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 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 93 struct pkcs1pad_ctx { 94 struct crypto_akcipher *child; 95 const char *hash_name; 96 unsigned int key_size; 97 }; 98 99 struct pkcs1pad_inst_ctx { 100 struct crypto_akcipher_spawn spawn; 101 const char *hash_name; 102 }; 103 104 struct pkcs1pad_request { 105 struct akcipher_request child_req; 106 107 struct scatterlist in_sg[3], out_sg[2]; 108 uint8_t *in_buf, *out_buf; 109 }; 110 111 static int pkcs1pad_set_pub_key(struct crypto_akcipher *tfm, const void *key, 112 unsigned int keylen) 113 { 114 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 115 int err, size; 116 117 err = crypto_akcipher_set_pub_key(ctx->child, key, keylen); 118 119 if (!err) { 120 /* Find out new modulus size from rsa implementation */ 121 size = crypto_akcipher_maxsize(ctx->child); 122 123 ctx->key_size = size > 0 ? size : 0; 124 if (size <= 0) 125 err = size; 126 } 127 128 return err; 129 } 130 131 static int pkcs1pad_set_priv_key(struct crypto_akcipher *tfm, const void *key, 132 unsigned int keylen) 133 { 134 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 135 int err, size; 136 137 err = crypto_akcipher_set_priv_key(ctx->child, key, keylen); 138 139 if (!err) { 140 /* Find out new modulus size from rsa implementation */ 141 size = crypto_akcipher_maxsize(ctx->child); 142 143 ctx->key_size = size > 0 ? size : 0; 144 if (size <= 0) 145 err = size; 146 } 147 148 return err; 149 } 150 151 static int pkcs1pad_get_max_size(struct crypto_akcipher *tfm) 152 { 153 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 154 155 /* 156 * The maximum destination buffer size for the encrypt/sign operations 157 * will be the same as for RSA, even though it's smaller for 158 * decrypt/verify. 159 */ 160 161 return ctx->key_size ?: -EINVAL; 162 } 163 164 static void pkcs1pad_sg_set_buf(struct scatterlist *sg, void *buf, size_t len, 165 struct scatterlist *next) 166 { 167 int nsegs = next ? 1 : 0; 168 169 if (offset_in_page(buf) + len <= PAGE_SIZE) { 170 nsegs += 1; 171 sg_init_table(sg, nsegs); 172 sg_set_buf(sg, buf, len); 173 } else { 174 nsegs += 2; 175 sg_init_table(sg, nsegs); 176 sg_set_buf(sg + 0, buf, PAGE_SIZE - offset_in_page(buf)); 177 sg_set_buf(sg + 1, buf + PAGE_SIZE - offset_in_page(buf), 178 offset_in_page(buf) + len - PAGE_SIZE); 179 } 180 181 if (next) 182 sg_chain(sg, nsegs, next); 183 } 184 185 static int pkcs1pad_encrypt_sign_complete(struct akcipher_request *req, int err) 186 { 187 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 188 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 189 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); 190 size_t pad_len = ctx->key_size - req_ctx->child_req.dst_len; 191 size_t chunk_len, pad_left; 192 struct sg_mapping_iter miter; 193 194 if (!err) { 195 if (pad_len) { 196 sg_miter_start(&miter, req->dst, 197 sg_nents_for_len(req->dst, pad_len), 198 SG_MITER_ATOMIC | SG_MITER_TO_SG); 199 200 pad_left = pad_len; 201 while (pad_left) { 202 sg_miter_next(&miter); 203 204 chunk_len = min(miter.length, pad_left); 205 memset(miter.addr, 0, chunk_len); 206 pad_left -= chunk_len; 207 } 208 209 sg_miter_stop(&miter); 210 } 211 212 sg_pcopy_from_buffer(req->dst, 213 sg_nents_for_len(req->dst, ctx->key_size), 214 req_ctx->out_buf, req_ctx->child_req.dst_len, 215 pad_len); 216 } 217 req->dst_len = ctx->key_size; 218 219 kfree(req_ctx->in_buf); 220 kzfree(req_ctx->out_buf); 221 222 return err; 223 } 224 225 static void pkcs1pad_encrypt_sign_complete_cb( 226 struct crypto_async_request *child_async_req, int err) 227 { 228 struct akcipher_request *req = child_async_req->data; 229 struct crypto_async_request async_req; 230 231 if (err == -EINPROGRESS) 232 return; 233 234 async_req.data = req->base.data; 235 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); 236 async_req.flags = child_async_req->flags; 