1 /* 2 * Cryptographic API. 3 * 4 * s390 implementation of the AES Cipher Algorithm. 5 * 6 * s390 Version: 7 * Copyright IBM Corp. 2005, 2017 8 * Author(s): Jan Glauber (jang@de.ibm.com) 9 * Sebastian Siewior (sebastian@breakpoint.cc> SW-Fallback 10 * Patrick Steuer <patrick.steuer@de.ibm.com> 11 * Harald Freudenberger <freude@de.ibm.com> 12 * 13 * Derived from "crypto/aes_generic.c" 14 * 15 * This program is free software; you can redistribute it and/or modify it 16 * under the terms of the GNU General Public License as published by the Free 17 * Software Foundation; either version 2 of the License, or (at your option) 18 * any later version. 19 * 20 */ 21 22 #define KMSG_COMPONENT "aes_s390" 23 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 24 25 #include <crypto/aes.h> 26 #include <crypto/algapi.h> 27 #include <crypto/ghash.h> 28 #include <crypto/internal/aead.h> 29 #include <crypto/internal/skcipher.h> 30 #include <crypto/scatterwalk.h> 31 #include <linux/err.h> 32 #include <linux/module.h> 33 #include <linux/cpufeature.h> 34 #include <linux/init.h> 35 #include <linux/spinlock.h> 36 #include <linux/fips.h> 37 #include <linux/string.h> 38 #include <crypto/xts.h> 39 #include <asm/cpacf.h> 40 41 static u8 *ctrblk; 42 static DEFINE_SPINLOCK(ctrblk_lock); 43 44 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions, 45 kma_functions; 46 47 struct s390_aes_ctx { 48 u8 key[AES_MAX_KEY_SIZE]; 49 int key_len; 50 unsigned long fc; 51 union { 52 struct crypto_skcipher *blk; 53 struct crypto_cipher *cip; 54 } fallback; 55 }; 56 57 struct s390_xts_ctx { 58 u8 key[32]; 59 u8 pcc_key[32]; 60 int key_len; 61 unsigned long fc; 62 struct crypto_skcipher *fallback; 63 }; 64 65 struct gcm_sg_walk { 66 struct scatter_walk walk; 67 unsigned int walk_bytes; 68 u8 *walk_ptr; 69 unsigned int walk_bytes_remain; 70 u8 buf[AES_BLOCK_SIZE]; 71 unsigned int buf_bytes; 72 u8 *ptr; 73 unsigned int nbytes; 74 }; 75 76 static int setkey_fallback_cip(struct crypto_tfm *tfm, const u8 *in_key, 77 unsigned int key_len) 78 { 79 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 80 int ret; 81 82 sctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK; 83 sctx->fallback.cip->base.crt_flags |= (tfm->crt_flags & 84 CRYPTO_TFM_REQ_MASK); 85 86 ret = crypto_cipher_setkey(sctx->fallback.cip, in_key, key_len); 87 if (ret) { 88 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; 89 tfm->crt_flags |= (sctx->fallback.cip->base.crt_flags & 90 CRYPTO_TFM_RES_MASK); 91 } 92 return ret; 93 } 94 95 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 96 unsigned int key_len) 97 { 98 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 99 unsigned long fc; 100 101 /* Pick the correct function code based on the key length */ 102 fc = (key_len == 16) ? CPACF_KM_AES_128 : 103 (key_len == 24) ? CPACF_KM_AES_192 : 104 (key_len == 32) ? CPACF_KM_AES_256 : 0; 105 106 /* Check if the function code is available */ 107 sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 108 if (!sctx->fc) 109 return setkey_fallback_cip(tfm, in_key, key_len); 110 111 sctx->key_len = key_len; 112 memcpy(sctx->key, in_key, key_len); 113 return 0; 114 } 115 116 static void aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) 117 { 118 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 119 120 if (unlikely(!sctx->fc)) { 121 crypto_cipher_encrypt_one(sctx->fallback.cip, out, in); 122 return; 123 } 124 cpacf_km(sctx->fc, &sctx->key, out, in, AES_BLOCK_SIZE); 125 } 126 127 static void aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) 128 { 129 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 130 131 if (unlikely(!sctx->fc)) { 132 crypto_cipher_decrypt_one(sctx->fallback.cip, out, in); 133 return; 134 } 135 cpacf_km(sctx->fc | CPACF_DECRYPT, 136 &sctx->key, out, in, AES_BLOCK_SIZE); 137 } 138 139 static int fallback_init_cip(struct crypto_tfm *tfm) 140 { 141 const char *name = tfm->__crt_alg->cra_name; 142 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 143 144 sctx->fallback.cip = crypto_alloc_cipher(name, 0, 145 CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK); 146 147 if (IS_ERR(sctx->fallback.cip)) { 148 pr_err("Allocating AES fallback algorithm %s failed\n", 149 name); 150 return