1/* 2 * Block chaining cipher operations. 3 * 4 * Generic encrypt/decrypt wrapper for ciphers, handles operations across 5 * multiple page boundaries by using temporary blocks. In user context, 6 * the kernel is given a chance to schedule us once per page. 7 * 8 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au> 9 * 10 * This program is free software; you can redistribute it and/or modify it 11 * under the terms of the GNU General Public License as published by the Free 12 * Software Foundation; either version 2 of the License, or (at your option) 13 * any later version. 14 * 15 */ 16 17#include <crypto/internal/skcipher.h> 18#include <crypto/scatterwalk.h> 19#include <linux/errno.h> 20#include <linux/hardirq.h> 21#include <linux/kernel.h> 22#include <linux/module.h> 23#include <linux/scatterlist.h> 24#include <linux/seq_file.h> 25#include <linux/slab.h> 26#include <linux/string.h> 27#include <linux/cryptouser.h> 28#include <net/netlink.h> 29 30#include "internal.h" 31 32enum { 33 BLKCIPHER_WALK_PHYS = 1 << 0, 34 BLKCIPHER_WALK_SLOW = 1 << 1, 35 BLKCIPHER_WALK_COPY = 1 << 2, 36 BLKCIPHER_WALK_DIFF = 1 << 3, 37}; 38 39static int blkcipher_walk_next(struct blkcipher_desc *desc, 40 struct blkcipher_walk *walk); 41static int blkcipher_walk_first(struct blkcipher_desc *desc, 42 struct blkcipher_walk *walk); 43 44static inline void blkcipher_map_src(struct blkcipher_walk *walk) 45{ 46 walk->src.virt.addr = scatterwalk_map(&walk->in); 47} 48 49static inline void blkcipher_map_dst(struct blkcipher_walk *walk) 50{ 51 walk->dst.virt.addr = scatterwalk_map(&walk->out); 52} 53 54static inline void blkcipher_unmap_src(struct blkcipher_walk *walk) 55{ 56 scatterwalk_unmap(walk->src.virt.addr); 57} 58 59static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk) 60{ 61 scatterwalk_unmap(walk->dst.virt.addr); 62} 63 64/* Get a spot of the specified length that does not straddle a page. 65 * The caller needs to ensure that there is enough space for this operation. 66 */ 67static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len) 68{ 69 u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK); 70 return max(start, end_page); 71} 72 73static inline unsigned int blkcipher_done_slow(struct blkcipher_walk *walk, 74 unsigned int bsize) 75{ 76 u8 *addr; 77 78 addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1); 79 addr = blkcipher_get_spot(addr, bsize); 80 scatterwalk_copychunks(addr, &walk->out, bsize, 1); 81 return bsize; 82} 83 84static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk, 85 unsigned int n) 86{ 87 if (walk->flags & BLKCIPHER_WALK_COPY) { 88 blkcipher_map_dst(walk); 89 memcpy(walk->dst.virt.addr, walk->page, n); 90 blkcipher_unmap_dst(walk); 91 } else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) { 92 if (walk->flags & BLKCIPHER_WALK_DIFF) 93 blkcipher_unmap_dst(walk); 94 blkcipher_unmap_src(walk); 95 } 96 97 scatterwalk_advance(&walk->in, n); 98 scatterwalk_advance(&walk->out, n); 99 100 return n; 101} 102 103int blkcipher_walk_done(struct blkcipher_desc *desc, 104 struct blkcipher_walk *walk, int err) 105{ 106 unsigned int nbytes = 0; 107 108 if (likely(err >= 0)) { 109 unsigned int n = walk->nbytes - err; 110 111 if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW))) 112 n = blkcipher_done_fast(walk, n); 113 else if (WARN_ON(err)) { 114 err = -EINVAL; 115 goto err; 116 } else 117 n = blkcipher_done_slow(walk, n); 118 119 nbytes = walk->total - n; 120 err = 0; 121 } 122 123 scatterwalk_done(&walk->in, 0, nbytes); 124 scatterwalk_done(&walk->out, 1, nbytes); 125 126err: 127 walk->total = nbytes; 128 walk->nbytes = nbytes; 129 130 if (nbytes) { 131 