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/cipher.h> 25 #include <crypto/internal/skcipher.h> 26 #include <crypto/scatterwalk.h> 27 #include <linux/err.h> 28 #include <linux/module.h> 29 #include <linux/cpufeature.h> 30 #include <linux/init.h> 31 #include <linux/mutex.h> 32 #include <linux/fips.h> 33 #include <linux/string.h> 34 #include <crypto/xts.h> 35 #include <asm/cpacf.h> 36 37 static u8 *ctrblk; 38 static DEFINE_MUTEX(ctrblk_lock); 39 40 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions, 41 kma_functions; 42 43 struct s390_aes_ctx { 44 u8 key[AES_MAX_KEY_SIZE]; 45 int key_len; 46 unsigned long fc; 47 union { 48 struct crypto_skcipher *skcipher; 49 struct crypto_cipher *cip; 50 } fallback; 51 }; 52 53 struct s390_xts_ctx { 54 u8 key[32]; 55 u8 pcc_key[32]; 56 int key_len; 57 unsigned long fc; 58 struct crypto_skcipher *fallback; 59 }; 60 61 struct gcm_sg_walk { 62 struct scatter_walk walk; 63 unsigned int walk_bytes; 64 u8 *walk_ptr; 65 unsigned int walk_bytes_remain; 66 u8 buf[AES_BLOCK_SIZE]; 67 unsigned int buf_bytes; 68 u8 *ptr; 69 unsigned int nbytes; 70 }; 71 72 static int setkey_fallback_cip(struct crypto_tfm *tfm, const u8 *in_key, 73 unsigned int key_len) 74 { 75 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 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 return crypto_cipher_setkey(sctx->fallback.cip, in_key, key_len); 82 } 83 84 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key, 85 unsigned int key_len) 86 { 87 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 88 unsigned long fc; 89 90 /* Pick the correct function code based on the key length */ 91 fc = (key_len == 16) ? CPACF_KM_AES_128 : 92 (key_len == 24) ? CPACF_KM_AES_192 : 93 (key_len == 32) ? CPACF_KM_AES_256 : 0; 94 95 /* Check if the function code is available */ 96 sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 97 if (!sctx->fc) 98 return setkey_fallback_cip(tfm, in_key, key_len); 99 100 sctx->key_len = key_len; 101 memcpy(sctx->key, in_key, key_len); 102 return 0; 103 } 104 105 static void crypto_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in) 106 { 107 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 108 109 if (unlikely(!sctx->fc)) { 110 crypto_cipher_encrypt_one(sctx->fallback.cip, out, in); 111 return; 112 } 113 cpacf_km(sctx->fc, &sctx->key, out, in, AES_BLOCK_SIZE); 114 } 115 116 static void crypto_aes_decrypt(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_decrypt_one(sctx->fallback.cip, out, in); 122 return; 123 } 124 cpacf_km(sctx->fc | CPACF_DECRYPT, 125 &sctx->key, out, in, AES_BLOCK_SIZE); 126 } 127 128 static int fallback_init_cip(struct crypto_tfm *tfm) 129 { 130 const char *name = tfm->__crt_alg->cra_name; 131 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 132 133 sctx->fallback.cip = crypto_alloc_cipher(name, 0, 134 CRYPTO_ALG_NEED_FALLBACK); 135 136 if (IS_ERR(sctx->fallback.cip)) { 137 pr_err("Allocating AES fallback algorithm %s failed\n", 138 name); 139 return PTR_ERR(sctx->fallback.cip); 140 } 141 142 return 0; 143 } 144 145 static void fallback_exit_cip(struct crypto_tfm *tfm) 146 { 147 struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm); 148 149 crypto_free_cipher(sctx->fallback.cip); 150 sctx->fallback.cip = NULL; 151 } 152 153 static struct crypto_alg aes_alg = { 154 .cra_name = "aes", 155 .cra_driver_name = "aes-s390", 156 .cra_priority = 300, 157 .cra_flags = CRYPTO_ALG_TYPE_CIPHER | 158 CRYPTO_ALG_NEED_FALLBACK, 159 .cra_blocksize = AES_BLOCK_SIZE, 160 .cra_ctxsize = sizeof(struct s390_aes_ctx), 161 .cra_module = THIS_MODULE, 162 .cra_init = fallback_init_cip, 163 .cra_exit = fallback_exit_cip, 164 .cra_u = { 165 .cipher = { 166 .cia_min_keysize = AES_MIN_KEY_SIZE, 167 .cia_max_keysize = AES_MAX_KEY_SIZE, 168 .cia_setkey = aes_set_key, 169 .cia_encrypt = crypto_aes_encrypt, 170 .cia_decrypt = crypto_aes_decrypt, 171 } 172 } 173 }; 174 175 static int setkey_fallback_skcipher(struct crypto_skcipher *tfm, const u8 *key, 176 unsigned int len) 177 { 178 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 179 180 crypto_skcipher_clear_flags(sctx->fallback.skcipher, 181 CRYPTO_TFM_REQ_MASK); 182 crypto_skcipher_set_flags(sctx->fallback.skcipher, 183 crypto_skcipher_get_flags(tfm) & 184 CRYPTO_TFM_REQ_MASK); 185 return crypto_skcipher_setkey(sctx->fallback.skcipher, key, len); 186 } 187 188 static int fallback_skcipher_crypt(struct s390_aes_ctx *sctx, 189 struct skcipher_request *req, 190 unsigned long modifier) 191 { 192 struct skcipher_request *subreq = skcipher_request_ctx(req); 193 194 *subreq = *req; 195 skcipher_request_set_tfm(subreq, sctx->fallback.skcipher); 196 return (modifier & CPACF_DECRYPT) ? 197 crypto_skcipher_decrypt(subreq) : 198 crypto_skcipher_encrypt(subreq); 199 } 200 201 static int ecb_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, 202 unsigned int key_len) 203 { 204 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 205 unsigned long fc; 206 207 /* Pick the correct function code based on the key length */ 208 fc = (key_len == 16) ? CPACF_KM_AES_128 : 209 (key_len == 24) ? CPACF_KM_AES_192 : 210 (key_len == 32) ? CPACF_KM_AES_256 : 0; 211 212 /* Check if the function code is available */ 213 sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 214 if (!sctx->fc) 215 return setkey_fallback_skcipher(tfm, in_key, key_len); 216 217 sctx->key_len = key_len; 218 memcpy(sctx->key, in_key, key_len); 219 return 0; 220 } 221 222 static int ecb_aes_crypt(struct skcipher_request *req, unsigned long modifier) 223 { 224 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 225 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 226 struct skcipher_walk walk; 227 unsigned int nbytes, n; 228 int ret; 229 230 if (unlikely(!sctx->fc)) 231 return fallback_skcipher_crypt(sctx, req, modifier); 232 233 ret = skcipher_walk_virt(&walk, req, false); 234 while ((nbytes = walk.nbytes) != 0) { 235 /* only use complete blocks */ 236 n = nbytes & ~(AES_BLOCK_SIZE - 1); 237 cpacf_km(sctx->fc | modifier, sctx->key, 238 walk.dst.virt.addr, walk.src.virt.addr, n); 239 ret = skcipher_walk_done(&walk, nbytes - n); 240 } 241 return ret; 242 } 243 244 static int ecb_aes_encrypt(struct skcipher_request *req) 245 { 246 return ecb_aes_crypt(req, 0); 247 } 248 249 static int ecb_aes_decrypt(struct skcipher_request *req) 250 { 251 return ecb_aes_crypt(req, CPACF_DECRYPT); 252 } 253 254 static int fallback_init_skcipher(struct crypto_skcipher *tfm) 255 { 256 const char *name = crypto_tfm_alg_name(&tfm->base); 257 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 258 259 sctx->fallback.skcipher = crypto_alloc_skcipher(name, 0, 260 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC); 261 262 if (IS_ERR(sctx->fallback.skcipher)) { 263 pr_err("Allocating AES fallback algorithm %s failed\n", 264 name); 265 return PTR_ERR(sctx->fallback.skcipher); 266 } 267 268 crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) + 269 crypto_skcipher_reqsize(sctx->fallback.skcipher)); 270 return 0; 271 } 272 273 static void fallback_exit_skcipher(struct crypto_skcipher *tfm) 274 { 275 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 276 277 crypto_free_skcipher(sctx->fallback.skcipher); 278 } 279 280 static struct skcipher_alg ecb_aes_alg = { 281 .base.cra_name = "ecb(aes)", 282 .base.cra_driver_name = "ecb-aes-s390", 283 .base.cra_priority = 401, /* combo: aes + ecb + 1 */ 284 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, 