PTR_ERR(sctx->fallback.cip); 151 } 152 153 return 0; 154 } 155 156 static void fallback_exit_cip(struct crypto_tfm *tfm) 157 { 158 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 159 160 crypto_free_cipher(sctx->fallback.cip); 161 sctx->fallback.cip = NULL; 162 } 163 164 static struct crypto_alg aes_alg = { 165 .cra_name = "aes", 166 .cra_driver_name = "aes-s390", 167 .cra_priority = 300, 168 .cra_flags = CRYPTO_ALG_TYPE_CIPHER | 169 CRYPTO_ALG_NEED_FALLBACK, 170 .cra_blocksize = AES_BLOCK_SIZE, 171 .cra_ctxsize = sizeof(struct s390_aes_ctx), 172 .cra_module = THIS_MODULE, 173 .cra_init = fallback_init_cip, 174 .cra_exit = fallback_exit_cip, 175 .cra_u = { 176 .cipher = { 177 .cia_min_keysize = AES_MIN_KEY_SIZE, 178 .cia_max_keysize = AES_MAX_KEY_SIZE, 179 .cia_setkey = aes_set_key, 180 .cia_encrypt = aes_encrypt, 181 .cia_decrypt = aes_decrypt, 182 } 183 } 184 }; 185 186 static int setkey_fallback_blk(struct crypto_tfm *tfm, const u8 *key, 187 unsigned int len) 188 { 189 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 190 unsigned int ret; 191 192 crypto_skcipher_clear_flags(sctx->fallback.blk, CRYPTO_TFM_REQ_MASK); 193 crypto_skcipher_set_flags(sctx->fallback.blk, tfm->crt_flags & 194 CRYPTO_TFM_REQ_MASK); 195 196 ret = crypto_skcipher_setkey(sctx->fallback.blk, key, len); 197 198 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; 199 tfm->crt_flags |= crypto_skcipher_get_flags(sctx->fallback.blk) & 200 CRYPTO_TFM_RES_MASK; 201 202 return ret; 203 } 204 205 static int fallback_blk_dec(struct blkcipher_desc *desc, 206 struct scatterlist *dst, struct scatterlist *src, 207 unsigned int nbytes) 208 { 209 unsigned int ret; 210 struct crypto_blkcipher *tfm = desc->tfm; 211 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(tfm); 212 SKCIPHER_REQUEST_ON_STACK(req, sctx->fallback.blk); 213 214 skcipher_request_set_tfm(req, sctx->fallback.blk); 215 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 216 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 217 218 ret = crypto_skcipher_decrypt(req); 219 220 skcipher_request_zero(req); 221 return ret; 222 } 223 224 static int fallback_blk_enc(struct blkcipher_desc *desc, 225 struct scatterlist *dst, struct scatterlist *src, 226 unsigned int nbytes) 227 { 228 unsigned int ret; 229 struct crypto_blkcipher *tfm = desc->tfm; 230 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(tfm); 231 SKCIPHER_REQUEST_ON_STACK(req, sctx->fallback.blk); 232 233 skcipher_request_set_tfm(req, sctx->fallback.blk); 234 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 235 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 236 237 ret = crypto_skcipher_encrypt(req); 238 return ret; 239 } 240 241 static int ecb_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 242 unsigned int key_len) 243 { 244 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 245 unsigned long fc; 246 247 /* Pick the correct function code based on the key length */ 248 fc = (key_len == 16) ? CPACF_KM_AES_128 : 249 (key_len == 24) ? CPACF_KM_AES_192 : 250 (key_len == 32) ? CPACF_KM_AES_256 : 0; 251 252 /* Check if the function code is available */ 253 sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 254 if (!sctx->fc) 255 return setkey_fallback_blk(tfm, in_key, key_len); 256 257 sctx->key_len = key_len; 258 memcpy(sctx->key, in_key, key_len); 259 return 0; 260 } 261 262 static int ecb_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier, 263 struct blkcipher_walk *walk) 264 { 265 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 266 unsigned int nbytes, n; 267 int ret; 268 269 ret = blkcipher_walk_virt(desc, walk); 270 while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) { 271 /* only use complete blocks */ 272 n = nbytes & ~(AES_BLOCK_SIZE - 1); 273 cpacf_km(sctx->fc | modifier, sctx->key, 274 walk->dst.virt.addr, walk->src.virt.addr, n); 275 ret = blkcipher_walk_done(desc, walk, nbytes - n); 276 } 277 278 return ret; 279 } 280 281 static int ecb_aes_encrypt(struct blkcipher_desc *desc, 282 struct scatterlist *dst, struct scatterlist *src, 283 unsigned int nbytes) 284 { 285 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 286 struct blkcipher_walk walk; 287 288 if (unlikely(!sctx->fc)) 289 return