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/mutex.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_MUTEX(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_sync_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_sync_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_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_sync_skcipher_clear_flags(sctx->fallback.blk, 188 CRYPTO_TFM_REQ_MASK); 189 crypto_sync_skcipher_set_flags(sctx->fallback.blk, tfm->crt_flags & 190 CRYPTO_TFM_REQ_MASK); 191 192 ret = crypto_sync_skcipher_setkey(sctx->fallback.blk, key, len); 193 194 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; 195 tfm->crt_flags |= crypto_sync_skcipher_get_flags(sctx->fallback.blk) & 196 CRYPTO_TFM_RES_MASK; 197 198 return ret; 199 } 200 201 static int fallback_blk_dec(struct blkcipher_desc *desc, 202 struct scatterlist *dst, struct scatterlist *src, 203 unsigned int nbytes) 204 { 205 unsigned int ret; 206 struct crypto_blkcipher *tfm = desc->tfm; 207 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(tfm); 208 SYNC_SKCIPHER_REQUEST_ON_STACK(req, sctx->fallback.blk); 209 210 skcipher_request_set_sync_tfm(req, sctx->fallback.blk); 211 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 212 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 213 214 ret = crypto_skcipher_decrypt(req); 215 216 skcipher_request_zero(req); 217 return ret; 218 } 219 220 static int fallback_blk_enc(struct blkcipher_desc *desc, 221 struct scatterlist *dst, struct scatterlist *src, 222 unsigned int nbytes) 223 { 224 unsigned int ret; 225 struct crypto_blkcipher *tfm = desc->tfm; 226 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(tfm); 227 SYNC_SKCIPHER_REQUEST_ON_STACK(req, sctx->fallback.blk); 228 229 skcipher_request_set_sync_tfm(req, sctx->fallback.blk); 230 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 231 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 232 233 ret = crypto_skcipher_encrypt(req); 234 return ret; 235 } 236 237 static int ecb_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 238 unsigned int key_len) 239 { 240 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 241 unsigned long fc; 242 243 /* Pick the correct function code based on the key length */ 244 fc = (key_len == 16) ? CPACF_KM_AES_128 : 245 (key_len == 24) ? CPACF_KM_AES_192 : 246 (key_len == 32) ? CPACF_KM_AES_256 : 0; 247 248 /* Check if the function code is available */ 249 sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 250 if (!sctx->fc) 251 return setkey_fallback_blk(tfm, in_key, key_len); 252 253 sctx->key_len = key_len; 254 memcpy(sctx->key, in_key, key_len); 255 return 0; 256 } 257 258 static int ecb_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier, 259 struct blkcipher_walk *walk) 260 { 261 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 262 unsigned int nbytes, n; 263 int ret; 264 265 ret = blkcipher_walk_virt(desc, walk); 266 while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) { 267 /* only use complete blocks */ 268 n = nbytes & ~(AES_BLOCK_SIZE - 1); 269 cpacf_km(sctx->fc | modifier, sctx->key, 270 walk->dst.virt.addr, walk->src.virt.addr, n); 271 ret = blkcipher_walk_done(desc, walk, nbytes - n); 272 } 273 274 return ret; 275 } 276 277 static int ecb_aes_encrypt(struct blkcipher_desc *desc, 278 struct scatterlist *dst, struct scatterlist *src, 279 unsigned int nbytes) 280 { 281 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 282 struct blkcipher_walk walk; 283 284 if (unlikely(!sctx->fc)) 285 return fallback_blk_enc(desc, dst, src, nbytes); 286 287 blkcipher_walk_init(&walk, dst, src, nbytes); 288 return ecb_aes_crypt(desc, 0, &walk); 289 } 290 291 static int ecb_aes_decrypt(struct blkcipher_desc *desc, 292 struct scatterlist *dst, struct scatterlist *src, 293 unsigned int nbytes) 294 { 295 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 296 struct blkcipher_walk walk; 297 298 if (unlikely(!sctx->fc)) 299 return fallback_blk_dec(desc, dst, src, nbytes); 