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 pr_fmt(fmt) "aes_s390: " fmt 18 19 #include <crypto/aes.h> 20 #include <crypto/algapi.h> 21 #include <crypto/ghash.h> 22 #include <crypto/internal/aead.h> 23 #include <crypto/internal/skcipher.h> 24 #include <crypto/scatterwalk.h> 25 #include <linux/err.h> 26 #include <linux/module.h> 27 #include <linux/cpufeature.h> 28 #include <linux/init.h> 29 #include <linux/mutex.h> 30 #include <linux/fips.h> 31 #include <linux/string.h> 32 #include <crypto/xts.h> 33 #include <asm/cpacf.h> 34 35 static u8 *ctrblk; 36 static DEFINE_MUTEX(ctrblk_lock); 37 38 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions, 39 kma_functions; 40 41 struct s390_aes_ctx { 42 u8 key[AES_MAX_KEY_SIZE]; 43 int key_len; 44 unsigned long fc; 45 union { 46 struct crypto_skcipher *skcipher; 47 } fallback; 48 }; 49 50 struct s390_xts_ctx { 51 union { 52 u8 keys[64]; 53 struct { 54 u8 key[32]; 55 u8 pcc_key[32]; 56 }; 57 }; 58 int key_len; 59 unsigned long fc; 60 struct crypto_skcipher *fallback; 61 }; 62 63 struct gcm_sg_walk { 64 struct scatter_walk walk; 65 unsigned int walk_bytes; 66 unsigned int walk_bytes_remain; 67 u8 buf[AES_BLOCK_SIZE]; 68 unsigned int buf_bytes; 69 u8 *ptr; 70 unsigned int nbytes; 71 }; 72 73 static int setkey_fallback_skcipher(struct crypto_skcipher *tfm, const u8 *key, 74 unsigned int len) 75 { 76 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 77 78 crypto_skcipher_clear_flags(sctx->fallback.skcipher, 79 CRYPTO_TFM_REQ_MASK); 80 crypto_skcipher_set_flags(sctx->fallback.skcipher, 81 crypto_skcipher_get_flags(tfm) & 82 CRYPTO_TFM_REQ_MASK); 83 return crypto_skcipher_setkey(sctx->fallback.skcipher, key, len); 84 } 85 86 static int fallback_skcipher_crypt(struct s390_aes_ctx *sctx, 87 struct skcipher_request *req, 88 unsigned long modifier) 89 { 90 struct skcipher_request *subreq = skcipher_request_ctx(req); 91 92 *subreq = *req; 93 skcipher_request_set_tfm(subreq, sctx->fallback.skcipher); 94 return (modifier & CPACF_DECRYPT) ? 95 crypto_skcipher_decrypt(subreq) : 96 crypto_skcipher_encrypt(subreq); 97 } 98 99 static int ecb_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, 100 unsigned int key_len) 101 { 102 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 103 unsigned long fc; 104 105 /* Pick the correct function code based on the key length */ 106 fc = (key_len == 16) ? CPACF_KM_AES_128 : 107 (key_len == 24) ? CPACF_KM_AES_192 : 108 (key_len == 32) ? CPACF_KM_AES_256 : 0; 109 110 /* Check if the function code is available */ 111 sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 112 if (!sctx->fc) 113 return setkey_fallback_skcipher(tfm, in_key, key_len); 114 115 sctx->key_len = key_len; 116 memcpy(sctx->key, in_key, key_len); 117 return 0; 118 } 119 120 static int ecb_aes_crypt(struct skcipher_request *req, unsigned long modifier) 121 { 122 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 123 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 124 struct skcipher_walk walk; 125 unsigned int nbytes, n; 126 int ret; 127 128 if (unlikely(!sctx->fc)) 129 return fallback_skcipher_crypt(sctx, req, modifier); 130 131 ret = skcipher_walk_virt(&walk, req, false); 132 while ((nbytes = walk.nbytes) != 0) { 133 /* only use complete blocks */ 134 n = nbytes & ~(AES_BLOCK_SIZE - 1); 135 cpacf_km(sctx->fc | modifier, sctx->key, 136 walk.dst.virt.addr, walk.src.virt.addr, n); 137 ret = skcipher_walk_done(&walk, nbytes - n); 138 } 139 return ret; 140 } 141 142 static int ecb_aes_encrypt(struct skcipher_request *req) 143 { 144 return ecb_aes_crypt(req, 0); 145 } 146 147 static int ecb_aes_decrypt(struct skcipher_request *req) 148 { 149 return ecb_aes_crypt(req, CPACF_DECRYPT); 150 } 151 152 static