1 /* 2 * Accelerated GHASH implementation with ARMv8 PMULL instructions. 3 * 4 * Copyright (C) 2014 - 2018 Linaro Ltd. <ard.biesheuvel@linaro.org> 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 version 2 as published 8 * by the Free Software Foundation. 9 */ 10 11 #include <asm/neon.h> 12 #include <asm/simd.h> 13 #include <asm/unaligned.h> 14 #include <crypto/aes.h> 15 #include <crypto/algapi.h> 16 #include <crypto/b128ops.h> 17 #include <crypto/gf128mul.h> 18 #include <crypto/internal/aead.h> 19 #include <crypto/internal/hash.h> 20 #include <crypto/internal/skcipher.h> 21 #include <crypto/scatterwalk.h> 22 #include <linux/cpufeature.h> 23 #include <linux/crypto.h> 24 #include <linux/module.h> 25 26 MODULE_DESCRIPTION("GHASH and AES-GCM using ARMv8 Crypto Extensions"); 27 MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>"); 28 MODULE_LICENSE("GPL v2"); 29 MODULE_ALIAS_CRYPTO("ghash"); 30 31 #define GHASH_BLOCK_SIZE 16 32 #define GHASH_DIGEST_SIZE 16 33 #define GCM_IV_SIZE 12 34 35 struct ghash_key { 36 u64 h[2]; 37 u64 h2[2]; 38 u64 h3[2]; 39 u64 h4[2]; 40 41 be128 k; 42 }; 43 44 struct ghash_desc_ctx { 45 u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)]; 46 u8 buf[GHASH_BLOCK_SIZE]; 47 u32 count; 48 }; 49 50 struct gcm_aes_ctx { 51 struct crypto_aes_ctx aes_key; 52 struct ghash_key ghash_key; 53 }; 54 55 asmlinkage void pmull_ghash_update_p64(int blocks, u64 dg[], const char *src, 56 struct ghash_key const *k, 57 const char *head); 58 59 asmlinkage void pmull_ghash_update_p8(int blocks, u64 dg[], const char *src, 60 struct ghash_key const *k, 61 const char *head); 62 63 asmlinkage void pmull_gcm_encrypt(int blocks, u64 dg[], u8 dst[], 64 const u8 src[], struct ghash_key const *k, 65 u8 ctr[], u32 const rk[], int rounds, 66 u8 ks[]); 67 68 asmlinkage void pmull_gcm_decrypt(int blocks, u64 dg[], u8 dst[], 69 const u8 src[], struct ghash_key const *k, 70 u8 ctr[], u32 const rk[], int rounds); 71 72 asmlinkage void pmull_gcm_encrypt_block(u8 dst[], u8 const src[], 73 u32 const rk[], int rounds); 74 75 asmlinkage void __aes_arm64_encrypt(u32 *rk, u8 *out, const u8 *in, int rounds); 76 77 static int ghash_init(struct shash_desc *desc) 78 { 79 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 80 81 *ctx = (struct ghash_desc_ctx){}; 82 return 0; 83 } 84 85 static void ghash_do_update(int blocks, u64 dg[], const char *src, 86 struct ghash_key *key, const char *head, 87 void (*simd_update)(int blocks, u64 dg[], 88 const char *src, 89 struct ghash_key const *k, 90 const char *head)) 91 { 92 if (likely(may_use_simd())) { 93 kernel_neon_begin(); 94 simd_update(blocks, dg, src, key, head); 95 kernel_neon_end(); 96 } else { 97 be128 dst = { cpu_to_be64(dg[1]), cpu_to_be64(dg[0]) }; 98 99 do { 100 const u8 *in = src; 101 102 if (head) { 103 in = head; 104 blocks++; 105 head = NULL; 106 } else { 107 src += GHASH_BLOCK_SIZE; 108 } 109 110 crypto_xor((u8 *)&dst, in, GHASH_BLOCK_SIZE); 111 gf128mul_lle(&dst, &key->k); 112 } while (--blocks); 113 114 dg[0] = be64_to_cpu(dst.b); 115 dg[1] = be64_to_cpu(dst.a); 116 } 117 } 118 119 /* avoid hogging the CPU for too long */ 120 #define MAX_BLOCKS (SZ_64K / GHASH_BLOCK_SIZE) 121 122 static int __ghash_update(struct shash_desc *desc, const u8 *src, 123 unsigned int len, 124 void (*simd_update)(int blocks, u64 dg[], 125 const char *src, 126 struct ghash_key