arch/s390/crypto/aes_s390.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Cryptographic API.
   4  *
   5  * s390 implementation of the AES Cipher Algorithm.
   6  *
   7  * s390 Version:
   8  *   Copyright IBM Corp. 2005, 2017
   9  *   Author(s): Jan Glauber (jang@de.ibm.com)
  10  *              Sebastian Siewior (sebastian@breakpoint.cc> SW-Fallback
  11  *              Patrick Steuer <patrick.steuer@de.ibm.com>
  12  *              Harald Freudenberger <freude@de.ibm.com>
  13  *
  14  * Derived from "crypto/aes_generic.c"
  15  */
  16
  17 #define KMSG_COMPONENT "aes_s390"
  18 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  19
  20 #include <crypto/aes.h>
  21 #include <crypto/algapi.h>
  22 #include <crypto/ghash.h>
  23 #include <crypto/internal/aead.h>
  24 #include <crypto/internal/skcipher.h>
  25 #include <crypto/scatterwalk.h>
  26 #include <linux/err.h>
  27 #include <linux/module.h>
  28 #include <linux/cpufeature.h>
  29 #include <linux/init.h>
  30 #include <linux/mutex.h>
  31 #include <linux/fips.h>
  32 #include <linux/string.h>
  33 #include <crypto/xts.h>
  34 #include <asm/cpacf.h>
  35
  36 static u8 *ctrblk;
  37 static DEFINE_MUTEX(ctrblk_lock);
  38
  39 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions,
  40                     kma_functions;
  41
  42 struct s390_aes_ctx {
  43         u8 key[AES_MAX_KEY_SIZE];
  44         int key_len;
  45         unsigned long fc;
  46         union {
  47                 struct crypto_skcipher *skcipher;
  48                 struct crypto_cipher *cip;
  49         } fallback;
  50 };
  51
  52 struct s390_xts_ctx {
  53         u8 key[32];
  54         u8 pcc_key[32];
  55         int key_len;
  56         unsigned long fc;
  57         struct crypto_skcipher *fallback;
  58 };
  59
  60 struct gcm_sg_walk {
  61         struct scatter_walk walk;
  62         unsigned int walk_bytes;
  63         u8 *walk_ptr;
  64         unsigned int walk_bytes_remain;
  65         u8 buf[AES_BLOCK_SIZE];
  66         unsigned int buf_bytes;
  67         u8 *ptr;
  68         unsigned int nbytes;
  69 };
  70
  71 static int setkey_fallback_cip(struct crypto_tfm *tfm, const u8 *in_key,
  72                 unsigned int key_len)
  73 {
  74         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
  75
  76         sctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
  77         sctx->fallback.cip->base.crt_flags |= (tfm->crt_flags &
  78                         CRYPTO_TFM_REQ_MASK);
  79
  80         return crypto_cipher_setkey(sctx->fallback.cip, in_key, key_len);
  81 }
  82
  83 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
  84                        unsigned int key_len)
  85 {
  86         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
  87         unsigned long fc;
  88
  89         /* Pick the correct function code based on the key length */
  90         fc = (key_len == 16) ? CPACF_KM_AES_128 :
  91              (key_len == 24) ? CPACF_KM_AES_192 :
  92              (key_len == 32) ? CPACF_KM_AES_256 : 0;
  93
  94         /* Check if the function code is available */
  95         sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
  96         if (!sctx->fc)
  97                 return setkey_fallback_cip(tfm, in_key, key_len);
  98
  99         sctx->key_len = key_len;
 100         memcpy(sctx->key, in_key, key_len);
 101         return 0;
 102 }
 103
 104 static void crypto_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 105 {
 106         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 107
 108         if (unlikely(!sctx->fc)) {
 109                 crypto_cipher_encrypt_one(sctx->fallback.cip, out, in);
 110                 return;
 111         }
 112         cpacf_km(sctx->fc, &sctx->key, out, in, AES_BLOCK_SIZE);
 113 }
 114
 115 static void crypto_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 116 {
 117         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 118
 119         if (unlikely(!sctx->fc)) {
 120                 crypto_cipher_decrypt_one(sctx->fallback.cip, out, in);
 121                 return;
 122         }
 123         cpacf_km(sctx->fc | CPACF_DECRYPT,
 124                  &sctx->key, out, in, AES_BLOCK_SIZE);
 125 }
 126
 127 static int fallback_init_cip(struct crypto_tfm *tfm)
 128 {
 129         const char *name = tfm->__crt_alg->cra_name;
 130         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 131
