1 /* 2 * Synchronous Cryptographic Hash operations. 3 * 4 * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au> 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 13 #include <crypto/scatterwalk.h> 14 #include <crypto/internal/hash.h> 15 #include <linux/err.h> 16 #include <linux/kernel.h> 17 #include <linux/module.h> 18 #include <linux/slab.h> 19 #include <linux/seq_file.h> 20 #include <linux/cryptouser.h> 21 #include <net/netlink.h> 22 23 #include "internal.h" 24 25 static const struct crypto_type crypto_shash_type; 26 27 static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key, 28 unsigned int keylen) 29 { 30 return -ENOSYS; 31 } 32 33 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key, 34 unsigned int keylen) 35 { 36 struct shash_alg *shash = crypto_shash_alg(tfm); 37 unsigned long alignmask = crypto_shash_alignmask(tfm); 38 unsigned long absize; 39 u8 *buffer, *alignbuffer; 40 int err; 41 42 absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1)); 43 buffer = kmalloc(absize, GFP_KERNEL); 44 if (!buffer) 45 return -ENOMEM; 46 47 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 48 memcpy(alignbuffer, key, keylen); 49 err = shash->setkey(tfm, alignbuffer, keylen); 50 kzfree(buffer); 51 return err; 52 } 53 54 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key, 55 unsigned int keylen) 56 { 57 struct shash_alg *shash = crypto_shash_alg(tfm); 58 unsigned long alignmask = crypto_shash_alignmask(tfm); 59 60 if ((unsigned long)key & alignmask) 61 return shash_setkey_unaligned(tfm, key, keylen); 62 63 return shash->setkey(tfm, key, keylen); 64 } 65 EXPORT_SYMBOL_GPL(crypto_shash_setkey); 66 67 static inline unsigned int shash_align_buffer_size(unsigned len, 68 unsigned long mask) 69 { 70 typedef u8 __attribute__ ((aligned)) u8_aligned; 71 return len + (mask & ~(__alignof__(u8_aligned) - 1)); 72 } 73 74 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data, 75 unsigned int len) 76 { 77 struct crypto_shash *tfm = desc->tfm; 78 struct shash_alg *shash = crypto_shash_alg(tfm); 79 unsigned long alignmask = crypto_shash_alignmask(tfm); 80 unsigned int unaligned_len = alignmask + 1 - 81 ((unsigned long)data & alignmask); 82 u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)] 83 __attribute__ ((aligned)); 84 u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1); 85 int err; 86 87 if (unaligned_len > len) 88 unaligned_len = len; 89 90 memcpy(buf, data, unaligned_len); 91 err = shash->update(desc, buf, unaligned_len); 92 memset(buf, 0, unaligned_len); 93 94 return err ?: 95 shash->update(desc, data + unaligned_len, len - unaligned_len); 96 } 97 98 int crypto_shash_update(struct shash_desc *desc, const u8 *data, 99 unsigned int len) 100 { 101 struct crypto_shash *tfm = desc->tfm; 102 struct shash_alg *shash = crypto_shash_alg(tfm); 103 unsigned long alignmask = crypto_shash_alignmask(tfm); 104 105 if ((unsigned long)data & alignmask) 106 return shash_update_unaligned(desc, data, len); 107 108 return shash->update(desc, data, len); 109 } 110 EXPORT_SYMBOL_GPL(crypto_shash_update); 111 112 static int shash_final_unaligned(struct shash_desc *desc, u8 *out) 113 { 114 struct crypto_shash *tfm = desc->tfm; 115 unsigned long alignmask = crypto_shash_alignmask(tfm); 116 struct shash_alg *shash = crypto_shash_alg(tfm); 117 unsigned int ds = crypto_shash_digestsize(tfm); 118 u8 ubuf[shash_align_buffer_size(ds, alignmask)] 119 __attribute__ ((aligned)); 120 u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1); 121 int err; 122 123 err = shash->final(desc, buf); 124 if (err) 125 goto out; 126 127 memcpy(out, buf, ds); 128 129 out: 130 memset(buf, 0, ds); 131 return err; 132 } 133 134 int crypto_shash_final(struct shash_desc *desc, u8 *out) 135 { 136 struct crypto_shash *tfm = desc->tfm; 137 struct shash_alg *shash = crypto_shash_alg(tfm); 