crypto_yield(desc->flags); 132 return blkcipher_walk_next(desc, walk); 133 } 134 135 if (walk->iv != desc->info) 136 memcpy(desc->info, walk->iv, walk->ivsize); 137 if (walk->buffer != walk->page) 138 kfree(walk->buffer); 139 if (walk->page) 140 free_page((unsigned long)walk->page); 141 142 return err; 143} 144EXPORT_SYMBOL_GPL(blkcipher_walk_done); 145 146static inline int blkcipher_next_slow(struct blkcipher_desc *desc, 147 struct blkcipher_walk *walk, 148 unsigned int bsize, 149 unsigned int alignmask) 150{ 151 unsigned int n; 152 unsigned aligned_bsize = ALIGN(bsize, alignmask + 1); 153 154 if (walk->buffer) 155 goto ok; 156 157 walk->buffer = walk->page; 158 if (walk->buffer) 159 goto ok; 160 161 n = aligned_bsize * 3 - (alignmask + 1) + 162 (alignmask & ~(crypto_tfm_ctx_alignment() - 1)); 163 walk->buffer = kmalloc(n, GFP_ATOMIC); 164 if (!walk->buffer) 165 return blkcipher_walk_done(desc, walk, -ENOMEM); 166 167ok: 168 walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer, 169 alignmask + 1); 170 walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize); 171 walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr + 172 aligned_bsize, bsize); 173 174 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0); 175 176 walk->nbytes = bsize; 177 walk->flags |= BLKCIPHER_WALK_SLOW; 178 179 return 0; 180} 181 182static inline int blkcipher_next_copy(struct blkcipher_walk *walk) 183{ 184 u8 *tmp = walk->page; 185 186 blkcipher_map_src(walk); 187 memcpy(tmp, walk->src.virt.addr, walk->nbytes); 188 blkcipher_unmap_src(walk); 189 190 walk->src.virt.addr = tmp; 191 walk->dst.virt.addr = tmp; 192 193 return 0; 194} 195 196static inline int blkcipher_next_fast(struct blkcipher_desc *desc, 197 struct blkcipher_walk *walk) 198{ 199 unsigned long diff; 200 201 walk->src.phys.page = scatterwalk_page(&walk->in); 202 walk->src.phys.offset = offset_in_page(walk->in.offset); 203 walk->dst.phys.page = scatterwalk_page(&walk->out); 204 walk->dst.phys.offset = offset_in_page(walk->out.offset); 205 206 if (walk->flags & BLKCIPHER_WALK_PHYS) 207 return 0; 208 209 diff = walk->src.phys.offset - walk->dst.phys.offset; 210 diff |= walk->src.virt.page - walk->dst.virt.page; 211 212 blkcipher_map_src(walk); 213 walk->dst.virt.addr = walk->src.virt.addr; 214 215 if (diff) { 216 walk->flags |= BLKCIPHER_WALK_DIFF; 217 blkcipher_map_dst(walk); 218 } 219 220 return 0; 221} 222 223static int blkcipher_walk_next(struct blkcipher_desc *desc, 224 struct blkcipher_walk *walk) 225{ 226 unsigned int bsize; 227 unsigned int n; 228 int err; 229 230 n = walk->total; 231 if (unlikely(n < walk->cipher_blocksize)) { 232 desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN; 233 return blkcipher_walk_done(desc, walk, -EINVAL); 234 } 235 236 walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY | 237 BLKCIPHER_WALK_DIFF); 238 if (!scatterwalk_aligned(&walk->in, walk->alignmask) || 239 !scatterwalk_aligned(&walk->out, walk->alignmask)) { 240 walk->flags |= BLKCIPHER_WALK_COPY; 241 if (!walk->page) { 242 walk->page = (void *)__get_free_page(GFP_ATOMIC); 243 if (!walk->page) 244 n = 0; 245 } 246 } 247 248 bsize = min(walk->walk_blocksize, n); 249 n = scatterwalk_clamp(&walk->in, n); 250 n = scatterwalk_clamp(&walk->out, n); 251 252 if (unlikely(n < bsize)) { 253 err = blkcipher_next_slow(desc, walk, bsize, walk->alignmask); 254 goto set_phys_lowmem; 255 } 256 257 walk->nbytes = n; 258 if (walk->flags & BLKCIPHER_WALK_COPY) { 259 err = blkcipher_next_copy(walk); 260 goto set_phys_lowmem; 261 } 262 263 return blkcipher_next_fast(desc, walk); 264 265set_phys_lowmem: 266 if (walk->flags & BLKCIPHER_WALK_PHYS) { 267 walk->src.phys.page = virt_to_page(walk->src.virt.addr); 268 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr); 269 walk->src.phys.offset &= PAGE_SIZE - 1; 270 walk->dst.phys.offset &= PAGE_SIZE - 1; 271 } 272 return err; 273} 274 275static inline int blkcipher_copy_iv(struct blkcipher_walk *walk) 276{ 277 unsigned bs = walk->walk_blocksize; 278 unsigned aligned_bs = ALIGN(bs, walk->alignmask + 1); 279 unsigned int size = aligned_bs * 2 + 280 walk->ivsize + max(aligned_bs, walk->ivsize) - 281 (walk->alignmask + 1); 282 u8 *iv; 283 284 size += walk->alignmask & ~(crypto_tfm_ctx_alignment() - 1); 285 walk->buffer = kmalloc(size, GFP_ATOMIC); 286 if (!walk->buffer) 287 return -ENOMEM; 288 289 iv = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1); 290 iv = blkcipher_get_spot(iv, bs) + aligned_bs; 291 iv = blkcipher_get_spot(iv, bs) + aligned_bs; 292 iv = blkcipher_get_spot(iv, walk->ivsize); 293 294 walk->iv = memcpy(iv, walk->iv, walk->ivsize); 295 return 0; 296} 297 298int blkcipher_walk_virt(struct blkcipher_desc *desc, 299 struct blkcipher_walk *walk) 300{ 301 walk->flags &= ~BLKCIPHER_WALK_PHYS; 302 walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm); 303 walk->cipher_blocksize = walk->walk_blocksize; 304 walk->ivsize = crypto_blkcipher_ivsize(desc->tfm); 305 walk->alignmask = crypto_blkcipher_alignmask(desc->tfm); 306 return blkcipher_walk_first(desc, walk); 307} 308EXPORT_SYMBOL_GPL(blkcipher_walk_virt); 309 310int blkcipher_walk_phys(struct blkcipher_desc *desc, 311 struct blkcipher_walk *walk) 312{ 313 walk->flags |= BLKCIPHER_WALK_PHYS; 314 walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm); 315 walk->cipher_blocksize = walk->walk_blocksize; 316 walk->ivsize = crypto_blkcipher_ivsize(desc->tfm); 317 walk->alignmask = crypto_blkcipher_alignmask(desc->tfm); 318 return blkcipher_walk_first(desc, walk); 319} 320EXPORT_SYMBOL_GPL(blkcipher_walk_phys); 321 322static int blkcipher_walk_first(struct blkcipher_desc *desc, 323 struct blkcipher_walk *walk) 324{ 325 if (WARN_ON_ONCE(in_irq())) 326 return -EDEADLK; 327 328 walk->nbytes = walk->total; 329 if (unlikely(!walk->total)) 330 return 0; 331 332 walk->buffer = NULL; 333 walk->iv = desc->info; 334 if (unlikely(((unsigned long)walk->iv & walk->alignmask))) { 335 int err = blkcipher_copy_iv(walk); 336 if (err) 337 return err; 338 } 339 340 scatterwalk_start(&walk->in, walk->in.sg); 341 scatterwalk_start(&walk->out, walk->out.sg); 342 walk->page = NULL; 343 344 return blkcipher_walk_next(desc, walk); 345} 346 347int blkcipher_walk_virt_block(struct blkcipher_desc *desc, 348 struct blkcipher_walk *walk, 349 unsigned int blocksize) 350{ 351 walk->flags &= ~BLKCIPHER_WALK_PHYS; 352 walk->walk_blocksize = blocksize; 353 walk->cipher_blocksize = crypto_blkcipher_blocksize(desc->tfm); 354 walk->ivsize = crypto_blkcipher_ivsize(desc->tfm); 355 walk->alignmask = crypto_blkcipher_alignmask(desc->tfm); 356 return blkcipher_walk_first(desc, walk); 357} 358EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block); 359 360int blkcipher_aead_walk_virt_block(struct blkcipher_desc *desc, 361 struct blkcipher_walk *walk, 362 struct crypto_aead *tfm, 363 unsigned int blocksize) 364{ 365 walk->flags &= ~BLKCIPHER_WALK_PHYS; 366 walk->walk_blocksize = blocksize; 367 walk->cipher_blocksize = crypto_aead_blocksize(tfm); 368 walk->ivsize = crypto_aead_ivsize(tfm); 369 walk->alignmask = crypto_aead_alignmask(tfm); 370 return blkcipher_walk_first(desc, walk); 371} 372EXPORT_SYMBOL_GPL(blkcipher_aead_walk_virt_block); 373 374static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key, 375 unsigned int keylen) 376{ 377 struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher; 378 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 379 int ret; 380 u8 *buffer, *alignbuffer; 381 unsigned long absize; 382 383 absize = keylen + alignmask; 384 buffer = kmalloc(absize, GFP_ATOMIC); 385 if (!buffer) 386 return -ENOMEM; 387 388 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1); 389 memcpy(alignbuffer, key, keylen); 390 ret = cipher->setkey(tfm, alignbuffer, keylen); 391 memset(alignbuffer, 0, keylen); 392 kfree(buffer); 393 return ret; 394} 395 396static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen) 397{ 398 struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher; 399 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm); 400 401 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) { 402 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; 403 return -EINVAL; 404 } 405 406 if ((unsigned long)key & alignmask) 407 return setkey_unaligned(tfm, key, keylen); 408 409 return cipher->setkey(tfm, key, keylen); 410} 411 412static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key, 413 unsigned int keylen) 414{ 415 return setkey(crypto_ablkcipher_tfm(tfm), key, keylen); 416} 417 418static int async_encrypt(struct ablkcipher_request *req) 419{ 420 struct crypto_tfm *tfm = req->base.tfm; 421 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 422 struct blkcipher_desc desc = { 423 .tfm = __crypto_blkcipher_cast(tfm), 424 .info = req->info, 425 .flags = req->base.flags, 426 }; 427 428 429 return alg->encrypt(&desc, req->dst, req->src, req->nbytes); 430} 431 432static int async_decrypt(struct ablkcipher_request *req) 433{ 434 struct crypto_tfm *tfm = req->base.tfm; 435 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 436 struct blkcipher_desc desc = { 437 .tfm = __crypto_blkcipher_cast(tfm), 438 .info = req->info, 439 .flags = req->base.flags, 440 }; 441 442 return alg->decrypt(&desc, req->dst, req->src, req->nbytes); 443} 444 445static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type, 446 u32 mask) 447{ 448 struct blkcipher_alg *cipher = &alg->cra_blkcipher; 449 unsigned int len = alg->cra_ctxsize; 450 451 if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK && 452 cipher->ivsize) { 453 len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1); 454 len += cipher->ivsize; 455 } 456 457 return len; 458} 459 460static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm) 461{ 462 struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher; 463 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 464 465 crt->setkey = async_setkey; 466 crt->encrypt = async_encrypt; 467 crt->decrypt = async_decrypt; 468 if (!alg->ivsize) { 469 crt->givencrypt = skcipher_null_givencrypt; 470 crt->givdecrypt = skcipher_null_givdecrypt; 471 } 472 crt->base = __crypto_ablkcipher_cast(tfm); 473 crt->ivsize = alg->ivsize; 474 475 return 0; 476} 477 478static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm) 479{ 480 struct blkcipher_tfm *crt = &tfm->crt_blkcipher; 481 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 482 unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1; 483 unsigned long addr; 484 485 crt->setkey = setkey; 486 crt->encrypt = alg->encrypt; 487 crt->decrypt = alg->decrypt; 488 489 addr = (unsigned long)crypto_tfm_ctx(tfm); 490 addr = ALIGN(addr, align); 491 addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align); 492 crt->iv = (void *)addr; 493 494 return 0; 495} 496 497static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask) 498{ 499 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher; 500 501 if (alg->ivsize > PAGE_SIZE / 8) 502 return -EINVAL; 503 504 