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         memzero_explicit(&param, sizeof(param));
 346         return ret;
 347 }
 348
 349 static int cbc_aes_encrypt(struct skcipher_request *req)
 350 {
 351         return cbc_aes_crypt(req, 0);
 352 }
 353
 354 static int cbc_aes_decrypt(struct skcipher_request *req)
 355 {
 356         return cbc_aes_crypt(req, CPACF_DECRYPT);
 357 }
 358
 359 static struct skcipher_alg cbc_aes_alg = {
 360         .base.cra_name          =       "cbc(aes)",
 361         .base.cra_driver_name   =       "cbc-aes-s390",
 362         .base.cra_priority      =       402,    /* ecb-aes-s390 + 1 */
 363         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 364         .base.cra_blocksize     =       AES_BLOCK_SIZE,
 365         .base.cra_ctxsize       =       sizeof(struct s390_aes_ctx),
 366         .base.cra_module        =       THIS_MODULE,
 367         .init                   =       fallback_init_skcipher,
 368         .exit                   =       fallback_exit_skcipher,
 369         .min_keysize            =       AES_MIN_KEY_SIZE,
 370         .max_keysize            =       AES_MAX_KEY_SIZE,
 371         .ivsize                 =       AES_BLOCK_SIZE,
 372         .setkey                 =       cbc_aes_set_key,
 373         .encrypt                =       cbc_aes_encrypt,
 374         .decrypt                =       cbc_aes_decrypt,
 375 };
 376
 377 static int xts_fallback_setkey(struct crypto_skcipher *tfm, const u8 *key,
 378                                unsigned int len)
 379 {
 380         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 381
 382         crypto_skcipher_clear_flags(xts_ctx->fallback, CRYPTO_TFM_REQ_MASK);
 383         crypto_skcipher_set_flags(xts_ctx->fallback,
 384                                   crypto_skcipher_get_flags(tfm) &
 385                                   CRYPTO_TFM_REQ_MASK);
 386         return crypto_skcipher_setkey(xts_ctx->fallback, key, len);
 387 }
 388
 389 static int xts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 390                            unsigned int key_len)
 391 {
 392         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 393         unsigned long fc;
 394         int err;
 395
 396         err = xts_fallback_setkey(tfm, in_key, key_len);
 397         if (err)
 398                 return err;
 399
 400         /* In fips mode only 128 bit or 256 bit keys are valid */
 401         if (fips_enabled && key_len != 32 && key_len != 64)
 402                 return -EINVAL;
 403
 404         /* Pick the correct function code based on the key length */
 405         fc = (key_len == 32) ? CPACF_KM_XTS_128 :
 406              (key_len == 64) ? CPACF_KM_XTS_256 : 0;
 407
 408         /* Check if the function code is available */
 409         xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
 410         if (!xts_ctx->fc)
 411                 return 0;
 412
 413         /* Split the XTS key into the two subkeys */
 414         key_len = key_len / 2;
 415         xts_ctx->key_len = key_len;
 416         memcpy(xts_ctx->key, in_key, key_len);
 417         memcpy(xts_ctx->pcc_key, in_key + key_len, key_len);
 418         return 0;
 419 }
 420
 421 static int xts_aes_crypt(struct skcipher_request *req, unsigned long modifier)
 422 {
 423         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 424         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 425         struct skcipher_walk walk;
 426         unsigned int offset, nbytes, n;
 427         int ret;
 428         struct {
 429                 u8 key[32];
 430                 u8 tweak[16];
 431                 u8 block[16];
 432                 u8 bit[16];
 433                 u8 xts[16];
 434         } pcc_param;
 435         struct {
 436                 u8 key[32];
 437                 u8 init[16];
 438         } xts_param;
 439
 440         if (req->cryptlen < AES_BLOCK_SIZE)
 441                 return -EINVAL;
 442
 443         if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) {
 444                 struct skcipher_request *subreq = skcipher_request_ctx(req);
 445
 446                 *subreq = *req;
 447                 skcipher_request_set_tfm(subreq, xts_ctx->fallback);
 448                 return (modifier & CPACF_DECRYPT) ?