int fallback_init_skcipher(struct crypto_skcipher *tfm) 153 { 154 const char *name = crypto_tfm_alg_name(&tfm->base); 155 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 156 157 sctx->fallback.skcipher = crypto_alloc_skcipher(name, 0, 158 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC); 159 160 if (IS_ERR(sctx->fallback.skcipher)) { 161 pr_err("Allocating AES fallback algorithm %s failed\n", 162 name); 163 return PTR_ERR(sctx->fallback.skcipher); 164 } 165 166 crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) + 167 crypto_skcipher_reqsize(sctx->fallback.skcipher)); 168 return 0; 169 } 170 171 static void fallback_exit_skcipher(struct crypto_skcipher *tfm) 172 { 173 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 174 175 crypto_free_skcipher(sctx->fallback.skcipher); 176 } 177 178 static struct skcipher_alg ecb_aes_alg = { 179 .base.cra_name = "ecb(aes)", 180 .base.cra_driver_name = "ecb-aes-s390", 181 .base.cra_priority = 401, /* combo: aes + ecb + 1 */ 182 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, 183 .base.cra_blocksize = AES_BLOCK_SIZE, 184 .base.cra_ctxsize = sizeof(struct s390_aes_ctx), 185 .base.cra_module = THIS_MODULE, 186 .init = fallback_init_skcipher, 187 .exit = fallback_exit_skcipher, 188 .min_keysize = AES_MIN_KEY_SIZE, 189 .max_keysize = AES_MAX_KEY_SIZE, 190 .setkey = ecb_aes_set_key, 191 .encrypt = ecb_aes_encrypt, 192 .decrypt = ecb_aes_decrypt, 193 }; 194 195 static int cbc_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, 196 unsigned int key_len) 197 { 198 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 199 unsigned long fc; 200 201 /* Pick the correct function code based on the key length */ 202 fc = (key_len == 16) ? CPACF_KMC_AES_128 : 203 (key_len == 24) ? CPACF_KMC_AES_192 : 204 (key_len == 32) ? CPACF_KMC_AES_256 : 0; 205 206 /* Check if the function code is available */ 207 sctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0; 208 if (!sctx->fc) 209 return setkey_fallback_skcipher(tfm, in_key, key_len); 210 211 sctx->key_len = key_len; 212 memcpy(sctx->key, in_key, key_len); 213 return 0; 214 } 215 216 static int cbc_aes_crypt(struct skcipher_request *req, unsigned long modifier) 217 { 218 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 219 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 220 struct skcipher_walk walk; 221 unsigned int nbytes, n; 222 int ret; 223 struct { 224 u8 iv[AES_BLOCK_SIZE]; 225 u8 key[AES_MAX_KEY_SIZE]; 226 } param; 227 228 if (unlikely(!sctx->fc)) 229 return fallback_skcipher_crypt(sctx, req, modifier); 230 231 ret = skcipher_walk_virt(&walk, req, false); 232 if (ret) 233 return ret; 234 memcpy(param.iv, walk.iv, AES_BLOCK_SIZE); 235 memcpy(param.key, sctx->key, sctx->key_len); 236 while ((nbytes = walk.nbytes) != 0) { 237 /* only use complete blocks */ 238 n = nbytes & ~(AES_BLOCK_SIZE - 1); 239 cpacf_kmc(sctx->fc | modifier, ¶m, 240 walk.dst.virt.addr, walk.src.virt.addr, n); 241 memcpy(walk.iv, param.iv, AES_BLOCK_SIZE); 242 ret = skcipher_walk_done(&walk, nbytes - n); 243 } 244 memzero_explicit(¶m, sizeof(param)); 245 return ret; 246 } 247 248 static int cbc_aes_encrypt(struct skcipher_request *req) 249 { 250 return cbc_aes_crypt(req, 0); 251 } 252 253 static int cbc_aes_decrypt(struct skcipher_request *req) 254 { 255 return cbc_aes_crypt(req, CPACF_DECRYPT); 256 } 257 258 static struct skcipher_alg cbc_aes_alg = { 259 .base.cra_name = "cbc(aes)", 260 .base.cra_driver_name = "cbc-aes-s390", 261 .base.cra_priority = 402, /* ecb-aes-s390 + 1 */ 262 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, 263 .base.cra_blocksize = AES_BLOCK_SIZE, 264 .base.cra_ctxsize = sizeof(struct s390_aes_ctx), 265 .base.cra_module = THIS_MODULE, 266 .init = fallback_init_skcipher, 267 .exit = fallback_exit_skcipher, 268 .min_keysize = AES_MIN_KEY_SIZE, 269 .max_keysize = AES_MAX_KEY_SIZE, 270 .ivsize = AES_BLOCK_SIZE, 271 .setkey = cbc_aes_set_key, 272 .encrypt = cbc_aes_encrypt, 273 .decrypt = cbc_aes_decrypt, 274 }; 275 276 static int xts_fallback_setkey(struct crypto_skcipher *tfm, const u8 *key, 277 unsigned int len) 278 { 279 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 280 281 crypto_skcipher_clear_flags(xts_ctx->fallback, CRYPTO_TFM_REQ_MASK); 282 crypto_skcipher_set_flags(xts_ctx->fallback, 283 crypto_skcipher_get_flags(tfm) & 284 CRYPTO_TFM_REQ_MASK); 285 return crypto_skcipher_setkey(xts_ctx->fallback, key, len); 286 } 287 288 static int xts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, 289 unsigned int key_len) 290 { 291 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 292 unsigned long fc; 293 int err; 294 295 err = xts_fallback_setkey(tfm, in_key, key_len); 296 if (err) 297 return err; 298 299 /* Pick the correct function code based on the key length */ 300 fc = (key_len == 32) ? CPACF_KM_XTS_128 : 301 (key_len == 64) ? CPACF_KM_XTS_256 : 0; 302 303 /* Check if the function code is available */ 304 xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 305 if (!xts_ctx->fc) 306 return 0; 307 308 /* Split the XTS key into the two subkeys */ 309 key_len = key_len / 2; 310 xts_ctx->key_len = key_len; 311 memcpy(xts_ctx->key, in_key, key_len); 312 memcpy(xts_ctx->pcc_key, in_key + key_len, key_len); 313 return 0; 314 } 315 316 static int xts_aes_crypt(struct skcipher_request *req, unsigned long modifier) 317 { 318 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 319 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 320 struct skcipher_walk walk; 321 unsigned int offset, nbytes, n; 322 int ret; 323 struct { 324 u8 key[32]; 325 u8 tweak[16]; 326 u8 block[16]; 327 u8 bit[16]; 328 u8 xts[16]; 329 } pcc_param; 330 struct { 331 u8 key[32]; 332 u8 init[16]; 333 } xts_param; 334 335 if (req->cryptlen < AES_BLOCK_SIZE) 336 return -EINVAL; 337 338 if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) { 339 struct skcipher_request *subreq = skcipher_request_ctx(req); 340 341 *subreq = *req; 342 skcipher_request_set_tfm(subreq, xts_ctx->fallback); 343 return (modifier & CPACF_DECRYPT) ? 344 crypto_skcipher_decrypt(subreq) : 345 crypto_skcipher_encrypt(subreq); 346 } 347 348 ret = skcipher_walk_virt(&walk, req, false); 349 if (ret) 350 return ret; 351 offset = xts_ctx->key_len & 0x10; 352 memset(pcc_param.block, 0, sizeof(pcc_param.block)); 353 memset(pcc_param.bit, 0, sizeof(pcc_param.bit)); 354 memset(pcc_param.xts, 0, sizeof(pcc_param.xts)); 355 memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak)); 356 memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len); 357 cpacf_pcc(xts_ctx->fc, pcc_param.key + offset); 358 359 memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len); 360 memcpy(xts_param.init, pcc_param.xts, 16); 361 362 while ((nbytes = walk.nbytes) != 0) { 363 /* only use complete blocks */ 364 n = nbytes & ~(AES_BLOCK_SIZE - 1); 365 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset, 366 walk.dst.virt.addr, walk.src.virt.addr, n); 367 ret = skcipher_walk_done(&walk, nbytes - n); 368 } 369 memzero_explicit(&pcc_param, sizeof(pcc_param)); 370 memzero_explicit(&xts_param, sizeof(xts_param)); 371 return ret; 372 } 373 374 static int xts_aes_encrypt(struct skcipher_request *req) 375 { 376 return xts_aes_crypt(req, 0); 377 } 378 379 static int xts_aes_decrypt(struct skcipher_request *req) 380 { 381 return xts_aes_crypt(req, CPACF_DECRYPT); 382 } 383 384 static int xts_fallback_init(struct crypto_skcipher *tfm) 385 { 386 const char *name = crypto_tfm_alg_name(&tfm->base); 387 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 388 389 xts_ctx->fallback = crypto_alloc_skcipher(name, 0, 390 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC); 391 392 if (IS_ERR(xts_ctx->fallback)) { 393 pr_err("Allocating XTS fallback algorithm %s failed\n", 394 name); 395 return PTR_ERR(xts_ctx->fallback); 396 } 397 crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) + 398 crypto_skcipher_reqsize(xts_ctx->fallback)); 399 return 0; 400 } 401 402 static void xts_fallback_exit(struct crypto_skcipher *tfm) 403 { 404 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 405 406 crypto_free_skcipher(xts_ctx->fallback); 407 } 408 409 static struct skcipher_alg xts_aes_alg = { 410 .base.cra_name = "xts(aes)", 411 .base.cra_driver_name = "xts-aes-s390", 412 .base.cra_priority = 402, /* ecb-aes-s390 + 1 */ 413 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, 414 .base.cra_blocksize = AES_BLOCK_SIZE, 415 .base.cra_ctxsize = sizeof(struct s390_xts_ctx), 416 .base.cra_module = THIS_MODULE, 417 .init = xts_fallback_init, 418 .exit = xts_fallback_exit, 419 .min_keysize = 2 * AES_MIN_KEY_SIZE, 420 .max_keysize = 2 * AES_MAX_KEY_SIZE, 421 .ivsize = AES_BLOCK_SIZE, 422 .setkey = xts_aes_set_key, 423 .encrypt = xts_aes_encrypt, 424 .decrypt = xts_aes_decrypt, 425 }; 426 427 static int fullxts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, 428 unsigned int key_len) 429 { 430 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 431 unsigned long fc; 432 int err; 433 434 err = xts_fallback_setkey(tfm, in_key, key_len); 435 if (err) 436 return err; 437 438 /* Pick the correct function code based on the key length */ 439 fc = (key_len == 32) ? CPACF_KM_XTS_128_FULL : 440 (key_len == 64) ? CPACF_KM_XTS_256_FULL : 0; 441 442 /* Check if the function code is available */ 443 xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0; 444 if (!xts_ctx->fc) 445 return 0; 446 447 /* Store double-key */ 448 memcpy(xts_ctx->keys, in_key, key_len); 449 xts_ctx->key_len = key_len; 450 return 0; 451 } 452 453 static int fullxts_aes_crypt(struct skcipher_request *req, unsigned long modifier) 454 { 455 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 456 struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm); 457 unsigned int offset, nbytes, n; 458 struct skcipher_walk walk; 459 int ret; 460 struct { 461 __u8 key[64]; 462 __u8 tweak[16]; 463 __u8 nap[16]; 464 } fxts_param = { 465 .nap = {0}, 466 }; 467 468 if (req->cryptlen < AES_BLOCK_SIZE) 469 return -EINVAL; 470 471 if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) { 472 struct skcipher_request *subreq = skcipher_request_ctx(req); 473 474 *subreq = *req; 475 skcipher_request_set_tfm(subreq, xts_ctx->fallback); 476 return (modifier & CPACF_DECRYPT) ? 477 crypto_skcipher_decrypt(subreq) : 478 crypto_skcipher_encrypt(subreq); 479 } 480 481 ret = skcipher_walk_virt(&walk, req, false); 482 if (ret) 483 return ret; 484 485 offset = xts_ctx->key_len & 0x20; 486 memcpy(fxts_param.key + offset, xts_ctx->keys, xts_ctx->key_len); 487 memcpy(fxts_param.tweak, req->iv, AES_BLOCK_SIZE); 488 fxts_param.nap[0] = 0x01; /* initial alpha power (1, little-endian) */ 489 490 while ((nbytes = walk.nbytes) != 0) { 491 /* only use complete blocks */ 492 n = nbytes & ~(AES_BLOCK_SIZE - 1); 493 cpacf_km(xts_ctx->fc | modifier, fxts_param.key + offset, 494 walk.dst.virt.addr, walk.src.virt.addr, n); 495 ret = skcipher_walk_done(&walk, nbytes - n); 496 } 497 memzero_explicit(&fxts_param, sizeof(fxts_param)); 498 return ret; 499 } 500 501 static int fullxts_aes_encrypt(struct skcipher_request *req) 502 { 503 return fullxts_aes_crypt(req, 0); 504 } 505 506 static int fullxts_aes_decrypt(struct