 132         sctx->fallback.cip = crypto_alloc_cipher(name, 0,
 133                                                  CRYPTO_ALG_NEED_FALLBACK);
 134
 135         if (IS_ERR(sctx->fallback.cip)) {
 136                 pr_err("Allocating AES fallback algorithm %s failed\n",
 137                        name);
 138                 return PTR_ERR(sctx->fallback.cip);
 139         }
 140
 141         return 0;
 142 }
 143
 144 static void fallback_exit_cip(struct crypto_tfm *tfm)
 145 {
 146         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 147
 148         crypto_free_cipher(sctx->fallback.cip);
 149         sctx->fallback.cip = NULL;
 150 }
 151
 152 static struct crypto_alg aes_alg = {
 153         .cra_name               =       "aes",
 154         .cra_driver_name        =       "aes-s390",
 155         .cra_priority           =       300,
 156         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER |
 157                                         CRYPTO_ALG_NEED_FALLBACK,
 158         .cra_blocksize          =       AES_BLOCK_SIZE,
 159         .cra_ctxsize            =       sizeof(struct s390_aes_ctx),
 160         .cra_module             =       THIS_MODULE,
 161         .cra_init               =       fallback_init_cip,
 162         .cra_exit               =       fallback_exit_cip,
 163         .cra_u                  =       {
 164                 .cipher = {
 165                         .cia_min_keysize        =       AES_MIN_KEY_SIZE,
 166                         .cia_max_keysize        =       AES_MAX_KEY_SIZE,
 167                         .cia_setkey             =       aes_set_key,
 168                         .cia_encrypt            =       crypto_aes_encrypt,
 169                         .cia_decrypt            =       crypto_aes_decrypt,
 170                 }
 171         }
 172 };
 173
 174 static int setkey_fallback_skcipher(struct crypto_skcipher *tfm, const u8 *key,
 175                                     unsigned int len)
 176 {
 177         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 178
 179         crypto_skcipher_clear_flags(sctx->fallback.skcipher,
 180                                     CRYPTO_TFM_REQ_MASK);
 181         crypto_skcipher_set_flags(sctx->fallback.skcipher,
 182                                   crypto_skcipher_get_flags(tfm) &
 183                                   CRYPTO_TFM_REQ_MASK);
 184         return crypto_skcipher_setkey(sctx->fallback.skcipher, key, len);
 185 }
 186
 187 static int fallback_skcipher_crypt(struct s390_aes_ctx *sctx,
 188                                    struct skcipher_request *req,
 189                                    unsigned long modifier)
 190 {
 191         struct skcipher_request *subreq = skcipher_request_ctx(req);
 192
 193         *subreq = *req;
 194         skcipher_request_set_tfm(subreq, sctx->fallback.skcipher);
 195         return (modifier & CPACF_DECRYPT) ?
 196                 crypto_skcipher_decrypt(subreq) :
 197                 crypto_skcipher_encrypt(subreq);
 198 }
 199
 200 static int ecb_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 201                            unsigned int key_len)
 202 {
 203         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 204         unsigned long fc;
 205
 206         /* Pick the correct function code based on the key length */
 207         fc = (key_len == 16) ? CPACF_KM_AES_128 :
 208              (key_len == 24) ? CPACF_KM_AES_192 :
 209              (key_len == 32) ? CPACF_KM_AES_256 : 0;
 210
 211         /* Check if the function code is available */
 212         sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
 213         if (!sctx->fc)
 214                 return setkey_fallback_skcipher(tfm, in_key, key_len);
 215
 216         sctx->key_len = key_len;
 217         memcpy(sctx->key, in_key, key_len);
 218         return 0;
 219 }
 220
 221 static int ecb_aes_crypt(struct skcipher_request *req, unsigned long modifier)
 222 {
 223         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 224         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 225         struct skcipher_walk walk;
 226         unsigned int nbytes, n;
 227         int ret;
 228
 229         if (unlikely(!sctx->fc))
 230                 return fallback_skcipher_crypt(sctx, req, modifier);
 231
 232         ret = skcipher_walk_virt(&walk, req, false);
 233         while ((nbytes = walk.nbytes) != 0) {
 234                 /* only use complete blocks */
