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/cipher.h>
  25 #include <crypto/internal/skcipher.h>
  26 #include <crypto/scatterwalk.h>
  27 #include <linux/err.h>
  28 #include <linux/module.h>
  29 #include <linux/cpufeature.h>
  30 #include <linux/init.h>
  31 #include <linux/mutex.h>
  32 #include <linux/fips.h>
  33 #include <linux/string.h>
  34 #include <crypto/xts.h>
  35 #include <asm/cpacf.h>
  36
  37 static u8 *ctrblk;
  38 static DEFINE_MUTEX(ctrblk_lock);
  39
  40 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions,
  41                     kma_functions;
  42
  43 struct s390_aes_ctx {
  44         u8 key[AES_MAX_KEY_SIZE];
  45         int key_len;
  46         unsigned long fc;
  47         union {
  48                 struct crypto_skcipher *skcipher;
  49                 struct crypto_cipher *cip;
  50         } fallback;
  51 };
  52
  53 struct s390_xts_ctx {
  54         u8 key[32];
  55         u8 pcc_key[32];
  56         int key_len;
  57         unsigned long fc;
  58         struct crypto_skcipher *fallback;
  59 };
  60
  61 struct gcm_sg_walk {
  62         struct scatter_walk walk;
  63         unsigned int walk_bytes;
  64         u8 *walk_ptr;
  65         unsigned int walk_bytes_remain;
  66         u8 buf[AES_BLOCK_SIZE];
  67         unsigned int buf_bytes;
  68         u8 *ptr;
  69         unsigned int nbytes;
  70 };
  71
  72 static int setkey_fallback_cip(struct crypto_tfm *tfm, const u8 *in_key,
  73                 unsigned int key_len)
  74 {
  75         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
  76
  77         sctx->fallback.cip->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
  78         sctx->fallback.cip->base.crt_flags |= (tfm->crt_flags &
  79                         CRYPTO_TFM_REQ_MASK);
  80
  81         return crypto_cipher_setkey(sctx->fallback.cip, in_key, key_len);
  82 }
  83
  84 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
  85                        unsigned int key_len)
  86 {
  87         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
  88         unsigned long fc;
  89
  90         /* Pick the correct function code based on the key length */
  91         fc = (key_len == 16) ? CPACF_KM_AES_128 :
  92              (key_len == 24) ? CPACF_KM_AES_192 :
  93              (key_len == 32) ? CPACF_KM_AES_256 : 0;
  94
  95         /* Check if the function code is available */
  96         sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
  97         if (!sctx->fc)
  98                 return setkey_fallback_cip(tfm, in_key, key_len);
  99
 100         sctx->key_len = key_len;
 101         memcpy(sctx->key, in_key, key_len);
 102         return 0;
 103 }
 104
 105 static void crypto_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 106 {
 107         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 108
 109         if (unlikely(!sctx->fc)) {
 110                 crypto_cipher_encrypt_one(sctx->fallback.cip, out, in);
 111                 return;
 112         }
 113         cpacf_km(sctx->fc, &sctx->key, out, in, AES_BLOCK_SIZE);
 114 }
 115
 116 static void crypto_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 117 {
 118         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 119
 120         if (unlikely(!sctx->fc)) {
 121                 crypto_cipher_decrypt_one(sctx->fallback.cip, out, in);
 122                 return;
 123         }
 124         cpacf_km(sctx->fc | CPACF_DECRYPT,
 125                  &sctx->key, out, in, AES_BLOCK_SIZE);
 126 }
 127
 128 static int fallback_init_cip(struct crypto_tfm *tfm)
 129 {
 130         const char *name = tfm->__crt_alg->cra_name;
 131         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 132
 133         sctx->fallback.cip = crypto_alloc_cipher(name, 0,
 134                                                  CRYPTO_ALG_NEED_FALLBACK);
 135
 136         if (IS_ERR(sctx->fallback.cip)) {
 137                 pr_err("Allocating AES fallback algorithm %s failed\n",
 138                        name);
 139                 return PTR_ERR(sctx->fallback.cip);
 140         }
 141
 142         return 0;
 143 }
 144
 145 static void fallback_exit_cip(struct crypto_tfm *tfm)
 146 {
