1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Accelerated GHASH implementation with ARMv8 PMULL instructions. 4 * 5 * Copyright (C) 2014 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org> 6 */ 7 8 #include <asm/neon.h> 9 #include <asm/simd.h> 10 #include <asm/unaligned.h> 11 #include <crypto/aes.h> 12 #include <crypto/algapi.h> 13 #include <crypto/b128ops.h> 14 #include <crypto/gf128mul.h> 15 #include <crypto/internal/aead.h> 16 #include <crypto/internal/hash.h> 17 #include <crypto/internal/simd.h> 18 #include <crypto/internal/skcipher.h> 19 #include <crypto/scatterwalk.h> 20 #include <linux/cpufeature.h> 21 #include <linux/crypto.h> 22 #include <linux/module.h> 23 24 MODULE_DESCRIPTION("GHASH and AES-GCM using ARMv8 Crypto Extensions"); 25 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); 26 MODULE_LICENSE("GPL v2"); 27 MODULE_ALIAS_CRYPTO("ghash"); 28 29 #define GHASH_BLOCK_SIZE 16 30 #define GHASH_DIGEST_SIZE 16 31 #define GCM_IV_SIZE 12 32 33 struct ghash_key { 34 u64 h[2]; 35 u64 h2[2]; 36 u64 h3[2]; 37 u64 h4[2]; 38 39 be128 k; 40 }; 41 42 struct ghash_desc_ctx { 43 u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)]; 44 u8 buf[GHASH_BLOCK_SIZE]; 45 u32 count; 46 }; 47 48 struct gcm_aes_ctx { 49 struct crypto_aes_ctx aes_key; 50 struct ghash_key ghash_key; 51 }; 52 53 asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src, 54 struct ghash_key const *k, 55 const char *head); 56 57 asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src, 58 struct ghash_key const *k, 59 const char *head); 60 61 asmlinkage void pmull_gcm_encrypt(int blocks, u64 dg[], u8 dst[], 62 const u8 src[], struct ghash_key const *k, 63 u8 ctr[], u32 const rk[], int rounds, 64 u8 ks[]); 65 66 asmlinkage void pmull_gcm_decrypt(int blocks, u64 dg[], u8 dst[], 67 const u8 src[], struct ghash_key const *k, 68 u8 ctr[], u32 const rk[], int rounds); 69 70 asmlinkage void pmull_gcm_encrypt_block(u8 dst[], u8 const src[], 71 u32 const rk[], int rounds); 72 73 static int ghash_init(struct shash_desc *desc) 74 { 75 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 76 77 *ctx = (struct ghash_desc_ctx){}; 78 return 0; 79 } 80 81 static void ghash_do_update(int blocks, u64 dg[], const char *src, 82 struct ghash_key *key, const char *head, 83 void (*simd_update)(int blocks, u64 dg[], 84 const char *src, 85 struct ghash_key const *k, 86 const char *head)) 87 { 88 if (likely(crypto_simd_usable())) { 89 kernel_neon_begin(); 90 simd_update(blocks, dg, src, key, head); 91 kernel_neon_end(); 92 } else { 93 be128 dst = { cpu_to_be64(dg[1]), cpu_to_be64(dg[0]) }; 94 95 do { 96 const u8 *in = src; 97 98 if (head) { 99 in = head; 100 blocks++; 101 head = NULL; 102 } else { 103 src += GHASH_BLOCK_SIZE; 104 } 105 106 crypto_xor((u8 *)&dst, in, GHASH_BLOCK_SIZE); 107 gf128mul_lle(&dst, &key->k); 108 } while (--blocks); 109 110 dg[0] = be64_to_cpu(dst.b); 111 dg[1] = be64_to_cpu(dst.a); 112 } 113 } 114 115 /* avoid hogging the CPU for too long */ 116 #define MAX_BLOCKS (SZ_64K / GHASH_BLOCK_SIZE) 117 118 static int __ghash_update(struct shash_desc *desc, const u8 *src, 119 unsigned int len, 120 void (*simd_update)(int blocks, u64 dg[], 121 const char *src, 122 struct ghash_key const *k, 123 const char *head)) 124 { 