 235                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 236                 cpacf_km(sctx->fc | modifier, sctx->key,
 237                          walk.dst.virt.addr, walk.src.virt.addr, n);
 238                 ret = skcipher_walk_done(&walk, nbytes - n);
 239         }
 240         return ret;
 241 }
 242
 243 static int ecb_aes_encrypt(struct skcipher_request *req)
 244 {
 245         return ecb_aes_crypt(req, 0);
 246 }
 247
 248 static int ecb_aes_decrypt(struct skcipher_request *req)
 249 {
 250         return ecb_aes_crypt(req, CPACF_DECRYPT);
 251 }
 252
 253 static int fallback_init_skcipher(struct crypto_skcipher *tfm)
 254 {
 255         const char *name = crypto_tfm_alg_name(&tfm->base);
 256         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 257
 258         sctx->fallback.skcipher = crypto_alloc_skcipher(name, 0,
 259                                 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
 260
 261         if (IS_ERR(sctx->fallback.skcipher)) {
 262                 pr_err("Allocating AES fallback algorithm %s failed\n",
 263                        name);
 264                 return PTR_ERR(sctx->fallback.skcipher);
 265         }
 266
 267         crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
 268                                     crypto_skcipher_reqsize(sctx->fallback.skcipher));
 269         return 0;
 270 }
 271
 272 static void fallback_exit_skcipher(struct crypto_skcipher *tfm)
 273 {
 274         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 275
 276         crypto_free_skcipher(sctx->fallback.skcipher);
 277 }
 278
 279 static struct skcipher_alg ecb_aes_alg = {
 280         .base.cra_name          =       "ecb(aes)",
 281         .base.cra_driver_name   =       "ecb-aes-s390",
 282         .base.cra_priority      =       401,    /* combo: aes + ecb + 1 */
 283         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 284         .base.cra_blocksize     =       AES_BLOCK_SIZE,
 285         .base.cra_ctxsize       =       sizeof(struct s390_aes_ctx),
 286         .base.cra_module        =       THIS_MODULE,
 287         .init                   =       fallback_init_skcipher,
 288         .exit                   =       fallback_exit_skcipher,
 289         .min_keysize            =       AES_MIN_KEY_SIZE,
 290         .max_keysize            =       AES_MAX_KEY_SIZE,
 291         .setkey                 =       ecb_aes_set_key,
 292         .encrypt                =       ecb_aes_encrypt,
 293         .decrypt                =       ecb_aes_decrypt,
 294 };
 295
 296 static int cbc_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 297                            unsigned int key_len)
 298 {
 299         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 300         unsigned long fc;
 301
 302         /* Pick the correct function code based on the key length */
 303         fc = (key_len == 16) ? CPACF_KMC_AES_128 :
 304              (key_len == 24) ? CPACF_KMC_AES_192 :
 305              (key_len == 32) ? CPACF_KMC_AES_256 : 0;
 306
 307         /* Check if the function code is available */
 308         sctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0;
 309         if (!sctx->fc)
 310                 return setkey_fallback_skcipher(tfm, in_key, key_len);
 311
 312         sctx->key_len = key_len;
 313         memcpy(sctx->key, in_key, key_len);
 314         return 0;
 315 }
 316
 317 static int cbc_aes_crypt(struct skcipher_request *req, unsigned long modifier)
 318 {
 319         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 320         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 321         struct skcipher_walk walk;
 322         unsigned int nbytes, n;
 323         int ret;
 324         struct {
 325                 u8 iv[AES_BLOCK_SIZE];
 326                 u8 key[AES_MAX_KEY_SIZE];
 327         } param;
 328
 329         if (unlikely(!sctx->fc))
 330                 return fallback_skcipher_crypt(sctx, req, modifier);
 331
 332         ret = skcipher_walk_virt(&walk, req, false);
 333         if (ret)
 334                 return ret;
 335         memcpy(param.iv, walk.iv, AES_BLOCK_SIZE);
 336         memcpy(param.key, sctx->key, sctx->key_len);
 337         while ((nbytes = walk.nbytes) != 0) {
 338                 /* only use complete blocks */
 339                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 340                 cpacf_kmc(sctx->fc | modifier, &param,