fallback_blk_enc(desc, dst, src, nbytes); 290 291 blkcipher_walk_init(&walk, dst, src, nbytes); 292 return ecb_aes_crypt(desc, 0, &walk); 293 } 294 295 static int ecb_aes_decrypt(struct blkcipher_desc *desc, 296 struct scatterlist *dst, struct scatterlist *src, 297 unsigned int nbytes) 298 { 299 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 300 struct blkcipher_walk walk; 301 302 if (unlikely(!sctx->fc)) 303 return fallback_blk_dec(desc, dst, src, nbytes); 304 305 blkcipher_walk_init(&walk, dst, src, nbytes); 306 return ecb_aes_crypt(desc, CPACF_DECRYPT, &walk); 307 } 308 309 static int fallback_init_blk(struct crypto_tfm *tfm) 310 { 311 const char *name = tfm->__crt_alg->cra_name; 312 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 313 314 sctx->fallback.blk = crypto_alloc_skcipher(name, 0, 315 CRYPTO_ALG_ASYNC | 316 CRYPTO_ALG_NEED_FALLBACK); 317 318 if (IS_ERR(sctx->fallback.blk)) { 319 pr_err("Allocating AES fallback algorithm %s failed\n", 320 name); 321 return PTR_ERR(sctx->fallback.blk); 322 } 323 324 return 0; 325 } 326 327 static void fallback_exit_blk(struct crypto_tfm *tfm) 328 { 329 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 330 331 crypto_free_skcipher(sctx->fallback.blk); 332 } 333 334 static struct crypto_alg ecb_aes_alg = { 335 .cra_name = "ecb(aes)", 336 .cra_driver_name = "ecb-aes-s390", 337 .cra_priority = 400, /* combo: aes + ecb */ 338 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | 339 CRYPTO_ALG_NEED_FALLBACK, 340 .cra_blocksize = AES_BLOCK_SIZE, 341 .cra_ctxsize = sizeof(struct s390_aes_ctx), 342 .cra_type = &crypto_blkcipher_type, 343 .cra_module = THIS_MODULE, 344 .cra_init = fallback_init_blk, 345 .cra_exit = fallback_exit_blk, 346 .cra_u = { 347 .blkcipher = { 348 .min_keysize = AES_MIN_KEY_SIZE, 349 .max_keysize = AES_MAX_KEY_SIZE, 350 .setkey = ecb_aes_set_key, 351 .encrypt = ecb_aes_encrypt, 352 .decrypt = ecb_aes_decrypt, 353 } 354 } 355 }; 356 357 static int cbc_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 358 unsigned int key_len) 359 { 360 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 361 unsigned long fc; 362 363 /* Pick the correct function code based on the key length */ 364 fc = (key_len == 16) ? CPACF_KMC_AES_128 : 365 (key_len == 24) ? CPACF_KMC_AES_192 : 366 (key_len == 32) ? CPACF_KMC_AES_256 : 0; 367 368 /* Check if the function code is available */ 369 sctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0; 370 if (!sctx->fc) 371 return setkey_fallback_blk(tfm, in_key, key_len); 372 373 sctx->key_len = key_len; 374 memcpy(sctx->key, in_key, key_len); 375 return 0; 376 } 377 378 static int cbc_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier, 379 struct blkcipher_walk *walk) 380 { 381 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 382 unsigned int nbytes, n; 383 int ret; 384 struct { 385 u8 iv[AES_BLOCK_SIZE]; 386 u8 key[AES_MAX_KEY_SIZE]; 387 } param; 388 389 ret = blkcipher_walk_virt(desc, walk); 390 memcpy(param.iv, walk->iv, AES_BLOCK_SIZE); 391 memcpy(param.key, sctx->key, sctx->key_len); 392 while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) { 393 /* only use complete blocks */ 394 n = nbytes & ~(AES_BLOCK_SIZE - 1); 395 cpacf_kmc(sctx->fc | modifier, ¶m, 396 walk->dst.virt.addr, walk->src.virt.addr, n); 397 ret = blkcipher_walk_done(desc, walk, nbytes - n); 398 } 399 memcpy(walk->iv, param.iv, AES_BLOCK_SIZE); 400 return ret; 401 } 402 403 static int cbc_aes_encrypt(struct blkcipher_desc *desc, 404 struct scatterlist *dst, struct scatterlist *src, 405 unsigned int nbytes) 406 { 407 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 408 struct blkcipher_walk walk; 409 410 if (unlikely(!sctx->fc)) 411 return fallback_blk_enc(desc, dst, src, nbytes); 412 413 blkcipher_walk_init(&walk, dst, src, nbytes); 414 return cbc_aes_crypt(desc, 0, &walk); 415 } 416 417 static int cbc_aes_decrypt(struct blkcipher_desc *desc, 418 struct scatterlist *dst, struct scatterlist *src, 419 unsigned int nbytes) 420 { 421 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 422 struct blkcipher_walk walk; 423 424 if (unlikely(!sctx->fc)) 425 return fallback_blk_dec(desc, dst, src, nbytes); 426 427 blkcipher_walk_init(&walk, dst, src, nbytes); 