 449                         crypto_skcipher_decrypt(subreq) :
 450                         crypto_skcipher_encrypt(subreq);
 451         }
 452
 453         ret = skcipher_walk_virt(&walk, req, false);
 454         if (ret)
 455                 return ret;
 456         offset = xts_ctx->key_len & 0x10;
 457         memset(pcc_param.block, 0, sizeof(pcc_param.block));
 458         memset(pcc_param.bit, 0, sizeof(pcc_param.bit));
 459         memset(pcc_param.xts, 0, sizeof(pcc_param.xts));
 460         memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
 461         memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len);
 462         cpacf_pcc(xts_ctx->fc, pcc_param.key + offset);
 463
 464         memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len);
 465         memcpy(xts_param.init, pcc_param.xts, 16);
 466
 467         while ((nbytes = walk.nbytes) != 0) {
 468                 /* only use complete blocks */
 469                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 470                 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset,
 471                          walk.dst.virt.addr, walk.src.virt.addr, n);
 472                 ret = skcipher_walk_done(&walk, nbytes - n);
 473         }
 474         memzero_explicit(&pcc_param, sizeof(pcc_param));
 475         memzero_explicit(&xts_param, sizeof(xts_param));
 476         return ret;
 477 }
 478
 479 static int xts_aes_encrypt(struct skcipher_request *req)
 480 {
 481         return xts_aes_crypt(req, 0);
 482 }
 483
 484 static int xts_aes_decrypt(struct skcipher_request *req)
 485 {
 486         return xts_aes_crypt(req, CPACF_DECRYPT);
 487 }
 488
 489 static int xts_fallback_init(struct crypto_skcipher *tfm)
 490 {
 491         const char *name = crypto_tfm_alg_name(&tfm->base);
 492         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 493
 494         xts_ctx->fallback = crypto_alloc_skcipher(name, 0,
 495                                 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
 496
 497         if (IS_ERR(xts_ctx->fallback)) {
 498                 pr_err("Allocating XTS fallback algorithm %s failed\n",
 499                        name);
 500                 return PTR_ERR(xts_ctx->fallback);
 501         }
 502         crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
 503                                     crypto_skcipher_reqsize(xts_ctx->fallback));
 504         return 0;
 505 }
 506
 507 static void xts_fallback_exit(struct crypto_skcipher *tfm)
 508 {
 509         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 510
 511         crypto_free_skcipher(xts_ctx->fallback);
 512 }
 513
 514 static struct skcipher_alg xts_aes_alg = {
 515         .base.cra_name          =       "xts(aes)",
 516         .base.cra_driver_name   =       "xts-aes-s390",
 517         .base.cra_priority      =       402,    /* ecb-aes-s390 + 1 */
 518         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 519         .base.cra_blocksize     =       AES_BLOCK_SIZE,
 520         .base.cra_ctxsize       =       sizeof(struct s390_xts_ctx),
 521         .base.cra_module        =       THIS_MODULE,
 522         .init                   =       xts_fallback_init,
 523         .exit                   =       xts_fallback_exit,
 524         .min_keysize            =       2 * AES_MIN_KEY_SIZE,
 525         .max_keysize            =       2 * AES_MAX_KEY_SIZE,
 526         .ivsize                 =       AES_BLOCK_SIZE,
 527         .setkey                 =       xts_aes_set_key,
 528         .encrypt                =       xts_aes_encrypt,
 529         .decrypt                =       xts_aes_decrypt,
 530 };
 531
 532 static int ctr_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 533                            unsigned int key_len)
 534 {
 535         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 536         unsigned long fc;
 537
 538         /* Pick the correct function code based on the key length */
 539         fc = (key_len == 16) ? CPACF_KMCTR_AES_128 :
 540              (key_len == 24) ? CPACF_KMCTR_AES_192 :
 541              (key_len == 32) ? CPACF_KMCTR_AES_256 : 0;
 542
 543         /* Check if the function code is available */
 544         sctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0;
 545         if (!sctx->fc)
 546                 return setkey_fallback_skcipher(tfm, in_key, key_len);
 547
 548         sctx->key_len = key_len;
 549         memcpy(sctx->key, in_key, key_len);
 550         return 0;
 551 }
 552
 553 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
 554 {
 555         unsigned int i, n;
 556
 557         /* only use complete blocks, max. PAGE_SIZE */
 558         memcpy(ctrptr, iv, AES_BLOCK_SIZE);
 559         n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1);