285 .base.cra_blocksize = AES_BLOCK_SIZE, 286 .base.cra_ctxsize = sizeof(struct s390_aes_ctx), 287 .base.cra_module = THIS_MODULE, 288 .init = fallback_init_skcipher, 289 .exit = fallback_exit_skcipher, 290 .min_keysize = AES_MIN_KEY_SIZE, 291 .max_keysize = AES_MAX_KEY_SIZE, 292 .setkey = ecb_aes_set_key, 293 .encrypt = ecb_aes_encrypt, 294 .decrypt = ecb_aes_decrypt, 295 }; 296 297 static int cbc_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, 298 unsigned int key_len) 299 { 300 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 301 unsigned long fc; 302 303 /* Pick the correct function code based on the key length */ 304 fc = (key_len == 16) ? CPACF_KMC_AES_128 : 305 (key_len == 24) ? CPACF_KMC_AES_192 : 306 (key_len == 32) ? CPACF_KMC_AES_256 : 0; 307 308 /* Check if the function code is available */ 309 sctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0; 310 if (!sctx->fc) 311 return setkey_fallback_skcipher(tfm, in_key, key_len); 312 313 sctx->key_len = key_len; 314 memcpy(sctx->key, in_key, key_len); 315 return 0; 316 } 317 318 static int cbc_aes_crypt(struct skcipher_request *req, unsigned long modifier) 319 { 320 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 321 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 322 struct skcipher_walk walk; 323 unsigned int nbytes, n; 324 int ret; 325 struct { 326 u8 iv[AES_BLOCK_SIZE]; 327 u8 key[AES_MAX_KEY_SIZE]; 328 } param; 329 330 if (unlikely(!sctx->fc)) 331 return fallback_skcipher_crypt(sctx, req, modifier); 332 333 ret = skcipher_walk_virt(&walk, req, false); 334 if (ret) 335 return ret; 336 memcpy(param.iv, walk.iv, AES_BLOCK_SIZE); 337 memcpy(param.key, sctx->key, sctx->key_len); 338 while ((nbytes = walk.nbytes) != 0) { 339 /* only use complete blocks */ 340 n = nbytes & ~(AES_BLOCK_SIZE - 1); 341 cpacf_kmc(sctx->fc | modifier, ¶m, 342 walk.dst.virt.addr, walk.src.virt.addr, n); 343 memcpy(walk.iv, param.iv, AES_BLOCK_SIZE); 344 ret = skcipher_walk_done(&walk, nbytes - n); 345 } 346 memzero_explicit(¶m, sizeof(param)); 347 return ret; 348 } 349 350 static int cbc_aes_encrypt(struct skcipher_request *req) 351 { 352 return cbc_aes_crypt(req, 0); 353 } 354 355 static int cbc_aes_decrypt(struct skcipher_request *req) 356 { 357 return cbc_aes_crypt(req, CPACF_DECRYPT); 358 } 359 360 static struct skcipher_alg cbc_aes_alg = { 361 .base.cra_name = "cbc(aes)", 362 .base.cra_driver_name = "cbc-aes-s390", 363 .base.cra_priority = 402, /* ecb-aes-s390 + 1 */ 364 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, 365 .base.cra_blocksize = AES_BLOCK_SIZE, 366 .base.cra_ctxsize = sizeof(struct s390_aes_ctx), 367 .base.cra_module = THIS_MODULE, 368 .init = fallback_init_skcipher, 369 .exit = fallback_exit_skcipher, 370 .min_keysize = AES_MIN_KEY_SIZE, 371 .max_keysize = AES_MAX_KEY_SIZE, 372 .ivsize = AES_BLOCK_SIZE, 373 .setkey = cbc_aes_set_key, 374 .encrypt = cbc_aes_encrypt, 375 .decrypt = cbc_aes_decrypt, 376 }; 377 378 static int xts_fallback_setkey(struct crypto_skcipher *tfm, const u8 *key, 379 unsigned int len) 380 { 381 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 382 383 crypto_skcipher_clear_flags(xts_ctx->fallback, CRYPTO_TFM_REQ_MASK); 384 crypto_skcipher_set_flags(xts_ctx->fallback, 385 crypto_skcipher_get_flags(tfm) & 386 CRYPTO_TFM_REQ_MASK); 387 return crypto_skcipher_setkey(xts_ctx->fallback, key, len); 388 } 389 390 static int xts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, 391 unsigned int key_len) 392 { 393 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 394 unsigned long fc; 395 int err; 396 397 err = xts_fallback_setkey(tfm, in_key, key_len); 398 if (err) 399 return err; 400 401 /* In fips mode only 128 bit