428 return cbc_aes_crypt(desc, CPACF_DECRYPT, &walk); 429 } 430 431 static struct crypto_alg cbc_aes_alg = { 432 .cra_name = "cbc(aes)", 433 .cra_driver_name = "cbc-aes-s390", 434 .cra_priority = 400, /* combo: aes + cbc */ 435 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | 436 CRYPTO_ALG_NEED_FALLBACK, 437 .cra_blocksize = AES_BLOCK_SIZE, 438 .cra_ctxsize = sizeof(struct s390_aes_ctx), 439 .cra_type = &crypto_blkcipher_type, 440 .cra_module = THIS_MODULE, 441 .cra_init = fallback_init_blk, 442 .cra_exit = fallback_exit_blk, 443 .cra_u = { 444 .blkcipher = { 445 .min_keysize = AES_MIN_KEY_SIZE, 446 .max_keysize = AES_MAX_KEY_SIZE, 447 .ivsize = AES_BLOCK_SIZE, 448 .setkey = cbc_aes_set_key, 449 .encrypt = cbc_aes_encrypt, 450 .decrypt = cbc_aes_decrypt, 451 } 452 } 453 }; 454 455 static int xts_fallback_setkey(struct crypto_tfm *tfm, const u8 *key, 456 unsigned int len) 457 { 458 struct s390_xts_ctx *xts_ctx = crypto_tfm_ctx(tfm); 459 unsigned int ret; 460 461 crypto_skcipher_clear_flags(xts_ctx->fallback, CRYPTO_TFM_REQ_MASK); 462 crypto_skcipher_set_flags(xts_ctx->fallback, tfm->crt_flags & 463 CRYPTO_TFM_REQ_MASK); 464 465 ret = crypto_skcipher_setkey(xts_ctx->fallback, key, len); 466 467 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK; 468 tfm->crt_flags |= crypto_skcipher_get_flags(xts_ctx->fallback) & 469 CRYPTO_TFM_RES_MASK; 470 471 return ret; 472 } 473 474 static int xts_fallback_decrypt(struct blkcipher_desc *desc, 475 struct scatterlist *dst, struct scatterlist *src, 476 unsigned int nbytes) 477 { 478 struct crypto_blkcipher *tfm = desc->tfm; 479 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(tfm); 480 SKCIPHER_REQUEST_ON_STACK(req, xts_ctx->fallback); 481 unsigned int ret; 482 483 skcipher_request_set_tfm(req, xts_ctx->fallback); 484 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 485 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 486 487 ret = crypto_skcipher_decrypt(req); 488 489 skcipher_request_zero(req); 490 return ret; 491 } 492 493 static int xts_fallback_encrypt(struct blkcipher_desc *desc, 494 struct scatterlist *dst, struct scatterlist *src, 495 unsigned int nbytes) 496 { 497 struct crypto_blkcipher *tfm = desc->tfm; 498 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(tfm); 499 SKCIPHER_REQUEST_ON_STACK(req, xts_ctx->fallback); 500 unsigned int ret; 501 502 skcipher_request_set_tfm(req, xts_ctx->fallback); 503 skcipher_request_set_callback(req, desc->flags, NULL, NULL); 504 skcipher_request_set_crypt(req, src, dst, nbytes, desc->info); 505 506 ret = crypto_skcipher_encrypt(req); 507 508 skcipher_request_zero(req); 509 return ret; 510 } 511 512 static int xts_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 513 unsigned int key_len) 514 { 515 struct s390_xts_ctx *xts_ctx = crypto_tfm_ctx(tfm); 516 unsigned long fc; 517 int err; 518 519 err = xts_check_key(tfm, in_key, key_len); 520 if (err) 521 return err; 522 523 /* In fips mode only 128 bit or 256 bit keys are valid */ 524 if (fips_enabled && key_len != 32 && key_len != 64) { 525 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN; 526 return -EINVAL; 527 } 528 529 /* Pick the correct function code based on the key length */ 530 fc = (key_len == 32) ? CPACF_KM_XTS_128 : 531 (key_len == 64) ? CPACF_KM_XTS_256 : 0; 532 533 /* Check if the function code is available */ 534 xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 535 if (!xts_ctx->fc) 536 return xts_fallback_setkey(tfm, in_key, key_len); 537 538 /* Split the XTS key into the two subkeys */ 539 key_len = key_len / 2; 540 xts_ctx->key_len = key_len; 541 memcpy(xts_ctx->key, in_key, key_len); 542 memcpy(xts_ctx->pcc_key, in_key + key_len, key_len); 543 return 0; 544 } 545 546 static int xts_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier, 547 struct blkcipher_walk *walk) 548 { 549 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(desc->tfm); 550 unsigned int offset, nbytes, n; 551 int ret; 552 struct { 553 u8 key[32]; 554 u8 tweak[16]; 555 u8 block[16]; 556 u8 bit[16]; 557 u8 xts[16]; 558 } pcc_param; 559 struct { 560 u8 key[32]; 561 u8 init[16]; 562 } xts_param; 563 564 ret = blkcipher_walk_virt(desc, walk); 565 offset = xts_ctx->key_len & 0x10; 566 