237 req->base.complete(&async_req, 238 pkcs1pad_encrypt_sign_complete(req, err)); 239 } 240 241 static int pkcs1pad_encrypt(struct akcipher_request *req) 242 { 243 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 244 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 245 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); 246 int err; 247 unsigned int i, ps_end; 248 249 if (!ctx->key_size) 250 return -EINVAL; 251 252 if (req->src_len > ctx->key_size - 11) 253 return -EOVERFLOW; 254 255 if (req->dst_len < ctx->key_size) { 256 req->dst_len = ctx->key_size; 257 return -EOVERFLOW; 258 } 259 260 if (ctx->key_size > PAGE_SIZE) 261 return -ENOTSUPP; 262 263 /* 264 * Replace both input and output to add the padding in the input and 265 * the potential missing leading zeros in the output. 266 */ 267 req_ctx->child_req.src = req_ctx->in_sg; 268 req_ctx->child_req.src_len = ctx->key_size - 1; 269 req_ctx->child_req.dst = req_ctx->out_sg; 270 req_ctx->child_req.dst_len = ctx->key_size; 271 272 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, 273 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 274 GFP_KERNEL : GFP_ATOMIC); 275 if (!req_ctx->in_buf) 276 return -ENOMEM; 277 278 ps_end = ctx->key_size - req->src_len - 2; 279 req_ctx->in_buf[0] = 0x02; 280 for (i = 1; i < ps_end; i++) 281 req_ctx->in_buf[i] = 1 + prandom_u32_max(255); 282 req_ctx->in_buf[ps_end] = 0x00; 283 284 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, 285 ctx->key_size - 1 - req->src_len, req->src); 286 287 req_ctx->out_buf = kmalloc(ctx->key_size, 288 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 289 GFP_KERNEL : GFP_ATOMIC); 290 if (!req_ctx->out_buf) { 291 kfree(req_ctx->in_buf); 292 return -ENOMEM; 293 } 294 295 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, 296 ctx->key_size, NULL); 297 298 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); 299 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, 300 pkcs1pad_encrypt_sign_complete_cb, req); 301 302 err = crypto_akcipher_encrypt(&req_ctx->child_req); 303 if (err != -EINPROGRESS && 304 (err != -EBUSY || 305 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) 306 return pkcs1pad_encrypt_sign_complete(req, err); 307 308 return err; 309 } 310 311 static int pkcs1pad_decrypt_complete(struct akcipher_request *req, int err) 312 { 313 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 314 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 315 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); 316 unsigned int pos; 317 318 if (err == -EOVERFLOW) 319 /* Decrypted value had no leading 0 byte */ 320 err = -EINVAL; 321 322 if (err) 323 goto done; 324 325 if (req_ctx->child_req.dst_len != ctx->key_size - 1) { 326 err = -EINVAL; 327 goto done; 328 } 329 330 if (req_ctx->out_buf[0] != 0x02) { 331 err = -EINVAL; 332 goto done; 333 } 334 for (pos = 1; pos < req_ctx->child_req.dst_len; pos++) 335 if (req_ctx->out_buf[pos] == 0x00) 336 break; 337 if (pos < 9 || pos == req_ctx->child_req.dst_len) { 338 err = -EINVAL; 339 goto done; 340 } 341 pos++; 342 343 if (req->dst_len < req_ctx->child_req.dst_len - pos) 344 err = -EOVERFLOW; 345 req->dst_len = req_ctx->child_req.dst_len - pos; 346 347 if (!err) 348 sg_copy_from_buffer(req->dst, 349 sg_nents_for_len(req->dst, req->dst_len), 350 req_ctx->out_buf + pos, req->dst_len); 351 352 done: 353 kzfree(req_ctx->out_buf); 354 355 return err; 356 } 357 358 static void pkcs1pad_decrypt_complete_cb( 359 struct crypto_async_request *child_async_req, int err) 360 { 361 struct akcipher_request *req = child_async_req->data; 362 struct crypto_async_request async_req; 363 364 if (err == -EINPROGRESS) 365 return; 366 367 async_req.data = req->base.data; 368 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); 369 async_req.flags = child_async_req->flags; 370 req->base.complete(&async_req, pkcs1pad_decrypt_complete(req, err)); 371 } 372 373 static