or 256 bit keys are valid */ 402 if (fips_enabled && key_len != 32 && key_len != 64) 403 return -EINVAL; 404 405 /* Pick the correct function code based on the key length */ 406 fc = (key_len == 32) ? CPACF_KM_XTS_128 : 407 (key_len == 64) ? CPACF_KM_XTS_256 : 0; 408 409 /* Check if the function code is available */ 410 xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 411 if (!xts_ctx->fc) 412 return 0; 413 414 /* Split the XTS key into the two subkeys */ 415 key_len = key_len / 2; 416 xts_ctx->key_len = key_len; 417 memcpy(xts_ctx->key, in_key, key_len); 418 memcpy(xts_ctx->pcc_key, in_key + key_len, key_len); 419 return 0; 420 } 421 422 static int xts_aes_crypt(struct skcipher_request *req, unsigned long modifier) 423 { 424 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 425 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 426 struct skcipher_walk walk; 427 unsigned int offset, nbytes, n; 428 int ret; 429 struct { 430 u8 key[32]; 431 u8 tweak[16]; 432 u8 block[16]; 433 u8 bit[16]; 434 u8 xts[16]; 435 } pcc_param; 436 struct { 437 u8 key[32]; 438 u8 init[16]; 439 } xts_param; 440 441 if (req->cryptlen < AES_BLOCK_SIZE) 442 return -EINVAL; 443 444 if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) { 445 struct skcipher_request *subreq = skcipher_request_ctx(req); 446 447 *subreq = *req; 448 skcipher_request_set_tfm(subreq, xts_ctx->fallback); 449 return (modifier & CPACF_DECRYPT) ? 450 crypto_skcipher_decrypt(subreq) : 451 crypto_skcipher_encrypt(subreq); 452 } 453 454 ret = skcipher_walk_virt(&walk, req, false); 455 if (ret) 456 return ret; 457 offset = xts_ctx->key_len & 0x10; 458 memset(pcc_param.block, 0, sizeof(pcc_param.block)); 459 memset(pcc_param.bit, 0, sizeof(pcc_param.bit)); 460 memset(pcc_param.xts, 0, sizeof(pcc_param.xts)); 461 memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak)); 462 memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len); 463 cpacf_pcc(xts_ctx->fc, pcc_param.key + offset); 464 465 memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len); 466 memcpy(xts_param.init, pcc_param.xts, 16); 467 468 while ((nbytes = walk.nbytes) != 0) { 469 /* only use complete blocks */ 470 n = nbytes & ~(AES_BLOCK_SIZE - 1); 471 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset, 472 walk.dst.virt.addr, walk.src.virt.addr, n); 473 ret = skcipher_walk_done(&walk, nbytes - n); 474 } 475 memzero_explicit(&pcc_param, sizeof(pcc_param)); 476 memzero_explicit(&xts_param, sizeof(xts_param)); 477 return ret; 478 } 479 480 static int xts_aes_encrypt(struct skcipher_request *req) 481 { 482 return xts_aes_crypt(req, 0); 483 } 484 485 static int xts_aes_decrypt(struct skcipher_request *req) 486 { 487 return xts_aes_crypt(req, CPACF_DECRYPT); 488 } 489 490 static int xts_fallback_init(struct crypto_skcipher *tfm) 491 { 492 const char *name = crypto_tfm_alg_name(&tfm->base); 493 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 494 495 xts_ctx->fallback = crypto_alloc_skcipher(name, 0, 496 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC); 497 498 if (IS_ERR(xts_ctx->fallback)) { 499 pr_err("Allocating XTS fallback algorithm %s failed\n", 500 name); 501 return PTR_ERR(xts_ctx->fallback); 502 } 503 crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) + 504 crypto_skcipher_reqsize(xts_ctx->fallback)); 505 return 0; 506 } 507 508 static void xts_fallback_exit(struct crypto_skcipher *tfm) 509 { 510 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 511 512 crypto_free_skcipher(xts_ctx->fallback); 513 } 514 515 static struct skcipher_alg xts_aes_alg = { 516 .base.cra_name = "xts(aes)", 517 .base.cra_driver_name = "xts-aes-s390", 518 .base.cra_priority = 402, /* ecb-aes-s390 + 1 */ 519 