 341                           walk.dst.virt.addr, walk.src.virt.addr, n);
 342                 memcpy(walk.iv, param.iv, AES_BLOCK_SIZE);
 343                 ret = skcipher_walk_done(&walk, nbytes - n);
 344         }
 345         return ret;
 346 }
 347
 348 static int cbc_aes_encrypt(struct skcipher_request *req)
 349 {
 350         return cbc_aes_crypt(req, 0);
 351 }
 352
 353 static int cbc_aes_decrypt(struct skcipher_request *req)
 354 {
 355         return cbc_aes_crypt(req, CPACF_DECRYPT);
 356 }
 357
 358 static struct skcipher_alg cbc_aes_alg = {
 359         .base.cra_name          =       "cbc(aes)",
 360         .base.cra_driver_name   =       "cbc-aes-s390",
 361         .base.cra_priority      =       402,    /* ecb-aes-s390 + 1 */
 362         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 363         .base.cra_blocksize     =       AES_BLOCK_SIZE,
 364         .base.cra_ctxsize       =       sizeof(struct s390_aes_ctx),
 365         .base.cra_module        =       THIS_MODULE,
 366         .init                   =       fallback_init_skcipher,
 367         .exit                   =       fallback_exit_skcipher,
 368         .min_keysize            =       AES_MIN_KEY_SIZE,
 369         .max_keysize            =       AES_MAX_KEY_SIZE,
 370         .ivsize                 =       AES_BLOCK_SIZE,
 371         .setkey                 =       cbc_aes_set_key,
 372         .encrypt                =       cbc_aes_encrypt,
 373         .decrypt                =       cbc_aes_decrypt,
 374 };
 375
 376 static int xts_fallback_setkey(struct crypto_skcipher *tfm, const u8 *key,
 377                                unsigned int len)
 378 {
 379         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 380
 381         crypto_skcipher_clear_flags(xts_ctx->fallback, CRYPTO_TFM_REQ_MASK);
 382         crypto_skcipher_set_flags(xts_ctx->fallback,
 383                                   crypto_skcipher_get_flags(tfm) &
 384                                   CRYPTO_TFM_REQ_MASK);
 385         return crypto_skcipher_setkey(xts_ctx->fallback, key, len);
 386 }
 387
 388 static int xts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 389                            unsigned int key_len)
 390 {
 391         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 392         unsigned long fc;
 393         int err;
 394
 395         err = xts_fallback_setkey(tfm, in_key, key_len);
 396         if (err)
 397                 return err;
 398
 399         /* In fips mode only 128 bit or 256 bit keys are valid */
 400         if (fips_enabled && key_len != 32 && key_len != 64)
 401                 return -EINVAL;
 402
 403         /* Pick the correct function code based on the key length */
 404         fc = (key_len == 32) ? CPACF_KM_XTS_128 :
 405              (key_len == 64) ? CPACF_KM_XTS_256 : 0;
 406
 407         /* Check if the function code is available */
 408         xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
 409         if (!xts_ctx->fc)
 410                 return 0;
 411
 412         /* Split the XTS key into the two subkeys */
 413         key_len = key_len / 2;
 414         xts_ctx->key_len = key_len;
 415         memcpy(xts_ctx->key, in_key, key_len);
 416         memcpy(xts_ctx->pcc_key, in_key + key_len, key_len);
 417         return 0;
 418 }
 419
 420 static int xts_aes_crypt(struct skcipher_request *req, unsigned long modifier)
 421 {
 422         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 423         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 424         struct skcipher_walk walk;
 425         unsigned int offset, nbytes, n;
 426         int ret;
 427         struct {
 428                 u8 key[32];
 429                 u8 tweak[16];
 430                 u8 block[16];
 431                 u8 bit[16];
 432                 u8 xts[16];
 433         } pcc_param;
 434         struct {
 435                 u8 key[32];
 436                 u8 init[16];
 437         } xts_param;
 438
 439         if (req->cryptlen < AES_BLOCK_SIZE)
 440                 return -EINVAL;
 441
 442         if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) {
 443                 struct skcipher_request *subreq = skcipher_request_ctx(req);
 444
 445                 *subreq = *req;
 446                 skcipher_request_set_tfm(subreq, xts_ctx->fallback);
 447                 return (modifier & CPACF_DECRYPT) ?