138 unsigned long alignmask = crypto_shash_alignmask(tfm); 139 140 if ((unsigned long)out & alignmask) 141 return shash_final_unaligned(desc, out); 142 143 return shash->final(desc, out); 144 } 145 EXPORT_SYMBOL_GPL(crypto_shash_final); 146 147 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data, 148 unsigned int len, u8 *out) 149 { 150 return crypto_shash_update(desc, data, len) ?: 151 crypto_shash_final(desc, out); 152 } 153 154 int crypto_shash_finup(struct shash_desc *desc, const u8 *data, 155 unsigned int len, u8 *out) 156 { 157 struct crypto_shash *tfm = desc->tfm; 158 struct shash_alg *shash = crypto_shash_alg(tfm); 159 unsigned long alignmask = crypto_shash_alignmask(tfm); 160 161 if (((unsigned long)data | (unsigned long)out) & alignmask) 162 return shash_finup_unaligned(desc, data, len, out); 163 164 return shash->finup(desc, data, len, out); 165 } 166 EXPORT_SYMBOL_GPL(crypto_shash_finup); 167 168 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data, 169 unsigned int len, u8 *out) 170 { 171 return crypto_shash_init(desc) ?: 172 crypto_shash_finup(desc, data, len, out); 173 } 174 175 int crypto_shash_digest(struct shash_desc *desc, const u8 *data, 176 unsigned int len, u8 *out) 177 { 178 struct crypto_shash *tfm = desc->tfm; 179 struct shash_alg *shash = crypto_shash_alg(tfm); 180 unsigned long alignmask = crypto_shash_alignmask(tfm); 181 182 if (((unsigned long)data | (unsigned long)out) & alignmask) 183 return shash_digest_unaligned(desc, data, len, out); 184 185 return shash->digest(desc, data, len, out); 186 } 187 EXPORT_SYMBOL_GPL(crypto_shash_digest); 188 189 static int shash_default_export(struct shash_desc *desc, void *out) 190 { 191 memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm)); 192 return 0; 193 } 194 195 static int shash_default_import(struct shash_desc *desc, const void *in) 196 { 197 memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm)); 198 return 0; 199 } 200 201 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key, 202 unsigned int keylen) 203 { 204 struct crypto_shash **ctx = crypto_ahash_ctx(tfm); 205 206 return crypto_shash_setkey(*ctx, key, keylen); 207 } 208 209 static int shash_async_init(struct ahash_request *req) 210 { 211 struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req)); 212 struct shash_desc *desc = ahash_request_ctx(req); 213 214 desc->tfm = *ctx; 215 desc->flags = req->base.flags; 216 217 return crypto_shash_init(desc); 218 } 219 220 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc) 221 { 222 struct crypto_hash_walk walk; 223 int nbytes; 224 225 for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0; 226 nbytes = crypto_hash_walk_done(&walk, nbytes)) 227 nbytes = crypto_shash_update(desc, walk.data, nbytes); 228 229 return nbytes; 230 } 231 EXPORT_SYMBOL_GPL(shash_ahash_update); 232 233 static int shash_async_update(struct ahash_request *req) 234 { 235 return shash_ahash_update(req, ahash_request_ctx(req)); 236 } 237 238 static int shash_async_final(struct ahash_request *req) 239 { 240 return crypto_shash_final(ahash_request_ctx(req), req->result); 241 } 242 243 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc) 244 { 245 struct crypto_hash_walk walk; 246 int nbytes; 247 248 nbytes = crypto_hash_walk_first(req, &walk); 249 if (!nbytes) 250 return crypto_shash_final(desc, req->result); 251 252 do { 253 nbytes = crypto_hash_walk_last(&walk) ? 