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, 520 .base.cra_blocksize = AES_BLOCK_SIZE, 521 .base.cra_ctxsize = sizeof(struct s390_xts_ctx), 522 .base.cra_module = THIS_MODULE, 523 .init = xts_fallback_init, 524 .exit = xts_fallback_exit, 525 .min_keysize = 2 * AES_MIN_KEY_SIZE, 526 .max_keysize = 2 * AES_MAX_KEY_SIZE, 527 .ivsize = AES_BLOCK_SIZE, 528 .setkey = xts_aes_set_key, 529 .encrypt = xts_aes_encrypt, 530 .decrypt = xts_aes_decrypt, 531 }; 532 533 static int ctr_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, 534 unsigned int key_len) 535 { 536 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 537 unsigned long fc; 538 539 /* Pick the correct function code based on the key length */ 540 fc = (key_len == 16) ? CPACF_KMCTR_AES_128 : 541 (key_len == 24) ? CPACF_KMCTR_AES_192 : 542 (key_len == 32) ? CPACF_KMCTR_AES_256 : 0; 543 544 /* Check if the function code is available */ 545 sctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0; 546 if (!sctx->fc) 547 return setkey_fallback_skcipher(tfm, in_key, key_len); 548 549 sctx->key_len = key_len; 550 memcpy(sctx->key, in_key, key_len); 551 return 0; 552 } 553 554 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes) 555 { 556 unsigned int i, n; 557 558 /* only use complete blocks, max. PAGE_SIZE */ 559 memcpy(ctrptr, iv, AES_BLOCK_SIZE); 560 n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1); 561 for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) { 562 memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE); 563 crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE); 564 ctrptr += AES_BLOCK_SIZE; 565 } 566 return n; 567 } 568 569 static int ctr_aes_crypt(struct skcipher_request *req) 570 { 571 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 572 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 573 u8 buf[AES_BLOCK_SIZE], *ctrptr; 574 struct skcipher_walk walk; 575 unsigned int n, nbytes; 576 int ret, locked; 577 578 if (unlikely(!sctx->fc)) 579 return fallback_skcipher_crypt(sctx, req, 0); 580 581 locked = mutex_trylock(&ctrblk_lock); 582 583 ret = skcipher_walk_virt(&walk, req, false); 584 while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) { 585 n = AES_BLOCK_SIZE; 586 587 if (nbytes >= 2*AES_BLOCK_SIZE && locked) 588 n = __ctrblk_init(ctrblk, walk.iv, nbytes); 589 ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv; 590 cpacf_kmctr(sctx->fc, sctx->key, walk.dst.virt.addr, 591 walk.src.virt.addr, n, ctrptr); 592 if (ctrptr == ctrblk) 593 memcpy(walk.iv, ctrptr + n - AES_BLOCK_SIZE, 594 AES_BLOCK_SIZE); 595 crypto_inc(walk.iv, AES_BLOCK_SIZE); 596 ret = skcipher_walk_done(&walk, nbytes - n); 597 } 598 if (locked) 599 mutex_unlock(&ctrblk_lock); 600 /* 601 * final block may be < AES_BLOCK_SIZE, copy only nbytes 602 */ 603 if (nbytes) { 604 cpacf_kmctr(sctx->fc, sctx->key, buf, walk.src.virt.addr, 605 AES_BLOCK_SIZE, walk.iv); 606 memcpy(walk.dst.virt.addr, buf, nbytes); 607 crypto_inc(walk.iv, AES_BLOCK_SIZE); 608 ret = skcipher_walk_done(&walk, 0); 609 } 610 611 return ret; 612 } 613 614 static struct skcipher_alg ctr_aes_alg = { 615 .base.cra_name = "ctr(aes)", 616 .base.cra_driver_name = "ctr-aes-s390", 617 .base.cra_priority = 402, /* ecb-aes-s390 + 1 */ 618 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, 619 .base.cra_blocksize = 1, 620 .base.cra_ctxsize = sizeof(struct s390_aes_ctx), 621 .base.cra_module = THIS_MODULE, 622 .init = fallback_init_skcipher, 623 .exit = fallback_exit_skcipher, 624 .min_keysize = AES_MIN_KEY_SIZE, 625 .max_keysize = AES_MAX_KEY_SIZE, 626 .ivsize = AES_BLOCK_SIZE, 627 .setkey = ctr_aes_set_key, 628 .encrypt = ctr_aes_crypt, 629 .decrypt = ctr_aes_crypt, 630 .chunksize = AES_BLOCK_SIZE, 631 }; 632 