1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Cryptographic API. 4 * 5 * s390 implementation of the AES Cipher Algorithm. 6 * 7 * s390 Version: 8 * Copyright IBM Corp. 2005, 2017 9 * Author(s): Jan Glauber (jang@de.ibm.com) 10 * Sebastian Siewior (sebastian@breakpoint.cc> SW-Fallback 11 * Patrick Steuer <patrick.steuer@de.ibm.com> 12 * Harald Freudenberger <freude@de.ibm.com> 13 * 14 * Derived from "crypto/aes_generic.c" 15 */ 16 17 #define KMSG_COMPONENT "aes_s390" 18 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 19 20 #include <crypto/aes.h> 21 #include <crypto/algapi.h> 22 #include <crypto/ghash.h> 23 #include <crypto/internal/aead.h> 24 #include <crypto/internal/skcipher.h> 25 #include <crypto/scatterwalk.h> 26 #include <linux/err.h> 27 #include <linux/module.h> 28 #include <linux/cpufeature.h> 29 #include <linux/init.h> 30 #include <linux/spinlock.h> 31 #include <linux/fips.h> 32 #include <linux/string.h> 33 #include <crypto/xts.h> 34 #include <asm/cpacf.h> 35 36 static u8 *ctrblk; 37 static DEFINE_SPINLOCK(ctrblk_lock); 38 39 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions, 40 kma_functions; 41 42 struct s390_aes_ctx { 43 u8 key[AES_MAX_KEY_SIZE]; 44 int key_len; 45 unsigned long fc; 46 union { 47 struct crypto_skcipher *blk; 48 struct crypto_cipher *cip; 49 } fallback; 50 }; 51 52 struct s390_xts_ctx { 53 u8 key[32]; 54 u8 pcc_key[32]; 55 int key_len; 56 unsigned long fc; 57 struct crypto_skcipher *fallback; 58 }; 59 60 struct gcm_sg_walk { 61 struct scatter_walk walk; 62 unsigned int walk_bytes; 63 u8 *walk_ptr; 64 unsigned int walk_bytes_remain; 65 u8 buf[AES_BLOCK_SIZE]; 66 unsigned int buf_bytes; 67 u8 *ptr; 68 unsigned int nbytes; 69 }; 70 71 static int setkey_fallback_cip(struct crypto_tfm *tfm, const u8 *in_key, 72 unsigned int key_len) 73 { 74 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 75 int ret; 76 77 sctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK; 78 sctx->fallback.cip->base.crt_flags |= (tfm->crt_flags & 79 CRYPTO_TFM_REQ_MASK); 80 81 ret = crypto_cipher_setkey(sctx->fallback.cip, in_key, key_len); 82 if (ret) { 83 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; 84 tfm->crt_flags |= (sctx->fallback.cip->base.crt_flags & 85 CRYPTO_TFM_RES_MASK); 86 } 87 return ret; 88 } 89 90 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 91 unsigned int key_len) 92 { 93 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 94 unsigned long fc; 95 96 /* Pick the correct function code based on the key length */ 97 fc = (key_len == 16) ? CPACF_KM_AES_128 : 98 (key_len == 24) ? CPACF_KM_AES_192 : 99 (key_len == 32) ? CPACF_KM_AES_256 : 0; 100 101 /* Check if the function code is available */ 102 sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 103 if (!sctx->fc) 104 return setkey_fallback_cip(tfm, in_key, key_len); 105 106 sctx->key_len = key_len; 107 memcpy(sctx->key, in_key, key_len); 108 return 0; 109 } 110 111 static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) 112 { 113 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 114 115 if (unlikely(!sctx->fc)) { 116 crypto_cipher_encrypt_one(sctx->fallback.cip, out, in); 117 return; 118 } 119 cpacf_km(sctx->fc, &sctx->key, out, in, AES_BLOCK_SIZE); 120 } 121 122 static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) 123 { 124 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 125 126 if (unlikely(!sctx->fc)) { 127 crypto_cipher_decrypt_one(sctx->fallback.cip, out, in); 128 return; 129 } 130 cpacf_km(sctx->fc | CPACF_DECRYPT, 131 &sctx->key, out, in, AES_BLOCK_SIZE); 132 } 133 134 static int fallback_init_cip(struct crypto_tfm *tfm) 135 { 136 const char *name = tfm->__crt_alg->cra_name; 137 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 138 139 sctx->fallback.cip = crypto_alloc_cipher(name, 0, 140 CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK); 141 142 if (IS_ERR(sctx->fallback.cip)) { 143 pr_err("Allocating AES fallback algorithm %s failed\n", 144 name); 145 return PTR_ERR(sctx->fallback.cip); 146 } 147 148 return 0; 149 } 150 151 static void fallback_exit_cip(struct crypto_tfm *tfm) 152 { 153 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 154 155 crypto_free_cipher(sctx->fallback.cip); 