 147         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 148
 149         crypto_free_cipher(sctx->fallback.cip);
 150         sctx->fallback.cip = NULL;
 151 }
 152
 153 static struct crypto_alg aes_alg = {
 154         .cra_name               =       "aes",
 155         .cra_driver_name        =       "aes-s390",
 156         .cra_priority           =       300,
 157         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER |
 158                                         CRYPTO_ALG_NEED_FALLBACK,
 159         .cra_blocksize          =       AES_BLOCK_SIZE,
 160         .cra_ctxsize            =       sizeof(struct s390_aes_ctx),
 161         .cra_module             =       THIS_MODULE,
 162         .cra_init               =       fallback_init_cip,
 163         .cra_exit               =       fallback_exit_cip,
 164         .cra_u                  =       {
 165                 .cipher = {
 166                         .cia_min_keysize        =       AES_MIN_KEY_SIZE,
 167                         .cia_max_keysize        =       AES_MAX_KEY_SIZE,
 168                         .cia_setkey             =       aes_set_key,
 169                         .cia_encrypt            =       crypto_aes_encrypt,
 170                         .cia_decrypt            =       crypto_aes_decrypt,
 171                 }
 172         }
 173 };
 174
 175 static int setkey_fallback_skcipher(struct crypto_skcipher *tfm, const u8 *key,
 176                                     unsigned int len)
 177 {
 178         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 179
 180         crypto_skcipher_clear_flags(sctx->fallback.skcipher,
 181                                     CRYPTO_TFM_REQ_MASK);
 182         crypto_skcipher_set_flags(sctx->fallback.skcipher,
 183                                   crypto_skcipher_get_flags(tfm) &
 184                                   CRYPTO_TFM_REQ_MASK);
 185         return crypto_skcipher_setkey(sctx->fallback.skcipher, key, len);
 186 }
 187
 188 static int fallback_skcipher_crypt(struct s390_aes_ctx *sctx,
 189                                    struct skcipher_request *req,
 190                                    unsigned long modifier)
 191 {
 192         struct skcipher_request *subreq = skcipher_request_ctx(req);
 193
 194         *subreq = *req;
 195         skcipher_request_set_tfm(subreq, sctx->fallback.skcipher);
 196         return (modifier & CPACF_DECRYPT) ?
 197                 crypto_skcipher_decrypt(subreq) :
 198                 crypto_skcipher_encrypt(subreq);
 199 }
 200
 201 static int ecb_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 202                            unsigned int key_len)
 203 {
 204         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 205         unsigned long fc;
 206
 207         /* Pick the correct function code based on the key length */
 208         fc = (key_len == 16) ? CPACF_KM_AES_128 :
 209              (key_len == 24) ? CPACF_KM_AES_192 :
 210              (key_len == 32) ? CPACF_KM_AES_256 : 0;
 211
 212         /* Check if the function code is available */
 213         sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
 214         if (!sctx->fc)
 215                 return setkey_fallback_skcipher(tfm, in_key, key_len);
 216
 217         sctx->key_len = key_len;
 218         memcpy(sctx->key, in_key, key_len);
 219         return 0;
 220 }
 221
 222 static int ecb_aes_crypt(struct skcipher_request *req, unsigned long modifier)
 223 {
 224         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 225         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 226         struct skcipher_walk walk;
 227         unsigned int nbytes, n;
 228         int ret;
 229
 230         if (unlikely(!sctx->fc))
 231                 return fallback_skcipher_crypt(sctx, req, modifier);
 232
 233         ret = skcipher_walk_virt(&walk, req, false);
 234         while ((nbytes = walk.nbytes) != 0) {
 235                 /* only use complete blocks */
 236                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 237                 cpacf_km(sctx->fc | modifier, sctx->key,
 238                          walk.dst.virt.addr, walk.src.virt.addr, n);
 239                 ret = skcipher_walk_done(&walk, nbytes - n);