633 static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *key, 634 unsigned int keylen) 635 { 636 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm); 637 638 switch (keylen) { 639 case AES_KEYSIZE_128: 640 ctx->fc = CPACF_KMA_GCM_AES_128; 641 break; 642 case AES_KEYSIZE_192: 643 ctx->fc = CPACF_KMA_GCM_AES_192; 644 break; 645 case AES_KEYSIZE_256: 646 ctx->fc = CPACF_KMA_GCM_AES_256; 647 break; 648 default: 649 return -EINVAL; 650 } 651 652 memcpy(ctx->key, key, keylen); 653 ctx->key_len = keylen; 654 return 0; 655 } 656 657 static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize) 658 { 659 switch (authsize) { 660 case 4: 661 case 8: 662 case 12: 663 case 13: 664 case 14: 665 case 15: 666 case 16: 667 break; 668 default: 669 return -EINVAL; 670 } 671 672 return 0; 673 } 674 675 static void gcm_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg, 676 unsigned int len) 677 { 678 memset(gw, 0, sizeof(*gw)); 679 gw->walk_bytes_remain = len; 680 scatterwalk_start(&gw->walk, sg); 681 } 682 683 static inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw) 684 { 685 struct scatterlist *nextsg; 686 687 gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain); 688 while (!gw->walk_bytes) { 689 nextsg = sg_next(gw->walk.sg); 690 if (!nextsg) 691 return 0; 692 scatterwalk_start(&gw->walk, nextsg); 693 gw->walk_bytes = scatterwalk_clamp(&gw->walk, 694 gw->walk_bytes_remain); 695 } 696 gw->walk_ptr = scatterwalk_map(&gw->walk); 697 return gw->walk_bytes; 698 } 699 700 static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw, 701 unsigned int nbytes) 702 { 703 gw->walk_bytes_remain -= nbytes; 704 scatterwalk_unmap(gw->walk_ptr); 705 scatterwalk_advance(&gw->walk, nbytes); 706 scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain); 707 gw->walk_ptr = NULL; 708 } 709 710 static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) 711 { 712 int n; 713 714 if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) { 715 gw->ptr = gw->buf; 716 gw->nbytes = gw->buf_bytes; 717 goto out; 718 } 719 720 if (gw->walk_bytes_remain == 0) { 721 gw->ptr = NULL; 722 gw->nbytes = 0; 723 goto out; 724 } 725 726 if (!_gcm_sg_clamp_and_map(gw)) { 727 gw->ptr = NULL; 728 gw->nbytes = 0; 729 goto out; 730 } 731 732 if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) { 733 gw->ptr = gw->walk_ptr; 734 gw->nbytes = gw->walk_bytes; 735 goto out; 736 } 737 738 while (1) { 739 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes); 740 memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n); 741 gw->buf_bytes += n; 742 _gcm_sg_unmap_and_advance(gw, n); 743 if (gw->buf_bytes >= minbytesneeded) { 744 gw->ptr = gw->buf; 745 gw->nbytes = gw->buf_bytes; 746 goto out; 747 } 748 if (!_gcm_sg_clamp_and_map(gw)) { 749 gw->ptr = NULL; 750 gw->nbytes = 0; 751 goto out; 752 } 753 } 754 755 out: 756 return gw->nbytes; 757 } 758 759 static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) 760 { 761 if (gw->walk_bytes_remain == 0) { 762 gw->ptr = NULL; 763 gw->nbytes = 0; 764 goto out; 765 } 766 767 if (!_gcm_sg_clamp_and_map(gw)) { 768 gw->ptr = NULL; 769 gw->nbytes = 0; 770 goto out; 771 } 772 773 if (gw->walk_bytes >= minbytesneeded) { 774 gw->ptr = gw->walk_ptr; 775 gw->nbytes = gw->walk_bytes; 776 goto out; 777 } 778 779 scatterwalk_unmap(gw->walk_ptr); 780 gw->walk_ptr = NULL; 781 782 gw->ptr = gw->buf; 783 gw->nbytes = sizeof(gw->buf); 784 785 out: 786 return gw->nbytes; 787 } 788 789 static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) 790 { 791 if (gw->ptr == NULL) 792 return 0; 793 794 if (gw->ptr == gw->buf) { 795 int n = gw->buf_bytes - bytesdone; 796 if (n > 0) { 797 memmove(gw->buf, gw->buf + bytesdone, n); 798 gw->buf_bytes = n; 799 } else 800 gw->buf_bytes = 0; 801 } else 802 _gcm_sg_unmap_and_advance(gw, bytesdone); 803 804 return bytesdone; 805 } 806 807 static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) 808 { 809 int i, n; 810 811 if (gw->ptr == NULL) 812 return 0; 813 814 if (gw->ptr == gw->buf) { 815 for (i = 0; i < bytesdone; i += n) { 816 if (!