 448                         crypto_skcipher_decrypt(subreq) :
 449                         crypto_skcipher_encrypt(subreq);
 450         }
 451
 452         ret = skcipher_walk_virt(&walk, req, false);
 453         if (ret)
 454                 return ret;
 455         offset = xts_ctx->key_len & 0x10;
 456         memset(pcc_param.block, 0, sizeof(pcc_param.block));
 457         memset(pcc_param.bit, 0, sizeof(pcc_param.bit));
 458         memset(pcc_param.xts, 0, sizeof(pcc_param.xts));
 459         memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
 460         memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len);
 461         cpacf_pcc(xts_ctx->fc, pcc_param.key + offset);
 462
 463         memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len);
 464         memcpy(xts_param.init, pcc_param.xts, 16);
 465
 466         while ((nbytes = walk.nbytes) != 0) {
 467                 /* only use complete blocks */
 468                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 469                 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset,
 470                          walk.dst.virt.addr, walk.src.virt.addr, n);
 471                 ret = skcipher_walk_done(&walk, nbytes - n);
 472         }
 473         return ret;
 474 }
 475
 476 static int xts_aes_encrypt(struct skcipher_request *req)
 477 {
 478         return xts_aes_crypt(req, 0);
 479 }
 480
 481 static int xts_aes_decrypt(struct skcipher_request *req)
 482 {
 483         return xts_aes_crypt(req, CPACF_DECRYPT);
 484 }
 485
 486 static int xts_fallback_init(struct crypto_skcipher *tfm)
 487 {
 488         const char *name = crypto_tfm_alg_name(&tfm->base);
 489         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 490
 491         xts_ctx->fallback = crypto_alloc_skcipher(name, 0,
 492                                 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
 493
 494         if (IS_ERR(xts_ctx->fallback)) {
 495                 pr_err("Allocating XTS fallback algorithm %s failed\n",
 496                        name);
 497                 return PTR_ERR(xts_ctx->fallback);
 498         }
 499         crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
 500                                     crypto_skcipher_reqsize(xts_ctx->fallback));
 501         return 0;
 502 }
 503
 504 static void xts_fallback_exit(struct crypto_skcipher *tfm)
 505 {
 506         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 507
 508         crypto_free_skcipher(xts_ctx->fallback);
 509 }
 510
 511 static struct skcipher_alg xts_aes_alg = {
 512         .base.cra_name          =       "xts(aes)",
 513         .base.cra_driver_name   =       "xts-aes-s390",
 514         .base.cra_priority      =       402,    /* ecb-aes-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                 =       xts_aes_set_key,
 525         .encrypt                =       xts_aes_encrypt,
 526         .decrypt                =       xts_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                 cpacf_kmctr(sctx->fc, sctx->key, buf, walk.src.virt.addr,
 601                             AES_BLOCK_SIZE, walk.iv);
 602                 memcpy(walk.dst.virt.addr, buf, nbytes);
 603                 crypto_inc(walk.iv, AES_BLOCK_SIZE);
 604                 ret = skcipher_walk_done(&walk, 0);
 605         }
 606
 607         return ret;
 608 }
 609
 610 static struct skcipher_alg ctr_aes_alg = {
 611         .base.cra_name          =       "ctr(aes)",
 612         .base.cra_driver_name   =       "ctr-aes-s390",
 613         .base.cra_priority      =       402,    /* ecb-aes-s390 + 1 */
 614         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 615         .base.cra_blocksize     =       1,
 616         .base.cra_ctxsize       =       sizeof(struct s390_aes_ctx),
 617         .base.cra_module        =       THIS_MODULE,
 618         .init                   =       fallback_init_skcipher,
 619         .exit                   =       fallback_exit_skcipher,
 620         .min_keysize            =       AES_MIN_KEY_SIZE,
 621         .max_keysize            =       AES_MAX_KEY_SIZE,
 622         .ivsize                 =       AES_BLOCK_SIZE,
 623         .setkey                 =       ctr_aes_set_key,
 624         .encrypt                =       ctr_aes_crypt,
 625         .decrypt                =       ctr_aes_crypt,
 626         .chunksize              =       AES_BLOCK_SIZE,
 627 };
 628
 629 static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *key,
 630                           unsigned int keylen)
 631 {
 632         struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
 633
 634         switch (keylen) {
 635         case AES_KEYSIZE_128:
 636                 ctx->fc = CPACF_KMA_GCM_AES_128;
 637                 break;
 638         case AES_KEYSIZE_192:
 639                 ctx->fc = CPACF_KMA_GCM_AES_192;
 640                 break;
 641         case AES_KEYSIZE_256:
 642                 ctx->fc = CPACF_KMA_GCM_AES_256;
 643                 break;
 644         default:
 645                 return -EINVAL;
