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 asmlinkage void __aes_arm64_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds); 74 75 static int ghash_init(struct shash_desc *desc) 76 { 77 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 78 79 *ctx = (struct ghash_desc_ctx){}; 80 return 0; 81 } 82 83 static void ghash_do_update(int blocks, u64 dg[], const char *src, 84 struct ghash_key *key, const char *head, 85 void (*simd_update)(int blocks, u64 dg[], 86 const char *src, 87 struct ghash_key const *k, 88 const char *head)) 89 { 90 if (likely(crypto_simd_usable())) { 91 kernel_neon_begin(); 92 simd_update(blocks, dg, src, key, head); 93 kernel_neon_end(); 94 } else { 95 be128 dst = { cpu_to_be64(dg[1]), cpu_to_be64(dg[0]) }; 96 97 do { 98 const u8 *in = src; 99 100 if (head) { 101 in = head; 102 blocks++; 103 head = NULL; 104 } else { 105 src += GHASH_BLOCK_SIZE; 106 } 107 108 crypto_xor((u8 *)&dst, in, GHASH_BLOCK_SIZE); 109 gf128mul_lle(&dst, &key->k); 110 } while (--blocks); 111 112 dg[0] = be64_to_cpu(dst.b); 113 dg[1] = be64_to_cpu(dst.a); 114 } 115 } 116 117 /* avoid hogging the CPU for too long */ 118 #define MAX_BLOCKS (SZ_64K / GHASH_BLOCK_SIZE) 119 120 static int __ghash_update(struct shash_desc *desc, const u8 *src, 121 unsigned int len, 122 void (*simd_update)(int blocks, u64 dg[], 123 const char *src, 124 struct ghash_key const *k, 125 const char *head)) 126 { 127 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 128 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 129 130 ctx->count += len; 131 132 if ((partial + len) >= GHASH_BLOCK_SIZE) { 133 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 134 int blocks; 135 136 if (partial) { 137 int p = GHASH_BLOCK_SIZE - partial; 138 139 memcpy(ctx->buf + partial, src, p); 140 src += p; 141 len -= p; 142 } 143 144 blocks = len / GHASH_BLOCK_SIZE; 145 len %= GHASH_BLOCK_SIZE; 146 147 do { 148 int chunk = min(blocks, MAX_BLOCKS); 149 150 ghash_do_update(chunk, ctx->digest, src, key, 151 partial ? ctx->buf : NULL, 152 simd_update); 153 154 blocks -= chunk; 155 src += chunk * GHASH_BLOCK_SIZE; 156 partial = 0; 157 } while (unlikely(blocks > 0)); 158 } 159 if (len) 160 memcpy(ctx->buf + partial, src, len); 161 return 0; 162 } 163 164 static int ghash_update_p8(struct shash_desc *desc, const u8 *src, 165 unsigned int len) 166 { 167 return __ghash_update(desc, src, len, pmull_ghash_update_p8); 168 } 169 170 static int ghash_update_p64(struct shash_desc *desc, const u8 *src, 171 unsigned int len) 172 { 173 return __ghash_update(desc, src, len, pmull_ghash_update_p64); 174 } 175 176 static int ghash_final_p8(struct shash_desc *desc, u8 *dst) 177 { 178 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 179 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 180 181 if (partial) { 182 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 183 184 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial); 185 186 ghash_do_update(1, ctx->digest, ctx->buf, key, NULL, 