_gcm_sg_clamp_and_map(gw)) 817 return i; 818 n = min(gw->walk_bytes, bytesdone - i); 819 memcpy(gw->walk_ptr, gw->buf + i, n); 820 _gcm_sg_unmap_and_advance(gw, n); 821 } 822 } else 823 _gcm_sg_unmap_and_advance(gw, bytesdone); 824 825 return bytesdone; 826 } 827 828 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags) 829 { 830 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 831 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm); 832 unsigned int ivsize = crypto_aead_ivsize(tfm); 833 unsigned int taglen = crypto_aead_authsize(tfm); 834 unsigned int aadlen = req->assoclen; 835 unsigned int pclen = req->cryptlen; 836 int ret = 0; 837 838 unsigned int n, len, in_bytes, out_bytes, 839 min_bytes, bytes, aad_bytes, pc_bytes; 840 struct gcm_sg_walk gw_in, gw_out; 841 u8 tag[GHASH_DIGEST_SIZE]; 842 843 struct { 844 u32 _[3]; /* reserved */ 845 u32 cv; /* Counter Value */ 846 u8 t[GHASH_DIGEST_SIZE];/* Tag */ 847 u8 h[AES_BLOCK_SIZE]; /* Hash-subkey */ 848 u64 taadl; /* Total AAD Length */ 849 u64 tpcl; /* Total Plain-/Cipher-text Length */ 850 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */ 851 u8 k[AES_MAX_KEY_SIZE]; /* Key */ 852 } param; 853 854 /* 855 * encrypt 856 * req->src: aad||plaintext 857 * req->dst: aad||ciphertext||tag 858 * decrypt 859 * req->src: aad||ciphertext||tag 860 * req->dst: aad||plaintext, return 0 or -EBADMSG 861 * aad, plaintext and ciphertext may be empty. 862 */ 863 if (flags & CPACF_DECRYPT) 864 pclen -= taglen; 865 len = aadlen + pclen; 866 867 memset(¶m, 0, sizeof(param)); 868 param.cv = 1; 869 param.taadl = aadlen * 8; 870 param.tpcl = pclen * 8; 871 memcpy(param.j0, req->iv, ivsize); 872 *(u32 *)(param.j0 + ivsize) = 1; 873 memcpy(param.k, ctx->key, ctx->key_len); 874 875 gcm_walk_start(&gw_in, req->src, len); 876 gcm_walk_start(&gw_out, req->dst, len); 877 878 do { 879 min_bytes = min_t(unsigned int, 880 aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE); 881 in_bytes = gcm_in_walk_go(&gw_in, min_bytes); 882 out_bytes = gcm_out_walk_go(&gw_out, min_bytes); 883 bytes = min(in_bytes, out_bytes); 884 885 if (aadlen + pclen <= bytes) { 886 aad_bytes = aadlen; 887 pc_bytes = pclen; 888 flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC; 889 } else { 890 if (aadlen <= bytes) { 891 aad_bytes = aadlen; 892 pc_bytes = (bytes - aadlen) & 893 ~(AES_BLOCK_SIZE - 1); 894 flags |= CPACF_KMA_LAAD; 895 } else { 896 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1); 897 pc_bytes = 0; 898 } 899 } 900 901 if (aad_bytes > 0) 902 memcpy(gw_out.ptr, gw_in.ptr, aad_bytes); 903 904 cpacf_kma(ctx->fc | flags, ¶m, 905 gw_out.ptr + aad_bytes, 906 gw_in.ptr + aad_bytes, pc_bytes, 907 gw_in.ptr, aad_bytes); 908 909 n = aad_bytes + pc_bytes; 910 if (gcm_in_walk_done(&gw_in, n) != n) 911 return -ENOMEM; 912 if (gcm_out_walk_done(&gw_out, n) != n) 913 return -ENOMEM; 914 aadlen -= aad_bytes; 915 pclen -= pc_bytes; 916 } while (aadlen + pclen > 0); 917 918 if (flags & CPACF_DECRYPT) { 919 scatterwalk_map_and_copy(tag, req->src, len, taglen, 0); 920 if (crypto_memneq(tag, param.t, taglen)) 921 ret = -EBADMSG; 922 } else 923 scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1); 924 925 memzero_explicit(¶m, sizeof(param)); 926 return ret; 927 } 928 929 static int gcm_aes_encrypt(struct aead_request *req) 930 { 931 return gcm_aes_crypt(req, CPACF_ENCRYPT); 932 } 933 934 static int