 240         }
 241         return ret;
 242 }
 243
 244 static int ecb_aes_encrypt(struct skcipher_request *req)
 245 {
 246         return ecb_aes_crypt(req, 0);
 247 }
 248
 249 static int ecb_aes_decrypt(struct skcipher_request *req)
 250 {
 251         return ecb_aes_crypt(req, CPACF_DECRYPT);
 252 }
 253
 254 static int fallback_init_skcipher(struct crypto_skcipher *tfm)
 255 {
 256         const char *name = crypto_tfm_alg_name(&tfm->base);
 257         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 258
 259         sctx->fallback.skcipher = crypto_alloc_skcipher(name, 0,
 260                                 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
 261
 262         if (IS_ERR(sctx->fallback.skcipher)) {
 263                 pr_err("Allocating AES fallback algorithm %s failed\n",
 264                        name);
 265                 return PTR_ERR(sctx->fallback.skcipher);
 266         }
 267
 268         crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
 269                                     crypto_skcipher_reqsize(sctx->fallback.skcipher));
 270         return 0;
 271 }
 272
 273 static void fallback_exit_skcipher(struct crypto_skcipher *tfm)
 274 {
 275         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 276
 277         crypto_free_skcipher(sctx->fallback.skcipher);
 278 }
 279
 280 static struct skcipher_alg ecb_aes_alg = {
 281         .base.cra_name          =       "ecb(aes)",
 282         .base.cra_driver_name   =       "ecb-aes-s390",
 283         .base.cra_priority      =       401,    /* combo: aes + ecb + 1 */
 284         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 285         .base.cra_blocksize     =       AES_BLOCK_SIZE,
 286         .base.cra_ctxsize       =       sizeof(struct s390_aes_ctx),
 287         .base.cra_module        =       THIS_MODULE,
 288         .init                   =       fallback_init_skcipher,
 289         .exit                   =       fallback_exit_skcipher,
 290         .min_keysize            =       AES_MIN_KEY_SIZE,
 291         .max_keysize            =       AES_MAX_KEY_SIZE,
 292         .setkey                 =       ecb_aes_set_key,
 293         .encrypt                =       ecb_aes_encrypt,
 294         .decrypt                =       ecb_aes_decrypt,
 295 };
 296
 297 static int cbc_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 298                            unsigned int key_len)
 299 {
 300         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 301         unsigned long fc;
 302
 303         /* Pick the correct function code based on the key length */
 304         fc = (key_len == 16) ? CPACF_KMC_AES_128 :
 305              (key_len == 24) ? CPACF_KMC_AES_192 :
 306              (key_len == 32) ? CPACF_KMC_AES_256 : 0;
 307
 308         /* Check if the function code is available */
 309         sctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0;
 310         if (!sctx->fc)
 311                 return setkey_fallback_skcipher(tfm, in_key, key_len);
 312
 313         sctx->key_len = key_len;
 314         memcpy(sctx->key, in_key, key_len);
 315         return 0;
 316 }
 317
 318 static int cbc_aes_crypt(struct skcipher_request *req, unsigned long modifier)
 319 {
 320         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 321         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 322         struct skcipher_walk walk;
 323         unsigned int nbytes, n;
 324         int ret;
 325         struct {
 326                 u8 iv[AES_BLOCK_SIZE];
 327                 u8 key[AES_MAX_KEY_SIZE];
 328         } param;
 329
 330         if (unlikely(!sctx->fc))
 331                 return fallback_skcipher_crypt(sctx, req, modifier);
 332
 333         ret = skcipher_walk_virt(&walk, req, false);
 334         if (ret)
 335                 return ret;
 336         memcpy(param.iv, walk.iv, AES_BLOCK_SIZE);
 337         memcpy(param.key, sctx->key, sctx->key_len);
 338         while ((nbytes = walk.nbytes) != 0) {
 339                 /* only use complete blocks */
 340                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 341                 cpacf_kmc(sctx->fc | modifier, &param,
 342                           walk.dst.virt.addr, walk.src.virt.addr, n);