156 sctx->fallback.cip = NULL; 157 } 158 159 static struct crypto_alg aes_alg = { 160 .cra_name = "aes", 161 .cra_driver_name = "aes-s390", 162 .cra_priority = 300, 163 .cra_flags = CRYPTO_ALG_TYPE_CIPHER | 164 CRYPTO_ALG_NEED_FALLBACK, 165 .cra_blocksize = AES_BLOCK_SIZE, 166 .cra_ctxsize = sizeof(struct s390_aes_ctx), 167 .cra_module = THIS_MODULE, 168 .cra_init = fallback_init_cip, 169 .cra_exit = fallback_exit_cip, 170 .cra_u = { 171 .cipher = { 172 .cia_min_keysize = AES_MIN_KEY_SIZE, 173 .cia_max_keysize = AES_MAX_KEY_SIZE, 174 .cia_setkey = aes_set_key, 175 .cia_encrypt = aes_encrypt, 176 .cia_decrypt = aes_decrypt, 177 } 178 } 179 }; 180 181 static int setkey_fallback_blk(struct crypto_tfm *tfm, const u8 *key, 182 unsigned int len) 183 { 184 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 185 unsigned int ret; 186 187 crypto_skcipher_clear_flags(sctx->fallback.blk, CRYPTO_TFM_REQ_MASK); 188 crypto_skcipher_set_flags(sctx->fallback.blk, tfm->crt_flags & 189 CRYPTO_TFM_REQ_MASK); 190 191 ret = crypto_skcipher_setkey(sctx->fallback.blk, key, len); 192 193 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; 194 tfm->crt_flags |= crypto_skcipher_get_flags(sctx->fallback.blk) & 195 CRYPTO_TFM_RES_MASK; 196 197 return ret; 198 } 199 200 static int fallback_blk_dec(struct blkcipher_desc *desc, 201 struct scatterlist *dst, struct scatterlist *src, 202 unsigned int nbytes) 203 { 204 unsigned int ret; 205 struct crypto_blkcipher *tfm = desc->tfm; 206 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(tfm); 207 SKCIPHER_REQUEST_ON_STACK(req, sctx->fallback.blk); 208 209 skcipher_request_set_tfm(req, sctx->fallback.blk); 210 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 211 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 212 213 ret = crypto_skcipher_decrypt(req); 214 215 skcipher_request_zero(req); 216 return ret; 217 } 218 219 static int fallback_blk_enc(struct blkcipher_desc *desc, 220 struct scatterlist *dst, struct scatterlist *src, 221 unsigned int nbytes) 222 { 223 unsigned int ret; 224 struct crypto_blkcipher *tfm = desc->tfm; 225 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(tfm); 226 SKCIPHER_REQUEST_ON_STACK(req, sctx->fallback.blk); 227 228 skcipher_request_set_tfm(req, sctx->fallback.blk); 229 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 230 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 231 232 ret = crypto_skcipher_encrypt(req); 233 return ret; 234 } 235 236 static int ecb_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 237 unsigned int key_len) 238 { 239 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 240 unsigned long fc; 241 242 /* Pick the correct function code based on the key length */ 243 fc = (key_len == 16) ? CPACF_KM_AES_128 : 244 (key_len == 24) ? CPACF_KM_AES_192 : 245 (key_len == 32) ? CPACF_KM_AES_256 : 0; 246 247 /* Check if the function code is available */ 248 sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 249 if (!sctx->fc) 250 return setkey_fallback_blk(tfm, in_key, key_len); 251 252 sctx->key_len = key_len; 253 memcpy(sctx->key, in_key, key_len); 254 return 0; 255 } 256 257 static int ecb_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier, 258 struct blkcipher_walk *walk) 259 { 260 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 261 unsigned int nbytes, n; 262 int ret; 263 264 ret = blkcipher_walk_virt(desc, walk); 265 while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) { 266 /* only use complete blocks */ 267 n = nbytes & ~(AES_BLOCK_SIZE - 1); 268 cpacf_km(sctx->fc | modifier, sctx->key, 269 walk->dst.virt.addr, walk->src.virt.addr, n); 270 ret = blkcipher_walk_done(desc, walk, nbytes - n); 271 } 272 273 return ret; 274 } 275 276 static int ecb_aes_encrypt(struct blkcipher_desc *desc, 277 struct scatterlist *dst, struct scatterlist *src, 278 unsigned int nbytes) 279 { 280 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 281 struct blkcipher_walk walk; 282 283 if (unlikely(!sctx->fc)) 284 return fallback_blk_enc(desc, dst, src, nbytes); 285 286 blkcipher_walk_init(&walk, dst, src, nbytes); 287 return ecb_aes_crypt(desc, 0, &walk); 288 } 289 290 static int ecb_aes_decrypt(struct blkcipher_desc *desc, 291 struct scatterlist *dst, struct scatterlist *src, 292 unsigned int nbytes) 293 { 294 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 295 struct blkcipher_walk walk; 296 297 if (unlikely(!sctx->fc)) 298 return fallback_blk_dec(desc, dst, src, nbytes); 299 300 blkcipher_walk_init(&walk, dst, src, nbytes); 301 return ecb_aes_crypt(desc, CPACF_DECRYPT, &walk); 302 } 303 304 static int fallback_init_blk(struct crypto_tfm *tfm) 305 { 306 const char *name = tfm->__crt_alg->cra_name; 307 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 308 309 sctx->fallback.blk = crypto_alloc_skcipher(name, 0, 310 CRYPTO_ALG_ASYNC | 311 CRYPTO_ALG_NEED_FALLBACK); 312 313 if (IS_ERR(sctx->fallback.blk)) { 314 pr_err("Allocating AES fallback algorithm %s failed\n", 315 name); 316 return PTR_ERR(sctx->fallback.blk); 317 } 318 319 return 0; 320 } 321 322 static void fallback_exit_blk(struct crypto_tfm *tfm) 323 { 324 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 325 326 crypto_free_skcipher(sctx->fallback.blk); 327 } 328 329 static struct crypto_alg ecb_aes_alg = { 330 .cra_name = "ecb(aes)", 331 .cra_driver_name = "ecb-aes-s390", 332 .cra_priority = 401, /* combo: aes + ecb + 1 */ 333 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | 334 CRYPTO_ALG_NEED_FALLBACK, 335 .cra_blocksize = AES_BLOCK_SIZE, 336 .cra_ctxsize = sizeof(struct s390_aes_ctx), 337 .cra_type = &crypto_blkcipher_type, 338 .cra_module = THIS_MODULE, 339 .cra_init = fallback_init_blk, 340 .cra_exit = fallback_exit_blk, 341 .cra_u = { 342 .blkcipher = { 343 .min_keysize = AES_MIN_KEY_SIZE, 344 .max_keysize = AES_MAX_KEY_SIZE, 345 .setkey = ecb_aes_set_key, 346 .encrypt = ecb_aes_encrypt, 347 .decrypt = ecb_aes_decrypt, 348 } 349 } 350 }; 351 352 static int cbc_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 353 unsigned int key_len) 354 { 355 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 356 unsigned long fc; 357 358 /* Pick the correct function code based on the key length */ 359 fc = (key_len == 16) ? CPACF_KMC_AES_128 : 360 (key_len == 24) ? CPACF_KMC_AES_192 : 361 (key_len == 32) ? CPACF_KMC_AES_256 : 0; 362 363 /* Check if the function code is available */ 364 sctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0; 365 if (!sctx->fc) 366 return setkey_fallback_blk(tfm, in_key, key_len); 367 368 sctx->key_len = key_len; 369 memcpy(sctx->key, in_key, key_len); 370 return 0; 371 } 372 373 static int cbc_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier, 374 struct blkcipher_walk *walk) 375 { 376 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 377 unsigned int nbytes, n; 378 int ret; 379 struct { 380 u8 iv[AES_BLOCK_SIZE]; 381 u8 key[AES_MAX_KEY_SIZE]; 382 } param; 383 384 ret = blkcipher_walk_virt(desc, walk); 385 memcpy(param.iv, walk->iv, AES_BLOCK_SIZE); 386 memcpy(param.key, sctx->key, sctx->key_len); 387 while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) { 388 /* only use complete blocks */ 389 n = nbytes & ~(AES_BLOCK_SIZE - 1); 390 cpacf_kmc(sctx->fc | modifier, ¶m, 391 walk->dst.virt.addr, walk->src.virt.addr, n); 392 ret = blkcipher_walk_done(desc, walk, nbytes - n); 393 } 394 memcpy(walk->iv, param.iv, AES_BLOCK_SIZE); 395 return ret; 396 } 397 398 static int cbc_aes_encrypt(struct blkcipher_desc *desc, 399 struct scatterlist *dst, struct scatterlist *src, 400 unsigned int nbytes) 401 { 402 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 403 struct blkcipher_walk walk; 404 405 if (unlikely(!sctx->fc)) 406 return fallback_blk_enc(desc, dst, src, nbytes); 407 408 blkcipher_walk_init(&walk, dst, src, nbytes); 409 return cbc_aes_crypt(desc, 0, &walk); 410 } 411 412 static int cbc_aes_decrypt(struct blkcipher_desc *desc, 413 struct scatterlist *dst, struct scatterlist *src, 414 unsigned int nbytes) 415 { 416 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 417 struct blkcipher_walk walk; 418 419 if (unlikely(!sctx->fc)) 420 return fallback_blk_dec(desc, dst, src, nbytes); 421 422 blkcipher_walk_init(&walk, dst, src, nbytes); 423 return cbc_aes_crypt(desc, CPACF_DECRYPT, &walk); 424 } 425 426 static struct crypto_alg cbc_aes_alg = { 427 .cra_name = "cbc(aes)", 428 .cra_driver_name = "cbc-aes-s390", 429 .cra_priority = 402, /* ecb-aes-s390 + 1 */ 430 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | 431 CRYPTO_ALG_NEED_FALLBACK, 432 .cra_blocksize = AES_BLOCK_SIZE, 433 .cra_ctxsize = sizeof(struct s390_aes_ctx), 434 .cra_type = &crypto_blkcipher_type, 435 .cra_module = THIS_MODULE, 436 .cra_init = fallback_init_blk, 437 .cra_exit = fallback_exit_blk, 438 .cra_u = { 439 .blkcipher = { 440 .min_keysize = AES_MIN_KEY_SIZE, 441 .max_keysize = AES_MAX_KEY_SIZE, 442 .ivsize = AES_BLOCK_SIZE, 443 .setkey = cbc_aes_set_key, 444 .encrypt = cbc_aes_encrypt, 445 .decrypt = cbc_aes_decrypt, 446 } 447 } 448 }; 449 450 static int xts_fallback_setkey(struct crypto_tfm *tfm, const u8 *key, 451 unsigned int len) 452 { 453 struct s390_xts_ctx *xts_ctx = crypto_tfm_ctx(tfm); 454 unsigned int ret; 455 456 crypto_skcipher_clear_flags(xts_ctx->fallback, CRYPTO_TFM_REQ_MASK); 457 crypto_skcipher_set_flags(xts_ctx->fallback, tfm->crt_flags & 458 CRYPTO_TFM_REQ_MASK); 459 460 ret = crypto_skcipher_setkey(xts_ctx->fallback, key, len); 461 462 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; 463 tfm->crt_flags |= crypto_skcipher_get_flags(xts_ctx->fallback) & 464 CRYPTO_TFM_RES_MASK; 465 466 return ret; 467 } 468 469 static int xts_fallback_decrypt(struct blkcipher_desc *desc, 470 struct scatterlist *dst, struct scatterlist *src, 471 unsigned int nbytes) 472 { 473 struct crypto_blkcipher *tfm = desc->tfm; 474 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(tfm); 475 SKCIPHER_REQUEST_ON_STACK(req, xts_ctx->fallback); 476 unsigned int ret; 477 478 skcipher_request_set_tfm(req, xts_ctx->fallback); 479 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 480 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 481 482 ret = crypto_skcipher_decrypt(req); 483 484 skcipher_request_zero(req); 485 return ret; 486 } 487 488 static int xts_fallback_encrypt(struct blkcipher_desc *desc, 489 struct scatterlist *dst, struct scatterlist *src, 490 unsigned int nbytes) 491 { 492 struct crypto_blkcipher *tfm = desc->tfm; 493 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(tfm); 494 SKCIPHER_REQUEST_ON_STACK(req, xts_ctx->fallback); 495 unsigned int ret; 496 497 skcipher_request_set_tfm(req, xts_ctx->fallback); 498 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 499 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 500 501 ret = crypto_skcipher_encrypt(req); 502 503 skcipher_request_zero(req); 504 return ret; 505 } 506 507 static int xts_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 508 unsigned int key_len) 509 { 510 struct s390_xts_ctx *xts_ctx = crypto_tfm_ctx(tfm); 511 unsigned long fc; 512 int err; 513 514 err = xts_check_key(tfm, in_key, key_len); 515 if (err) 516 return err; 517 518 /* In fips mode only 128 bit or 256 bit keys are valid */ 519 if (fips_enabled && key_len != 32 && key_len != 64) { 520 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; 521 return -EINVAL; 522 } 523 524 /* Pick the correct function code based on the key length */ 525 fc = (key_len == 32) ? CPACF_KM_XTS_128 : 526 (key_len == 64) ? CPACF_KM_XTS_256 : 0; 527 528 /* Check if the function code is available */ 529 xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 530 if (!xts_ctx->fc) 531 return xts_fallback_setkey(tfm, in_key, key_len); 532 533 /* Split the XTS key into the two subkeys */ 534 key_len = key_len / 2; 535 xts_ctx->key_len = key_len; 536 memcpy(xts_ctx->key, in_key, key_len); 537 memcpy(xts_ctx->pcc_key, in_key + key_len, key_len); 538 return 0; 539 } 540 541 static int xts_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier, 542 struct blkcipher_walk *walk) 543 { 544 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(desc->tfm); 545 unsigned int offset, nbytes, n; 546 int ret; 547 struct { 548 u8 key[32]; 549 u8 tweak[16]; 550 u8 block[16]; 551 u8 bit[16]; 552 u8 xts[16]; 553 } pcc_param; 554 struct { 555 u8 key[32]; 556 u8 init[16]; 557 } xts_param; 558 559 ret = blkcipher_walk_virt(desc, walk); 560 offset = xts_ctx->key_len & 0x10; 561 memset(pcc_param.block, 0, sizeof(pcc_param.block)); 562 memset(pcc_param.bit, 0, sizeof(pcc_param.bit)); 563 memset(pcc_param.xts, 0, sizeof(pcc_param.xts)); 564 