gcm_aes_decrypt(struct aead_request *req) 935 { 936 return gcm_aes_crypt(req, CPACF_DECRYPT); 937 } 938 939 static struct aead_alg gcm_aes_aead = { 940 .setkey = gcm_aes_setkey, 941 .setauthsize = gcm_aes_setauthsize, 942 .encrypt = gcm_aes_encrypt, 943 .decrypt = gcm_aes_decrypt, 944 945 .ivsize = GHASH_BLOCK_SIZE - sizeof(u32), 946 .maxauthsize = GHASH_DIGEST_SIZE, 947 .chunksize = AES_BLOCK_SIZE, 948 949 .base = { 950 .cra_blocksize = 1, 951 .cra_ctxsize = sizeof(struct s390_aes_ctx), 952 .cra_priority = 900, 953 .cra_name = "gcm(aes)", 954 .cra_driver_name = "gcm-aes-s390", 955 .cra_module = THIS_MODULE, 956 }, 957 }; 958 959 static struct crypto_alg *aes_s390_alg; 960 static struct skcipher_alg *aes_s390_skcipher_algs[4]; 961 static int aes_s390_skciphers_num; 962 static struct aead_alg *aes_s390_aead_alg; 963 964 static int aes_s390_register_skcipher(struct skcipher_alg *alg) 965 { 966 int ret; 967 968 ret = crypto_register_skcipher(alg); 969 if (!ret) 970 aes_s390_skcipher_algs[aes_s390_skciphers_num++] = alg; 971 return ret; 972 } 973 974 static void aes_s390_fini(void) 975 { 976 if (aes_s390_alg) 977 crypto_unregister_alg(aes_s390_alg); 978 while (aes_s390_skciphers_num--) 979 crypto_unregister_skcipher(aes_s390_skcipher_algs[aes_s390_skciphers_num]); 980 if (ctrblk) 981 free_page((unsigned long) ctrblk); 982 983 if (aes_s390_aead_alg) 984 crypto_unregister_aead(aes_s390_aead_alg); 985 } 986 987 static int __init aes_s390_init(void) 988 { 989 int ret; 990 991 /* Query available functions for KM, KMC, KMCTR and KMA */ 992 cpacf_query(CPACF_KM, &km_functions); 993 cpacf_query(CPACF_KMC, &kmc_functions); 994 cpacf_query(CPACF_KMCTR, &kmctr_functions); 995 cpacf_query(CPACF_KMA, &kma_functions); 996 997 if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) || 998 cpacf_test_func(&km_functions, CPACF_KM_AES_192) || 999 cpacf_test_func(&km_functions, CPACF_KM_AES_256)) { 1000 ret = crypto_register_alg(&aes_alg); 1001 if (ret) 1002 goto out_err; 1003 aes_s390_alg = &aes_alg; 1004 ret = aes_s390_register_skcipher(&ecb_aes_alg); 1005 if (ret) 1006 goto out_err; 1007 } 1008 1009 if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) || 1010 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) || 1011 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) { 1012 ret = aes_s390_register_skcipher(&cbc_aes_alg); 1013 if (ret) 1014 goto out_err; 1015 } 1016 1017 if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) || 1018 cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) { 1019 ret = aes_s390_register_skcipher(&xts_aes_alg); 1020 if (ret) 1021 goto out_err; 1022 } 1023 1024 if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) || 1025 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) || 1026 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) { 1027 ctrblk = (u8 *) __get_free_page(GFP_KERNEL); 1028 if (!ctrblk) { 1029 ret = -ENOMEM; 1030 goto out_err; 1031 } 1032 ret = aes_s390_register_skcipher(&ctr_aes_alg); 1033 if (ret) 1034 goto out_err; 1035 } 1036 1037 if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) || 1038 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) || 1039 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) { 1040 ret = crypto_register_aead(&gcm_aes_aead); 1041 if (ret) 1042 goto out_err; 1043 aes_s390_aead_alg = &gcm_aes_aead; 1044 } 1045 1046 return 0; 1047 out_err: 1048 aes_s390_fini(); 1049 return ret; 1050 } 1051 1052 module_cpu_feature_match(S390_CPU_FEATURE_MSA, aes_s390_init); 1053 module_exit(aes_s390_fini); 1054 1055 MODULE_ALIAS_CRYPTO("aes-all"); 1056 1057 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); 1058 MODULE_LICENSE("GPL"); 1059 MODULE_IMPORT_NS(CRYPTO_INTERNAL); 1060