skcipher_request *req) 507 { 508 return fullxts_aes_crypt(req, CPACF_DECRYPT); 509 } 510 511 static struct skcipher_alg fullxts_aes_alg = { 512 .base.cra_name = "xts(aes)", 513 .base.cra_driver_name = "full-xts-aes-s390", 514 .base.cra_priority = 403, /* aes-xts-s390 + 1 */ 515 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, 516 .base.cra_blocksize = AES_BLOCK_SIZE, 517 .base.cra_ctxsize = sizeof(struct s390_xts_ctx), 518 .base.cra_module = THIS_MODULE, 519 .init = xts_fallback_init, 520 .exit = xts_fallback_exit, 521 .min_keysize = 2 * AES_MIN_KEY_SIZE, 522 .max_keysize = 2 * AES_MAX_KEY_SIZE, 523 .ivsize = AES_BLOCK_SIZE, 524 .setkey = fullxts_aes_set_key, 525 .encrypt = fullxts_aes_encrypt, 526 .decrypt = fullxts_aes_decrypt, 527 }; 528 529 static int ctr_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key, 530 unsigned int key_len) 531 { 532 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 533 unsigned long fc; 534 535 /* Pick the correct function code based on the key length */ 536 fc = (key_len == 16) ? CPACF_KMCTR_AES_128 : 537 (key_len == 24) ? CPACF_KMCTR_AES_192 : 538 (key_len == 32) ? CPACF_KMCTR_AES_256 : 0; 539 540 /* Check if the function code is available */ 541 sctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0; 542 if (!sctx->fc) 543 return setkey_fallback_skcipher(tfm, in_key, key_len); 544 545 sctx->key_len = key_len; 546 memcpy(sctx->key, in_key, key_len); 547 return 0; 548 } 549 550 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes) 551 { 552 unsigned int i, n; 553 554 /* only use complete blocks, max. PAGE_SIZE */ 555 memcpy(ctrptr, iv, AES_BLOCK_SIZE); 556 n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1); 557 for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) { 558 memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE); 559 crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE); 560 ctrptr += AES_BLOCK_SIZE; 561 } 562 return n; 563 } 564 565 static int ctr_aes_crypt(struct skcipher_request *req) 566 { 567 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 568 struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm); 569 u8 buf[AES_BLOCK_SIZE], *ctrptr; 570 struct skcipher_walk walk; 571 unsigned int n, nbytes; 572 int ret, locked; 573 574 if (unlikely(!sctx->fc)) 575 return fallback_skcipher_crypt(sctx, req, 0); 576 577 locked = mutex_trylock(&ctrblk_lock); 578 579 ret = skcipher_walk_virt(&walk, req, false); 580 while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) { 581 n = AES_BLOCK_SIZE; 582 583 if (nbytes >= 2*AES_BLOCK_SIZE && locked) 584 n = __ctrblk_init(ctrblk, walk.iv, nbytes); 585 ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv; 586 cpacf_kmctr(sctx->fc, sctx->key, walk.dst.virt.addr, 587 walk.src.virt.addr, n, ctrptr); 588 if (ctrptr == ctrblk) 589 memcpy(walk.iv, ctrptr + n - AES_BLOCK_SIZE, 590 AES_BLOCK_SIZE); 591 crypto_inc(walk.iv, AES_BLOCK_SIZE); 592 ret = skcipher_walk_done(&walk, nbytes - n); 593 } 594 if (locked) 595 mutex_unlock(&ctrblk_lock); 596 /* 597 * final block may be < AES_BLOCK_SIZE, copy only nbytes 598 */ 599 if (nbytes) { 600 memset(buf, 0, AES_BLOCK_SIZE); 601 memcpy(buf, walk.src.virt.addr, nbytes); 602 cpacf_kmctr(sctx->fc, sctx->key, buf, buf, 603 AES_BLOCK_SIZE, walk.iv); 604 memcpy(walk.dst.virt.addr, buf, nbytes); 605 crypto_inc(walk.iv, AES_BLOCK_SIZE); 606 ret = skcipher_walk_done(&walk, 0); 607 } 608 609 return ret; 610 } 611 612 static struct skcipher_alg ctr_aes_alg = { 613 .base.cra_name = "ctr(aes)", 614 .base.cra_driver_name = "ctr-aes-s390", 615 .base.cra_priority = 402, /* ecb-aes-s390 + 1 */ 616 .base.cra_flags = CRYPTO_ALG_NEED_FALLBACK, 617 .base.cra_blocksize = 1, 618 .base.cra_ctxsize = sizeof(struct