memset(pcc_param.block, 0, sizeof(pcc_param.block)); 567 memset(pcc_param.bit, 0, sizeof(pcc_param.bit)); 568 memset(pcc_param.xts, 0, sizeof(pcc_param.xts)); 569 memcpy(pcc_param.tweak, walk->iv, sizeof(pcc_param.tweak)); 570 memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len); 571 cpacf_pcc(xts_ctx->fc, pcc_param.key + offset); 572 573 memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len); 574 memcpy(xts_param.init, pcc_param.xts, 16); 575 576 while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) { 577 /* only use complete blocks */ 578 n = nbytes & ~(AES_BLOCK_SIZE - 1); 579 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset, 580 walk->dst.virt.addr, walk->src.virt.addr, n); 581 ret = blkcipher_walk_done(desc, walk, nbytes - n); 582 } 583 return ret; 584 } 585 586 static int xts_aes_encrypt(struct blkcipher_desc *desc, 587 struct scatterlist *dst, struct scatterlist *src, 588 unsigned int nbytes) 589 { 590 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(desc->tfm); 591 struct blkcipher_walk walk; 592 593 if (unlikely(!xts_ctx->fc)) 594 return xts_fallback_encrypt(desc, dst, src, nbytes); 595 596 blkcipher_walk_init(&walk, dst, src, nbytes); 597 return xts_aes_crypt(desc, 0, &walk); 598 } 599 600 static int xts_aes_decrypt(struct blkcipher_desc *desc, 601 struct scatterlist *dst, struct scatterlist *src, 602 unsigned int nbytes) 603 { 604 struct s390_xts_ctx *xts_ctx = crypto_blkcipher_ctx(desc->tfm); 605 struct blkcipher_walk walk; 606 607 if (unlikely(!xts_ctx->fc)) 608 return xts_fallback_decrypt(desc, dst, src, nbytes); 609 610 blkcipher_walk_init(&walk, dst, src, nbytes); 611 return xts_aes_crypt(desc, CPACF_DECRYPT, &walk); 612 } 613 614 static int xts_fallback_init(struct crypto_tfm *tfm) 615 { 616 const char *name = tfm->__crt_alg->cra_name; 617 struct s390_xts_ctx *xts_ctx = crypto_tfm_ctx(tfm); 618 619 xts_ctx->fallback = crypto_alloc_skcipher(name, 0, 620 CRYPTO_ALG_ASYNC | 621 CRYPTO_ALG_NEED_FALLBACK); 622 623 if (IS_ERR(xts_ctx->fallback)) { 624 pr_err("Allocating XTS fallback algorithm %s failed\n", 625 name); 626 return PTR_ERR(xts_ctx->fallback); 627 } 628 return 0; 629 } 630 631 static void xts_fallback_exit(struct crypto_tfm *tfm) 632 { 633 struct s390_xts_ctx *xts_ctx = crypto_tfm_ctx(tfm); 634 635 crypto_free_skcipher(xts_ctx->fallback); 636 } 637 638 static struct crypto_alg xts_aes_alg = { 639 .cra_name = "xts(aes)", 640 .cra_driver_name = "xts-aes-s390", 641 .cra_priority = 400, /* combo: aes + xts */ 642 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | 643 CRYPTO_ALG_NEED_FALLBACK, 644 .cra_blocksize = AES_BLOCK_SIZE, 645 .cra_ctxsize = sizeof(struct s390_xts_ctx), 646 .cra_type = &crypto_blkcipher_type, 647 .cra_module = THIS_MODULE, 648 .cra_init = xts_fallback_init, 649 .cra_exit = xts_fallback_exit, 650 .cra_u = { 651 .blkcipher = { 652 .min_keysize = 2 * AES_MIN_KEY_SIZE, 653 .max_keysize = 2 * AES_MAX_KEY_SIZE, 654 .ivsize = AES_BLOCK_SIZE, 655 .setkey = xts_aes_set_key, 656 .encrypt = xts_aes_encrypt, 657 .decrypt = xts_aes_decrypt, 658 } 659 } 660 }; 661 662 static int ctr_aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 663 unsigned int key_len) 664 { 665 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 666 unsigned long fc; 667 668 /* Pick the correct function code based on the key length */ 669 fc = (key_len == 16) ? CPACF_KMCTR_AES_128 : 670 (key_len == 24) ? CPACF_KMCTR_AES_192 : 671 (key_len == 32) ? CPACF_KMCTR_AES_256 : 0; 672 673 /* Check if the function code is available */ 674 sctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0; 675 if (!sctx->fc) 676 return setkey_fallback_blk(tfm, in_key, key_len); 677 678 sctx->key_len = key_len; 679 memcpy(sctx->key, in_key, key_len); 680 return 0; 681 } 682 683 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes) 684 { 685 unsigned int i, n; 686 687 /* only use complete blocks, max. PAGE_SIZE */ 688 memcpy(ctrptr, iv, AES_BLOCK_SIZE); 689 n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1); 690 for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) { 691 memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE); 692 crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE); 693 ctrptr += AES_BLOCK_SIZE; 694 } 695 return n; 696 } 697 698 static int ctr_aes_crypt(struct blkcipher_desc *desc, unsigned long modifier, 699 struct blkcipher_walk *walk) 700 { 701 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 702 u8 buf[AES_BLOCK_SIZE], *ctrptr; 703 unsigned int n, nbytes; 704 int ret, locked; 705 706 locked = spin_trylock(&ctrblk_lock); 707 708 ret = blkcipher_walk_virt_block(desc, walk, AES_BLOCK_SIZE); 709 while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) { 710 n = AES_BLOCK_SIZE; 711 if (nbytes >= 2*AES_BLOCK_SIZE && locked) 712 n = __ctrblk_init(ctrblk, walk->iv, nbytes); 713 ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk->iv; 714 cpacf_kmctr(sctx->fc | modifier, sctx->key, 715 walk->dst.virt.addr, walk->src.virt.addr, 716 n, ctrptr); 717 if (ctrptr == ctrblk) 718 memcpy(walk->iv, ctrptr + n - AES_BLOCK_SIZE, 719 AES_BLOCK_SIZE); 720 crypto_inc(walk->iv, AES_BLOCK_SIZE); 721 ret = blkcipher_walk_done(desc, walk, nbytes - n); 722 } 723 if (locked) 724 spin_unlock(&ctrblk_lock); 725 /* 726 * final block may be < AES_BLOCK_SIZE, copy only nbytes 727 */ 728 if (nbytes) { 729 cpacf_kmctr(sctx->fc | modifier, sctx->key, 730 buf, walk->src.virt.addr, 731 AES_BLOCK_SIZE, walk->iv); 732 memcpy(walk->dst.virt.addr, buf, nbytes); 733 crypto_inc(walk->iv, AES_BLOCK_SIZE); 734 ret = blkcipher_walk_done(desc, walk, 0); 735 } 736 737 return ret; 738 } 739 740 static int ctr_aes_encrypt(struct blkcipher_desc *desc, 741 struct scatterlist *dst, struct scatterlist *src, 742 unsigned int nbytes) 743 { 744 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 745 struct blkcipher_walk walk; 746 747 if (unlikely(!sctx->fc)) 748 return fallback_blk_enc(desc, dst, src, nbytes); 749 750 blkcipher_walk_init(&walk, dst, src, nbytes); 751 return ctr_aes_crypt(desc, 0, &walk); 752 } 753 754 static int ctr_aes_decrypt(struct blkcipher_desc *desc, 755 struct scatterlist *dst, struct scatterlist *src, 756 unsigned int nbytes) 757 { 758 struct s390_aes_ctx *sctx = crypto_blkcipher_ctx(desc->tfm); 759 struct blkcipher_walk walk; 760 761 if (unlikely(!sctx->fc)) 762 return fallback_blk_dec(desc, dst, src, nbytes); 763 764 blkcipher_walk_init(&walk, dst, src, nbytes); 765 return ctr_aes_crypt(desc, CPACF_DECRYPT, &walk); 766 } 767 768 static struct crypto_alg ctr_aes_alg = { 769 .cra_name = "ctr(aes)", 770 .cra_driver_name = "ctr-aes-s390", 771 .cra_priority = 400, /* combo: aes + ctr */ 772 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | 773 CRYPTO_ALG_NEED_FALLBACK, 774 .cra_blocksize = 1, 775 .cra_ctxsize = sizeof(struct s390_aes_ctx), 776 .cra_type = &crypto_blkcipher_type, 777 .cra_module = THIS_MODULE, 778 .cra_init = fallback_init_blk, 779 .cra_exit = fallback_exit_blk, 780 .cra_u = { 781 .blkcipher = { 782 .min_keysize = AES_MIN_KEY_SIZE, 783 .max_keysize = AES_MAX_KEY_SIZE, 784 .ivsize = AES_BLOCK_SIZE, 785 .setkey = ctr_aes_set_key, 786 .encrypt = ctr_aes_encrypt, 787 .decrypt = ctr_aes_decrypt, 788 } 789 } 790 }; 791 792 static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *key, 793 unsigned int keylen) 794 { 795 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm); 796 797 switch (keylen) { 798 case AES_KEYSIZE_128: 799 ctx->fc = CPACF_KMA_GCM_AES_128; 800 break; 801 case AES_KEYSIZE_192: 802 ctx->fc = CPACF_KMA_GCM_AES_192; 803 break; 804 case AES_KEYSIZE_256: 805 ctx->fc = CPACF_KMA_GCM_AES_256; 806 break; 807 default: 808 return -EINVAL; 809 } 810 811 memcpy(ctx->key, key, keylen); 812 ctx->key_len = keylen; 813 return 0; 814 } 815 816 static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize) 817 { 818 switch (authsize) { 819 case 4: 820 case 8: 821 case 12: 822 case 13: 823 case 14: 824 case 15: 825 case 16: 826 break; 827 default: 828 return -EINVAL; 829 } 830 831 return 0; 832 } 833 834 static void gcm_sg_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg, 835 unsigned int len) 836 { 837 memset(gw, 0, sizeof(*gw)); 838 gw->walk_bytes_remain = len; 839 scatterwalk_start(&gw->walk, sg); 840 } 841 842 static int gcm_sg_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) 843 { 844 int n; 845 846 /* minbytesneeded <= AES_BLOCK_SIZE */ 847 if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) { 848 gw->ptr = gw->buf; 849 