const *k, 127 const char *head)) 128 { 129 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 130 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 131 132 ctx->count += len; 133 134 if ((partial + len) >= GHASH_BLOCK_SIZE) { 135 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 136 int blocks; 137 138 if (partial) { 139 int p = GHASH_BLOCK_SIZE - partial; 140 141 memcpy(ctx->buf + partial, src, p); 142 src += p; 143 len -= p; 144 } 145 146 blocks = len / GHASH_BLOCK_SIZE; 147 len %= GHASH_BLOCK_SIZE; 148 149 do { 150 int chunk = min(blocks, MAX_BLOCKS); 151 152 ghash_do_update(chunk, ctx->digest, src, key, 153 partial ? ctx->buf : NULL, 154 simd_update); 155 156 blocks -= chunk; 157 src += chunk * GHASH_BLOCK_SIZE; 158 partial = 0; 159 } while (unlikely(blocks > 0)); 160 } 161 if (len) 162 memcpy(ctx->buf + partial, src, len); 163 return 0; 164 } 165 166 static int ghash_update_p8(struct shash_desc *desc, const u8 *src, 167 unsigned int len) 168 { 169 return __ghash_update(desc, src, len, pmull_ghash_update_p8); 170 } 171 172 static int ghash_update_p64(struct shash_desc *desc, const u8 *src, 173 unsigned int len) 174 { 175 return __ghash_update(desc, src, len, pmull_ghash_update_p64); 176 } 177 178 static int ghash_final_p8(struct shash_desc *desc, u8 *dst) 179 { 180 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 181 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 182 183 if (partial) { 184 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 185 186 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial); 187 188 ghash_do_update(1, ctx->digest, ctx->buf, key, NULL, 189 pmull_ghash_update_p8); 190 } 191 put_unaligned_be64(ctx->digest[1], dst); 192 put_unaligned_be64(ctx->digest[0], dst + 8); 193 194 *ctx = (struct ghash_desc_ctx){}; 195 return 0; 196 } 197 198 static int ghash_final_p64(struct shash_desc *desc, u8 *dst) 199 { 200 struct ghash_desc_ctx *ctx = shash_desc_ctx(desc); 201 unsigned int partial = ctx->count % GHASH_BLOCK_SIZE; 202 203 if (partial) { 204 struct ghash_key *key = crypto_shash_ctx(desc->tfm); 205 206 memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial); 207 208 ghash_do_update(1, ctx->digest, ctx->buf, key, NULL, 209 pmull_ghash_update_p64); 210 } 211 put_unaligned_be64(ctx->digest[1], dst); 212 put_unaligned_be64(ctx->digest[0], dst + 8); 213 214 *ctx = (struct ghash_desc_ctx){}; 215 return 0; 216 } 217 218 static void ghash_reflect(u64 h[], const be128 *k) 219 { 220 u64 carry = be64_to_cpu(k->a) & BIT(63) ? 1 : 0; 221 222 h[0] = (be64_to_cpu(k->b) << 1) | carry; 223 h[1] = (be64_to_cpu(k->a) << 1) | (be64_to_cpu(k->b) >> 63); 224 225 if (carry) 226 h[1] ^= 0xc200000000000000UL; 227 } 228 229 static int __ghash_setkey(struct ghash_key *key, 230 const u8 *inkey, unsigned int keylen) 231 { 232 be128 h; 233 234 /* needed for the fallback */ 235 memcpy(&key->k, inkey, GHASH_BLOCK_SIZE); 236 237 ghash_reflect(key->h, &key->k); 238 239 h = key->k; 240 gf128mul_lle(&h, &key->k); 241 ghash_reflect(key->h2, &h); 242 243 gf128mul_lle(&h, &key->k); 244 ghash_reflect(key->h3, &h); 245 246 gf128mul_lle(&h, &key->k); 247 ghash_reflect(key->h4, &h); 248 249 return 0; 250 } 251 252 static int ghash_setkey(struct crypto_shash *tfm, 253 const u8 *inkey, unsigned int keylen) 254 { 255 struct ghash_key *key = crypto_shash_ctx(tfm); 256 257 if (keylen != GHASH_BLOCK_SIZE) { 258 crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 259 return -EINVAL; 260 } 261 262 return __ghash_setkey(key, inkey, keylen); 263 } 264 265 static struct shash_alg ghash_alg[] = {{ 266 .base.cra_name = "ghash", 267 .base.cra_driver_name = "ghash-neon", 268 .base.cra_priority = 100, 269 .base.cra_blocksize = GHASH_BLOCK_SIZE, 270 .base.cra_ctxsize = sizeof(struct ghash_key), 271 .base.cra_module = THIS_MODULE, 272 273 .digestsize = GHASH_DIGEST_SIZE, 274 .init = ghash_init, 275 .update = ghash_update_p8, 276 .final = ghash_final_p8, 277 .setkey = ghash_setkey, 278 .descsize = sizeof(struct ghash_desc_ctx), 279 }, { 280 .base.cra_name = "ghash", 281 .base.cra_driver_name = "ghash-ce", 282 .base.cra_priority = 200, 283 .base.cra_blocksize = GHASH_BLOCK_SIZE, 284 .base.cra_ctxsize = sizeof(struct ghash_key), 285 .base.cra_module = THIS_MODULE, 286 287 .digestsize = GHASH_DIGEST_SIZE, 288 .init = ghash_init, 289 .update = ghash_update_p64, 290 .final = ghash_final_p64, 291 .setkey = ghash_setkey, 292 .descsize = sizeof(struct ghash_desc_ctx), 293 }}; 294 295 static int num_rounds(struct crypto_aes_ctx *ctx) 296 { 297 /* 298 * # of rounds specified by AES: 299 * 128 bit key 10 rounds 300 * 192 bit key 12 rounds 301 * 256 bit key 14 rounds 302 * => n byte key => 6 + (n/4) rounds 303 */ 304 return 6 + ctx->key_length / 4; 305 } 306 307 static int gcm_setkey(struct crypto_aead *tfm, const u8 *inkey, 308 unsigned int keylen) 309 { 310 struct gcm_aes_ctx *ctx = crypto_aead_ctx(tfm); 311 u8 key[GHASH_BLOCK_SIZE]; 312 int ret; 313 314 ret = crypto_aes_expand_key(&ctx->aes_key, inkey, keylen); 315 if (ret) { 316 tfm->base.crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; 317 return -EINVAL; 318 } 319 320 __aes_arm64_encrypt(ctx->aes_key.key_enc, key, (u8[AES_BLOCK_SIZE]){}, 321 num_rounds(&ctx->aes_key)); 322 323 return __ghash_setkey(&ctx->ghash_key, key, sizeof(be128)); 324 } 325 326 static int gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize) 327 { 328 switch (authsize) { 329 case 4: 330 case 8: 331 case 12 ... 16: 332 break; 333 default: 334 return -EINVAL; 335 } 336 return 0; 337 } 338 339 static void gcm_update_mac(u64 dg[], const u8 *src, int count, u8 buf[], 340 int *buf_count, struct gcm_aes_ctx *ctx) 341 { 342 if (*buf_count > 0) { 343 int buf_added = min(count, GHASH_BLOCK_SIZE - *buf_count); 344 345 memcpy(&buf[*buf_count], src, buf_added); 346 347 *buf_count += buf_added; 348 src += buf_added; 349 count -= buf_added; 350 } 351 352 if (count >= GHASH_BLOCK_SIZE || *buf_count == GHASH_BLOCK_SIZE) { 353 int blocks = count / GHASH_BLOCK_SIZE; 354 355 ghash_do_update(blocks, dg, src, &ctx->ghash_key, 356 *buf_count ? buf : NULL, 357 pmull_ghash_update_p64); 358 359 src += blocks * GHASH_BLOCK_SIZE; 360 count %= GHASH_BLOCK_SIZE; 361 *buf_count = 0; 362 } 363 364 if (count > 0) { 365 memcpy(buf, src, count); 366 *buf_count = count; 367 } 368 } 369 370 static void gcm_calculate_auth_mac(struct aead_request *req, u64 dg[]) 371 { 372 struct crypto_aead *aead = crypto_aead_reqtfm(req); 373 struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); 374 u8 buf[GHASH_BLOCK_SIZE]; 375 struct scatter_walk walk; 376 u32 len = req->assoclen; 377 int buf_count = 0; 378 379 scatterwalk_start(&walk, req->src); 380 381 do { 382 u32 n = scatterwalk_clamp(&walk, len); 383 u8 *p; 384 