if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK) 505 return crypto_init_blkcipher_ops_sync(tfm); 506 else 507 return crypto_init_blkcipher_ops_async(tfm); 508} 509 510#ifdef CONFIG_NET 511static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 512{ 513 struct crypto_report_blkcipher rblkcipher; 514 515 strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type)); 516 strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>", 517 sizeof(rblkcipher.geniv)); 518 519 rblkcipher.blocksize = alg->cra_blocksize; 520 rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize; 521 rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize; 522 rblkcipher.ivsize = alg->cra_blkcipher.ivsize; 523 524 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER, 525 sizeof(struct crypto_report_blkcipher), &rblkcipher)) 526 goto nla_put_failure; 527 return 0; 528 529nla_put_failure: 530 return -EMSGSIZE; 531} 532#else 533static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg) 534{ 535 return -ENOSYS; 536} 537#endif 538 539static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg) 540 __attribute__ ((unused)); 541static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg) 542{ 543 seq_printf(m, "type : blkcipher\n"); 544 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize); 545 seq_printf(m, "min keysize : %u\n", alg->cra_blkcipher.min_keysize); 546 seq_printf(m, "max keysize : %u\n", alg->cra_blkcipher.max_keysize); 547 seq_printf(m, "ivsize : %u\n", alg->cra_blkcipher.ivsize); 548 seq_printf(m, "geniv : %s\n", alg->cra_blkcipher.geniv ?: 549 "<default>"); 550} 551 552const struct crypto_type crypto_blkcipher_type = { 553 .ctxsize = crypto_blkcipher_ctxsize, 554 .init = crypto_init_blkcipher_ops, 555#ifdef CONFIG_PROC_FS 556 .show = crypto_blkcipher_show, 557#endif 558 .report = crypto_blkcipher_report, 559}; 560EXPORT_SYMBOL_GPL(crypto_blkcipher_type); 561 562static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn, 563 const char *name, u32 type, u32 mask) 564{ 565 struct crypto_alg *alg; 566 int err; 567 568 type = crypto_skcipher_type(type); 569 mask = crypto_skcipher_mask(mask)| CRYPTO_ALG_GENIV; 570 571 alg = crypto_alg_mod_lookup(name, type, mask); 572 if (IS_ERR(alg)) 573 return PTR_ERR(alg); 574 575 err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask); 576 crypto_mod_put(alg); 577 return err; 578} 579 580struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl, 581 struct rtattr **tb, u32 type, 582 u32 mask) 583{ 584 struct { 585 int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key, 586 unsigned int keylen); 587 int (*encrypt)(struct ablkcipher_request *req); 588 int (*decrypt)(struct ablkcipher_request *req); 589 590 unsigned int min_keysize; 591 unsigned int max_keysize; 592 unsigned int ivsize; 593 594 const char *geniv; 595 } balg; 596 const char *name; 597 struct crypto_skcipher_spawn *spawn; 598 struct crypto_attr_type *algt; 599 struct crypto_instance *inst; 600 struct crypto_alg *alg; 601 int err; 602 603 algt = crypto_get_attr_type(tb); 604 if (IS_ERR(algt)) 605 return ERR_CAST(algt); 606 607 if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) & 608 algt->mask) 609 return ERR_PTR(-EINVAL); 610 611 name = crypto_attr_alg_name(tb[1]); 612 if (IS_ERR(name)) 613 return ERR_CAST(name); 614 615 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL); 616 if (!inst) 617 return ERR_PTR(-ENOMEM); 618 619 spawn = crypto_instance_ctx(inst); 620 621 /* Ignore async algorithms if necessary. */ 622 mask |= crypto_requires_sync(algt->type, algt->mask); 623 624 crypto_set_skcipher_spawn(spawn, inst); 625 err = crypto_grab_nivcipher(spawn, name, type, mask); 