int pkcs1pad_decrypt(struct akcipher_request *req) 374 { 375 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 376 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 377 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); 378 int err; 379 380 if (!ctx->key_size || req->src_len != ctx->key_size) 381 return -EINVAL; 382 383 if (ctx->key_size > PAGE_SIZE) 384 return -ENOTSUPP; 385 386 /* Reuse input buffer, output to a new buffer */ 387 req_ctx->child_req.src = req->src; 388 req_ctx->child_req.src_len = req->src_len; 389 req_ctx->child_req.dst = req_ctx->out_sg; 390 req_ctx->child_req.dst_len = ctx->key_size ; 391 392 req_ctx->out_buf = kmalloc(ctx->key_size, 393 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 394 GFP_KERNEL : GFP_ATOMIC); 395 if (!req_ctx->out_buf) 396 return -ENOMEM; 397 398 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, 399 ctx->key_size, NULL); 400 401 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); 402 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, 403 pkcs1pad_decrypt_complete_cb, req); 404 405 err = crypto_akcipher_decrypt(&req_ctx->child_req); 406 if (err != -EINPROGRESS && 407 (err != -EBUSY || 408 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) 409 return pkcs1pad_decrypt_complete(req, err); 410 411 return err; 412 } 413 414 static int pkcs1pad_sign(struct akcipher_request *req) 415 { 416 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 417 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 418 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); 419 const struct rsa_asn1_template *digest_info = NULL; 420 int err; 421 unsigned int ps_end, digest_size = 0; 422 423 if (!ctx->key_size) 424 return -EINVAL; 425 426 if (ctx->hash_name) { 427 digest_info = rsa_lookup_asn1(ctx->hash_name); 428 if (!digest_info) 429 return -EINVAL; 430 431 digest_size = digest_info->size; 432 } 433 434 if (req->src_len + digest_size > ctx->key_size - 11) 435 return -EOVERFLOW; 436 437 if (req->dst_len < ctx->key_size) { 438 req->dst_len = ctx->key_size; 439 return -EOVERFLOW; 440 } 441 442 if (ctx->key_size > PAGE_SIZE) 443 return -ENOTSUPP; 444 445 /* 446 * Replace both input and output to add the padding in the input and 447 * the potential missing leading zeros in the output. 448 */ 449 req_ctx->child_req.src = req_ctx->in_sg; 450 req_ctx->child_req.src_len = ctx->key_size - 1; 451 req_ctx->child_req.dst = req_ctx->out_sg; 452 req_ctx->child_req.dst_len = ctx->key_size; 453 454 req_ctx->in_buf = kmalloc(ctx->key_size - 1 - req->src_len, 455 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 456 GFP_KERNEL : GFP_ATOMIC); 457 if (!req_ctx->in_buf) 458 return -ENOMEM; 459 460 ps_end = ctx->key_size - digest_size - req->src_len - 2; 461 req_ctx->in_buf[0] = 0x01; 462 memset(req_ctx->in_buf + 1, 0xff, ps_end - 1); 463 req_ctx->in_buf[ps_end] = 0x00; 464 465 if (digest_info) { 466 memcpy(req_ctx->in_buf + ps_end + 1, digest_info->data, 467 digest_info->size); 468 } 469 470 pkcs1pad_sg_set_buf(req_ctx->in_sg, req_ctx->in_buf, 471 ctx->key_size - 1 - req->src_len, req->src); 472 473 req_ctx->out_buf = kmalloc(ctx->key_size, 474 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 475 GFP_KERNEL : GFP_ATOMIC); 476 if (!req_ctx->out_buf) { 477 kfree(req_ctx->in_buf); 478 return -ENOMEM; 479 } 480 481 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, 482 ctx->key_size, NULL); 483 484 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); 485 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, 486 pkcs1pad_encrypt_sign_complete_cb, req); 487 488 err = crypto_akcipher_sign(&req_ctx->child_req); 489 if (err != -EINPROGRESS && 490 (err != -EBUSY || 491 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) 492 return pkcs1pad_encrypt_sign_complete(req, err); 493 494 return err; 495 } 496 497 static int pkcs1pad_verify_complete(struct akcipher_request *req, int err) 498 { 499 