gw->nbytes = gw->buf_bytes; 850 goto out; 851 } 852 853 if (gw->walk_bytes_remain == 0) { 854 gw->ptr = NULL; 855 gw->nbytes = 0; 856 goto out; 857 } 858 859 gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain); 860 if (!gw->walk_bytes) { 861 scatterwalk_start(&gw->walk, sg_next(gw->walk.sg)); 862 gw->walk_bytes = scatterwalk_clamp(&gw->walk, 863 gw->walk_bytes_remain); 864 } 865 gw->walk_ptr = scatterwalk_map(&gw->walk); 866 867 if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) { 868 gw->ptr = gw->walk_ptr; 869 gw->nbytes = gw->walk_bytes; 870 goto out; 871 } 872 873 while (1) { 874 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes); 875 memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n); 876 gw->buf_bytes += n; 877 gw->walk_bytes_remain -= n; 878 scatterwalk_unmap(&gw->walk); 879 scatterwalk_advance(&gw->walk, n); 880 scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain); 881 882 if (gw->buf_bytes >= minbytesneeded) { 883 gw->ptr = gw->buf; 884 gw->nbytes = gw->buf_bytes; 885 goto out; 886 } 887 888 gw->walk_bytes = scatterwalk_clamp(&gw->walk, 889 gw->walk_bytes_remain); 890 if (!gw->walk_bytes) { 891 scatterwalk_start(&gw->walk, sg_next(gw->walk.sg)); 892 gw->walk_bytes = scatterwalk_clamp(&gw->walk, 893 gw->walk_bytes_remain); 894 } 895 gw->walk_ptr = scatterwalk_map(&gw->walk); 896 } 897 898 out: 899 return gw->nbytes; 900 } 901 902 static void gcm_sg_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) 903 { 904 int n; 905 906 if (gw->ptr == NULL) 907 return; 908 909 if (gw->ptr == gw->buf) { 910 n = gw->buf_bytes - bytesdone; 911 if (n > 0) { 912 memmove(gw->buf, gw->buf + bytesdone, n); 913 gw->buf_bytes -= n; 914 } else 915 gw->buf_bytes = 0; 916 } else { 917 gw->walk_bytes_remain -= bytesdone; 918 scatterwalk_unmap(&gw->walk); 919 scatterwalk_advance(&gw->walk, bytesdone); 920 scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain); 921 } 922 } 923 924 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags) 925 { 926 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 927 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm); 928 unsigned int ivsize = crypto_aead_ivsize(tfm); 929 unsigned int taglen = crypto_aead_authsize(tfm); 930 unsigned int aadlen = req->assoclen; 931 unsigned int pclen = req->cryptlen; 932 int ret = 0; 933 934 unsigned int len, in_bytes, out_bytes, 935 min_bytes, bytes, aad_bytes, pc_bytes; 936 struct gcm_sg_walk gw_in, gw_out; 937 u8 tag[GHASH_DIGEST_SIZE]; 938 939 struct { 940 u32 _[3]; /* reserved */ 941 u32 cv; /* Counter Value */ 942 u8 t[GHASH_DIGEST_SIZE];/* Tag */ 943 u8 h[AES_BLOCK_SIZE]; /* Hash-subkey */ 944 u64 taadl; /* Total AAD Length */ 945 u64 tpcl; /* Total Plain-/Cipher-text Length */ 946 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */ 947 u8 k[AES_MAX_KEY_SIZE]; /* Key */ 948 } param; 949 950 /* 951 * encrypt 952 * req->src: aad||plaintext 953 * req->dst: aad||ciphertext||tag 954 * decrypt 955 * req->src: aad||ciphertext||tag 956 * req->dst: aad||plaintext, return 0 or -EBADMSG 957 * aad, plaintext and ciphertext may be empty. 958 */ 959 if (flags & CPACF_DECRYPT) 960 pclen -= taglen; 961 len = aadlen + pclen; 962 963 memset(¶m, 0, sizeof(param)); 964 param.cv = 1; 965 param.taadl = aadlen * 8; 966 param.tpcl = pclen * 8; 967 memcpy(param.j0, req->iv, ivsize); 968 *(u32 *)(param.j0 + ivsize) = 1; 969 memcpy(param.k, ctx->key, ctx->key_len); 970 971 gcm_sg_walk_start(&gw_in, req->src, len); 972 gcm_sg_walk_start(&gw_out, req->dst, len); 973 974 do { 975 min_bytes = min_t(unsigned int, 976 aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE); 977 in_bytes = gcm_sg_walk_go(&gw_in, min_bytes); 978 out_bytes = gcm_sg_walk_go(&gw_out, min_bytes); 979 bytes = min(in_bytes, out_bytes); 980 981 if (aadlen + pclen <= bytes) { 982 aad_bytes = aadlen; 983 pc_bytes = pclen; 984 flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC; 985 } else { 986 if (aadlen <= bytes) { 987 aad_bytes = aadlen; 988 pc_bytes = (bytes - aadlen) & 989 ~(AES_BLOCK_SIZE - 1); 990 flags |= CPACF_KMA_LAAD; 991 } else { 992 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1); 993 pc_bytes = 0; 994 } 995 } 996 997 if (aad_bytes > 0) 998 memcpy(gw_out.ptr, gw_in.ptr, aad_bytes); 