187 pmull_ghash_update_p8); 188 } 189 put_unaligned_be64(ctx->digest[1], dst); 190 put_unaligned_be64(ctx->digest[0], dst + 8); 191 192 *ctx = (struct ghash_desc_ctx){}; 193 return 0; 194 } 195 196 static int ghash_final_p64(struct shash_desc *desc, u8 *dst) 197 { 198 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 199 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 200 201 if (partial) { 202 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 203 204 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial); 205 206 ghash_do_update(1, ctx->digest, ctx->buf, key, NULL, 207 pmull_ghash_update_p64); 208 } 209 put_unaligned_be64(ctx->digest[1], dst); 210 put_unaligned_be64(ctx->digest[0], dst + 8); 211 212 *ctx = (struct ghash_desc_ctx){}; 213 return 0; 214 } 215 216 static void ghash_reflect(u64 h[], const be128 *k) 217 { 218 u64 carry = be64_to_cpu(k->a) & BIT(63) ? 1 : 0; 219 220 h[0] = (be64_to_cpu(k->b) << 1) | carry; 221 h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63); 222 223 if (carry) 224 h[1] ^= 0xc200000000000000UL; 225 } 226 227 static int __ghash_setkey(struct ghash_key *key, 228 const u8 *inkey, unsigned int keylen) 229 { 230 be128 h; 231 232 /* needed for the fallback */ 233 memcpy(&key->k, inkey, GHASH_BLOCK_SIZE); 234 235 ghash_reflect(key->h, &key->k); 236 237 h = key->k; 238 gf128mul_lle(&h, &key->k); 239 ghash_reflect(key->h2, &h); 240 241 gf128mul_lle(&h, &key->k); 242 ghash_reflect(key->h3, &h); 243 244 gf128mul_lle(&h, &key->k); 245 ghash_reflect(key->h4, &h); 246 247 return 0; 248 } 249 250 static int ghash_setkey(struct crypto_shash *tfm, 251 const u8 *inkey, unsigned int keylen) 252 { 253 struct ghash_key *key = crypto_shash_ctx(tfm); 254 255 if (keylen != GHASH_BLOCK_SIZE) { 256 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 257 return -EINVAL; 258 } 259 260 return __ghash_setkey(key, inkey, keylen); 261 } 262 263 static struct shash_alg ghash_alg[] = {{ 264 .base.cra_name = "ghash", 265 .base.cra_driver_name = "ghash-neon", 266 .base.cra_priority = 100, 267 .base.cra_blocksize = GHASH_BLOCK_SIZE, 268 .base.cra_ctxsize = sizeof(struct ghash_key), 269 .base.cra_module = THIS_MODULE, 270 271 .digestsize = GHASH_DIGEST_SIZE, 272 .init = ghash_init, 273 .update = ghash_update_p8, 274 .final = ghash_final_p8, 275 .setkey = ghash_setkey, 276 .descsize = sizeof(struct ghash_desc_ctx), 277 }, { 278 .base.cra_name = "ghash", 279 .base.cra_driver_name = "ghash-ce", 280 .base.cra_priority = 200, 281 .base.cra_blocksize = GHASH_BLOCK_SIZE, 282 .base.cra_ctxsize = sizeof(struct ghash_key), 283 .base.cra_module = THIS_MODULE, 284 285 .digestsize = GHASH_DIGEST_SIZE, 286 .init = ghash_init, 287 .update = ghash_update_p64, 288 .final = ghash_final_p64, 289 .setkey = ghash_setkey, 290 .descsize = sizeof(struct ghash_desc_ctx), 291 }}; 292 293 static int num_rounds(struct crypto_aes_ctx *ctx) 294 { 295 /* 296 * # of rounds specified by AES: 297 * 128 bit key 10 rounds 298 * 192 bit key 12 rounds 299 * 256 