125 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 126 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 127 128 ctx->count += len; 129 130 if ((partial + len) >= GHASH_BLOCK_SIZE) { 131 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 132 int blocks; 133 134 if (partial) { 135 int p = GHASH_BLOCK_SIZE - partial; 136 137 memcpy(ctx->buf + partial, src, p); 138 src += p; 139 len -= p; 140 } 141 142 blocks = len / GHASH_BLOCK_SIZE; 143 len %= GHASH_BLOCK_SIZE; 144 145 do { 146 int chunk = min(blocks, MAX_BLOCKS); 147 148 ghash_do_update(chunk, ctx->digest, src, key, 149 partial ? ctx->buf : NULL, 150 simd_update); 151 152 blocks -= chunk; 153 src += chunk * GHASH_BLOCK_SIZE; 154 partial = 0; 155 } while (unlikely(blocks > 0)); 156 } 157 if (len) 158 memcpy(ctx->buf + partial, src, len); 159 return 0; 160 } 161 162 static int ghash_update_p8(struct shash_desc *desc, const u8 *src, 163 unsigned int len) 164 { 165 return __ghash_update(desc, src, len, pmull_ghash_update_p8); 166 } 167 168 static int ghash_update_p64(struct shash_desc *desc, const u8 *src, 169 unsigned int len) 170 { 171 return __ghash_update(desc, src, len, pmull_ghash_update_p64); 172 } 173 174 static int ghash_final_p8(struct shash_desc *desc, u8 *dst) 175 { 176 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 177 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 178 179 if (partial) { 180 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 181 182 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial); 183 184 ghash_do_update(1, ctx->digest, ctx->buf, key, NULL, 185 pmull_ghash_update_p8); 186 } 187 put_unaligned_be64(ctx->digest[1], dst); 188 put_unaligned_be64(ctx->digest[0], dst + 8); 189 190 *ctx = (struct ghash_desc_ctx){}; 191 return 0; 192 } 193 194 static int ghash_final_p64(struct shash_desc *desc, u8 *dst) 195 { 196 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 197 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 198 199 if (partial) { 200 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 201 202 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial); 203 204 ghash_do_update(1, ctx->digest, ctx->buf, key, NULL, 205 pmull_ghash_update_p64); 206 } 207 put_unaligned_be64(ctx->digest[1], dst); 208 put_unaligned_be64(ctx->digest[0], dst + 8); 209 210 *ctx = (struct ghash_desc_ctx){}; 211 return 0; 212 } 213 214 static void ghash_reflect(u64 h[], const be128 *k) 215 { 216 u64 carry = be64_to_cpu(k->a) & BIT(63) ? 1 : 0; 217 218 h[0] = (be64_to_cpu(k->b) << 1) | carry; 219 h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63); 220 221 if (carry) 222 h[1] ^= 0xc200000000000000UL; 223 } 224 225 static int __ghash_setkey(struct ghash_key *key, 226 const u8 *inkey, unsigned int keylen) 227 { 228 be128 h; 229 230 /* needed for the fallback */ 231 memcpy(&key->k, inkey, GHASH_BLOCK_SIZE); 232 233 ghash_reflect(key->h, &key->k); 234 235 h = key->k; 236 gf128mul_lle(&h, &key->k); 237 ghash_reflect(key->h2, &h); 238 239 gf128mul_lle(&h, &key->k); 240 ghash_reflect(key->h3, &h); 241 242 gf128mul_lle(&h, &key->k); 243 ghash_reflect(key->h4, &h); 244 245 return 0; 246 } 247 248 static int ghash_setkey(struct crypto_shash *tfm, 249 const u8 *inkey, unsigned int keylen) 250 { 251 struct ghash_key *key = crypto_shash_ctx(tfm); 252 253 if (keylen != GHASH_BLOCK_SIZE) { 254 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 255 return -EINVAL; 256 } 257 258 return __ghash_setkey(key, inkey, keylen); 259 } 260 261 static struct shash_alg ghash_alg[] = {{ 262 .base.cra_name = "ghash", 263 .base.cra_driver_name = "ghash-neon", 264 .base.cra_priority = 100, 265 .base.cra_blocksize = GHASH_BLOCK_SIZE, 266 .base.cra_ctxsize = sizeof(struct ghash_key), 267 .base.cra_module = THIS_MODULE, 268 269 .digestsize = GHASH_DIGEST_SIZE, 270 .init = ghash_init, 271 .update = ghash_update_p8, 272 .final = ghash_final_p8, 273 .setkey = ghash_setkey, 274 .descsize = sizeof(struct ghash_desc_ctx), 275 }, { 276 .base.cra_name = "ghash", 277 .base.cra_driver_name = "ghash-ce", 278 .base.cra_priority = 200, 279 .base.cra_blocksize = GHASH_BLOCK_SIZE, 280 .base.cra_ctxsize = sizeof(struct ghash_key), 281 .base.cra_module = THIS_MODULE, 282 283 .digestsize = GHASH_DIGEST_SIZE, 284 .init = ghash_init, 285 .update = ghash_update_p64, 286 .final = ghash_final_p64, 287 .setkey = ghash_setkey, 288 .descsize = sizeof(struct ghash_desc_ctx), 289 }}; 290 291 static int num_rounds(struct crypto_aes_ctx *ctx) 292 { 293 /* 294 * # of rounds specified by AES: 295 * 128 bit key 10 rounds 296 * 192 bit key 12 rounds 297 * 256 bit key 14 rounds 298 * => n byte key => 6 + (n/4) rounds 299 */ 300 return 6 + ctx->key_length / 4; 301 } 302 303 static int gcm_setkey(struct crypto_aead *tfm, const u8 *inkey, 304 unsigned int keylen) 305 { 306 struct gcm_aes_ctx *ctx = crypto_aead_ctx(tfm); 307 u8 key[GHASH_BLOCK_SIZE]; 308 int ret; 309 310 ret = aes_expandkey(&ctx->aes_key, inkey, keylen); 311 if (ret) { 312 tfm->base.crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; 313 return -EINVAL; 314 } 315 316 aes_encrypt(&ctx->aes_key, key, (u8[AES_BLOCK_SIZE]){}); 317 318 return __ghash_setkey(&ctx->ghash_key, key, sizeof(be128)); 319 } 320 321 static int gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize) 322 { 323 switch (authsize) { 324 case 4: 325 case 8: 326 case 12 ... 16: 327 break; 328 default: 329 return -EINVAL; 330 } 331 return 0; 332 } 333 334 static void gcm_update_mac(u64 dg[], const u8 *src, int count, u8 buf[], 335 int *buf_count, struct gcm_aes_ctx *ctx) 336 { 337 if (*buf_count > 0) { 338 int buf_added = min(count, GHASH_BLOCK_SIZE - *buf_count); 339 340 memcpy(&buf[*buf_count], src, buf_added); 341 342 *buf_count += buf_added; 343 src += buf_added; 344 count -= buf_added; 345 } 346 347 if (count >= GHASH_BLOCK_SIZE || *buf_count == GHASH_BLOCK_SIZE) { 348 int blocks = count / GHASH_BLOCK_SIZE; 349 350 ghash_do_update(blocks, dg, src, &ctx->ghash_key, 351 *buf_count ? buf : NULL, 352 pmull_ghash_update_p64); 353 354 src += blocks * GHASH_BLOCK_SIZE; 355 count %= GHASH_BLOCK_SIZE; 356 *buf_count = 0; 357 } 358 359 if (count > 0) { 360 memcpy(buf, src, count); 361 *buf_count = count; 362 } 363 } 364 365 static void gcm_calculate_auth_mac(struct aead_request *req, u64 dg[]) 366 { 367 struct crypto_aead *aead = crypto_aead_reqtfm(req); 368 struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); 369 u8 buf[GHASH_BLOCK_SIZE]; 370 struct scatter_walk walk; 371 u32 len = req->assoclen; 372 int buf_count = 0; 373 