254 crypto_shash_finup(desc, walk.data, nbytes, 255 req->result) : 256 crypto_shash_update(desc, walk.data, nbytes); 257 nbytes = crypto_hash_walk_done(&walk, nbytes); 258 } while (nbytes > 0); 259 260 return nbytes; 261 } 262 EXPORT_SYMBOL_GPL(shash_ahash_finup); 263 264 static int shash_async_finup(struct ahash_request *req) 265 { 266 struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req)); 267 struct shash_desc *desc = ahash_request_ctx(req); 268 269 desc->tfm = *ctx; 270 desc->flags = req->base.flags; 271 272 return shash_ahash_finup(req, desc); 273 } 274 275 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc) 276 { 277 struct scatterlist *sg = req->src; 278 unsigned int offset = sg->offset; 279 unsigned int nbytes = req->nbytes; 280 int err; 281 282 if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) { 283 void *data; 284 285 data = kmap_atomic(sg_page(sg)); 286 err = crypto_shash_digest(desc, data + offset, nbytes, 287 req->result); 288 kunmap_atomic(data); 289 crypto_yield(desc->flags); 290 } else 291 err = crypto_shash_init(desc) ?: 292 shash_ahash_finup(req, desc); 293 294 return err; 295 } 296 EXPORT_SYMBOL_GPL(shash_ahash_digest); 297 298 static int shash_async_digest(struct ahash_request *req) 299 { 300 struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req)); 301 struct shash_desc *desc = ahash_request_ctx(req); 302 303 desc->tfm = *ctx; 304 desc->flags = req->base.flags; 305 306 return shash_ahash_digest(req, desc); 307 } 308 309 static int shash_async_export(struct ahash_request *req, void *out) 310 { 311 return crypto_shash_export(ahash_request_ctx(req), out); 312 } 313 314 static int shash_async_import(struct ahash_request *req, const void *in) 315 { 316 struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req)); 317 struct shash_desc *desc = ahash_request_ctx(req); 318 319 desc->tfm = *ctx; 320 desc->flags = req->base.flags; 321 322 return crypto_shash_import(desc, in); 323 } 324 325 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm) 326 { 327 struct crypto_shash **ctx = crypto_tfm_ctx(tfm); 328 329 crypto_free_shash(*ctx); 330 } 331 332 int crypto_init_shash_ops_async(struct crypto_tfm *tfm) 333 { 334 struct crypto_alg *calg = tfm->__crt_alg; 335 struct shash_alg *alg = __crypto_shash_alg(calg); 336 struct crypto_ahash *crt = __crypto_ahash_cast(tfm); 337 struct crypto_shash **ctx = crypto_tfm_ctx(tfm); 338 struct crypto_shash *shash; 339 340 if (!crypto_mod_get(calg)) 341 return -EAGAIN; 342 343 shash = crypto_create_tfm(calg, &crypto_shash_type); 344 if (IS_ERR(shash)) { 345 crypto_mod_put(calg); 346 return PTR_ERR(shash); 347 } 348 349 *ctx = shash; 350 tfm->exit = crypto_exit_shash_ops_async; 351 352 crt->init = shash_async_init; 353 crt->update = shash_async_update; 354 crt->final = shash_async_final; 355 crt->finup = shash_async_finup; 356 crt->digest = shash_async_digest; 357 358 if (alg->setkey) 359 crt->setkey = shash_async_setkey; 360 if (alg->export) 361 crt->export = shash_async_export; 362 if (alg->import) 363 crt->import = shash_async_import; 364 365 crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash); 366 367 return 0; 368 } 369 370 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key, 371 unsigned int keylen) 372 { 373 struct shash_desc **descp = crypto_hash_ctx(tfm); 374 struct shash_desc *desc = *descp; 375 376 return crypto_shash_setkey(desc->tfm, key, keylen); 377 } 378 379 static int shash_compat_init(struct hash_desc *hdesc) 380 { 381 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm); 382 struct shash_desc *desc = *descp; 383 384 desc->flags = hdesc->flags; 385 386 return crypto_shash_init(desc); 387 } 388 389 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg, 390 unsigned int len) 391 { 392 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm); 393 struct shash_desc *desc = *descp; 394 struct crypto_hash_walk walk; 395 int nbytes; 396 397 for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len); 398 nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes)) 399 nbytes = crypto_shash_update(desc, walk.data, nbytes); 400 401 return nbytes; 402 } 403 404 static int shash_compat_final(struct hash_desc *hdesc, u8 *out) 405 { 406 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm); 