 343                 memcpy(walk.iv, param.iv, AES_BLOCK_SIZE);
 344                 ret = skcipher_walk_done(&walk, nbytes - n);
 345         }
 346         memzero_explicit(&param, sizeof(param));
 347         return ret;
 348 }
 349
 350 static int cbc_aes_encrypt(struct skcipher_request *req)
 351 {
 352         return cbc_aes_crypt(req, 0);
 353 }
 354
 355 static int cbc_aes_decrypt(struct skcipher_request *req)
 356 {
 357         return cbc_aes_crypt(req, CPACF_DECRYPT);
 358 }
 359
 360 static struct skcipher_alg cbc_aes_alg = {
 361         .base.cra_name          =       "cbc(aes)",
 362         .base.cra_driver_name   =       "cbc-aes-s390",
 363         .base.cra_priority      =       402,    /* ecb-aes-s390 + 1 */
 364         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 365         .base.cra_blocksize     =       AES_BLOCK_SIZE,
 366         .base.cra_ctxsize       =       sizeof(struct s390_aes_ctx),
 367         .base.cra_module        =       THIS_MODULE,
 368         .init                   =       fallback_init_skcipher,
 369         .exit                   =       fallback_exit_skcipher,
 370         .min_keysize            =       AES_MIN_KEY_SIZE,
 371         .max_keysize            =       AES_MAX_KEY_SIZE,
 372         .ivsize                 =       AES_BLOCK_SIZE,
 373         .setkey                 =       cbc_aes_set_key,
 374         .encrypt                =       cbc_aes_encrypt,
 375         .decrypt                =       cbc_aes_decrypt,
 376 };
 377
 378 static int xts_fallback_setkey(struct crypto_skcipher *tfm, const u8 *key,
 379                                unsigned int len)
 380 {
 381         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 382
 383         crypto_skcipher_clear_flags(xts_ctx->fallback, CRYPTO_TFM_REQ_MASK);
 384         crypto_skcipher_set_flags(xts_ctx->fallback,
 385                                   crypto_skcipher_get_flags(tfm) &
 386                                   CRYPTO_TFM_REQ_MASK);
 387         return crypto_skcipher_setkey(xts_ctx->fallback, key, len);
 388 }
 389
 390 static int xts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 391                            unsigned int key_len)
 392 {
 393         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 394         unsigned long fc;
 395         int err;
 396
 397         err = xts_fallback_setkey(tfm, in_key, key_len);
 398         if (err)
 399                 return err;
 400
 401         /* Pick the correct function code based on the key length */
 402         fc = (key_len == 32) ? CPACF_KM_XTS_128 :
 403              (key_len == 64) ? CPACF_KM_XTS_256 : 0;
 404
 405         /* Check if the function code is available */
 406         xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
 407         if (!xts_ctx->fc)
 408                 return 0;
 409
 410         /* Split the XTS key into the two subkeys */
 411         key_len = key_len / 2;
 412         xts_ctx->key_len = key_len;
 413         memcpy(xts_ctx->key, in_key, key_len);
 414         memcpy(xts_ctx->pcc_key, in_key + key_len, key_len);
 415         return 0;
 416 }
 417
 418 static int xts_aes_crypt(struct skcipher_request *req, unsigned long modifier)
 419 {
 420         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 421         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 422         struct skcipher_walk walk;
 423         unsigned int offset, nbytes, n;
 424         int ret;
 425         struct {
 426                 u8 key[32];
 427                 u8 tweak[16];
 428                 u8 block[16];
 429                 u8 bit[16];
 430                 u8 xts[16];
 431         } pcc_param;
 432         struct {
 433                 u8 key[32];
 434                 u8 init[16];
 435         } xts_param;
 436
 437         if (req->cryptlen < AES_BLOCK_SIZE)
 438                 return -EINVAL;
 439
 440         if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) {
 441                 struct skcipher_request *subreq = skcipher_request_ctx(req);
 442
 443                 *subreq = *req;
 444                 skcipher_request_set_tfm(subreq, xts_ctx->fallback);
 445                 return (modifier & CPACF_DECRYPT) ?