374 scatterwalk_start(&walk, req->src); 375 376 do { 377 u32 n = scatterwalk_clamp(&walk, len); 378 u8 *p; 379 380 if (!n) { 381 scatterwalk_start(&walk, sg_next(walk.sg)); 382 n = scatterwalk_clamp(&walk, len); 383 } 384 p = scatterwalk_map(&walk); 385 386 gcm_update_mac(dg, p, n, buf, &buf_count, ctx); 387 len -= n; 388 389 scatterwalk_unmap(p); 390 scatterwalk_advance(&walk, n); 391 scatterwalk_done(&walk, 0, len); 392 } while (len); 393 394 if (buf_count) { 395 memset(&buf[buf_count], 0, GHASH_BLOCK_SIZE - buf_count); 396 ghash_do_update(1, dg, buf, &ctx->ghash_key, NULL, 397 pmull_ghash_update_p64); 398 } 399 } 400 401 static void gcm_final(struct aead_request *req, struct gcm_aes_ctx *ctx, 402 u64 dg[], u8 tag[], int cryptlen) 403 { 404 u8 mac[AES_BLOCK_SIZE]; 405 u128 lengths; 406 407 lengths.a = cpu_to_be64(req->assoclen * 8); 408 lengths.b = cpu_to_be64(cryptlen * 8); 409 410 ghash_do_update(1, dg, (void *)&lengths, &ctx->ghash_key, NULL, 411 pmull_ghash_update_p64); 412 413 put_unaligned_be64(dg[1], mac); 414 put_unaligned_be64(dg[0], mac + 8); 415 416 crypto_xor(tag, mac, AES_BLOCK_SIZE); 417 } 418 419 static int gcm_encrypt(struct aead_request *req) 420 { 421 struct crypto_aead *aead = crypto_aead_reqtfm(req); 422 struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); 423 struct skcipher_walk walk; 424 u8 iv[AES_BLOCK_SIZE]; 425 u8 ks[2 * AES_BLOCK_SIZE]; 426 u8 tag[AES_BLOCK_SIZE]; 427 u64 dg[2] = {}; 428 int nrounds = num_rounds(&ctx->aes_key); 429 int err; 430 431 if (req->assoclen) 432 gcm_calculate_auth_mac(req, dg); 433 434 memcpy(iv, req->iv, GCM_IV_SIZE); 435 put_unaligned_be32(1, iv + GCM_IV_SIZE); 436 437 err = skcipher_walk_aead_encrypt(&walk, req, false); 438 439 if (likely(crypto_simd_usable() && walk.total >= 2 * AES_BLOCK_SIZE)) { 440 u32 const *rk = NULL; 441 442 kernel_neon_begin(); 443 pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc, nrounds); 444 put_unaligned_be32(2, iv + GCM_IV_SIZE); 445 pmull_gcm_encrypt_block(ks, iv, NULL, nrounds); 446 put_unaligned_be32(3, iv + GCM_IV_SIZE); 447 pmull_gcm_encrypt_block(ks + AES_BLOCK_SIZE, iv, NULL, nrounds); 448 put_unaligned_be32(4, iv + GCM_IV_SIZE); 449 450 do { 451 int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; 452 453 if (rk) 454 kernel_neon_begin(); 455 456 pmull_gcm_encrypt(blocks, dg, walk.dst.virt.addr, 457 walk.src.virt.addr, &ctx->ghash_key, 458 iv, rk, nrounds, ks); 459 kernel_neon_end(); 460 461 err = skcipher_walk_done(&walk, 462 walk.nbytes % (2 * AES_BLOCK_SIZE)); 463 464 rk = ctx->aes_key.key_enc; 465 } while (walk.nbytes >= 2 * AES_BLOCK_SIZE); 466 } else { 467 aes_encrypt(&ctx->aes_key, tag, iv); 468 put_unaligned_be32(2, iv + GCM_IV_SIZE); 469 470 while (walk.nbytes >= (2 * AES_BLOCK_SIZE)) { 471 const int blocks = 472 walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; 473 u8 *dst = walk.dst.virt.addr; 474 u8 *src = walk.src.virt.addr; 475 int remaining = blocks; 476 477 do { 478 aes_encrypt(&ctx->aes_key, ks, iv); 479 crypto_xor_cpy(dst, src, ks, AES_BLOCK_SIZE); 480 crypto_inc(iv, AES_BLOCK_SIZE); 481 482 dst += AES_BLOCK_SIZE; 483 src += AES_BLOCK_SIZE; 484 } while (--remaining > 0); 485 486 ghash_do_update(blocks, dg, 487 walk.dst.virt.addr, &ctx->ghash_key, 488 