 646         }
 647
 648         memcpy(ctx->key, key, keylen);
 649         ctx->key_len = keylen;
 650         return 0;
 651 }
 652
 653 static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
 654 {
 655         switch (authsize) {
 656         case 4:
 657         case 8:
 658         case 12:
 659         case 13:
 660         case 14:
 661         case 15:
 662         case 16:
 663                 break;
 664         default:
 665                 return -EINVAL;
 666         }
 667
 668         return 0;
 669 }
 670
 671 static void gcm_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg,
 672                            unsigned int len)
 673 {
 674         memset(gw, 0, sizeof(*gw));
 675         gw->walk_bytes_remain = len;
 676         scatterwalk_start(&gw->walk, sg);
 677 }
 678
 679 static inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw)
 680 {
 681         struct scatterlist *nextsg;
 682
 683         gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain);
 684         while (!gw->walk_bytes) {
 685                 nextsg = sg_next(gw->walk.sg);
 686                 if (!nextsg)
 687                         return 0;
 688                 scatterwalk_start(&gw->walk, nextsg);
 689                 gw->walk_bytes = scatterwalk_clamp(&gw->walk,
 690                                                    gw->walk_bytes_remain);
 691         }
 692         gw->walk_ptr = scatterwalk_map(&gw->walk);
 693         return gw->walk_bytes;
 694 }
 695
 696 static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw,
 697                                              unsigned int nbytes)
 698 {
 699         gw->walk_bytes_remain -= nbytes;
 700         scatterwalk_unmap(&gw->walk);
 701         scatterwalk_advance(&gw->walk, nbytes);
 702         scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
 703         gw->walk_ptr = NULL;
 704 }
 705
 706 static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
 707 {
 708         int n;
 709
 710         if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) {
 711                 gw->ptr = gw->buf;
 712                 gw->nbytes = gw->buf_bytes;
 713                 goto out;
 714         }
 715
 716         if (gw->walk_bytes_remain == 0) {
 717                 gw->ptr = NULL;
 718                 gw->nbytes = 0;
 719                 goto out;
 720         }
 721
 722         if (!_gcm_sg_clamp_and_map(gw)) {
 723                 gw->ptr = NULL;
 724                 gw->nbytes = 0;
 725                 goto out;
 726         }
 727
 728         if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) {
 729                 gw->ptr = gw->walk_ptr;
 730                 gw->nbytes = gw->walk_bytes;
 731                 goto out;
 732         }
 733
 734         while (1) {
 735                 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes);
 736                 memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n);
 737                 gw->buf_bytes += n;
 738                 _gcm_sg_unmap_and_advance(gw, n);
 739                 if (gw->buf_bytes >= minbytesneeded) {
 740                         gw->ptr = gw->buf;
 741                         gw->nbytes = gw->buf_bytes;
 742                         goto out;
 743                 }
 744                 if (!_gcm_sg_clamp_and_map(gw)) {
 745                         gw->ptr = NULL;
 746                         gw->nbytes = 0;
 747                         goto out;
 748                 }
 749         }
 750
 751 out:
 752         return gw->nbytes;
 753 }
 754
 755 static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
 756 {
 757         if (gw->walk_bytes_remain == 0) {
 758                 gw->ptr = NULL;
 759                 gw->nbytes = 0;
 760                 goto out;
 761         }
 762
 763         if (!_gcm_sg_clamp_and_map(gw)) {
 764                 gw->ptr = NULL;
 765                 gw->nbytes = 0;
 766                 goto out;
 767         }
 768
 769         if (gw->walk_bytes >= minbytesneeded) {
 770                 gw->ptr = gw->walk_ptr;
 771                 gw->nbytes = gw->walk_bytes;
 772                 goto out;
 773         }
 774
 775         scatterwalk_unmap(&gw->walk);
 776         gw->walk_ptr = NULL;
 777
 778         gw->ptr = gw->buf;
 779         gw->nbytes = sizeof(gw->buf);
 780
 781 out:
 782         return gw->nbytes;
 783 }
 784
 785 static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
 786 {
 787         if (gw->ptr == NULL)
 788                 return 0;
 789
 790         if (gw->ptr == gw->buf) {
 791                 int n = gw->buf_bytes - bytesdone;
 792                 if (n > 0) {
 793                         memmove(gw->buf, gw->buf + bytesdone, n);
 794                         gw->buf_bytes = n;
 795                 } else
 796                         gw->buf_bytes = 0;
 797         } else
 798                 _gcm_sg_unmap_and_advance(gw, bytesdone);
 799
 800         return bytesdone;
 801 }
 802
 803 static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
 804 {
 805         int i, n;