626 if (err) 627 goto err_free_inst; 628 629 alg = crypto_skcipher_spawn_alg(spawn); 630 631 if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == 632 CRYPTO_ALG_TYPE_BLKCIPHER) { 633 balg.ivsize = alg->cra_blkcipher.ivsize; 634 balg.min_keysize = alg->cra_blkcipher.min_keysize; 635 balg.max_keysize = alg->cra_blkcipher.max_keysize; 636 637 balg.setkey = async_setkey; 638 balg.encrypt = async_encrypt; 639 balg.decrypt = async_decrypt; 640 641 balg.geniv = alg->cra_blkcipher.geniv; 642 } else { 643 balg.ivsize = alg->cra_ablkcipher.ivsize; 644 balg.min_keysize = alg->cra_ablkcipher.min_keysize; 645 balg.max_keysize = alg->cra_ablkcipher.max_keysize; 646 647 balg.setkey = alg->cra_ablkcipher.setkey; 648 balg.encrypt = alg->cra_ablkcipher.encrypt; 649 balg.decrypt = alg->cra_ablkcipher.decrypt; 650 651 balg.geniv = alg->cra_ablkcipher.geniv; 652 } 653 654 err = -EINVAL; 655 if (!balg.ivsize) 656 goto err_drop_alg; 657 658 /* 659 * This is only true if we're constructing an algorithm with its 660 * default IV generator. For the default generator we elide the 661 * template name and double-check the IV generator. 662 */ 663 if (algt->mask & CRYPTO_ALG_GENIV) { 664 if (!balg.geniv) 665 balg.geniv = crypto_default_geniv(alg); 666 err = -EAGAIN; 667 if (strcmp(tmpl->name, balg.geniv)) 668 goto err_drop_alg; 669 670 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME); 671 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name, 672 CRYPTO_MAX_ALG_NAME); 673 } else { 674 err = -ENAMETOOLONG; 675 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, 676 "%s(%s)", tmpl->name, alg->cra_name) >= 677 CRYPTO_MAX_ALG_NAME) 678 goto err_drop_alg; 679 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, 680 "%s(%s)", tmpl->name, alg->cra_driver_name) >= 681 CRYPTO_MAX_ALG_NAME) 682 goto err_drop_alg; 683 } 684 685 inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV; 686 inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC; 687 inst->alg.cra_priority = alg->cra_priority; 688 inst->alg.cra_blocksize = alg->cra_blocksize; 689 inst->alg.cra_alignmask = alg->cra_alignmask; 690 inst->alg.cra_type = &crypto_givcipher_type; 691 692 inst->alg.cra_ablkcipher.ivsize = balg.ivsize; 693 inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize; 694 inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize; 695 inst->alg.cra_ablkcipher.geniv = balg.geniv; 696 697 inst->alg.cra_ablkcipher.setkey = balg.setkey; 698 inst->alg.cra_ablkcipher.encrypt = balg.encrypt; 699 inst->alg.cra_ablkcipher.decrypt = balg.decrypt; 700 701out: 702 return inst; 703 704err_drop_alg: 705 crypto_drop_skcipher(spawn); 706err_free_inst: 707 kfree(inst); 708 inst = ERR_PTR(err); 709 goto out; 710} 711EXPORT_SYMBOL_GPL(skcipher_geniv_alloc); 712 713void skcipher_geniv_free(struct crypto_instance *inst) 714{ 715 crypto_drop_skcipher(crypto_instance_ctx(inst)); 716 kfree(inst); 717} 718EXPORT_SYMBOL_GPL(skcipher_geniv_free); 719 720int skcipher_geniv_init(struct crypto_tfm *tfm) 721{ 722 struct crypto_instance *inst = (void *)tfm->__crt_alg; 723 struct crypto_ablkcipher *cipher; 724 725 cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst)); 726 if (IS_ERR(cipher)) 727 return PTR_ERR(cipher); 728 729 tfm->crt_ablkcipher.base = cipher; 730 tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher); 731 732 return 0; 733} 734EXPORT_SYMBOL_GPL(skcipher_geniv_init); 735 736void skcipher_geniv_exit(struct crypto_tfm *tfm) 737{ 738 crypto_free_ablkcipher(tfm->crt_ablkcipher.base); 739} 740EXPORT_SYMBOL_GPL(skcipher_geniv_exit); 741 742MODULE_LICENSE("GPL"); 743MODULE_DESCRIPTION("Generic block chaining cipher type"); 744