memcpy(pcc_param.tweak, walk->iv, sizeof(pcc_param.tweak)); 565 memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len); 566 cpacf_pcc(xts_ctx->fc, pcc_param.key + offset); 567 568 memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len); 569 memcpy(xts_param.init, pcc_param.xts, 16); 570 571 while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) { 572 /* only use complete blocks */ 573 n = nbytes & ~(AES_BLOCK_SIZE - 1); 574 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset, 575 walk->dst.virt.addr, walk->src.virt.addr, n); 576 ret = blkcipher_walk_done(desc, walk, nbytes - n); 577 } 578 return ret; 579 } 580 581 static int xts_aes_encrypt(struct blkcipher_desc *desc, 582 struct scatterlist *dst, struct scatterlist *src, 583 unsigned int nbytes) 584 { 585 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(desc->tfm); 586 struct blkcipher_walk walk; 587 588 if (unlikely(!xts_ctx->fc)) 589 return xts_fallback_encrypt(desc, dst, src, nbytes); 590 591 blkcipher_walk_init(&walk, dst, src, nbytes); 592 return xts_aes_crypt(desc, 0, &walk); 593 } 594 595 static int xts_aes_decrypt(struct blkcipher_desc *desc, 596 struct scatterlist *dst, struct scatterlist *src, 597 unsigned int nbytes) 598 { 599 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(desc->tfm); 600 struct blkcipher_walk walk; 601 602 if (unlikely(!xts_ctx->fc)) 603 return xts_fallback_decrypt(desc, dst, src, nbytes); 604 605 blkcipher_walk_init(&walk, dst, src, nbytes); 606 return xts_aes_crypt(desc, CPACF_DECRYPT, &walk); 607 } 608 609 static int xts_fallback_init(struct crypto_tfm *tfm) 610 { 611 const char *name = tfm->__crt_alg->cra_name; 612 struct s390_xts_ctx *xts_ctx = crypto_tfm_ctx(tfm); 613 614 xts_ctx->fallback = crypto_alloc_skcipher(name, 0, 615 CRYPTO_ALG_ASYNC | 616 CRYPTO_ALG_NEED_FALLBACK); 617 618 if (IS_ERR(xts_ctx->fallback)) { 619 pr_err("Allocating XTS fallback algorithm %s failed\n", 620 name); 621 return PTR_ERR(xts_ctx->fallback); 622 } 623 return 0; 624 } 625 626 static void xts_fallback_exit(struct crypto_tfm *tfm) 627 { 628 struct s390_xts_ctx *xts_ctx = crypto_tfm_ctx(tfm); 629 630 crypto_free_skcipher(xts_ctx->fallback); 631 } 632 633 static struct crypto_alg xts_aes_alg = { 634 .cra_name = "xts(aes)", 635 .cra_driver_name = "xts-aes-s390", 636 .cra_priority = 402, /* ecb-aes-s390 + 1 */ 637 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | 638 CRYPTO_ALG_NEED_FALLBACK, 639 .cra_blocksize = AES_BLOCK_SIZE, 640 .cra_ctxsize = sizeof(struct s390_xts_ctx), 641 .cra_type = &crypto_blkcipher_type, 642 .cra_module = THIS_MODULE, 643 .cra_init = xts_fallback_init, 644 .cra_exit = xts_fallback_exit, 645 .cra_u = { 646 .blkcipher = { 647 .min_keysize = 2 * AES_MIN_KEY_SIZE, 648 .max_keysize = 2 * AES_MAX_KEY_SIZE, 649 .ivsize = AES_BLOCK_SIZE, 650 .setkey = xts_aes_set_key, 651 .encrypt = xts_aes_encrypt, 652 .decrypt = xts_aes_decrypt, 653 } 654 } 655 }; 656 657 static int ctr_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 658 unsigned int key_len) 659 { 660 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 661 unsigned long fc; 662 663 /* Pick the correct function code based on the key length */ 664 fc = (key_len == 16) ? CPACF_KMCTR_AES_128 : 665 (key_len == 24) ? CPACF_KMCTR_AES_192 : 666 (key_len == 32) ? CPACF_KMCTR_AES_256 : 0; 667 668 /* Check if the function code is available */ 669 sctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0; 670 if (!sctx->fc) 671 return setkey_fallback_blk(tfm, in_key, key_len); 672 673 sctx->key_len = key_len; 674 memcpy(sctx->key, in_key, key_len); 675 return 0; 676 } 677 678 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes) 679 { 680 unsigned int i, n; 681 682 /* only use complete blocks, max. PAGE_SIZE */ 683 memcpy(ctrptr, iv, AES_BLOCK_SIZE); 684 n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1); 685 for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) { 686 memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE); 687 crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE); 688 ctrptr += AES_BLOCK_SIZE; 689 } 690 return n; 691 } 692 693 static int ctr_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier, 694 struct blkcipher_walk *walk) 695 { 696 