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 500 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 501 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); 502 const struct rsa_asn1_template *digest_info; 503 unsigned int pos; 504 505 if (err == -EOVERFLOW) 506 /* Decrypted value had no leading 0 byte */ 507 err = -EINVAL; 508 509 if (err) 510 goto done; 511 512 if (req_ctx->child_req.dst_len != ctx->key_size - 1) { 513 err = -EINVAL; 514 goto done; 515 } 516 517 err = -EBADMSG; 518 if (req_ctx->out_buf[0] != 0x01) 519 goto done; 520 521 for (pos = 1; pos < req_ctx->child_req.dst_len; pos++) 522 if (req_ctx->out_buf[pos] != 0xff) 523 break; 524 525 if (pos < 9 || pos == req_ctx->child_req.dst_len || 526 req_ctx->out_buf[pos] != 0x00) 527 goto done; 528 pos++; 529 530 if (ctx->hash_name) { 531 digest_info = rsa_lookup_asn1(ctx->hash_name); 532 if (!digest_info) 533 goto done; 534 535 if (memcmp(req_ctx->out_buf + pos, digest_info->data, 536 digest_info->size)) 537 goto done; 538 539 pos += digest_info->size; 540 } 541 542 err = 0; 543 544 if (req->dst_len < req_ctx->child_req.dst_len - pos) 545 err = -EOVERFLOW; 546 req->dst_len = req_ctx->child_req.dst_len - pos; 547 548 if (!err) 549 sg_copy_from_buffer(req->dst, 550 sg_nents_for_len(req->dst, req->dst_len), 551 req_ctx->out_buf + pos, req->dst_len); 552 done: 553 kzfree(req_ctx->out_buf); 554 555 return err; 556 } 557 558 static void pkcs1pad_verify_complete_cb( 559 struct crypto_async_request *child_async_req, int err) 560 { 561 struct akcipher_request *req = child_async_req->data; 562 struct crypto_async_request async_req; 563 564 if (err == -EINPROGRESS) 565 return; 566 567 async_req.data = req->base.data; 568 async_req.tfm = crypto_akcipher_tfm(crypto_akcipher_reqtfm(req)); 569 async_req.flags = child_async_req->flags; 570 req->base.complete(&async_req, pkcs1pad_verify_complete(req, err)); 571 } 572 573 /* 574 * The verify operation is here for completeness similar to the verification 575 * defined in RFC2313 section 10.2 except that block type 0 is not accepted, 576 * as in RFC2437. RFC2437 section 9.2 doesn't define any operation to 577 * retrieve the DigestInfo from a signature, instead the user is expected 578 * to call the sign operation to generate the expected signature and compare 579 * signatures instead of the message-digests. 580 */ 581 static int pkcs1pad_verify(struct akcipher_request *req) 582 { 583 struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); 584 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 585 struct pkcs1pad_request *req_ctx = akcipher_request_ctx(req); 586 int err; 587 588 if (!ctx->key_size || req->src_len < ctx->key_size) 589 return -EINVAL; 590 591 if (ctx->key_size > PAGE_SIZE) 592 return -ENOTSUPP; 593 594 /* Reuse input buffer, output to a new buffer */ 595 req_ctx->child_req.src = req->src; 596 req_ctx->child_req.src_len = req->src_len; 597 req_ctx->child_req.dst = req_ctx->out_sg; 598 req_ctx->child_req.dst_len = ctx->key_size; 599 600 req_ctx->out_buf = kmalloc(ctx->key_size, 601 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? 602 GFP_KERNEL : GFP_ATOMIC); 603 if (!req_ctx->out_buf) 604 return -ENOMEM; 605 606 pkcs1pad_sg_set_buf(req_ctx->out_sg, req_ctx->out_buf, 607 ctx->key_size, NULL); 608 609 akcipher_request_set_tfm(&req_ctx->child_req, ctx->child); 610 akcipher_request_set_callback(&req_ctx->child_req, req->base.flags, 611 pkcs1pad_verify_complete_cb, req); 612 613 err = crypto_akcipher_verify(&req_ctx->child_req); 614 if (err != -EINPROGRESS && 615 (err != -EBUSY || 616 !