NULL, pmull_ghash_update_p64); 489 490 err = skcipher_walk_done(&walk, 491 walk.nbytes % (2 * AES_BLOCK_SIZE)); 492 } 493 if (walk.nbytes) { 494 aes_encrypt(&ctx->aes_key, ks, iv); 495 if (walk.nbytes > AES_BLOCK_SIZE) { 496 crypto_inc(iv, AES_BLOCK_SIZE); 497 aes_encrypt(&ctx->aes_key, ks + AES_BLOCK_SIZE, iv); 498 } 499 } 500 } 501 502 /* handle the tail */ 503 if (walk.nbytes) { 504 u8 buf[GHASH_BLOCK_SIZE]; 505 unsigned int nbytes = walk.nbytes; 506 u8 *dst = walk.dst.virt.addr; 507 u8 *head = NULL; 508 509 crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, ks, 510 walk.nbytes); 511 512 if (walk.nbytes > GHASH_BLOCK_SIZE) { 513 head = dst; 514 dst += GHASH_BLOCK_SIZE; 515 nbytes %= GHASH_BLOCK_SIZE; 516 } 517 518 memcpy(buf, dst, nbytes); 519 memset(buf + nbytes, 0, GHASH_BLOCK_SIZE - nbytes); 520 ghash_do_update(!!nbytes, dg, buf, &ctx->ghash_key, head, 521 pmull_ghash_update_p64); 522 523 err = skcipher_walk_done(&walk, 0); 524 } 525 526 if (err) 527 return err; 528 529 gcm_final(req, ctx, dg, tag, req->cryptlen); 530 531 /* copy authtag to end of dst */ 532 scatterwalk_map_and_copy(tag, req->dst, req->assoclen + req->cryptlen, 533 crypto_aead_authsize(aead), 1); 534 535 return 0; 536 } 537 538 static int gcm_decrypt(struct aead_request *req) 539 { 540 struct crypto_aead *aead = crypto_aead_reqtfm(req); 541 struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); 542 unsigned int authsize = crypto_aead_authsize(aead); 543 struct skcipher_walk walk; 544 u8 iv[2 * AES_BLOCK_SIZE]; 545 u8 tag[AES_BLOCK_SIZE]; 546 u8 buf[2 * GHASH_BLOCK_SIZE]; 547 u64 dg[2] = {}; 548 int nrounds = num_rounds(&ctx->aes_key); 549 int err; 550 551 if (req->assoclen) 552 gcm_calculate_auth_mac(req, dg); 553 554 memcpy(iv, req->iv, GCM_IV_SIZE); 555 put_unaligned_be32(1, iv + GCM_IV_SIZE); 556 557 err = skcipher_walk_aead_decrypt(&walk, req, false); 558 559 if (likely(crypto_simd_usable() && walk.total >= 2 * AES_BLOCK_SIZE)) { 560 u32 const *rk = NULL; 561 562 kernel_neon_begin(); 563 pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc, nrounds); 564 put_unaligned_be32(2, iv + GCM_IV_SIZE); 565 566 do { 567 int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; 568 int rem = walk.total - blocks * AES_BLOCK_SIZE; 569 570 if (rk) 571 kernel_neon_begin(); 572 573 pmull_gcm_decrypt(blocks, dg, walk.dst.virt.addr, 574 walk.src.virt.addr, &ctx->ghash_key, 575 iv, rk, nrounds); 576 577 /* check if this is the final iteration of the loop */ 578 if (rem < (2 * AES_BLOCK_SIZE)) { 579 u8 *iv2 = iv + AES_BLOCK_SIZE; 580 581 if (rem > AES_BLOCK_SIZE) { 582 memcpy(iv2, iv, AES_BLOCK_SIZE); 583 crypto_inc(iv2, AES_BLOCK_SIZE); 584 } 585 586 pmull_gcm_encrypt_block(iv, iv, NULL, nrounds); 587 588 if (rem > AES_BLOCK_SIZE) 589 pmull_gcm_encrypt_block(iv2, iv2, NULL, 590 nrounds); 591 } 592 593 kernel_neon_end(); 594 595 err = skcipher_walk_done(&walk, 596 walk.nbytes % (2 * AES_BLOCK_SIZE)); 597 598 rk = ctx->aes_key.key_enc; 599 } while (walk.nbytes >= 2 * AES_BLOCK_SIZE); 600 } else { 601 aes_encrypt(&ctx->aes_key, tag, iv); 602 put_unaligned_be32(2, iv + GCM_IV_SIZE); 603 604 while (walk.nbytes >= (2 * AES_BLOCK_SIZE)) { 605 int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; 606 u8 *dst = walk.dst.virt.addr; 607 u8 *src = walk.src.virt.addr; 608 609 ghash_do_update(blocks, dg, walk.src.virt.addr, 610 &ctx->ghash_key, NULL, 611 pmull_ghash_update_p64); 612 613 do { 614 aes_encrypt(&ctx->aes_key, buf, iv); 615 crypto_xor_cpy(dst, src, buf, AES_BLOCK_SIZE); 616 crypto_inc(iv, AES_BLOCK_SIZE); 617 618 dst += AES_BLOCK_SIZE; 619 src += AES_BLOCK_SIZE; 620 } while (--blocks > 0); 621 622 err = skcipher_walk_done(&walk, 623 walk.nbytes % (2 * AES_BLOCK_SIZE)); 624 } 625 if (walk.nbytes) { 626 if (walk.nbytes > AES_BLOCK_SIZE) { 627 u8 *iv2 = iv + AES_BLOCK_SIZE; 628 629 memcpy(iv2, iv, AES_BLOCK_SIZE); 630 crypto_inc(iv2, AES_BLOCK_SIZE); 631 632 aes_encrypt(&ctx->aes_key, iv2, iv2); 633 } 634 aes_encrypt(&ctx->aes_key, iv, iv); 635 } 636 } 637 638 /* handle the tail */ 639 if (walk.nbytes) { 640 const u8 *src = walk.src.virt.addr; 641 const u8 *head = NULL; 642 unsigned int nbytes = walk.nbytes; 643 644 if (walk.nbytes > GHASH_BLOCK_SIZE) { 645 head = src; 646 src += GHASH_BLOCK_SIZE; 647 nbytes %= GHASH_BLOCK_SIZE; 648 } 649 650 memcpy(buf, src, nbytes); 651 memset(buf + nbytes, 0, GHASH_BLOCK_SIZE - nbytes); 652 ghash_do_update(!!nbytes, dg, buf, &ctx->ghash_key, head, 653 pmull_ghash_update_p64); 654 655 crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, iv, 656 walk.nbytes); 657 658 err = skcipher_walk_done(&walk, 0); 659 } 660 661 if (err) 662 return err; 663 664 gcm_final(req, ctx, dg, tag, req->cryptlen - authsize); 665 666 /* compare calculated auth tag with the stored one */ 667 scatterwalk_map_and_copy(buf, req->src, 668 req->assoclen + req->cryptlen - authsize, 669 authsize, 0); 670 671 if (crypto_memneq(tag, buf, authsize)) 672 return -EBADMSG; 673 return 0; 674 } 675 676 static struct aead_alg gcm_aes_alg = { 677 .ivsize = GCM_IV_SIZE, 678 .chunksize = 2 * AES_BLOCK_SIZE, 679 .maxauthsize = AES_BLOCK_SIZE, 680 .setkey = gcm_setkey, 681 .setauthsize = gcm_setauthsize, 682 .encrypt = gcm_encrypt, 683 .decrypt = gcm_decrypt, 684 685 .base.cra_name = "gcm(aes)", 686 .base.cra_driver_name = "gcm-aes-ce", 687 .base.cra_priority = 300, 688 .base.cra_blocksize = 1, 689 .base.cra_ctxsize = sizeof(struct gcm_aes_ctx), 690 .base.cra_module = THIS_MODULE, 691 }; 692 693 static int __init ghash_ce_mod_init(void) 694 { 695 int ret; 696 697 if (!cpu_have_named_feature(ASIMD)) 698 return -ENODEV; 699 700 if (cpu_have_named_feature(PMULL)) 701 ret = crypto_register_shashes(ghash_alg, 702 ARRAY_SIZE(ghash_alg)); 703 else 704 /* only register the first array element */ 705 ret = crypto_register_shash(ghash_alg); 706 707 if (ret) 708 return ret; 709 710 if (cpu_have_named_feature(PMULL)) { 711 ret = crypto_register_aead(&gcm_aes_alg); 712 if (ret) 713 crypto_unregister_shashes(ghash_alg, 714 ARRAY_SIZE(ghash_alg)); 715 } 716 return ret; 717 } 718 719 static void __exit ghash_ce_mod_exit(void) 720 { 721 if (cpu_have_named_feature(PMULL)) 722 crypto_unregister_shashes(ghash_alg, ARRAY_SIZE(ghash_alg)); 723 else 724 crypto_unregister_shash(ghash_alg); 725 crypto_unregister_aead(&gcm_aes_alg); 726 } 727 728 static const struct cpu_feature ghash_cpu_feature[] = { 729 { cpu_feature(PMULL) }, { } 730 }; 731 MODULE_DEVICE_TABLE(cpu, ghash_cpu_feature); 732 733 module_init(ghash_ce_mod_init); 734 module_exit(ghash_ce_mod_exit); 735