 806
 807         if (gw->ptr == NULL)
 808                 return 0;
 809
 810         if (gw->ptr == gw->buf) {
 811                 for (i = 0; i < bytesdone; i += n) {
 812                         if (!_gcm_sg_clamp_and_map(gw))
 813                                 return i;
 814                         n = min(gw->walk_bytes, bytesdone - i);
 815                         memcpy(gw->walk_ptr, gw->buf + i, n);
 816                         _gcm_sg_unmap_and_advance(gw, n);
 817                 }
 818         } else
 819                 _gcm_sg_unmap_and_advance(gw, bytesdone);
 820
 821         return bytesdone;
 822 }
 823
 824 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags)
 825 {
 826         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 827         struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
 828         unsigned int ivsize = crypto_aead_ivsize(tfm);
 829         unsigned int taglen = crypto_aead_authsize(tfm);
 830         unsigned int aadlen = req->assoclen;
 831         unsigned int pclen = req->cryptlen;
 832         int ret = 0;
 833
 834         unsigned int n, len, in_bytes, out_bytes,
 835                      min_bytes, bytes, aad_bytes, pc_bytes;
 836         struct gcm_sg_walk gw_in, gw_out;
 837         u8 tag[GHASH_DIGEST_SIZE];
 838
 839         struct {
 840                 u32 _[3];               /* reserved */
 841                 u32 cv;                 /* Counter Value */
 842                 u8 t[GHASH_DIGEST_SIZE];/* Tag */
 843                 u8 h[AES_BLOCK_SIZE];   /* Hash-subkey */
 844                 u64 taadl;              /* Total AAD Length */
 845                 u64 tpcl;               /* Total Plain-/Cipher-text Length */
 846                 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */
 847                 u8 k[AES_MAX_KEY_SIZE]; /* Key */
 848         } param;
 849
 850         /*
 851          * encrypt
 852          *   req->src: aad||plaintext
 853          *   req->dst: aad||ciphertext||tag
 854          * decrypt
 855          *   req->src: aad||ciphertext||tag
 856          *   req->dst: aad||plaintext, return 0 or -EBADMSG
 857          * aad, plaintext and ciphertext may be empty.
 858          */
 859         if (flags & CPACF_DECRYPT)
 860                 pclen -= taglen;
 861         len = aadlen + pclen;
 862
 863         memset(&param, 0, sizeof(param));
 864         param.cv = 1;
 865         param.taadl = aadlen * 8;
 866         param.tpcl = pclen * 8;
 867         memcpy(param.j0, req->iv, ivsize);
 868         *(u32 *)(param.j0 + ivsize) = 1;
 869         memcpy(param.k, ctx->key, ctx->key_len);
 870
 871         gcm_walk_start(&gw_in, req->src, len);
 872         gcm_walk_start(&gw_out, req->dst, len);
 873
 874         do {
 875                 min_bytes = min_t(unsigned int,
 876                                   aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE);
 877                 in_bytes = gcm_in_walk_go(&gw_in, min_bytes);
 878                 out_bytes = gcm_out_walk_go(&gw_out, min_bytes);
 879                 bytes = min(in_bytes, out_bytes);
 880
 881                 if (aadlen + pclen <= bytes) {
 882                         aad_bytes = aadlen;
 883                         pc_bytes = pclen;
 884                         flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC;
 885                 } else {
 886                         if (aadlen <= bytes) {
 887                                 aad_bytes = aadlen;
 888                                 pc_bytes = (bytes - aadlen) &
 889                                            ~(AES_BLOCK_SIZE - 1);
 890                                 flags |= CPACF_KMA_LAAD;
 891                         } else {
 892                                 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1);
 893                                 pc_bytes = 0;
 894                         }
 895                 }
 896
 897                 if (aad_bytes > 0)
 898                         memcpy(gw_out.ptr, gw_in.ptr, aad_bytes);
 899
 900                 cpacf_kma(ctx->fc | flags, &param,
 901                           gw_out.ptr + aad_bytes,
 902                           gw_in.ptr + aad_bytes, pc_bytes,
 903                           gw_in.ptr, aad_bytes);
 904
 905                 n = aad_bytes + pc_bytes;
 906                 if (gcm_in_walk_done(&gw_in, n) != n)
 907                         return -ENOMEM;
 908                 if (gcm_out_walk_done(&gw_out, n) != n)
 909                         return -ENOMEM;
 910                 aadlen -= aad_bytes;
 911                 pclen -= pc_bytes;
 912         } while (aadlen + pclen > 0);
 913
 914         if (flags & CPACF_DECRYPT) {
 915                 scatterwalk_map_and_copy(tag, req->src, len, taglen, 0);
 916                 if (crypto_memneq(tag, param.t, taglen))
 917                         ret = -EBADMSG;
 918         } else
 919                 scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1);
 920
 921         memzero_explicit(&param, sizeof(param));
 922         return ret;
 923 }
 924