bit key 14 rounds 300 * => n byte key => 6 + (n/4) rounds 301 */ 302 return 6 + ctx->key_length / 4; 303 } 304 305 static int gcm_setkey(struct crypto_aead *tfm, const u8 *inkey, 306 unsigned int keylen) 307 { 308 struct gcm_aes_ctx *ctx = crypto_aead_ctx(tfm); 309 u8 key[GHASH_BLOCK_SIZE]; 310 int ret; 311 312 ret = crypto_aes_expand_key(&ctx->aes_key, inkey, keylen); 313 if (ret) { 314 tfm->base.crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; 315 return -EINVAL; 316 } 317 318 __aes_arm64_encrypt(ctx->aes_key.key_enc, key, (u8[AES_BLOCK_SIZE]){}, 319 num_rounds(&ctx->aes_key)); 320 321 return __ghash_setkey(&ctx->ghash_key, key, sizeof(be128)); 322 } 323 324 static int gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize) 325 { 326 switch (authsize) { 327 case 4: 328 case 8: 329 case 12 ... 16: 330 break; 331 default: 332 return -EINVAL; 333 } 334 return 0; 335 } 336 337 static void gcm_update_mac(u64 dg[], const u8 *src, int count, u8 buf[], 338 int *buf_count, struct gcm_aes_ctx *ctx) 339 { 340 if (*buf_count > 0) { 341 int buf_added = min(count, GHASH_BLOCK_SIZE - *buf_count); 342 343 memcpy(&buf[*buf_count], src, buf_added); 344 345 *buf_count += buf_added; 346 src += buf_added; 347 count -= buf_added; 348 } 349 350 if (count >= GHASH_BLOCK_SIZE || *buf_count == GHASH_BLOCK_SIZE) { 351 int blocks = count / GHASH_BLOCK_SIZE; 352 353 ghash_do_update(blocks, dg, src, &ctx->ghash_key, 354 *buf_count ? buf : NULL, 355 pmull_ghash_update_p64); 356 357 src += blocks * GHASH_BLOCK_SIZE; 358 count %= GHASH_BLOCK_SIZE; 359 *buf_count = 0; 360 } 361 362 if (count > 0) { 363 memcpy(buf, src, count); 364 *buf_count = count; 365 } 366 } 367 368 static void gcm_calculate_auth_mac(struct aead_request *req, u64 dg[]) 369 { 370 struct crypto_aead *aead = crypto_aead_reqtfm(req); 371 struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); 372 u8 buf[GHASH_BLOCK_SIZE]; 373 struct scatter_walk walk; 374 u32 len = req->assoclen; 375 int buf_count = 0; 376 377 scatterwalk_start(&walk, req->src); 378 379 do { 380 u32 n = scatterwalk_clamp(&walk, len); 381 u8 *p; 382 383 if (!n) { 384 scatterwalk_start(&walk, sg_next(walk.sg)); 385 n = scatterwalk_clamp(&walk, len); 386 } 387 p = scatterwalk_map(&walk); 388 389 gcm_update_mac(dg, p, n, buf, &buf_count, ctx); 390 len -= n; 391 392 scatterwalk_unmap(p); 393 scatterwalk_advance(&walk, n); 394 scatterwalk_done(&walk, 0, len); 395 } while (len); 396 397 if (buf_count) { 398 memset(&buf[buf_count], 0, GHASH_BLOCK_SIZE - buf_count); 399 ghash_do_update(1, dg, buf, &ctx->ghash_key, NULL, 400 pmull_ghash_update_p64); 401 } 402 } 403 404 static void gcm_final(struct aead_request *req, struct gcm_aes_ctx *ctx, 405 u64 dg[], u8 tag[], int cryptlen) 406 { 407 u8 mac[AES_BLOCK_SIZE]; 408 u128 lengths; 409 410 lengths.a = cpu_to_be64(req->assoclen * 8); 411 lengths.b = cpu_to_be64(cryptlen * 8); 412 413 ghash_do_update(1, dg, (void *)&lengths, &ctx->ghash_key, NULL, 414 pmull_ghash_update_p64); 415 416 