385 if (!n) { 386 scatterwalk_start(&walk, sg_next(walk.sg)); 387 n = scatterwalk_clamp(&walk, len); 388 } 389 p = scatterwalk_map(&walk); 390 391 gcm_update_mac(dg, p, n, buf, &buf_count, ctx); 392 len -= n; 393 394 scatterwalk_unmap(p); 395 scatterwalk_advance(&walk, n); 396 scatterwalk_done(&walk, 0, len); 397 } while (len); 398 399 if (buf_count) { 400 memset(&buf[buf_count], 0, GHASH_BLOCK_SIZE - buf_count); 401 ghash_do_update(1, dg, buf, &ctx->ghash_key, NULL, 402 pmull_ghash_update_p64); 403 } 404 } 405 406 static void gcm_final(struct aead_request *req, struct gcm_aes_ctx *ctx, 407 u64 dg[], u8 tag[], int cryptlen) 408 { 409 u8 mac[AES_BLOCK_SIZE]; 410 u128 lengths; 411 412 lengths.a = cpu_to_be64(req->assoclen * 8); 413 lengths.b = cpu_to_be64(cryptlen * 8); 414 415 ghash_do_update(1, dg, (void *)&lengths, &ctx->ghash_key, NULL, 416 pmull_ghash_update_p64); 417 418 put_unaligned_be64(dg[1], mac); 419 put_unaligned_be64(dg[0], mac + 8); 420 421 crypto_xor(tag, mac, AES_BLOCK_SIZE); 422 } 423 424 static int gcm_encrypt(struct aead_request *req) 425 { 426 struct crypto_aead *aead = crypto_aead_reqtfm(req); 427 struct gcm_aes_ctx *ctx = crypto_aead_ctx(aead); 428 struct skcipher_walk walk; 429 u8 iv[AES_BLOCK_SIZE]; 430 u8 ks[2 * AES_BLOCK_SIZE]; 431 u8 tag[AES_BLOCK_SIZE]; 432 u64 dg[2] = {}; 433 int nrounds = num_rounds(&ctx->aes_key); 434 int err; 435 436 if (req->assoclen) 437 gcm_calculate_auth_mac(req, dg); 438 439 memcpy(iv, req->iv, GCM_IV_SIZE); 440 put_unaligned_be32(1, iv + GCM_IV_SIZE); 441 442 err = skcipher_walk_aead_encrypt(&walk, req, false); 443 444 if (likely(may_use_simd() && walk.total >= 2 * AES_BLOCK_SIZE)) { 445 u32 const *rk = NULL; 446 447 kernel_neon_begin(); 448 pmull_gcm_encrypt_block(tag, iv, ctx->aes_key.key_enc, nrounds); 449 put_unaligned_be32(2, iv + GCM_IV_SIZE); 450 pmull_gcm_encrypt_block(ks, iv, NULL, nrounds); 451 put_unaligned_be32(3, iv + GCM_IV_SIZE); 452 pmull_gcm_encrypt_block(ks + AES_BLOCK_SIZE, iv, NULL, nrounds); 453 put_unaligned_be32(4, iv + GCM_IV_SIZE); 454 455 do { 456 int blocks = walk.nbytes / (2 * AES_BLOCK_SIZE) * 2; 457 458 if (rk) 459 kernel_neon_begin(); 460 461 pmull_gcm_encrypt(blocks, dg, walk.dst.virt.addr, 462 walk.src.virt.addr, &ctx->ghash_key, 463 iv, rk, nrounds, ks); 464 kernel_neon_end(); 465 466 err = skcipher_walk_done(&walk, 467 walk.nbytes % (2 * AES_BLOCK_SIZE)); 468 469 rk = ctx->aes_key.key_enc; 470 } while (walk.nbytes >= 2 * AES_BLOCK_SIZE); 471 } else { 472 __aes_arm64_encrypt(ctx->aes_key.key_enc, tag, iv, nrounds); 473 put_unaligned_be32(2, iv + GCM_IV_SIZE); 474 475 while (walk.nbytes >= (2 * AES_BLOCK_SIZE)) { 476 int blocks = walk.nbytes / AES_BLOCK_SIZE; 477 u8 *dst = walk.dst.virt.addr; 478 u8 *src = walk.src.virt.addr; 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 (--blocks > 0); 489 490 ghash_do_update(walk.nbytes / AES_BLOCK_SIZE, 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(may_use_simd() && 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 / AES_BLOCK_SIZE; 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 (!(elf_hwcap & HWCAP_ASIMD)) 708 return -ENODEV; 709 710 if (elf_hwcap & HWCAP_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 (elf_hwcap & HWCAP_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 (elf_hwcap & HWCAP_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