300 301 blkcipher_walk_init(&walk, dst, src, nbytes); 302 return ecb_aes_crypt(desc, CPACF_DECRYPT, &walk); 303 } 304 305 static int fallback_init_blk(struct crypto_tfm *tfm) 306 { 307 const char *name = tfm->__crt_alg->cra_name; 308 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 309 310 sctx->fallback.blk = crypto_alloc_sync_skcipher(name, 0, 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_sync_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_sync_skcipher_clear_flags(xts_ctx->fallback, 457 CRYPTO_TFM_REQ_MASK); 458 crypto_sync_skcipher_set_flags(xts_ctx->fallback, tfm->crt_flags & 459 CRYPTO_TFM_REQ_MASK); 460 461 ret = crypto_sync_skcipher_setkey(xts_ctx->fallback, key, len); 462 463 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; 464 tfm->crt_flags |= crypto_sync_skcipher_get_flags(xts_ctx->fallback) & 465 CRYPTO_TFM_RES_MASK; 466 467 return ret; 468 } 469 470 static int xts_fallback_decrypt(struct blkcipher_desc *desc, 471 struct scatterlist *dst, struct scatterlist *src, 472 unsigned int nbytes) 473 { 474 struct crypto_blkcipher *tfm = desc->tfm; 475 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(tfm); 476 SYNC_SKCIPHER_REQUEST_ON_STACK(req, xts_ctx->fallback); 477 unsigned int ret; 478 479 skcipher_request_set_sync_tfm(req, xts_ctx->fallback); 480 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 481 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 482 483 ret = crypto_skcipher_decrypt(req); 484 485 skcipher_request_zero(req); 486 return ret; 487 } 488 489 static int xts_fallback_encrypt(struct blkcipher_desc *desc, 490 struct scatterlist *dst, struct scatterlist *src, 491 unsigned int nbytes) 492 { 493 struct crypto_blkcipher *tfm = desc->tfm; 494 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(tfm); 495 SYNC_SKCIPHER_REQUEST_ON_STACK(req, xts_ctx->fallback); 496 unsigned int ret; 497 498 skcipher_request_set_sync_tfm(req, xts_ctx->fallback); 499 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 500 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 501 502 ret = crypto_skcipher_encrypt(req); 503 504 skcipher_request_zero(req); 505 return ret; 506 } 507 508 static int xts_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 509 unsigned int key_len) 510 { 511 struct s390_xts_ctx *xts_ctx = crypto_tfm_ctx(tfm); 512 unsigned long fc; 513 int err; 514 515 err = xts_check_key(tfm, in_key, key_len); 516 if (err) 517 return err; 518 519 /* In fips mode only 128 bit or 256 bit keys are valid */ 520 if (fips_enabled && key_len != 32 && key_len != 64) { 521 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; 522 return -EINVAL; 523 } 524 525 /* Pick the correct function code based on the key length */ 526 fc = (key_len == 32) ? CPACF_KM_XTS_128 : 527 (key_len == 64) ? CPACF_KM_XTS_256 : 0; 528 529 /* Check if the function code is available */ 530 xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 531 if (!xts_ctx->fc) 532 return xts_fallback_setkey(tfm, in_key, key_len); 533 534 /* Split the XTS key into the two subkeys */ 535 key_len = key_len / 2; 536 xts_ctx->key_len = key_len; 537 memcpy(xts_ctx->key, in_key, key_len); 538 memcpy(xts_ctx->pcc_key, in_key + key_len, key_len); 539 return 0; 540 } 541 542 static int xts_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier, 543 struct blkcipher_walk *walk) 544 { 545 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(desc->tfm); 546 unsigned int offset, nbytes, n; 547 int ret; 548 struct { 549 u8 key[32]; 550 u8 tweak[16]; 551 u8 block[16]; 552 u8 bit[16]; 553 u8 xts[16]; 554 } pcc_param; 555 struct { 556 u8 key[32]; 557 u8 init[16]; 558 } xts_param; 559 560 ret = blkcipher_walk_virt(desc, walk); 561 offset = xts_ctx->key_len & 0x10; 562 memset(pcc_param.block, 0, sizeof(pcc_param.block)); 563 memset(pcc_param.bit, 0, sizeof(pcc_param.bit)); 564 memset(pcc_param.xts, 0, sizeof(pcc_param.xts)); 565 memcpy(pcc_param.tweak, walk->iv, sizeof(pcc_param.tweak)); 566 memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len); 567 cpacf_pcc(xts_ctx->fc, pcc_param.key + offset); 568 569 memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len); 570 memcpy(xts_param.init, pcc_param.xts, 16); 571 572 while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) { 573 /* only use complete blocks */ 574 n = nbytes & ~(AES_BLOCK_SIZE - 1); 575 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset, 576 walk->dst.virt.addr, walk->src.virt.addr, n); 577 ret = blkcipher_walk_done(desc, walk, nbytes - n); 578 } 579 return ret; 580 } 581 582 static int xts_aes_encrypt(struct blkcipher_desc *desc, 583 struct scatterlist *dst, struct scatterlist *src, 584 unsigned int nbytes) 585 { 586 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(desc->tfm); 587 struct blkcipher_walk walk; 588 589 if (unlikely(!xts_ctx->fc)) 590 return xts_fallback_encrypt(desc, dst, src, nbytes); 591 592 blkcipher_walk_init(&walk, dst, src, nbytes); 593 return xts_aes_crypt(desc, 0, &walk); 594 } 595 596 static int xts_aes_decrypt(struct blkcipher_desc *desc, 597 struct scatterlist *dst, struct scatterlist *src, 598 unsigned int nbytes) 599 { 600 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(desc->tfm); 601 struct blkcipher_walk walk; 602 603 if (unlikely(!xts_ctx->fc)) 604 return xts_fallback_decrypt(desc, dst, src, nbytes); 605 606 blkcipher_walk_init(&walk, dst, src, nbytes); 607 return xts_aes_crypt(desc, CPACF_DECRYPT, &walk); 608 } 609 610 static int xts_fallback_init(struct crypto_tfm *tfm) 611 { 612 const char *name = tfm->__crt_alg->cra_name; 613 struct s390_xts_ctx *xts_ctx = crypto_tfm_ctx(tfm); 614 615 xts_ctx->fallback = crypto_alloc_sync_skcipher(name, 0, 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_sync_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 = mutex_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 mutex_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_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 inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw) 838 { 839 struct scatterlist *nextsg; 840 841 gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain); 842 while (!gw->walk_bytes) { 843 nextsg = sg_next(gw->walk.sg); 844 if (!nextsg) 845 return 0; 846 scatterwalk_start(&gw->walk, nextsg); 847 gw->walk_bytes = scatterwalk_clamp(&gw->walk, 848 gw->walk_bytes_remain); 849 } 850 gw->walk_ptr = scatterwalk_map(&gw->walk); 851 return gw->walk_bytes; 852 } 853 854 static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw, 855 unsigned int nbytes) 856 { 857 gw->walk_bytes_remain -= nbytes; 858 scatterwalk_unmap(&gw->walk); 859 scatterwalk_advance(&gw->walk, nbytes); 860 scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain); 861 gw->walk_ptr = NULL; 862 } 863 864 static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) 865 { 866 int n; 867 868 if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) { 869 gw->ptr = gw->buf; 870 gw->nbytes = gw->buf_bytes; 871 goto out; 872 } 873 874 if (gw->walk_bytes_remain == 0) { 875 gw->ptr = NULL; 876 gw->nbytes = 0; 877 goto out; 878 } 879 880 if (!_gcm_sg_clamp_and_map(gw)) { 881 gw->ptr = NULL; 882 gw->nbytes = 0; 883 goto out; 884 } 885 886 if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) { 887 gw->ptr = gw->walk_ptr; 888 gw->nbytes = gw->walk_bytes; 889 goto out; 890 } 891 892 while (1) { 893 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes); 894 memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n); 895 gw->buf_bytes += n; 896 _gcm_sg_unmap_and_advance(gw, n); 897 if (gw->buf_bytes >= minbytesneeded) { 898 gw->ptr = gw->buf; 899 gw->nbytes = gw->buf_bytes; 900 goto out; 901 } 902 if (!_gcm_sg_clamp_and_map(gw)) { 903 gw->ptr = NULL; 904 gw->nbytes = 0; 905 goto out; 906 } 907 } 908 909 out: 910 return gw->nbytes; 911 } 912 913 static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) 914 { 915 if (gw->walk_bytes_remain == 0) { 916 gw->ptr = NULL; 917 gw->nbytes = 0; 918 goto out; 919 } 920 921 if (!