 560         for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) {
 561                 memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE);
 562                 crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE);
 563                 ctrptr += AES_BLOCK_SIZE;
 564         }
 565         return n;
 566 }
 567
 568 static int ctr_aes_crypt(struct skcipher_request *req)
 569 {
 570         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 571         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 572         u8 buf[AES_BLOCK_SIZE], *ctrptr;
 573         struct skcipher_walk walk;
 574         unsigned int n, nbytes;
 575         int ret, locked;
 576
 577         if (unlikely(!sctx->fc))
 578                 return fallback_skcipher_crypt(sctx, req, 0);
 579
 580         locked = mutex_trylock(&ctrblk_lock);
 581
 582         ret = skcipher_walk_virt(&walk, req, false);
 583         while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
 584                 n = AES_BLOCK_SIZE;
 585
 586                 if (nbytes >= 2*AES_BLOCK_SIZE && locked)
 587                         n = __ctrblk_init(ctrblk, walk.iv, nbytes);
 588                 ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv;
 589                 cpacf_kmctr(sctx->fc, sctx->key, walk.dst.virt.addr,
 590                             walk.src.virt.addr, n, ctrptr);
 591                 if (ctrptr == ctrblk)
 592                         memcpy(walk.iv, ctrptr + n - AES_BLOCK_SIZE,
 593                                AES_BLOCK_SIZE);
 594                 crypto_inc(walk.iv, AES_BLOCK_SIZE);
 595                 ret = skcipher_walk_done(&walk, nbytes - n);
 596         }
 597         if (locked)
 598                 mutex_unlock(&ctrblk_lock);
 599         /*
 600          * final block may be < AES_BLOCK_SIZE, copy only nbytes
 601          */
 602         if (nbytes) {
 603                 cpacf_kmctr(sctx->fc, sctx->key, buf, walk.src.virt.addr,
 604                             AES_BLOCK_SIZE, walk.iv);
 605                 memcpy(walk.dst.virt.addr, buf, nbytes);
 606                 crypto_inc(walk.iv, AES_BLOCK_SIZE);
 607                 ret = skcipher_walk_done(&walk, 0);
 608         }
 609
 610         return ret;
 611 }
 612
 613 static struct skcipher_alg ctr_aes_alg = {
 614         .base.cra_name          =       "ctr(aes)",
 615         .base.cra_driver_name   =       "ctr-aes-s390",
 616         .base.cra_priority      =       402,    /* ecb-aes-s390 + 1 */
 617         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 618         .base.cra_blocksize     =       1,
 619         .base.cra_ctxsize       =       sizeof(struct s390_aes_ctx),
 620         .base.cra_module        =       THIS_MODULE,
 621         .init                   =       fallback_init_skcipher,
 622         .exit                   =       fallback_exit_skcipher,
 623         .min_keysize            =       AES_MIN_KEY_SIZE,
 624         .max_keysize            =       AES_MAX_KEY_SIZE,
 625         .ivsize                 =       AES_BLOCK_SIZE,
 626         .setkey                 =       ctr_aes_set_key,
 627         .encrypt                =       ctr_aes_crypt,
 628         .decrypt                =       ctr_aes_crypt,
 629         .chunksize              =       AES_BLOCK_SIZE,
 630 };
 631
 632 static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *key,
 633                           unsigned int keylen)
 634 {
 635         struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
 636
 637         switch (keylen) {
 638         case AES_KEYSIZE_128:
 639                 ctx->fc = CPACF_KMA_GCM_AES_128;
 640                 break;
 641         case AES_KEYSIZE_192:
 642                 ctx->fc = CPACF_KMA_GCM_AES_192;
 643                 break;
 644         case AES_KEYSIZE_256:
 645                 ctx->fc = CPACF_KMA_GCM_AES_256;
 646                 break;
 647         default:
 648                 return -EINVAL;
 649         }
 650
 651         memcpy(ctx->key, key, keylen);
 652         ctx->key_len = keylen;
 653         return 0;
 654 }
 655
 656 static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
 657 {
 658         switch (authsize) {
 659         case 4:
 660         case 8:
 661         case 12:
 662         case 13:
 663         case 14:
 664         case 15:
 665         case 16:
 666                 break;
 667         default:
 668                 return -EINVAL;
 669         }
 670
 671         return 0;
 672 }
 673
 674 static void gcm_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg,
 675                            unsigned int len)
 676 {
 677         memset(gw, 0, sizeof(*gw));
 678         gw->walk_bytes_remain = len;
 679         scatterwalk_start(&gw->walk, sg);
 680 }
 681