 925 static int gcm_aes_encrypt(struct aead_request *req)
 926 {
 927         return gcm_aes_crypt(req, CPACF_ENCRYPT);
 928 }
 929
 930 static int gcm_aes_decrypt(struct aead_request *req)
 931 {
 932         return gcm_aes_crypt(req, CPACF_DECRYPT);
 933 }
 934
 935 static struct aead_alg gcm_aes_aead = {
 936         .setkey                 = gcm_aes_setkey,
 937         .setauthsize            = gcm_aes_setauthsize,
 938         .encrypt                = gcm_aes_encrypt,
 939         .decrypt                = gcm_aes_decrypt,
 940
 941         .ivsize                 = GHASH_BLOCK_SIZE - sizeof(u32),
 942         .maxauthsize            = GHASH_DIGEST_SIZE,
 943         .chunksize              = AES_BLOCK_SIZE,
 944
 945         .base                   = {
 946                 .cra_blocksize          = 1,
 947                 .cra_ctxsize            = sizeof(struct s390_aes_ctx),
 948                 .cra_priority           = 900,
 949                 .cra_name               = "gcm(aes)",
 950                 .cra_driver_name        = "gcm-aes-s390",
 951                 .cra_module             = THIS_MODULE,
 952         },
 953 };
 954
 955 static struct crypto_alg *aes_s390_alg;
 956 static struct skcipher_alg *aes_s390_skcipher_algs[4];
 957 static int aes_s390_skciphers_num;
 958 static struct aead_alg *aes_s390_aead_alg;
 959
 960 static int aes_s390_register_skcipher(struct skcipher_alg *alg)
 961 {
 962         int ret;
 963
 964         ret = crypto_register_skcipher(alg);
 965         if (!ret)
 966                 aes_s390_skcipher_algs[aes_s390_skciphers_num++] = alg;
 967         return ret;
 968 }
 969
 970 static void aes_s390_fini(void)
 971 {
 972         if (aes_s390_alg)
 973                 crypto_unregister_alg(aes_s390_alg);
 974         while (aes_s390_skciphers_num--)
 975                 crypto_unregister_skcipher(aes_s390_skcipher_algs[aes_s390_skciphers_num]);
 976         if (ctrblk)
 977                 free_page((unsigned long) ctrblk);
 978
 979         if (aes_s390_aead_alg)
 980                 crypto_unregister_aead(aes_s390_aead_alg);
 981 }
 982
 983 static int __init aes_s390_init(void)
 984 {
 985         int ret;
 986
 987         /* Query available functions for KM, KMC, KMCTR and KMA */
 988         cpacf_query(CPACF_KM, &km_functions);
 989         cpacf_query(CPACF_KMC, &kmc_functions);
 990         cpacf_query(CPACF_KMCTR, &kmctr_functions);
 991         cpacf_query(CPACF_KMA, &kma_functions);
 992
 993         if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) ||
 994             cpacf_test_func(&km_functions, CPACF_KM_AES_192) ||
 995             cpacf_test_func(&km_functions, CPACF_KM_AES_256)) {
 996                 ret = crypto_register_alg(&aes_alg);
 997                 if (ret)
 998                         goto out_err;
 999                 aes_s390_alg = &aes_alg;
1000                 ret = aes_s390_register_skcipher(&ecb_aes_alg);
1001                 if (ret)
1002                         goto out_err;
1003         }
1004
1005         if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) ||
1006             cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) ||
1007             cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) {
1008                 ret = aes_s390_register_skcipher(&cbc_aes_alg);
1009                 if (ret)
1010                         goto out_err;
1011         }
1012
1013         if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) ||
1014             cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) {
1015                 ret = aes_s390_register_skcipher(&xts_aes_alg);
1016                 if (ret)
1017                         goto out_err;
1018         }
1019
1020         if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) ||
1021             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) ||
1022             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) {
1023                 ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
1024                 if (!ctrblk) {
1025                         ret = -ENOMEM;
1026                         goto out_err;
1027                 }
1028                 ret = aes_s390_register_skcipher(&ctr_aes_alg);
1029                 if (ret)
1030                         goto out_err;
1031         }
1032
1033         if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) ||
1034             cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) ||
1035             cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) {
1036                 ret = crypto_register_aead(&gcm_aes_aead);
1037                 if (ret)
1038                         goto out_err;
1039                 aes_s390_aead_alg = &gcm_aes_aead;
1040         }
1041
1042         return 0;
1043 out_err:
1044         aes_s390_fini();
1045         return ret;
1046 }
1047
1048 module_cpu_feature_match(MSA, aes_s390_init);
1049 module_exit(aes_s390_fini);
1050
1051 MODULE_ALIAS_CRYPTO("aes-all");
1052
1053 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
1054 MODULE_LICENSE("GPL");