 446                         crypto_skcipher_decrypt(subreq) :
 447                         crypto_skcipher_encrypt(subreq);
 448         }
 449
 450         ret = skcipher_walk_virt(&walk, req, false);
 451         if (ret)
 452                 return ret;
 453         offset = xts_ctx->key_len & 0x10;
 454         memset(pcc_param.block, 0, sizeof(pcc_param.block));
 455         memset(pcc_param.bit, 0, sizeof(pcc_param.bit));
 456         memset(pcc_param.xts, 0, sizeof(pcc_param.xts));
 457         memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
 458         memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len);
 459         cpacf_pcc(xts_ctx->fc, pcc_param.key + offset);
 460
 461         memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len);
 462         memcpy(xts_param.init, pcc_param.xts, 16);
 463
 464         while ((nbytes = walk.nbytes) != 0) {
 465                 /* only use complete blocks */
 466                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 467                 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset,
 468                          walk.dst.virt.addr, walk.src.virt.addr, n);
 469                 ret = skcipher_walk_done(&walk, nbytes - n);
 470         }
 471         memzero_explicit(&pcc_param, sizeof(pcc_param));
 472         memzero_explicit(&xts_param, sizeof(xts_param));
 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                 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         struct scatterlist *nextsg;
 684
 685         gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain);
 686         while (!gw->walk_bytes) {
 687                 nextsg = sg_next(gw->walk.sg);
 688                 if (!nextsg)
 689                         return 0;
 690                 scatterwalk_start(&gw->walk, nextsg);
 691                 gw->walk_bytes = scatterwalk_clamp(&gw->walk,
 692                                                    gw->walk_bytes_remain);
 693         }
 694         gw->walk_ptr = scatterwalk_map(&gw->walk);
 695         return gw->walk_bytes;
 696 }
 697
 698 static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw,
 699                                              unsigned int nbytes)
 700 {
 701         gw->walk_bytes_remain -= nbytes;
 702         scatterwalk_unmap(gw->walk_ptr);
 703         scatterwalk_advance(&gw->walk, nbytes);
 704         scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
 705         gw->walk_ptr = NULL;
 706 }
 707
 708 static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
 709 {
 710         int n;
 711
 712         if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) {
 713                 gw->ptr = gw->buf;
 714                 gw->nbytes = gw->buf_bytes;
 715                 goto out;
 716         }
 717
 718         if (gw->walk_bytes_remain == 0) {
 719                 gw->ptr = NULL;
 720                 gw->nbytes = 0;
 721                 goto out;
 722         }
 723
 724         if (!_gcm_sg_clamp_and_map(gw)) {
 725                 gw->ptr = NULL;
 726                 gw->nbytes = 0;
 727                 goto out;
 728         }
 729
 730         if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) {
 731                 gw->ptr = gw->walk_ptr;
 732                 gw->nbytes = gw->walk_bytes;
 733                 goto out;
 734         }
 735
 736         while (1) {
 737                 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes);
 738                 memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n);
 739                 gw->buf_bytes += n;
 740                 _gcm_sg_unmap_and_advance(gw, n);
 741                 if (gw->buf_bytes >= minbytesneeded) {
 742                         gw->ptr = gw->buf;
 743                         gw->nbytes = gw->buf_bytes;
 744                         goto out;
 745                 }
 746                 if (!_gcm_sg_clamp_and_map(gw)) {