s390_aes_ctx), 619 .base.cra_module = THIS_MODULE, 620 .init = fallback_init_skcipher, 621 .exit = fallback_exit_skcipher, 622 .min_keysize = AES_MIN_KEY_SIZE, 623 .max_keysize = AES_MAX_KEY_SIZE, 624 .ivsize = AES_BLOCK_SIZE, 625 .setkey = ctr_aes_set_key, 626 .encrypt = ctr_aes_crypt, 627 .decrypt = ctr_aes_crypt, 628 .chunksize = AES_BLOCK_SIZE, 629 }; 630 631 static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *key, 632 unsigned int keylen) 633 { 634 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm); 635 636 switch (keylen) { 637 case AES_KEYSIZE_128: 638 ctx->fc = CPACF_KMA_GCM_AES_128; 639 break; 640 case AES_KEYSIZE_192: 641 ctx->fc = CPACF_KMA_GCM_AES_192; 642 break; 643 case AES_KEYSIZE_256: 644 ctx->fc = CPACF_KMA_GCM_AES_256; 645 break; 646 default: 647 return -EINVAL; 648 } 649 650 memcpy(ctx->key, key, keylen); 651 ctx->key_len = keylen; 652 return 0; 653 } 654 655 static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize) 656 { 657 switch (authsize) { 658 case 4: 659 case 8: 660 case 12: 661 case 13: 662 case 14: 663 case 15: 664 case 16: 665 break; 666 default: 667 return -EINVAL; 668 } 669 670 return 0; 671 } 672 673 static void gcm_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg, 674 unsigned int len) 675 { 676 memset(gw, 0, sizeof(*gw)); 677 gw->walk_bytes_remain = len; 678 scatterwalk_start(&gw->walk, sg); 679 } 680 681 static inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw) 682 { 683 if (gw->walk_bytes_remain == 0) 684 return 0; 685 gw->walk_bytes = scatterwalk_next(&gw->walk, gw->walk_bytes_remain); 686 return gw->walk_bytes; 687 } 688 689 static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw, 690 unsigned int nbytes, bool out) 691 { 692 gw->walk_bytes_remain -= nbytes; 693 if (out) 694 scatterwalk_done_dst(&gw->walk, nbytes); 695 else 696 scatterwalk_done_src(&gw->walk, nbytes); 697 } 698 699 static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) 700 { 701 int n; 702 703 if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) { 704 gw->ptr = gw->buf; 705 gw->nbytes = gw->buf_bytes; 706 goto out; 707 } 708 709 if (gw->walk_bytes_remain == 0) { 710 gw->ptr = NULL; 711 gw->nbytes = 0; 712 goto out; 713 } 714 715 if (!_gcm_sg_clamp_and_map(gw)) { 716 gw->ptr = NULL; 717 gw->nbytes = 0; 718 goto out; 719 } 720 721 if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) { 722 gw->ptr = gw->walk.addr; 723 gw->nbytes = gw->walk_bytes; 724 goto out; 725 } 726 727 while (1) { 728 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes); 729 memcpy(gw->buf + gw->buf_bytes, gw->walk.addr, n); 730 gw->buf_bytes += n; 731 _gcm_sg_unmap_and_advance(gw, n, false); 732 if (gw->buf_bytes >= minbytesneeded) { 733 gw->ptr = gw->buf; 734 gw->nbytes = gw->buf_bytes; 735 goto out; 736 } 737 if (!_gcm_sg_clamp_and_map(gw)) { 738 gw->ptr = NULL; 739 gw->nbytes = 0; 740 goto out; 741 } 742 } 743 744 out: 745 return gw->nbytes; 746 } 747 748 static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded) 749 { 750 if (gw->walk_bytes_remain == 0) { 751 gw->ptr = NULL; 752 gw->nbytes = 0; 753 goto out; 754 } 755 756 if (!_gcm_sg_clamp_and_map(gw)) { 757 gw->ptr = NULL; 758 gw->nbytes = 0; 759 goto out; 760 } 761 762 if (gw->walk_bytes >= minbytesneeded) { 763 gw->ptr = gw->walk.addr; 764 gw->nbytes = gw->walk_bytes; 765 goto out; 766 } 767 768 scatterwalk_unmap(&gw->walk); 769 770 gw->ptr = gw->buf; 771 gw->nbytes = sizeof(gw->buf); 772 773 out: 774 return gw->nbytes; 775 } 776 777 static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) 778 { 779 if (gw->ptr == NULL) 780 return 0; 781 782 if (gw->ptr == gw->buf) { 783 int n = gw->buf_bytes - bytesdone; 784 if (n > 0) { 785 memmove(gw->buf, gw->buf + bytesdone, n); 786 gw->buf_bytes = n; 787 } else 788 gw->buf_bytes = 0; 789 } else 790 _gcm_sg_unmap_and_advance(gw, bytesdone, false); 791 792 return bytesdone; 793 } 794 795 static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone) 796 { 797 int i, n; 798 799 if (gw->ptr == NULL) 800 return 0; 801 802 if (gw->ptr == gw->buf) { 803 for (i = 0; i < bytesdone; i += n) { 804 if (!