(req->base.flags & CRYPTO_TFM_REQ_MAY_BACKLOG))) 617 return pkcs1pad_verify_complete(req, err); 618 619 return err; 620 } 621 622 static int pkcs1pad_init_tfm(struct crypto_akcipher *tfm) 623 { 624 struct akcipher_instance *inst = akcipher_alg_instance(tfm); 625 struct pkcs1pad_inst_ctx *ictx = akcipher_instance_ctx(inst); 626 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 627 struct crypto_akcipher *child_tfm; 628 629 child_tfm = crypto_spawn_akcipher(akcipher_instance_ctx(inst)); 630 if (IS_ERR(child_tfm)) 631 return PTR_ERR(child_tfm); 632 633 ctx->child = child_tfm; 634 ctx->hash_name = ictx->hash_name; 635 return 0; 636 } 637 638 static void pkcs1pad_exit_tfm(struct crypto_akcipher *tfm) 639 { 640 struct pkcs1pad_ctx *ctx = akcipher_tfm_ctx(tfm); 641 642 crypto_free_akcipher(ctx->child); 643 } 644 645 static void pkcs1pad_free(struct akcipher_instance *inst) 646 { 647 struct pkcs1pad_inst_ctx *ctx = akcipher_instance_ctx(inst); 648 struct crypto_akcipher_spawn *spawn = &ctx->spawn; 649 650 crypto_drop_akcipher(spawn); 651 kfree(ctx->hash_name); 652 kfree(inst); 653 } 654 655 static int pkcs1pad_create(struct crypto_template *tmpl, struct rtattr **tb) 656 { 657 struct crypto_attr_type *algt; 658 struct akcipher_instance *inst; 659 struct pkcs1pad_inst_ctx *ctx; 660 struct crypto_akcipher_spawn *spawn; 661 struct akcipher_alg *rsa_alg; 662 const char *rsa_alg_name; 663 const char *hash_name; 664 int err; 665 666 algt = crypto_get_attr_type(tb); 667 if (IS_ERR(algt)) 668 return PTR_ERR(algt); 669 670 if ((algt->type ^ CRYPTO_ALG_TYPE_AKCIPHER) & algt->mask) 671 return -EINVAL; 672 673 rsa_alg_name = crypto_attr_alg_name(tb[1]); 674 if (IS_ERR(rsa_alg_name)) 675 return PTR_ERR(rsa_alg_name); 676 677 hash_name = crypto_attr_alg_name(tb[2]); 678 if (IS_ERR(hash_name)) 679 hash_name = NULL; 680 681 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL); 682 if (!inst) 683 return -ENOMEM; 684 685 ctx = akcipher_instance_ctx(inst); 686 spawn = &ctx->spawn; 687 ctx->hash_name = hash_name ? kstrdup(hash_name, GFP_KERNEL) : NULL; 688 689 crypto_set_spawn(&spawn->base, akcipher_crypto_instance(inst)); 690 err = crypto_grab_akcipher(spawn, rsa_alg_name, 0, 691 crypto_requires_sync(algt->type, algt->mask)); 692 if (err) 693 goto out_free_inst; 694 695 rsa_alg = crypto_spawn_akcipher_alg(spawn); 696 697 err = -ENAMETOOLONG; 698 699 if (!hash_name) { 700 if (snprintf(inst->alg.base.cra_name, 701 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)", 702 rsa_alg->base.cra_name) >= 703 CRYPTO_MAX_ALG_NAME || 704 snprintf(inst->alg.base.cra_driver_name, 705 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s)", 706 rsa_alg->base.cra_driver_name) >= 707 CRYPTO_MAX_ALG_NAME) 708 goto out_drop_alg; 709 } else { 710 if (snprintf(inst->alg.base.cra_name, 711 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)", 712 rsa_alg->base.cra_name, hash_name) >= 713 CRYPTO_MAX_ALG_NAME || 714 snprintf(inst->alg.base.cra_driver_name, 715 CRYPTO_MAX_ALG_NAME, "pkcs1pad(%s,%s)", 716 rsa_alg->base.cra_driver_name, hash_name) >= 717 CRYPTO_MAX_ALG_NAME) 718 goto out_free_hash; 719 } 720 721 inst->alg.base.cra_flags = rsa_alg->base.cra_flags & CRYPTO_ALG_ASYNC; 722 inst->alg.base.cra_priority = rsa_alg->base.cra_priority; 723 inst->alg.base.cra_ctxsize = sizeof(struct pkcs1pad_ctx); 724 725 inst->alg.init = pkcs1pad_init_tfm; 726 inst->alg.exit = pkcs1pad_exit_tfm; 727 728 inst->alg.encrypt = pkcs1pad_encrypt; 729 inst->alg.decrypt = pkcs1pad_decrypt; 730 inst->alg.sign = pkcs1pad_sign; 731 inst->alg.verify = pkcs1pad_verify; 732 inst->alg.set_pub_key = pkcs1pad_set_pub_key; 733 inst->alg.set_priv_key = pkcs1pad_set_priv_key; 734 inst->alg.max_size = pkcs1pad_get_max_size; 735 inst->alg.reqsize = sizeof(struct pkcs1pad_request) + rsa_alg->reqsize; 736 737 inst->free = pkcs1pad_free; 738 739 err = akcipher_register_instance(tmpl, inst); 740 if (err) 741 goto out_free_hash; 742 743 return 0; 744 745 out_free_hash: 746 kfree(ctx->hash_name); 747 out_drop_alg: 748 crypto_drop_akcipher(spawn); 749 out_free_inst: 750 kfree(inst); 751 return err; 752 } 753 754 struct crypto_template rsa_pkcs1pad_tmpl = { 755 .name = "pkcs1pad", 756 .create = pkcs1pad_create, 757 .module = THIS_MODULE, 758 }; 759