 682 static inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw)
 683 {
 684         struct scatterlist *nextsg;
 685
 686         gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain);
 687         while (!gw->walk_bytes) {
 688                 nextsg = sg_next(gw->walk.sg);
 689                 if (!nextsg)
 690                         return 0;
 691                 scatterwalk_start(&gw->walk, nextsg);
 692                 gw->walk_bytes = scatterwalk_clamp(&gw->walk,
 693                                                    gw->walk_bytes_remain);
 694         }
 695         gw->walk_ptr = scatterwalk_map(&gw->walk);
 696         return gw->walk_bytes;
 697 }
 698
 699 static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw,
 700                                              unsigned int nbytes)
 701 {
 702         gw->walk_bytes_remain -= nbytes;
 703         scatterwalk_unmap(&gw->walk);
 704         scatterwalk_advance(&gw->walk, nbytes);
 705         scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
 706         gw->walk_ptr = NULL;
 707 }
 708
 709 static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
 710 {
 711         int n;
 712
 713         if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) {
 714                 gw->ptr = gw->buf;
 715                 gw->nbytes = gw->buf_bytes;
 716                 goto out;
 717         }
 718
 719         if (gw->walk_bytes_remain == 0) {
 720                 gw->ptr = NULL;
 721                 gw->nbytes = 0;
 722                 goto out;
 723         }
 724
 725         if (!_gcm_sg_clamp_and_map(gw)) {
 726                 gw->ptr = NULL;
 727                 gw->nbytes = 0;
 728                 goto out;
 729         }
 730
 731         if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) {
 732                 gw->ptr = gw->walk_ptr;
 733                 gw->nbytes = gw->walk_bytes;
 734                 goto out;
 735         }
 736
 737         while (1) {
 738                 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes);
 739                 memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n);
 740                 gw->buf_bytes += n;
 741                 _gcm_sg_unmap_and_advance(gw, n);
 742                 if (gw->buf_bytes >= minbytesneeded) {
 743                         gw->ptr = gw->buf;
 744                         gw->nbytes = gw->buf_bytes;
 745                         goto out;
 746                 }
 747                 if (!_gcm_sg_clamp_and_map(gw)) {
 748                         gw->ptr = NULL;
 749                         gw->nbytes = 0;
 750                         goto out;
 751                 }
 752         }
 753
 754 out:
 755         return gw->nbytes;
 756 }
 757
 758 static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
 759 {
 760         if (gw->walk_bytes_remain == 0) {
 761                 gw->ptr = NULL;
 762                 gw->nbytes = 0;
 763                 goto out;
 764         }
 765
 766         if (!_gcm_sg_clamp_and_map(gw)) {
 767                 gw->ptr = NULL;
 768                 gw->nbytes = 0;
 769                 goto out;
 770         }
 771
 772         if (gw->walk_bytes >= minbytesneeded) {
 773                 gw->ptr = gw->walk_ptr;
 774                 gw->nbytes = gw->walk_bytes;
 775                 goto out;
 776         }
 777
 778         scatterwalk_unmap(&gw->walk);
 779         gw->walk_ptr = NULL;
 780
 781         gw->ptr = gw->buf;
 782         gw->nbytes = sizeof(gw->buf);
 783
 784 out:
 785         return gw->nbytes;
 786 }
 787
 788 static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
 789 {
 790         if (gw->ptr == NULL)
 791                 return 0;
 792
 793         if (gw->ptr == gw->buf) {
 794                 int n = gw->buf_bytes - bytesdone;
 795                 if (n > 0) {
 796                         memmove(gw->buf, gw->buf + bytesdone, n);
 797                         gw->buf_bytes = n;
 798                 } else
 799                         gw->buf_bytes = 0;
 800         } else
 801                 _gcm_sg_unmap_and_advance(gw, bytesdone);
 802
 803         return bytesdone;
 804 }
 805
 806 static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
 807 {
 808         int i, n;
 809
 810         if (gw->ptr == NULL)
 811                 return 0;
 812
 813         if (gw->ptr == gw->buf) {
 814                 for (i = 0; i < bytesdone; i += n) {
 815                         if (!_gcm_sg_clamp_and_map(gw))
 816                                 return i;
 817                         n = min(gw->walk_bytes, bytesdone - i);
 818                         memcpy(gw->walk_ptr, gw->buf + i, n);
 819                         _gcm_sg_unmap_and_advance(gw, n);
 820                 }
 821         } else
 822                 _gcm_sg_unmap_and_advance(gw, bytesdone);