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 697 u8 buf[AES_BLOCK_SIZE], *ctrptr; 698 unsigned int n, nbytes; 699 int ret, locked; 700 701 locked = spin_trylock(&ctrblk_lock); 702 703 ret = blkcipher_walk_virt_block(desc, walk, AES_BLOCK_SIZE); 704 while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) { 705 n = AES_BLOCK_SIZE; 706 if (nbytes >= 2*AES_BLOCK_SIZE && locked) 707 n = __ctrblk_init(ctrblk, walk->iv, nbytes); 708 ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk->iv; 709 cpacf_kmctr(sctx->fc | modifier, sctx->key, 710 walk->dst.virt.addr, walk->src.virt.addr, 711 n, ctrptr); 712 if (ctrptr == ctrblk) 713 memcpy(walk->iv, ctrptr + n - AES_BLOCK_SIZE, 714 AES_BLOCK_SIZE); 715 crypto_inc(walk->iv, AES_BLOCK_SIZE); 716 ret = blkcipher_walk_done(desc, walk, nbytes - n); 717 } 718 if (locked) 719 spin_unlock(&ctrblk_lock); 720 /* 721 * final block may be < AES_BLOCK_SIZE, copy only nbytes 722 */ 723 if (nbytes) { 724 cpacf_kmctr(sctx->fc | modifier, sctx->key, 725 buf, walk->src.virt.addr, 726 AES_BLOCK_SIZE, walk->iv); 727 memcpy(walk->dst.virt.addr, buf, nbytes); 728 crypto_inc(walk->iv, AES_BLOCK_SIZE); 729 ret = blkcipher_walk_done(desc, walk, 0); 730 } 731 732 return ret; 733 } 734 735 static int ctr_aes_encrypt(struct blkcipher_desc *desc, 736 struct scatterlist *dst, struct scatterlist *src, 737 unsigned int nbytes) 738 { 739 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 740 struct blkcipher_walk walk; 741 742 if (unlikely(!sctx->fc)) 743 return fallback_blk_enc(desc, dst, src, nbytes); 744 745 blkcipher_walk_init(&walk, dst, src, nbytes); 746 return ctr_aes_crypt(desc, 0, &walk); 747 } 748 749 static int ctr_aes_decrypt(struct blkcipher_desc *desc, 750 struct scatterlist *dst, struct scatterlist *src, 751 unsigned int nbytes) 752 { 753 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 754 struct blkcipher_walk walk; 755 756 if (unlikely(!sctx->fc)) 757 return fallback_blk_dec(desc, dst, src, nbytes); 758 759 blkcipher_walk_init(&walk, dst, src, nbytes); 760 return ctr_aes_crypt(desc, CPACF_DECRYPT, &walk); 761 } 762 763 static struct crypto_alg ctr_aes_alg = { 764 .cra_name = "ctr(aes)", 765 .cra_driver_name = "ctr-aes-s390", 766 .cra_priority = 402, /* ecb-aes-s390 + 1 */ 767 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | 768 CRYPTO_ALG_NEED_FALLBACK, 769 .cra_blocksize = 1, 770 .cra_ctxsize = sizeof(struct s390_aes_ctx), 771 .cra_type = &crypto_blkcipher_type, 772 .cra_module = THIS_MODULE, 773 .cra_init = fallback_init_blk, 774 .cra_exit = fallback_exit_blk, 775 .cra_u = { 776 .blkcipher = { 777 .min_keysize = AES_MIN_KEY_SIZE, 778 .max_keysize = AES_MAX_KEY_SIZE, 779 .ivsize = AES_BLOCK_SIZE, 780 .setkey = ctr_aes_set_key, 781 .encrypt = ctr_aes_encrypt, 782 .decrypt = ctr_aes_decrypt, 783 } 784 } 785 }; 786 787 static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *key, 788 unsigned int keylen) 789 { 790 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm); 791 792 switch (keylen) { 793 case AES_KEYSIZE_128: 794 ctx->fc = CPACF_KMA_GCM_AES_128; 795 break; 796 case AES_KEYSIZE_192: 797 ctx->fc = CPACF_KMA_GCM_AES_192; 798 break; 799 case AES_KEYSIZE_256: 800 ctx->fc = CPACF_KMA_GCM_AES_256; 801 break; 802 default: 803 return -EINVAL; 804 } 805 806 memcpy(ctx->key, key, keylen); 807 ctx->key_len = keylen; 808 return 0; 809 } 810 811 static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize) 812 { 813 switch (authsize) { 814 case 4: 815 case 8: 816 case 12: 817 case 13: 818 case 14: 819 case 15: 820 case 16: 821 break; 822 default: 823 return -EINVAL; 824 } 825 826 return 0; 827 } 828 829 static void gcm_sg_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg, 830 unsigned int len) 831 { 832 memset(gw, 0, sizeof(*gw)); 833 gw->walk_bytes_remain = len; 834 scatterwalk_start(&gw->walk, sg); 835 } 836 837 static int gcm_sg_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) 838 { 839 int n; 840 841 /* minbytesneeded <= AES_BLOCK_SIZE */ 842 if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) { 843 gw->ptr = gw->buf; 844 gw->nbytes = gw->buf_bytes; 845 goto out; 846 } 847 848 if (gw->walk_bytes_remain == 0) { 849 gw->ptr = NULL; 850 gw->nbytes = 0; 851 goto out; 852 } 853 