407 408 return crypto_shash_final(*descp, out); 409 } 410 411 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg, 412 unsigned int nbytes, u8 *out) 413 { 414 unsigned int offset = sg->offset; 415 int err; 416 417 if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) { 418 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm); 419 struct shash_desc *desc = *descp; 420 void *data; 421 422 desc->flags = hdesc->flags; 423 424 data = kmap_atomic(sg_page(sg)); 425 err = crypto_shash_digest(desc, data + offset, nbytes, out); 426 kunmap_atomic(data); 427 crypto_yield(desc->flags); 428 goto out; 429 } 430 431 err = shash_compat_init(hdesc); 432 if (err) 433 goto out; 434 435 err = shash_compat_update(hdesc, sg, nbytes); 436 if (err) 437 goto out; 438 439 err = shash_compat_final(hdesc, out); 440 441 out: 442 return err; 443 } 444 445 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm) 446 { 447 struct shash_desc **descp = crypto_tfm_ctx(tfm); 448 struct shash_desc *desc = *descp; 449 450 crypto_free_shash(desc->tfm); 451 kzfree(desc); 452 } 453 454 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm) 455 { 456 struct hash_tfm *crt = &tfm->crt_hash; 457 struct crypto_alg *calg = tfm->__crt_alg; 458 struct shash_alg *alg = __crypto_shash_alg(calg); 459 struct shash_desc **descp = crypto_tfm_ctx(tfm); 460 struct crypto_shash *shash; 461 struct shash_desc *desc; 462 463 if (!crypto_mod_get(calg)) 464 return -EAGAIN; 465 466 shash = crypto_create_tfm(calg, &crypto_shash_type); 467 if (IS_ERR(shash)) { 468 crypto_mod_put(calg); 469 return PTR_ERR(shash); 470 } 471 472 desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash), 473 GFP_KERNEL); 474 if (!desc) { 475 crypto_free_shash(shash); 476 return -ENOMEM; 477 } 478 479 *descp = desc; 480 desc->tfm = shash; 481 tfm->exit = crypto_exit_shash_ops_compat; 482 483 crt->init = shash_compat_init; 484 crt->update = shash_compat_update; 485 crt->final = shash_compat_final; 486 crt->digest = shash_compat_digest; 487 crt->setkey = shash_compat_setkey; 488 489 crt->digestsize = alg->digestsize; 490 491 return 0; 492 } 493 494 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask) 495 { 496 switch (mask & CRYPTO_ALG_TYPE_MASK) { 497 case CRYPTO_ALG_TYPE_HASH_MASK: 498 return crypto_init_shash_ops_compat(tfm); 499 } 500 501 return -EINVAL; 502 } 503 504 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type, 505 u32 mask) 506 { 507 switch (mask & CRYPTO_ALG_TYPE_MASK) { 508 case CRYPTO_ALG_TYPE_HASH_MASK: 509 return sizeof(struct shash_desc *); 510 } 511 512 return 0; 513 } 514 515 static int crypto_shash_init_tfm(struct crypto_tfm *tfm) 516 { 517 struct crypto_shash *hash = __crypto_shash_cast(tfm); 518 519 hash->descsize = crypto_shash_alg(hash)->descsize; 520 return 0; 521 } 522 523 #ifdef CONFIG_NET 524 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg) 525 { 526 struct crypto_report_hash rhash; 527 struct shash_alg *salg = __crypto_shash_alg(alg); 528 529 strncpy(rhash.type, "shash", sizeof(rhash.type)); 530 531 rhash.blocksize = alg->cra_blocksize; 532 rhash.digestsize = salg->digestsize; 533 534 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH, 535 sizeof(struct crypto_report_hash), &rhash)) 536 goto nla_put_failure; 537 return 0; 538 539 nla_put_failure: 540 return -EMSGSIZE; 541 } 542 #else 543 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg) 544 { 545 return -ENOSYS; 546 } 547 #endif 548 549 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg) 550 __attribute__ ((unused)); 551 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg) 552 { 553 struct shash_alg *salg = __crypto_shash_alg(alg); 554 555 seq_printf(m, "type : shash\n"); 556 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 557 seq_printf(m, "digestsize : %u\n", salg->digestsize); 558 } 559 560 static const struct