 747                         gw->ptr = NULL;
 748                         gw->nbytes = 0;
 749                         goto out;
 750                 }
 751         }
 752
 753 out:
 754         return gw->nbytes;
 755 }
 756
 757 static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
 758 {
 759         if (gw->walk_bytes_remain == 0) {
 760                 gw->ptr = NULL;
 761                 gw->nbytes = 0;
 762                 goto out;
 763         }
 764
 765         if (!_gcm_sg_clamp_and_map(gw)) {
 766                 gw->ptr = NULL;
 767                 gw->nbytes = 0;
 768                 goto out;
 769         }
 770
 771         if (gw->walk_bytes >= minbytesneeded) {
 772                 gw->ptr = gw->walk_ptr;
 773                 gw->nbytes = gw->walk_bytes;
 774                 goto out;
 775         }
 776
 777         scatterwalk_unmap(gw->walk_ptr);
 778         gw->walk_ptr = NULL;
 779
 780         gw->ptr = gw->buf;
 781         gw->nbytes = sizeof(gw->buf);
 782
 783 out:
 784         return gw->nbytes;
 785 }
 786
 787 static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
 788 {
 789         if (gw->ptr == NULL)
 790                 return 0;
 791
 792         if (gw->ptr == gw->buf) {
 793                 int n = gw->buf_bytes - bytesdone;
 794                 if (n > 0) {
 795                         memmove(gw->buf, gw->buf + bytesdone, n);
 796                         gw->buf_bytes = n;
 797                 } else
 798                         gw->buf_bytes = 0;
 799         } else
 800                 _gcm_sg_unmap_and_advance(gw, bytesdone);
 801
 802         return bytesdone;
 803 }
 804
 805 static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
 806 {
 807         int i, n;
 808
 809         if (gw->ptr == NULL)
 810                 return 0;
 811
 812         if (gw->ptr == gw->buf) {
 813                 for (i = 0; i < bytesdone; i += n) {
 814                         if (!_gcm_sg_clamp_and_map(gw))
 815                                 return i;
 816                         n = min(gw->walk_bytes, bytesdone - i);
 817                         memcpy(gw->walk_ptr, gw->buf + i, n);
 818                         _gcm_sg_unmap_and_advance(gw, n);
 819                 }
 820         } else
 821                 _gcm_sg_unmap_and_advance(gw, bytesdone);
 822
 823         return bytesdone;
 824 }
 825
 826 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags)
 827 {
 828         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 829         struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
 830         unsigned int ivsize = crypto_aead_ivsize(tfm);
 831         unsigned int taglen = crypto_aead_authsize(tfm);
 832         unsigned int aadlen = req->assoclen;
 833         unsigned int pclen = req->cryptlen;
 834         int ret = 0;
 835
 836         unsigned int n, len, in_bytes, out_bytes,
 837                      min_bytes, bytes, aad_bytes, pc_bytes;
 838         struct gcm_sg_walk gw_in, gw_out;
 839         u8 tag[GHASH_DIGEST_SIZE];
 840
 841         struct {
 842                 u32 _[3];               /* reserved */
 843                 u32 cv;                 /* Counter Value */
 844                 u8 t[GHASH_DIGEST_SIZE];/* Tag */
 845                 u8 h[AES_BLOCK_SIZE];   /* Hash-subkey */
 846                 u64 taadl;              /* Total AAD Length */
 847                 u64 tpcl;               /* Total Plain-/Cipher-text Length */
 848                 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */
 849                 u8 k[AES_MAX_KEY_SIZE]; /* Key */
 850         } param;
 851
 852         /*
 853          * encrypt
 854          *   req->src: aad||plaintext
 855          *   req->dst: aad||ciphertext||tag
 856          * decrypt
 857          *   req->src: aad||ciphertext||tag
 858          *   req->dst: aad||plaintext, return 0 or -EBADMSG
 859          * aad, plaintext and ciphertext may be empty.