 823
 824         return bytesdone;
 825 }
 826
 827 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags)
 828 {
 829         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 830         struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
 831         unsigned int ivsize = crypto_aead_ivsize(tfm);
 832         unsigned int taglen = crypto_aead_authsize(tfm);
 833         unsigned int aadlen = req->assoclen;
 834         unsigned int pclen = req->cryptlen;
 835         int ret = 0;
 836
 837         unsigned int n, len, in_bytes, out_bytes,
 838                      min_bytes, bytes, aad_bytes, pc_bytes;
 839         struct gcm_sg_walk gw_in, gw_out;
 840         u8 tag[GHASH_DIGEST_SIZE];
 841
 842         struct {
 843                 u32 _[3];               /* reserved */
 844                 u32 cv;                 /* Counter Value */
 845                 u8 t[GHASH_DIGEST_SIZE];/* Tag */
 846                 u8 h[AES_BLOCK_SIZE];   /* Hash-subkey */
 847                 u64 taadl;              /* Total AAD Length */
 848                 u64 tpcl;               /* Total Plain-/Cipher-text Length */
 849                 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */
 850                 u8 k[AES_MAX_KEY_SIZE]; /* Key */
 851         } param;
 852
 853         /*
 854          * encrypt
 855          *   req->src: aad||plaintext
 856          *   req->dst: aad||ciphertext||tag
 857          * decrypt
 858          *   req->src: aad||ciphertext||tag
 859          *   req->dst: aad||plaintext, return 0 or -EBADMSG
 860          * aad, plaintext and ciphertext may be empty.
 861          */
 862         if (flags & CPACF_DECRYPT)
 863                 pclen -= taglen;
 864         len = aadlen + pclen;
 865
 866         memset(&param, 0, sizeof(param));
 867         param.cv = 1;
 868         param.taadl = aadlen * 8;
 869         param.tpcl = pclen * 8;
 870         memcpy(param.j0, req->iv, ivsize);
 871         *(u32 *)(param.j0 + ivsize) = 1;
 872         memcpy(param.k, ctx->key, ctx->key_len);
 873
 874         gcm_walk_start(&gw_in, req->src, len);
 875         gcm_walk_start(&gw_out, req->dst, len);
 876
 877         do {
 878                 min_bytes = min_t(unsigned int,
 879                                   aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE);
 880                 in_bytes = gcm_in_walk_go(&gw_in, min_bytes);
 881                 out_bytes = gcm_out_walk_go(&gw_out, min_bytes);
 882                 bytes = min(in_bytes, out_bytes);
 883
 884                 if (aadlen + pclen <= bytes) {
 885                         aad_bytes = aadlen;
 886                         pc_bytes = pclen;
 887                         flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC;
 888                 } else {
 889                         if (aadlen <= bytes) {
 890                                 aad_bytes = aadlen;
 891                                 pc_bytes = (bytes - aadlen) &
 892                                            ~(AES_BLOCK_SIZE - 1);
 893                                 flags |= CPACF_KMA_LAAD;
 894                         } else {
 895                                 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1);
 896                                 pc_bytes = 0;
 897                         }
 898                 }
 899
 900                 if (aad_bytes > 0)
 901                         memcpy(gw_out.ptr, gw_in.ptr, aad_bytes);
 902
 903                 cpacf_kma(ctx->fc | flags, &param,
 904                           gw_out.ptr + aad_bytes,
 905                           gw_in.ptr + aad_bytes, pc_bytes,
 906                           gw_in.ptr, aad_bytes);
 907
 908                 n = aad_bytes + pc_bytes;
 909                 if (gcm_in_walk_done(&gw_in, n) != n)
 910                         return -ENOMEM;
 911                 if (gcm_out_walk_done(&gw_out, n) != n)
 912                         return -ENOMEM;
 913                 aadlen -= aad_bytes;
 914                 pclen -= pc_bytes;
 915         } while (aadlen + pclen > 0);
 916
 917         if (flags & CPACF_DECRYPT) {
 918                 scatterwalk_map_and_copy(tag, req->src, len, taglen, 0);
 919                 if (crypto_memneq(tag, param.t, taglen))
 920                         ret = -EBADMSG;
 921         } else
 922                 scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1);
 923
 924         memzero_explicit(&param, sizeof(param));
 925         return ret;
 926 }
 927
 928 static int gcm_aes_encrypt(struct aead_request *req)
 929 {
 930         return gcm_aes_crypt(req, CPACF_ENCRYPT);
 931 }
 932
 933 static int gcm_aes_decrypt(struct aead_request *req)
 934 {
 935         return gcm_aes_crypt(req, CPACF_DECRYPT);
 936 }
 937