_gcm_sg_clamp_and_map(gw)) 805 return i; 806 n = min(gw->walk_bytes, bytesdone - i); 807 memcpy(gw->walk.addr, gw->buf + i, n); 808 _gcm_sg_unmap_and_advance(gw, n, true); 809 } 810 } else 811 _gcm_sg_unmap_and_advance(gw, bytesdone, true); 812 813 return bytesdone; 814 } 815 816 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags) 817 { 818 struct crypto_aead *tfm = crypto_aead_reqtfm(req); 819 struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm); 820 unsigned int ivsize = crypto_aead_ivsize(tfm); 821 unsigned int taglen = crypto_aead_authsize(tfm); 822 unsigned int aadlen = req->assoclen; 823 unsigned int pclen = req->cryptlen; 824 int ret = 0; 825 826 unsigned int n, len, in_bytes, out_bytes, 827 min_bytes, bytes, aad_bytes, pc_bytes; 828 struct gcm_sg_walk gw_in, gw_out; 829 u8 tag[GHASH_DIGEST_SIZE]; 830 831 struct { 832 u32 _[3]; /* reserved */ 833 u32 cv; /* Counter Value */ 834 u8 t[GHASH_DIGEST_SIZE];/* Tag */ 835 u8 h[AES_BLOCK_SIZE]; /* Hash-subkey */ 836 u64 taadl; /* Total AAD Length */ 837 u64 tpcl; /* Total Plain-/Cipher-text Length */ 838 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */ 839 u8 k[AES_MAX_KEY_SIZE]; /* Key */ 840 } param; 841 842 /* 843 * encrypt 844 * req->src: aad||plaintext 845 * req->dst: aad||ciphertext||tag 846 * decrypt 847 * req->src: aad||ciphertext||tag 848 * req->dst: aad||plaintext, return 0 or -EBADMSG 849 * aad, plaintext and ciphertext may be empty. 850 */ 851 if (flags & CPACF_DECRYPT) 852 pclen -= taglen; 853 len = aadlen + pclen; 854 855 memset(¶m, 0, sizeof(param)); 856 param.cv = 1; 857 param.taadl = aadlen * 8; 858 param.tpcl = pclen * 8; 859 memcpy(param.j0, req->iv, ivsize); 860 *(u32 *)(param.j0 + ivsize) = 1; 861 memcpy(param.k, ctx->key, ctx->key_len); 862 863 gcm_walk_start(&gw_in, req->src, len); 864 gcm_walk_start(&gw_out, req->dst, len); 865 866 do { 867 min_bytes = min_t(unsigned int, 868 aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE); 869 in_bytes = gcm_in_walk_go(&gw_in, min_bytes); 870 out_bytes = gcm_out_walk_go(&gw_out, min_bytes); 871 bytes = min(in_bytes, out_bytes); 872 873 if (aadlen + pclen <= bytes) { 874 aad_bytes = aadlen; 875 pc_bytes = pclen; 876 flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC; 877 } else { 878 if (aadlen <= bytes) { 879 aad_bytes = aadlen; 880 pc_bytes = (bytes - aadlen) & 881 ~(AES_BLOCK_SIZE - 1); 882 flags |= CPACF_KMA_LAAD; 883 } else { 884 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1); 885 pc_bytes = 0; 886 } 887 } 888 889 if (aad_bytes > 0) 890 memcpy(gw_out.ptr, gw_in.ptr, aad_bytes); 891 892 cpacf_kma(ctx->fc | flags, ¶m, 893 gw_out.ptr + aad_bytes, 894 gw_in.ptr + aad_bytes, pc_bytes, 895 gw_in.ptr, aad_bytes); 896 897 n = aad_bytes + pc_bytes; 898 if (gcm_in_walk_done(&gw_in, n) != n) 899 return -ENOMEM; 900 if (gcm_out_walk_done(&gw_out, n) != n) 901 return -ENOMEM; 902 aadlen -= aad_bytes; 903 pclen -= pc_bytes; 904 } while (aadlen + pclen > 0); 905 906 if (flags & CPACF_DECRYPT) { 907 scatterwalk_map_and_copy(tag, req->src, len, taglen, 0); 908 if (crypto_memneq(tag, param.t, taglen)) 909 ret = -EBADMSG; 910 } else 911 scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1); 912 913 memzero_explicit(¶m, sizeof(param)); 914 return ret; 915 } 916 917 static int gcm_aes_encrypt(struct aead_request *req) 918 { 919 return gcm_aes_crypt(req, CPACF_ENCRYPT); 