999 1000 cpacf_kma(ctx->fc | flags, ¶m, 1001 gw_out.ptr + aad_bytes, 1002 gw_in.ptr + aad_bytes, pc_bytes, 1003 gw_in.ptr, aad_bytes); 1004 1005 gcm_sg_walk_done(&gw_in, aad_bytes + pc_bytes); 1006 gcm_sg_walk_done(&gw_out, aad_bytes + pc_bytes); 1007 aadlen -= aad_bytes; 1008 pclen -= pc_bytes; 1009 } while (aadlen + pclen > 0); 1010 1011 if (flags & CPACF_DECRYPT) { 1012 scatterwalk_map_and_copy(tag, req->src, len, taglen, 0); 1013 if (crypto_memneq(tag, param.t, taglen)) 1014 ret = -EBADMSG; 1015 } else 1016 scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1); 1017 1018 memzero_explicit(¶m, sizeof(param)); 1019 return ret; 1020 } 1021 1022 static int gcm_aes_encrypt(struct aead_request *req) 1023 { 1024 return gcm_aes_crypt(req, CPACF_ENCRYPT); 1025 } 1026 1027 static int gcm_aes_decrypt(struct aead_request *req) 1028 { 1029 return gcm_aes_crypt(req, CPACF_DECRYPT); 1030 } 1031 1032 static struct aead_alg gcm_aes_aead = { 1033 .setkey = gcm_aes_setkey, 1034 .setauthsize = gcm_aes_setauthsize, 1035 .encrypt = gcm_aes_encrypt, 1036 .decrypt = gcm_aes_decrypt, 1037 1038 .ivsize = GHASH_BLOCK_SIZE - sizeof(u32), 1039 .maxauthsize = GHASH_DIGEST_SIZE, 1040 .chunksize = AES_BLOCK_SIZE, 1041 1042 .base = { 1043 .cra_flags = CRYPTO_ALG_TYPE_AEAD, 1044 .cra_blocksize = 1, 1045 .cra_ctxsize = sizeof(struct s390_aes_ctx), 1046 .cra_priority = 900, 1047 .cra_name = "gcm(aes)", 1048 .cra_driver_name = "gcm-aes-s390", 1049 .cra_module = THIS_MODULE, 1050 }, 1051 }; 1052 1053 static struct crypto_alg *aes_s390_algs_ptr[5]; 1054 static int aes_s390_algs_num; 1055 1056 static int aes_s390_register_alg(struct crypto_alg *alg) 1057 { 1058 int ret; 1059 1060 ret = crypto_register_alg(alg); 1061 if (!ret) 1062 aes_s390_algs_ptr[aes_s390_algs_num++] = alg; 1063 return ret; 1064 } 1065 1066 static void aes_s390_fini(void) 1067 { 1068 while (aes_s390_algs_num--) 1069 crypto_unregister_alg(aes_s390_algs_ptr[aes_s390_algs_num]); 1070 if (ctrblk) 1071 free_page((unsigned long) ctrblk); 1072 1073 crypto_unregister_aead(&gcm_aes_aead); 1074 } 1075 1076 static int __init aes_s390_init(void) 1077 { 1078 int ret; 1079 1080 /* Query available functions for KM, KMC, KMCTR and KMA */ 1081 cpacf_query(CPACF_KM, &km_functions); 1082 cpacf_query(CPACF_KMC, &kmc_functions); 1083 cpacf_query(CPACF_KMCTR, &kmctr_functions); 1084 cpacf_query(CPACF_KMA, &kma_functions); 1085 1086 if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) || 1087 cpacf_test_func(&km_functions, CPACF_KM_AES_192) || 1088 cpacf_test_func(&km_functions, CPACF_KM_AES_256)) { 1089 ret = aes_s390_register_alg(&aes_alg); 1090 if (ret) 1091 goto out_err; 1092 ret = aes_s390_register_alg(&ecb_aes_alg); 1093 if (ret) 1094 goto out_err; 1095 } 1096 1097 if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) || 1098 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) || 1099 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) { 1100 ret = aes_s390_register_alg(&cbc_aes_alg); 1101 if (ret) 1102 goto out_err; 1103 } 1104 1105 if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) || 1106 cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) { 1107 ret = aes_s390_register_alg(&xts_aes_alg); 1108 if (ret) 1109 goto out_err; 1110 } 1111 1112 if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) || 1113 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) || 1114 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) { 1115 ctrblk = (u8 *) __get_free_page(GFP_KERNEL); 1116 if (!ctrblk) { 1117 ret = -ENOMEM; 1118 goto out_err; 1119 } 1120 ret = aes_s390_register_alg(&ctr_aes_alg); 1121 if (ret) 1122 goto out_err; 1123 } 1124 1125 if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) || 1126 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) || 1127 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) { 1128 ret = crypto_register_aead(&gcm_aes_aead); 1129 if (ret) 1130 goto out_err; 1131 } 1132 1133 return 0; 1134 out_err: 1135 aes_s390_fini(); 1136 return ret; 1137 } 1138 1139 module_cpu_feature_match(MSA, aes_s390_init); 1140 module_exit(aes_s390_fini); 1141 1142 MODULE_ALIAS_CRYPTO("aes-all"); 1143 1144 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); 1145 MODULE_LICENSE("GPL"); 1146