854 gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain); 855 if (!gw->walk_bytes) { 856 scatterwalk_start(&gw->walk, sg_next(gw->walk.sg)); 857 gw->walk_bytes = scatterwalk_clamp(&gw->walk, 858 gw->walk_bytes_remain); 859 } 860 gw->walk_ptr = scatterwalk_map(&gw->walk); 861 862 if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) { 863 gw->ptr = gw->walk_ptr; 864 gw->nbytes = gw->walk_bytes; 865 goto out; 866 } 867 868 while (1) { 869 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes); 870 memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n); 871 gw->buf_bytes += n; 872 gw->walk_bytes_remain -= n; 873 scatterwalk_unmap(&gw->walk); 874 scatterwalk_advance(&gw->walk, n); 875 scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain); 876 877 if (gw->buf_bytes >= minbytesneeded) { 878 gw->ptr = gw->buf; 879 gw->nbytes = gw->buf_bytes; 880 goto out; 881 } 882 883 gw->walk_bytes = scatterwalk_clamp(&gw->walk, 884 gw->walk_bytes_remain); 885 if (!gw->walk_bytes) { 886 scatterwalk_start(&gw->walk, sg_next(gw->walk.sg)); 887 gw->walk_bytes = scatterwalk_clamp(&gw->walk, 888 gw->walk_bytes_remain); 889 } 890 gw->walk_ptr = scatterwalk_map(&gw->walk); 891 } 892 893 out: 894 return gw->nbytes; 895 } 896 897 static void gcm_sg_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) 898 { 899 int n; 900 901 if (gw->ptr == NULL) 902 return; 903 904 if (gw->ptr == gw->buf) { 905 n = gw->buf_bytes - bytesdone; 906 if (n > 0) { 907 memmove(gw->buf, gw->buf + bytesdone, n); 908 gw->buf_bytes -= n; 909 } else 910 gw->buf_bytes = 0; 911 } else { 912 gw->walk_bytes_remain -= bytesdone; 913 scatterwalk_unmap(&gw->walk); 914 scatterwalk_advance(&gw->walk, bytesdone); 915 scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain); 916 } 917 } 918 919 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags) 920 { 921 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 922 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm); 923 unsigned int ivsize = crypto_aead_ivsize(tfm); 924 unsigned int taglen = crypto_aead_authsize(tfm); 925 unsigned int aadlen = req->assoclen; 926 unsigned int pclen = req->cryptlen; 927 int ret = 0; 928 929 unsigned int len, in_bytes, out_bytes, 930 min_bytes, bytes, aad_bytes, pc_bytes; 931 struct gcm_sg_walk gw_in, gw_out; 932 u8 tag[GHASH_DIGEST_SIZE]; 933 934 struct { 935 u32 _[3]; /* reserved */ 936 u32 cv; /* Counter Value */ 937 u8 t[GHASH_DIGEST_SIZE];/* Tag */ 938 u8 h[AES_BLOCK_SIZE]; /* Hash-subkey */ 939 u64 taadl; /* Total AAD Length */ 940 u64 tpcl; /* Total Plain-/Cipher-text Length */ 941 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */ 942 u8 k[AES_MAX_KEY_SIZE]; /* Key */ 943 } param; 944 945 /* 946 * encrypt 947 * req->src: aad||plaintext 948 * req->dst: aad||ciphertext||tag 949 * decrypt 950 * req->src: aad||ciphertext||tag 951 * req->dst: aad||plaintext, return 0 or -EBADMSG 952 * aad, plaintext and ciphertext may be empty. 953 */ 954 if (flags & CPACF_DECRYPT) 955 pclen -= taglen; 956 len = aadlen + pclen; 957 958 memset(¶m, 0, sizeof(param)); 959 param.cv = 1; 960 param.taadl = aadlen * 8; 961 param.tpcl = pclen * 8; 962 memcpy(param.j0, req->iv, ivsize); 963 *(u32 *)(param.j0 + ivsize) = 1; 964 memcpy(param.k, ctx->key, ctx->key_len); 965 966 gcm_sg_walk_start(&gw_in, req->src, len); 967 gcm_sg_walk_start(&gw_out, req->dst, len); 968 969 do { 970 min_bytes = min_t(unsigned int, 971 aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE); 972 in_bytes = gcm_sg_walk_go(&gw_in, min_bytes); 973 out_bytes = gcm_sg_walk_go(&gw_out, min_bytes); 974 bytes = min(in_bytes, out_bytes); 975 976 if (aadlen + pclen <= bytes) { 977 aad_bytes = aadlen; 978 pc_bytes = pclen; 979 flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC; 980 } else { 981 if (aadlen <= bytes) { 982 aad_bytes = aadlen; 983 pc_bytes = (bytes - aadlen) & 984 ~(AES_BLOCK_SIZE - 1); 985 flags |= CPACF_KMA_LAAD; 986 } else { 987 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1); 988 pc_bytes = 0; 989 } 990 } 991 992 if (aad_bytes > 0) 993 memcpy(gw_out.ptr, gw_in.ptr, aad_bytes); 994 995 cpacf_kma(ctx->fc | flags, ¶m, 996 gw_out.ptr + aad_bytes, 997 gw_in.ptr + aad_bytes, pc_bytes, 998 gw_in.ptr, aad_bytes); 