crypto_type crypto_shash_type = { 561 .ctxsize = crypto_shash_ctxsize, 562 .extsize = crypto_alg_extsize, 563 .init = crypto_init_shash_ops, 564 .init_tfm = crypto_shash_init_tfm, 565 #ifdef CONFIG_PROC_FS 566 .show = crypto_shash_show, 567 #endif 568 .report = crypto_shash_report, 569 .maskclear = ~CRYPTO_ALG_TYPE_MASK, 570 .maskset = CRYPTO_ALG_TYPE_MASK, 571 .type = CRYPTO_ALG_TYPE_SHASH, 572 .tfmsize = offsetof(struct crypto_shash, base), 573 }; 574 575 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type, 576 u32 mask) 577 { 578 return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask); 579 } 580 EXPORT_SYMBOL_GPL(crypto_alloc_shash); 581 582 static int shash_prepare_alg(struct shash_alg *alg) 583 { 584 struct crypto_alg *base = &alg->base; 585 586 if (alg->digestsize > PAGE_SIZE / 8 || 587 alg->descsize > PAGE_SIZE / 8 || 588 alg->statesize > PAGE_SIZE / 8) 589 return -EINVAL; 590 591 base->cra_type = &crypto_shash_type; 592 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK; 593 base->cra_flags |= CRYPTO_ALG_TYPE_SHASH; 594 595 if (!alg->finup) 596 alg->finup = shash_finup_unaligned; 597 if (!alg->digest) 598 alg->digest = shash_digest_unaligned; 599 if (!alg->export) { 600 alg->export = shash_default_export; 601 alg->import = shash_default_import; 602 alg->statesize = alg->descsize; 603 } 604 if (!alg->setkey) 605 alg->setkey = shash_no_setkey; 606 607 return 0; 608 } 609 610 int crypto_register_shash(struct shash_alg *alg) 611 { 612 struct crypto_alg *base = &alg->base; 613 int err; 614 615 err = shash_prepare_alg(alg); 616 if (err) 617 return err; 618 619 return crypto_register_alg(base); 620 } 621 EXPORT_SYMBOL_GPL(crypto_register_shash); 622 623 int crypto_unregister_shash(struct shash_alg *alg) 624 { 625 return crypto_unregister_alg(&alg->base); 626 } 627 EXPORT_SYMBOL_GPL(crypto_unregister_shash); 628 629 int crypto_register_shashes(struct shash_alg *algs, int count) 630 { 631 int i, ret; 632 633 for (i = 0; i < count; i++) { 634 ret = crypto_register_shash(&algs[i]); 635 if (ret) 636 goto err; 637 } 638 639 return 0; 640 641 err: 642 for (--i; i >= 0; --i) 643 crypto_unregister_shash(&algs[i]); 644 645 return ret; 646 } 647 EXPORT_SYMBOL_GPL(crypto_register_shashes); 648 649 int crypto_unregister_shashes(struct shash_alg *algs, int count) 650 { 651 int i, ret; 652 653 for (i = count - 1; i >= 0; --i) { 654 ret = crypto_unregister_shash(&algs[i]); 655 if (ret) 656 pr_err("Failed to unregister %s %s: %d\n", 657 algs[i].base.cra_driver_name, 658 algs[i].base.cra_name, ret); 659 } 660 661 return 0; 662 } 663 EXPORT_SYMBOL_GPL(crypto_unregister_shashes); 664 665 int shash_register_instance(struct crypto_template *tmpl, 666 struct shash_instance *inst) 667 { 668 int err; 669 670 err = shash_prepare_alg(&inst->alg); 671 if (err) 672 return err; 673 674 return crypto_register_instance(tmpl, shash_crypto_instance(inst)); 675 } 676 EXPORT_SYMBOL_GPL(shash_register_instance); 677 678 void shash_free_instance(struct crypto_instance *inst) 679 { 680 crypto_drop_spawn(crypto_instance_ctx(inst)); 681 kfree(shash_instance(inst)); 682 } 683 EXPORT_SYMBOL_GPL(shash_free_instance); 684 685 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn, 686 struct shash_alg *alg, 687 struct crypto_instance *inst) 688 { 689 return crypto_init_spawn2(&spawn->base, &alg->base, inst, 690 &crypto_shash_type); 691 } 692 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn); 693 694 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask) 695 { 696 struct crypto_alg *alg; 697 698 alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask); 699 return IS_ERR(alg) ? ERR_CAST(alg) : 700 container_of(alg, struct shash_alg, base); 701 } 702 EXPORT_SYMBOL_GPL(shash_attr_alg); 703 704 MODULE_LICENSE("GPL"); 705 MODULE_DESCRIPTION("Synchronous cryptographic hash type"); 706