_gcm_sg_clamp_and_map(gw)) { 922 gw->ptr = NULL; 923 gw->nbytes = 0; 924 goto out; 925 } 926 927 if (gw->walk_bytes >= minbytesneeded) { 928 gw->ptr = gw->walk_ptr; 929 gw->nbytes = gw->walk_bytes; 930 goto out; 931 } 932 933 scatterwalk_unmap(&gw->walk); 934 gw->walk_ptr = NULL; 935 936 gw->ptr = gw->buf; 937 gw->nbytes = sizeof(gw->buf); 938 939 out: 940 return gw->nbytes; 941 } 942 943 static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) 944 { 945 if (gw->ptr == NULL) 946 return 0; 947 948 if (gw->ptr == gw->buf) { 949 int n = gw->buf_bytes - bytesdone; 950 if (n > 0) { 951 memmove(gw->buf, gw->buf + bytesdone, n); 952 gw->buf_bytes = n; 953 } else 954 gw->buf_bytes = 0; 955 } else 956 _gcm_sg_unmap_and_advance(gw, bytesdone); 957 958 return bytesdone; 959 } 960 961 static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) 962 { 963 int i, n; 964 965 if (gw->ptr == NULL) 966 return 0; 967 968 if (gw->ptr == gw->buf) { 969 for (i = 0; i < bytesdone; i += n) { 970 if (!_gcm_sg_clamp_and_map(gw)) 971 return i; 972 n = min(gw->walk_bytes, bytesdone - i); 973 memcpy(gw->walk_ptr, gw->buf + i, n); 974 _gcm_sg_unmap_and_advance(gw, n); 975 } 976 } else 977 _gcm_sg_unmap_and_advance(gw, bytesdone); 978 979 return bytesdone; 980 } 981 982 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags) 983 { 984 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 985 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm); 986 unsigned int ivsize = crypto_aead_ivsize(tfm); 987 unsigned int taglen = crypto_aead_authsize(tfm); 988 unsigned int aadlen = req->assoclen; 989 unsigned int pclen = req->cryptlen; 990 int ret = 0; 991 992 unsigned int n, len, in_bytes, out_bytes, 993 min_bytes, bytes, aad_bytes, pc_bytes; 994 struct gcm_sg_walk gw_in, gw_out; 995 u8 tag[GHASH_DIGEST_SIZE]; 996 997 struct { 998 u32 _[3]; /* reserved */ 999 u32 cv; /* Counter Value */ 1000 u8 t[GHASH_DIGEST_SIZE];/* Tag */ 1001 u8 h[AES_BLOCK_SIZE]; /* Hash-subkey */ 1002 u64 taadl; /* Total AAD Length */ 1003 u64 tpcl; /* Total Plain-/Cipher-text Length */ 1004 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */ 1005 u8 k[AES_MAX_KEY_SIZE]; /* Key */ 1006 } param; 1007 1008 /* 1009 * encrypt 1010 * req->src: aad||plaintext 1011 * req->dst: aad||ciphertext||tag 1012 * decrypt 1013 * req->src: aad||ciphertext||tag 1014 * req->dst: aad||plaintext, return 0 or -EBADMSG 1015 * aad, plaintext and ciphertext may be empty. 1016 */ 1017 if (flags & CPACF_DECRYPT) 1018 pclen -= taglen; 1019 len = aadlen + pclen; 1020 1021 memset(¶m, 0, sizeof(param)); 1022 param.cv = 1; 1023 param.taadl = aadlen * 8; 1024 param.tpcl = pclen * 8; 1025 memcpy(param.j0, req->iv, ivsize); 1026 *(u32 *)(param.j0 + ivsize) = 1; 1027 memcpy(param.k, ctx->key, ctx->key_len); 1028 1029 gcm_walk_start(&gw_in, req->src, len); 1030 gcm_walk_start(&gw_out, req->dst, len); 1031 1032 do { 1033 min_bytes = min_t(unsigned int, 1034 aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE); 1035 in_bytes = gcm_in_walk_go(&gw_in, min_bytes); 1036 out_bytes = gcm_out_walk_go(&gw_out, min_bytes); 1037 bytes = min(in_bytes, out_bytes); 1038 1039 if (aadlen + pclen <= bytes) { 1040 aad_bytes = aadlen; 1041 pc_bytes = pclen; 1042 flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC; 1043 } else { 1044 if (aadlen <= bytes) { 1045 aad_bytes = aadlen; 1046 pc_bytes = (bytes - aadlen) & 1047 ~(AES_BLOCK_SIZE - 1); 1048 flags |= CPACF_KMA_LAAD; 1049 } else { 1050 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1); 1051 pc_bytes = 0; 1052 } 1053 } 1054 1055 if (aad_bytes > 0) 1056 memcpy(gw_out.ptr, gw_in.ptr, aad_bytes); 1057 1058 cpacf_kma(ctx->fc | flags, ¶m, 1059 gw_out.ptr + aad_bytes, 1060 gw_in.ptr + aad_bytes, pc_bytes, 1061 gw_in.ptr, aad_bytes); 1062 1063 n = aad_bytes + pc_bytes; 1064 if (gcm_in_walk_done(&gw_in, n) != n) 1065 return -ENOMEM; 1066 if (gcm_out_walk_done(&gw_out, n) != n) 1067 return -ENOMEM; 1068 aadlen -= aad_bytes; 1069 pclen -= pc_bytes; 1070 } while (aadlen + pclen > 0); 1071 1072 if (flags & CPACF_DECRYPT) { 1073 scatterwalk_map_and_copy(tag, req->src, len, taglen, 0); 1074 if (crypto_memneq(tag, param.t, taglen)) 1075 ret = -EBADMSG; 1076 } else 1077 scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1); 1078 1079 memzero_explicit(¶m, sizeof(param)); 1080 return ret; 1081 } 1082 1083 static int gcm_aes_encrypt(struct aead_request *req) 1084 { 1085 return gcm_aes_crypt(req, CPACF_ENCRYPT); 1086 } 1087 1088 static int gcm_aes_decrypt(struct aead_request *req) 1089 { 1090 return gcm_aes_crypt(req, CPACF_DECRYPT); 1091 } 1092 1093 static struct aead_alg gcm_aes_aead = { 1094 .setkey = gcm_aes_setkey, 1095 .setauthsize = gcm_aes_setauthsize, 1096 .encrypt = gcm_aes_encrypt, 1097 .decrypt = gcm_aes_decrypt, 1098 1099 .ivsize = GHASH_BLOCK_SIZE - sizeof(u32), 1100 .maxauthsize = GHASH_DIGEST_SIZE, 1101 .chunksize = AES_BLOCK_SIZE, 1102 1103 .base = { 1104 .cra_blocksize = 1, 1105 .cra_ctxsize = sizeof(struct s390_aes_ctx), 1106 .cra_priority = 900, 1107 .cra_name = "gcm(aes)", 1108 .cra_driver_name = "gcm-aes-s390", 1109 .cra_module = THIS_MODULE, 1110 }, 1111 }; 1112 1113 static struct crypto_alg *aes_s390_algs_ptr[5]; 1114 static int aes_s390_algs_num; 1115 static struct aead_alg *aes_s390_aead_alg; 1116 1117 static int aes_s390_register_alg(struct crypto_alg *alg) 1118 { 1119 int ret; 1120 1121 ret = crypto_register_alg(alg); 1122 if (!ret) 1123 aes_s390_algs_ptr[aes_s390_algs_num++] = alg; 1124 return ret; 1125 } 1126 1127 static void aes_s390_fini(void) 1128 { 1129 while (aes_s390_algs_num--) 1130 crypto_unregister_alg(aes_s390_algs_ptr[aes_s390_algs_num]); 1131 if (ctrblk) 1132 free_page((unsigned long) ctrblk); 1133 1134 if (aes_s390_aead_alg) 1135 crypto_unregister_aead(aes_s390_aead_alg); 1136 } 1137 1138 static int __init aes_s390_init(void) 1139 { 1140 int ret; 1141 1142 /* Query available functions for KM, KMC, KMCTR and KMA */ 1143 cpacf_query(CPACF_KM, &km_functions); 1144 cpacf_query(CPACF_KMC, &kmc_functions); 1145 cpacf_query(CPACF_KMCTR, &kmctr_functions); 1146 cpacf_query(CPACF_KMA, &kma_functions); 1147 1148 if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) || 1149 cpacf_test_func(&km_functions, CPACF_KM_AES_192) || 1150 cpacf_test_func(&km_functions, CPACF_KM_AES_256)) { 1151 ret = aes_s390_register_alg(&aes_alg); 1152 if (ret) 1153 goto out_err; 1154 ret = aes_s390_register_alg(&ecb_aes_alg); 1155 if (ret) 1156 goto out_err; 1157 } 1158 1159 if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) || 1160 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) || 1161 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) { 1162 ret = aes_s390_register_alg(&cbc_aes_alg); 1163 if (ret) 1164 goto out_err; 1165 } 1166 1167 if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) || 1168 cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) { 1169 ret = aes_s390_register_alg(&xts_aes_alg); 1170 if (ret) 1171 goto out_err; 1172 } 1173 1174 if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) || 1175 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) || 1176 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) { 1177 ctrblk = (u8 *) __get_free_page(GFP_KERNEL); 1178 if (!ctrblk) { 1179 ret = -ENOMEM; 1180 goto out_err; 1181 } 1182 ret = aes_s390_register_alg(&ctr_aes_alg); 1183 if (ret) 1184 goto out_err; 1185 } 1186 1187 if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) || 1188 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) || 1189 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) { 1190 ret = crypto_register_aead(&gcm_aes_aead); 1191 if (ret) 1192 goto out_err; 1193 aes_s390_aead_alg = &gcm_aes_aead; 1194 } 1195 1196 return 0; 1197 out_err: 1198 aes_s390_fini(); 1199 return ret; 1200 } 1201 1202 module_cpu_feature_match(MSA, aes_s390_init); 1203 module_exit(aes_s390_fini); 1204 1205 MODULE_ALIAS_CRYPTO("aes-all"); 1206 1207 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); 1208 MODULE_LICENSE("GPL"); 1209