920 } 921 922 static int gcm_aes_decrypt(struct aead_request *req) 923 { 924 return gcm_aes_crypt(req, CPACF_DECRYPT); 925 } 926 927 static struct aead_alg gcm_aes_aead = { 928 .setkey = gcm_aes_setkey, 929 .setauthsize = gcm_aes_setauthsize, 930 .encrypt = gcm_aes_encrypt, 931 .decrypt = gcm_aes_decrypt, 932 933 .ivsize = GHASH_BLOCK_SIZE - sizeof(u32), 934 .maxauthsize = GHASH_DIGEST_SIZE, 935 .chunksize = AES_BLOCK_SIZE, 936 937 .base = { 938 .cra_blocksize = 1, 939 .cra_ctxsize = sizeof(struct s390_aes_ctx), 940 .cra_priority = 900, 941 .cra_name = "gcm(aes)", 942 .cra_driver_name = "gcm-aes-s390", 943 .cra_module = THIS_MODULE, 944 }, 945 }; 946 947 static struct skcipher_alg *aes_s390_skcipher_algs[5]; 948 static int aes_s390_skciphers_num; 949 static struct aead_alg *aes_s390_aead_alg; 950 951 static int aes_s390_register_skcipher(struct skcipher_alg *alg) 952 { 953 int ret; 954 955 ret = crypto_register_skcipher(alg); 956 if (!ret) 957 aes_s390_skcipher_algs[aes_s390_skciphers_num++] = alg; 958 return ret; 959 } 960 961 static void aes_s390_fini(void) 962 { 963 while (aes_s390_skciphers_num--) 964 crypto_unregister_skcipher(aes_s390_skcipher_algs[aes_s390_skciphers_num]); 965 if (ctrblk) 966 free_page((unsigned long) ctrblk); 967 968 if (aes_s390_aead_alg) 969 crypto_unregister_aead(aes_s390_aead_alg); 970 } 971 972 static int __init aes_s390_init(void) 973 { 974 int ret; 975 976 /* Query available functions for KM, KMC, KMCTR and KMA */ 977 cpacf_query(CPACF_KM, &km_functions); 978 cpacf_query(CPACF_KMC, &kmc_functions); 979 cpacf_query(CPACF_KMCTR, &kmctr_functions); 980 cpacf_query(CPACF_KMA, &kma_functions); 981 982 if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) || 983 cpacf_test_func(&km_functions, CPACF_KM_AES_192) || 984 cpacf_test_func(&km_functions, CPACF_KM_AES_256)) { 985 ret = aes_s390_register_skcipher(&ecb_aes_alg); 986 if (ret) 987 goto out_err; 988 } 989 990 if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) || 991 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) || 992 cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) { 993 ret = aes_s390_register_skcipher(&cbc_aes_alg); 994 if (ret) 995 goto out_err; 996 } 997 998 if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128_FULL) || 999 cpacf_test_func(&km_functions, CPACF_KM_XTS_256_FULL)) { 1000 ret = aes_s390_register_skcipher(&fullxts_aes_alg); 1001 if (ret) 1002 goto out_err; 1003 } 1004 1005 if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) || 1006 cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) { 1007 ret = aes_s390_register_skcipher(&xts_aes_alg); 1008 if (ret) 1009 goto out_err; 1010 } 1011 1012 if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) || 1013 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) || 1014 cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) { 1015 ctrblk = (u8 *) __get_free_page(GFP_KERNEL); 1016 if (!ctrblk) { 1017 ret = -ENOMEM; 1018 goto out_err; 1019 } 1020 ret = aes_s390_register_skcipher(&ctr_aes_alg); 1021 if (ret) 1022 goto out_err; 1023 } 1024 1025 if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) || 1026 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) || 1027 cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) { 1028 ret = crypto_register_aead(&gcm_aes_aead); 1029 if (ret) 1030 goto out_err; 1031 aes_s390_aead_alg = &gcm_aes_aead; 1032 } 1033 1034 return 0; 1035 out_err: 1036 aes_s390_fini(); 1037 return ret; 1038 } 1039 1040 module_cpu_feature_match(S390_CPU_FEATURE_MSA, aes_s390_init); 1041 module_exit(aes_s390_fini); 1042 1043 MODULE_ALIAS_CRYPTO("aes-all"); 1044 1045 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm"); 1046 MODULE_LICENSE("GPL"); 1047