 938 static struct aead_alg gcm_aes_aead = {
 939         .setkey                 = gcm_aes_setkey,
 940         .setauthsize            = gcm_aes_setauthsize,
 941         .encrypt                = gcm_aes_encrypt,
 942         .decrypt                = gcm_aes_decrypt,
 943
 944         .ivsize                 = GHASH_BLOCK_SIZE - sizeof(u32),
 945         .maxauthsize            = GHASH_DIGEST_SIZE,
 946         .chunksize              = AES_BLOCK_SIZE,
 947
 948         .base                   = {
 949                 .cra_blocksize          = 1,
 950                 .cra_ctxsize            = sizeof(struct s390_aes_ctx),
 951                 .cra_priority           = 900,
 952                 .cra_name               = "gcm(aes)",
 953                 .cra_driver_name        = "gcm-aes-s390",
 954                 .cra_module             = THIS_MODULE,
 955         },
 956 };
 957
 958 static struct crypto_alg *aes_s390_alg;
 959 static struct skcipher_alg *aes_s390_skcipher_algs[4];
 960 static int aes_s390_skciphers_num;
 961 static struct aead_alg *aes_s390_aead_alg;
 962
 963 static int aes_s390_register_skcipher(struct skcipher_alg *alg)
 964 {
 965         int ret;
 966
 967         ret = crypto_register_skcipher(alg);
 968         if (!ret)
 969                 aes_s390_skcipher_algs[aes_s390_skciphers_num++] = alg;
 970         return ret;
 971 }
 972
 973 static void aes_s390_fini(void)
 974 {
 975         if (aes_s390_alg)
 976                 crypto_unregister_alg(aes_s390_alg);
 977         while (aes_s390_skciphers_num--)
 978                 crypto_unregister_skcipher(aes_s390_skcipher_algs[aes_s390_skciphers_num]);
 979         if (ctrblk)
 980                 free_page((unsigned long) ctrblk);
 981
 982         if (aes_s390_aead_alg)
 983                 crypto_unregister_aead(aes_s390_aead_alg);
 984 }
 985
 986 static int __init aes_s390_init(void)
 987 {
 988         int ret;
 989
 990         /* Query available functions for KM, KMC, KMCTR and KMA */
 991         cpacf_query(CPACF_KM, &km_functions);
 992         cpacf_query(CPACF_KMC, &kmc_functions);
 993         cpacf_query(CPACF_KMCTR, &kmctr_functions);
 994         cpacf_query(CPACF_KMA, &kma_functions);
 995
 996         if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) ||
 997             cpacf_test_func(&km_functions, CPACF_KM_AES_192) ||
 998             cpacf_test_func(&km_functions, CPACF_KM_AES_256)) {
 999                 ret = crypto_register_alg(&aes_alg);
1000                 if (ret)
1001                         goto out_err;
1002                 aes_s390_alg = &aes_alg;
1003                 ret = aes_s390_register_skcipher(&ecb_aes_alg);
1004                 if (ret)
1005                         goto out_err;
1006         }
1007
1008         if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) ||
1009             cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) ||
1010             cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) {
1011                 ret = aes_s390_register_skcipher(&cbc_aes_alg);
1012                 if (ret)
1013                         goto out_err;
1014         }
1015
1016         if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) ||
1017             cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) {
1018                 ret = aes_s390_register_skcipher(&xts_aes_alg);
1019                 if (ret)
1020                         goto out_err;
1021         }
1022
1023         if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) ||
1024             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) ||
1025             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) {
1026                 ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
1027                 if (!ctrblk) {
1028                         ret = -ENOMEM;
1029                         goto out_err;
1030                 }
1031                 ret = aes_s390_register_skcipher(&ctr_aes_alg);
1032                 if (ret)
1033                         goto out_err;
1034         }
1035
1036         if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) ||
1037             cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) ||
1038             cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) {
1039                 ret = crypto_register_aead(&gcm_aes_aead);
1040                 if (ret)
1041                         goto out_err;
1042                 aes_s390_aead_alg = &gcm_aes_aead;
1043         }
1044
1045         return 0;
1046 out_err:
1047         aes_s390_fini();
1048         return ret;
1049 }
1050
1051 module_cpu_feature_match(MSA, aes_s390_init);
1052 module_exit(aes_s390_fini);
1053
1054 MODULE_ALIAS_CRYPTO("aes-all");
1055
1056 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
1057 MODULE_LICENSE("GPL");