999 1000 gcm_sg_walk_done(&gw_in, aad_bytes + pc_bytes); 1001 gcm_sg_walk_done(&gw_out, aad_bytes + pc_bytes); 1002 aadlen -= aad_bytes; 1003 pclen -= pc_bytes; 1004 } while (aadlen + pclen > 0); 1005 1006 if (flags & CPACF_DECRYPT) { 1007 scatterwalk_map_and_copy(tag, req->src, len, taglen, 0); 1008 if (crypto_memneq(tag, param.t, taglen)) 1009 ret = -EBADMSG; 1010 } else 1011 scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1); 1012 1013 memzero_explicit(¶m, sizeof(param)); 1014 return ret; 1015 } 1016 1017 static int gcm_aes_encrypt(struct aead_request *req) 1018 { 1019 return gcm_aes_crypt(req, CPACF_ENCRYPT); 1020 } 1021 1022 static int gcm_aes_decrypt(struct aead_request *req) 1023 { 1024 return gcm_aes_crypt(req, CPACF_DECRYPT); 1025 } 1026 1027 static struct aead_alg gcm_aes_aead = { 1028 .setkey = gcm_aes_setkey, 1029 .setauthsize = gcm_aes_setauthsize, 1030 .encrypt = gcm_aes_encrypt, 1031 .decrypt = gcm_aes_decrypt, 1032 1033 .ivsize = GHASH_BLOCK_SIZE - sizeof(u32), 1034 .maxauthsize = GHASH_DIGEST_SIZE, 1035 .chunksize = AES_BLOCK_SIZE, 1036 1037 .base = { 1038 .cra_flags = CRYPTO_ALG_TYPE_AEAD, 1039 .cra_blocksize = 1, 1040 .cra_ctxsize = sizeof(struct s390_aes_ctx), 1041 .cra_priority = 900, 1042 .cra_name = "gcm(aes)", 1043 .cra_driver_name = "gcm-aes-s390", 1044 .cra_module = THIS_MODULE, 1045 }, 1046 }; 1047 1048 static struct crypto_alg *aes_s390_algs_ptr[5]; 1049 static int aes_s390_algs_num; 1050 static struct aead_alg *aes_s390_aead_alg; 1051 1052 static int aes_s390_register_alg(struct crypto_alg *alg) 1053 { 1054 int ret; 1055 1056 ret = crypto_register_alg(alg); 1057 if (!ret) 1058 aes_s390_algs_ptr[aes_s390_algs_num++] = alg; 1059 return ret; 1060 } 1061 1062 static void aes_s390_fini(void) 1063 { 1064 while (aes_s390_algs_num--) 1065 crypto_unregister_alg(aes_s390_algs_ptr[aes_s390_algs_num]); 1066 if (ctrblk) 1067 free_page((unsigned long) ctrblk); 1068 1069 if (aes_s390_aead_alg) 1070 crypto_unregister_aead(aes_s390_aead_alg); 1071 } 1072 1073 static int __init aes_s390_init(void) 1074 { 1075 int ret; 1076 1077 /* Query available functions for KM, KMC, KMCTR and KMA */ 1078 cpacf_query(CPACF_KM, &km_functions); 1079 cpacf_query(CPACF_KMC, &kmc_functions); 1080 cpacf_query(CPACF_KMCTR, &kmctr_functions); 1081 cpacf_query(CPACF_KMA, &kma_functions); 1082 1083 if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) || 1084 cpacf_test_func(&km_functions, CPACF_KM_AES_192) || 1085 cpacf_test_func(&km_functions, CPACF_KM_AES_256)) { 1086 ret = aes_s390_register_alg(&aes_alg); 1087 if (ret) 1088 goto out_err; 1089 ret = aes_s390_register_alg(&ecb_aes_alg); 1090 if (ret) 1091 goto out_err; 1092 } 1093 1094 if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) || 1095 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) || 1096 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) { 1097 ret = aes_s390_register_alg(&cbc_aes_alg); 1098 if (ret) 1099 goto out_err; 1100 } 1101 1102 if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) || 1103 cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) { 1104 ret = aes_s390_register_alg(&xts_aes_alg); 1105 if (ret) 1106 goto out_err; 1107 } 1108 1109 if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) || 1110 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) || 1111 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) { 1112 ctrblk = (u8 *) __get_free_page(GFP_KERNEL); 1113 if (!ctrblk) { 1114 ret = -ENOMEM; 1115 goto out_err; 1116 } 1117 ret = aes_s390_register_alg(&ctr_aes_alg); 1118 if (ret) 1119 goto out_err; 1120 } 1121 1122 if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) || 1123 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) || 1124 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) { 1125 ret = crypto_register_aead(&gcm_aes_aead); 1126 if (ret) 1127 goto out_err; 1128 aes_s390_aead_alg = &gcm_aes_aead; 1129 } 1130 1131 return 0; 1132 out_err: 1133 aes_s390_fini(); 1134 return ret; 1135 } 1136 1137 module_cpu_feature_match(MSA, aes_s390_init); 1138 module_exit(aes_s390_fini); 1139 1140 MODULE_ALIAS_CRYPTO("aes-all"); 1141 1142 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); 1143 MODULE_LICENSE("GPL"); 1144