 860          */
 861         if (flags & CPACF_DECRYPT)
 862                 pclen -= taglen;
 863         len = aadlen + pclen;
 864
 865         memset(&param, 0, sizeof(param));
 866         param.cv = 1;
 867         param.taadl = aadlen * 8;
 868         param.tpcl = pclen * 8;
 869         memcpy(param.j0, req->iv, ivsize);
 870         *(u32 *)(param.j0 + ivsize) = 1;
 871         memcpy(param.k, ctx->key, ctx->key_len);
 872
 873         gcm_walk_start(&gw_in, req->src, len);
 874         gcm_walk_start(&gw_out, req->dst, len);
 875
 876         do {
 877                 min_bytes = min_t(unsigned int,
 878                                   aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE);
 879                 in_bytes = gcm_in_walk_go(&gw_in, min_bytes);
 880                 out_bytes = gcm_out_walk_go(&gw_out, min_bytes);
 881                 bytes = min(in_bytes, out_bytes);
 882
 883                 if (aadlen + pclen <= bytes) {
 884                         aad_bytes = aadlen;
 885                         pc_bytes = pclen;
 886                         flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC;
 887                 } else {
 888                         if (aadlen <= bytes) {
 889                                 aad_bytes = aadlen;
 890                                 pc_bytes = (bytes - aadlen) &
 891                                            ~(AES_BLOCK_SIZE - 1);
 892                                 flags |= CPACF_KMA_LAAD;
 893                         } else {
 894                                 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1);
 895                                 pc_bytes = 0;
 896                         }
 897                 }
 898
 899                 if (aad_bytes > 0)
 900                         memcpy(gw_out.ptr, gw_in.ptr, aad_bytes);
 901
 902                 cpacf_kma(ctx->fc | flags, &param,
 903                           gw_out.ptr + aad_bytes,
 904                           gw_in.ptr + aad_bytes, pc_bytes,
 905                           gw_in.ptr, aad_bytes);
 906
 907                 n = aad_bytes + pc_bytes;
 908                 if (gcm_in_walk_done(&gw_in, n) != n)
 909                         return -ENOMEM;
 910                 if (gcm_out_walk_done(&gw_out, n) != n)
 911                         return -ENOMEM;
 912                 aadlen -= aad_bytes;
 913                 pclen -= pc_bytes;
 914         } while (aadlen + pclen > 0);
 915
 916         if (flags & CPACF_DECRYPT) {
 917                 scatterwalk_map_and_copy(tag, req->src, len, taglen, 0);
 918                 if (crypto_memneq(tag, param.t, taglen))
 919                         ret = -EBADMSG;
 920         } else
 921                 scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1);
 922
 923         memzero_explicit(&param, sizeof(param));
 924         return ret;
 925 }
 926
 927 static int gcm_aes_encrypt(struct aead_request *req)
 928 {
 929         return gcm_aes_crypt(req, CPACF_ENCRYPT);
 930 }
 931
 932 static int gcm_aes_decrypt(struct aead_request *req)
 933 {
 934         return gcm_aes_crypt(req, CPACF_DECRYPT);
 935 }
 936
 937 static struct aead_alg gcm_aes_aead = {
 938         .setkey                 = gcm_aes_setkey,
 939         .setauthsize            = gcm_aes_setauthsize,
 940         .encrypt                = gcm_aes_encrypt,
 941         .decrypt                = gcm_aes_decrypt,
 942
 943         .ivsize                 = GHASH_BLOCK_SIZE - sizeof(u32),
 944         .maxauthsize            = GHASH_DIGEST_SIZE,
 945         .chunksize              = AES_BLOCK_SIZE,
 946
 947         .base                   = {
 948                 .cra_blocksize          = 1,
 949                 .cra_ctxsize            = sizeof(struct s390_aes_ctx),
 950                 .cra_priority           = 900,
 951                 .cra_name               = "gcm(aes)",
 952                 .cra_driver_name        = "gcm-aes-s390",
 953                 .cra_module             = THIS_MODULE,