put_unaligned_be64(dg[1], mac); 417 put_unaligned_be64(dg[0], mac + 8); 418 419 crypto_xor(tag, mac, AES_BLOCK_SIZE); 420 } 421 422 static int gcm_encrypt(struct aead_request *req) 423 { 424 struct crypto_aead *aead = crypto_aead_reqtfm(req); 425 struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); 426 struct skcipher_walk walk; 427 u8 iv[AES_BLOCK_SIZE]; 428 u8 ks[2 * AES_BLOCK_SIZE]; 429 u8 tag[AES_BLOCK_SIZE]; 430 u64 dg[2] = {}; 431 int nrounds = num_rounds(&ctx->aes_key); 432 int err; 433 434 if (req->assoclen) 435 gcm_calculate_auth_mac(req, dg); 436 437 memcpy(iv, req->iv, GCM_IV_SIZE); 438 put_unaligned_be32(1, iv + GCM_IV_SIZE); 439 440 err = skcipher_walk_aead_encrypt(&walk, req, false); 441 442 if (likely(crypto_simd_usable() && walk.total >= 2 * AES_BLOCK_SIZE)) { 443 u32 const *rk = NULL; 444 445 kernel_neon_begin(); 446 pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc, nrounds); 447 put_unaligned_be32(2, iv + GCM_IV_SIZE); 448 pmull_gcm_encrypt_block(ks, iv, NULL, nrounds); 449 put_unaligned_be32(3, iv + GCM_IV_SIZE); 450 pmull_gcm_encrypt_block(ks + AES_BLOCK_SIZE, iv, NULL, nrounds); 451 put_unaligned_be32(4, iv + GCM_IV_SIZE); 452 453 do { 454 int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; 455 456 if (rk) 457 kernel_neon_begin(); 458 459 pmull_gcm_encrypt(blocks, dg, walk.dst.virt.addr, 460 walk.src.virt.addr, &ctx->ghash_key, 461 iv, rk, nrounds, ks); 462 kernel_neon_end(); 463 464 err = skcipher_walk_done(&walk, 465 walk.nbytes % (2 * AES_BLOCK_SIZE)); 466 467 rk = ctx->aes_key.key_enc; 468 } while (walk.nbytes >= 2 * AES_BLOCK_SIZE); 469 } else { 470 __aes_arm64_encrypt(ctx->aes_key.key_enc, tag, iv, nrounds); 471 put_unaligned_be32(2, iv + GCM_IV_SIZE); 472 473 while (walk.nbytes >= (2 * AES_BLOCK_SIZE)) { 474 const int blocks = 475 walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; 476 u8 *dst = walk.dst.virt.addr; 477 u8 *src = walk.src.virt.addr; 478 int remaining = blocks; 479 480 do { 481 __aes_arm64_encrypt(ctx->aes_key.key_enc, 482 ks, iv, nrounds); 483 crypto_xor_cpy(dst, src, ks, AES_BLOCK_SIZE); 484 crypto_inc(iv, AES_BLOCK_SIZE); 485 486 dst += AES_BLOCK_SIZE; 487 src += AES_BLOCK_SIZE; 488 } while (--remaining > 0); 489 490 ghash_do_update(blocks, dg, 491 walk.dst.virt.addr, &ctx->ghash_key, 492 NULL, pmull_ghash_update_p64); 493 494 err = skcipher_walk_done(&walk, 495 walk.nbytes % (2 * AES_BLOCK_SIZE)); 496 } 497 if (walk.nbytes) { 498 __aes_arm64_encrypt(ctx->aes_key.key_enc, ks, iv, 499 nrounds); 500 if (walk.nbytes > AES_BLOCK_SIZE) { 501 crypto_inc(iv, AES_BLOCK_SIZE); 502 __aes_arm64_encrypt(ctx->aes_key.key_enc, 503 ks + AES_BLOCK_SIZE, iv, 504 nrounds); 505 } 506 } 507 } 508 509 /* handle the tail */ 510 if (walk.nbytes) { 511 u8 buf[GHASH_BLOCK_SIZE]; 512 unsigned int nbytes = walk.nbytes; 513 u8 *dst = walk.dst.virt.addr; 514 u8 *head = NULL; 515 516 crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, ks, 517 walk.nbytes); 518 519 if (walk.nbytes > GHASH_BLOCK_SIZE) { 