algt->mask)); | |
661 | if (err) | |
662 | goto out_free_inst; | |
663 | ||
664 | rsa_alg = crypto_spawn_akcipher_alg(spawn); | |
665 | ||
666 | err = -ENAMETOOLONG; | |
a49de377 | 667 | |
c0d20d22 HX |
668 | if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME, |
669 | "pkcs1pad(%s,%s)", rsa_alg->base.cra_name, hash_name) >= | |
670 | CRYPTO_MAX_ALG_NAME || | |
671 | snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME, | |
672 | "pkcs1pad(%s,%s)", | |
673 | rsa_alg->base.cra_driver_name, hash_name) >= | |
674 | CRYPTO_MAX_ALG_NAME) | |
3d5b1ecd AZ |
675 | goto out_drop_alg; |
676 | ||
677 | inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC; | |
678 | inst->alg.base.cra_priority = rsa_alg->base.cra_priority; | |
679 | inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx); | |
680 | ||
681 | inst->alg.init = pkcs1pad_init_tfm; | |
682 | inst->alg.exit = pkcs1pad_exit_tfm; | |
683 | ||
684 | inst->alg.encrypt = pkcs1pad_encrypt; | |
685 | inst->alg.decrypt = pkcs1pad_decrypt; | |
686 | inst->alg.sign = pkcs1pad_sign; | |
687 | inst->alg.verify = pkcs1pad_verify; | |
688 | inst->alg.set_pub_key = pkcs1pad_set_pub_key; | |
689 | inst->alg.set_priv_key = pkcs1pad_set_priv_key; | |
690 | inst->alg.max_size = pkcs1pad_get_max_size; | |
691 | inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize; | |
692 | ||
693 | inst->free = pkcs1pad_free; | |
694 | ||
695 | err = akcipher_register_instance(tmpl, inst); | |
696 | if (err) | |
c0d20d22 | 697 | goto out_drop_alg; |
3d5b1ecd AZ |
698 | |
699 | return 0; | |
700 | ||
701 | out_drop_alg: | |
702 | crypto_drop_akcipher(spawn); | |
703 | out_free_inst: | |
704 | kfree(inst); | |
705 | return err; | |
706 | } | |
707 | ||
708 | struct crypto_template rsa_pkcs1pad_tmpl = { | |
709 | .name = "pkcs1pad", | |
710 | .create = pkcs1pad_create, | |
711 | .module = THIS_MODULE, | |
712 | }; |