 954         },
 955 };
 956
 957 static struct crypto_alg *aes_s390_alg;
 958 static struct skcipher_alg *aes_s390_skcipher_algs[4];
 959 static int aes_s390_skciphers_num;
 960 static struct aead_alg *aes_s390_aead_alg;
 961
 962 static int aes_s390_register_skcipher(struct skcipher_alg *alg)
 963 {
 964         int ret;
 965
 966         ret = crypto_register_skcipher(alg);
 967         if (!ret)
 968                 aes_s390_skcipher_algs[aes_s390_skciphers_num++] = alg;
 969         return ret;
 970 }
 971
 972 static void aes_s390_fini(void)
 973 {
 974         if (aes_s390_alg)
 975                 crypto_unregister_alg(aes_s390_alg);
 976         while (aes_s390_skciphers_num--)
 977                 crypto_unregister_skcipher(aes_s390_skcipher_algs[aes_s390_skciphers_num]);
 978         if (ctrblk)
 979                 free_page((unsigned long) ctrblk);
 980
 981         if (aes_s390_aead_alg)
 982                 crypto_unregister_aead(aes_s390_aead_alg);
 983 }
 984
 985 static int __init aes_s390_init(void)
 986 {
 987         int ret;
 988
 989         /* Query available functions for KM, KMC, KMCTR and KMA */
 990         cpacf_query(CPACF_KM, &km_functions);
 991         cpacf_query(CPACF_KMC, &kmc_functions);
 992         cpacf_query(CPACF_KMCTR, &kmctr_functions);
 993         cpacf_query(CPACF_KMA, &kma_functions);
 994
 995         if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) ||
 996             cpacf_test_func(&km_functions, CPACF_KM_AES_192) ||
 997             cpacf_test_func(&km_functions, CPACF_KM_AES_256)) {
 998                 ret = crypto_register_alg(&aes_alg);
 999                 if (ret)
1000                         goto out_err;
1001                 aes_s390_alg = &aes_alg;
1002                 ret = aes_s390_register_skcipher(&ecb_aes_alg);
1003                 if (ret)
1004                         goto out_err;
1005         }
1006
1007         if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) ||
1008             cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) ||
1009             cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) {
1010                 ret = aes_s390_register_skcipher(&cbc_aes_alg);
1011                 if (ret)
1012                         goto out_err;
1013         }
1014
1015         if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) ||
1016             cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) {
1017                 ret = aes_s390_register_skcipher(&xts_aes_alg);
1018                 if (ret)
1019                         goto out_err;
1020         }
1021
1022         if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) ||
1023             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) ||
1024             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) {
1025                 ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
1026                 if (!ctrblk) {
1027                         ret = -ENOMEM;
1028                         goto out_err;
1029                 }
1030                 ret = aes_s390_register_skcipher(&ctr_aes_alg);
1031                 if (ret)
1032                         goto out_err;
1033         }
1034
1035         if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) ||
1036             cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) ||
1037             cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) {
1038                 ret = crypto_register_aead(&gcm_aes_aead);
1039                 if (ret)
1040                         goto out_err;
1041                 aes_s390_aead_alg = &gcm_aes_aead;
1042         }
1043
1044         return 0;
1045 out_err:
1046         aes_s390_fini();
1047         return ret;
1048 }
1049
1050 module_cpu_feature_match(S390_CPU_FEATURE_MSA, aes_s390_init);
1051 module_exit(aes_s390_fini);
1052
1053 MODULE_ALIAS_CRYPTO("aes-all");
1054
1055 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
1056 MODULE_LICENSE("GPL");
1057 MODULE_IMPORT_NS(CRYPTO_INTERNAL);