520 head = dst; 521 dst += GHASH_BLOCK_SIZE; 522 nbytes %= GHASH_BLOCK_SIZE; 523 } 524 525 memcpy(buf, dst, nbytes); 526 memset(buf + nbytes, 0, GHASH_BLOCK_SIZE - nbytes); 527 ghash_do_update(!!nbytes, dg, buf, &ctx->ghash_key, head, 528 pmull_ghash_update_p64); 529 530 err = skcipher_walk_done(&walk, 0); 531 } 532 533 if (err) 534 return err; 535 536 gcm_final(req, ctx, dg, tag, req->cryptlen); 537 538 /* copy authtag to end of dst */ 539 scatterwalk_map_and_copy(tag, req->dst, req->assoclen + req->cryptlen, 540 crypto_aead_authsize(aead), 1); 541 542 return 0; 543 } 544 545 static int gcm_decrypt(struct aead_request *req) 546 { 547 struct crypto_aead *aead = crypto_aead_reqtfm(req); 548 struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); 549 unsigned int authsize = crypto_aead_authsize(aead); 550 struct skcipher_walk walk; 551 u8 iv[2 * AES_BLOCK_SIZE]; 552 u8 tag[AES_BLOCK_SIZE]; 553 u8 buf[2 * GHASH_BLOCK_SIZE]; 554 u64 dg[2] = {}; 555 int nrounds = num_rounds(&ctx->aes_key); 556 int err; 557 558 if (req->assoclen) 559 gcm_calculate_auth_mac(req, dg); 560 561 memcpy(iv, req->iv, GCM_IV_SIZE); 562 put_unaligned_be32(1, iv + GCM_IV_SIZE); 563 564 err = skcipher_walk_aead_decrypt(&walk, req, false); 565 566 if (likely(crypto_simd_usable() && walk.total >= 2 * AES_BLOCK_SIZE)) { 567 u32 const *rk = NULL; 568 569 kernel_neon_begin(); 570 pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc, nrounds); 571 put_unaligned_be32(2, iv + GCM_IV_SIZE); 572 573 do { 574 int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; 575 int rem = walk.total - blocks * AES_BLOCK_SIZE; 576 577 if (rk) 578 kernel_neon_begin(); 579 580 pmull_gcm_decrypt(blocks, dg, walk.dst.virt.addr, 581 walk.src.virt.addr, &ctx->ghash_key, 582 iv, rk, nrounds); 583 584 /* check if this is the final iteration of the loop */ 585 if (rem < (2 * AES_BLOCK_SIZE)) { 586 u8 *iv2 = iv + AES_BLOCK_SIZE; 587 588 if (rem > AES_BLOCK_SIZE) { 589 memcpy(iv2, iv, AES_BLOCK_SIZE); 590 crypto_inc(iv2, AES_BLOCK_SIZE); 591 } 592 593 pmull_gcm_encrypt_block(iv, iv, NULL, nrounds); 594 595 if (rem > AES_BLOCK_SIZE) 596 pmull_gcm_encrypt_block(iv2, iv2, NULL, 597 nrounds); 598 } 599 600 kernel_neon_end(); 601 602 err = skcipher_walk_done(&walk, 603 walk.nbytes % (2 * AES_BLOCK_SIZE)); 604 605 rk = ctx->aes_key.key_enc; 606 } while (walk.nbytes >= 2 * AES_BLOCK_SIZE); 607 } else { 608 __aes_arm64_encrypt(ctx->aes_key.key_enc, tag, iv, nrounds); 609 put_unaligned_be32(2, iv + GCM_IV_SIZE); 610 611 while (walk.nbytes >= (2 * AES_BLOCK_SIZE)) { 612 int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; 613 u8 *dst = walk.dst.virt.addr; 614 u8 *src = walk.src.virt.addr; 615 616 ghash_do_update(blocks, dg, walk.src.virt.addr, 617 &ctx->ghash_key, NULL, 618 pmull_ghash_update_p64); 619 620 do { 621 __aes_arm64_encrypt(ctx->aes_key.key_enc, 622 buf, iv, nrounds); 623 crypto_xor_cpy(dst, src, buf, AES_BLOCK_SIZE); 624 crypto_inc(iv, AES_BLOCK_SIZE); 625 626 dst += AES_BLOCK_SIZE; 627 src += AES_BLOCK_SIZE; 628 } while (--blocks > 0); 629 630 err = skcipher_walk_done(&walk, 631 walk.nbytes % (2 * AES_BLOCK_SIZE)); 632 } 633 if (walk.nbytes) { 634 if (walk.nbytes > AES_BLOCK_SIZE) { 635 u8 *iv2 = iv + AES_BLOCK_SIZE; 636 637 memcpy(iv2, iv, AES_BLOCK_SIZE); 638 crypto_inc(iv2, AES_BLOCK_SIZE); 639 640 __aes_arm64_encrypt(ctx->aes_key.key_enc, iv2, 641 iv2, nrounds); 642 } 643 __aes_arm64_encrypt(ctx->aes_key.key_enc, iv, iv, 644 nrounds); 645 } 646 } 647 648 /* handle the tail */ 649 if (walk.nbytes) { 650 const u8 *src = walk.src.virt.addr; 651 const u8 *head = NULL; 652 unsigned int nbytes = walk.nbytes; 653 654 if (walk.nbytes > GHASH_BLOCK_SIZE) { 655 head = src; 656 src += GHASH_BLOCK_SIZE; 657 nbytes %= GHASH_BLOCK_SIZE; 658 } 659 660 memcpy(buf, src, nbytes); 661 memset(buf + nbytes, 0, GHASH_BLOCK_SIZE - nbytes); 662 ghash_do_update(!!nbytes, dg, buf, &ctx->ghash_key, head, 663 pmull_ghash_update_p64); 664 665 crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, iv, 666 walk.nbytes); 667 668 err = skcipher_walk_done(&walk, 0); 669 } 670 671 if (err) 672 return err; 673 674 gcm_final(req, ctx, dg, tag, req->cryptlen - authsize); 675 676 /* compare calculated auth tag with the stored one */ 677 scatterwalk_map_and_copy(buf, req->src, 678 req->assoclen + req->cryptlen - authsize, 679 authsize, 0); 680 681 if (crypto_memneq(tag, buf, authsize)) 682 return -EBADMSG; 683 return 0; 684 } 685 686 static struct aead_alg gcm_aes_alg = { 687 .ivsize = GCM_IV_SIZE, 688 .chunksize = 2 * AES_BLOCK_SIZE, 689 .maxauthsize = AES_BLOCK_SIZE, 690 .setkey = gcm_setkey, 691 .setauthsize = gcm_setauthsize, 692 .encrypt = gcm_encrypt, 693 .decrypt = gcm_decrypt, 694 695 .base.cra_name = "gcm(aes)", 696 .base.cra_driver_name = "gcm-aes-ce", 697 .base.cra_priority = 300, 698 .base.cra_blocksize = 1, 699 .base.cra_ctxsize = sizeof(struct gcm_aes_ctx), 700 .base.cra_module = THIS_MODULE, 701 }; 702 703 static int __init ghash_ce_mod_init(void) 704 { 705 int ret; 706 707 if (!cpu_have_named_feature(ASIMD)) 708 return -ENODEV; 709 710 if (cpu_have_named_feature(PMULL)) 711 ret = crypto_register_shashes(ghash_alg, 712 ARRAY_SIZE(ghash_alg)); 713 else 714 /* only register the first array element */ 715 ret = crypto_register_shash(ghash_alg); 716 717 if (ret) 718 return ret; 719 720 if (cpu_have_named_feature(PMULL)) { 721 ret = crypto_register_aead(&gcm_aes_alg); 722 if (ret) 723 crypto_unregister_shashes(ghash_alg, 724 ARRAY_SIZE(ghash_alg)); 725 } 726 return ret; 727 } 728 729 static void __exit ghash_ce_mod_exit(void) 730 { 731 if (cpu_have_named_feature(PMULL)) 732 crypto_unregister_shashes(ghash_alg, ARRAY_SIZE(ghash_alg)); 733 else 734 crypto_unregister_shash(ghash_alg); 735 crypto_unregister_aead(&gcm_aes_alg); 736 } 737 738 static const struct cpu_feature ghash_cpu_feature[] = { 739 { cpu_feature(PMULL) }, { } 740 }; 741 MODULE_DEVICE_TABLE(cpu, ghash_cpu_feature); 742 743 module_init(ghash_ce_mod_init); 744 module_exit(ghash_ce_mod_exit); 745