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         /* In fips mode only 128 bit or 256 bit keys are valid */
 402         if (fips_enabled && key_len != 32 && key_len != 64)
 403                 return -EINVAL;
 404
 405         /* Pick the correct function code based on the key length */
 406         fc = (key_len == 32) ? CPACF_KM_XTS_128 :
 407              (key_len == 64) ? CPACF_KM_XTS_256 : 0;
 408
 409         /* Check if the function code is available */
 410         xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
 411         if (!xts_ctx->fc)
 412                 return 0;
 413
 414         /* Split the XTS key into the two subkeys */
 415         key_len = key_len / 2;
 416         xts_ctx->key_len = key_len;
 417         memcpy(xts_ctx->key, in_key, key_len);
 418         memcpy(xts_ctx->pcc_key, in_key + key_len, key_len);
 419         return 0;
 420 }
 421
 422 static int xts_aes_crypt(struct skcipher_request *req, unsigned long modifier)
 423 {
 424         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 425         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 426         struct skcipher_walk walk;
 427         unsigned int offset, nbytes, n;
 428         int ret;
 429         struct {
 430                 u8 key[32];
 431                 u8 tweak[16];
 432                 u8 block[16];
 433                 u8 bit[16];
 434                 u8 xts[16];
 435         } pcc_param;
 436         struct {
 437                 u8 key[32];
 438                 u8 init[16];
 439         } xts_param;
 440
 441         if (req->cryptlen < AES_BLOCK_SIZE)
 442                 return -EINVAL;
 443
 444         if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) {
 445                 struct skcipher_request *subreq = skcipher_request_ctx(req);
 446
 447                 *subreq = *req;
 448                 skcipher_request_set_tfm(subreq, xts_ctx->fallback);
 449                 return (modifier & CPACF_DECRYPT) ?
 450                         crypto_skcipher_decrypt(subreq) :
 451                         crypto_skcipher_encrypt(subreq);
 452         }
 453
 454         ret = skcipher_walk_virt(&walk, req, false);
 455         if (ret)
 456                 return ret;
 457         offset = xts_ctx->key_len & 0x10;
 458         memset(pcc_param.block, 0, sizeof(pcc_param.block));
 459         memset(pcc_param.bit, 0, sizeof(pcc_param.bit));
 460         memset(pcc_param.xts, 0, sizeof(pcc_param.xts));
 461         memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
 462         memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len);
 463         cpacf_pcc(xts_ctx->fc, pcc_param.key + offset);
 464
 465         memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len);
 466         memcpy(xts_param.init, pcc_param.xts, 16);
 467
 468         while ((nbytes = walk.nbytes) != 0) {
 469                 /* only use complete blocks */
 470                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 471                 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset,
 472                          walk.dst.virt.addr, walk.src.virt.addr, n);
 473                 ret = skcipher_walk_done(&walk, nbytes - n);
 474         }
 475         memzero_explicit(&pcc_param, sizeof(pcc_param));
 476         memzero_explicit(&xts_param, sizeof(xts_param));
 477         return ret;
 478 }
 479
 480 static int xts_aes_encrypt(struct skcipher_request *req)
 481 {
 482         return xts_aes_crypt(req, 0);
 483 }
 484
 485 static int xts_aes_decrypt(struct skcipher_request *req)
 486 {
 487         return xts_aes_crypt(req, CPACF_DECRYPT);
 488 }
 489
 490 static int xts_fallback_init(struct crypto_skcipher *tfm)
 491 {
 492         const char *name = crypto_tfm_alg_name(&tfm->base);
 493         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 494
 495         xts_ctx->fallback = crypto_alloc_skcipher(name, 0,
 496                                 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
 497
 498         if (IS_ERR(xts_ctx->fallback)) {
 499                 pr_err("Allocating XTS fallback algorithm %s failed\n",
 500                        name);
 501                 return PTR_ERR(xts_ctx->fallback);
 502         }
 503         crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
 504                                     crypto_skcipher_reqsize(xts_ctx->fallback));
 505         return 0;
 506 }
 507
 508 static void xts_fallback_exit(struct crypto_skcipher *tfm)
 509 {
 510         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 511
 512         crypto_free_skcipher(xts_ctx->fallback);
 513 }
 514
 515 static struct skcipher_alg xts_aes_alg = {
 516         .base.cra_name          =       "xts(aes)",
 517         .base.cra_driver_name   =       "xts-aes-s390",
 518         .base.cra_priority      =       402,    /* ecb-aes-s390 + 1 */
 519         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 520         .base.cra_blocksize     =       AES_BLOCK_SIZE,
 521         .base.cra_ctxsize       =       sizeof(struct s390_xts_ctx),
 522         .base.cra_module        =       THIS_MODULE,
 523         .init                   =       xts_fallback_init,
 524         .exit                   =       xts_fallback_exit,
 525         .min_keysize            =       2 * AES_MIN_KEY_SIZE,
 526         .max_keysize            =       2 * AES_MAX_KEY_SIZE,
 527         .ivsize                 =       AES_BLOCK_SIZE,
 528         .setkey                 =       xts_aes_set_key,
 529         .encrypt                =       xts_aes_encrypt,
 530         .decrypt                =       xts_aes_decrypt,
 531 };
 532
 533 static int ctr_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 534                            unsigned int key_len)
 535 {
 536         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 537         unsigned long fc;
 538
 539         /* Pick the correct function code based on the key length */
 540         fc = (key_len == 16) ? CPACF_KMCTR_AES_128 :
 541              (key_len == 24) ? CPACF_KMCTR_AES_192 :
 542              (key_len == 32) ? CPACF_KMCTR_AES_256 : 0;
 543
 544         /* Check if the function code is available */
 545         sctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0;
 546         if (!sctx->fc)
 547                 return setkey_fallback_skcipher(tfm, in_key, key_len);
 548
 549         sctx->key_len = key_len;
 550         memcpy(sctx->key, in_key, key_len);
 551         return 0;
 552 }
 553
 554 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
 555 {
 556         unsigned int i, n;
 557
 558         /* only use complete blocks, max. PAGE_SIZE */
 559         memcpy(ctrptr, iv, AES_BLOCK_SIZE);
 560         n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1);
 561         for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) {
 562                 memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE);
 563                 crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE);
 564                 ctrptr += AES_BLOCK_SIZE;
 565         }
 566         return n;
 567 }
 568
 569 static int ctr_aes_crypt(struct skcipher_request *req)
 570 {
 571         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 572         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 573         u8 buf[AES_BLOCK_SIZE], *ctrptr;
 574         struct skcipher_walk walk;
 575         unsigned int n, nbytes;
 576         int ret, locked;
 577
 578         if (unlikely(!sctx->fc))
 579                 return fallback_skcipher_crypt(sctx, req, 0);
 580
 581         locked = mutex_trylock(&ctrblk_lock);
 582
 583         ret = skcipher_walk_virt(&walk, req, false);
 584         while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
 585                 n = AES_BLOCK_SIZE;
 586
 587                 if (nbytes >= 2*AES_BLOCK_SIZE && locked)
 588                         n = __ctrblk_init(ctrblk, walk.iv, nbytes);
 589                 ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv;
 590                 cpacf_kmctr(sctx->fc, sctx->key, walk.dst.virt.addr,
 591                             walk.src.virt.addr, n, ctrptr);
 592                 if (ctrptr == ctrblk)
 593                         memcpy(walk.iv, ctrptr + n - AES_BLOCK_SIZE,
 594                                AES_BLOCK_SIZE);
 595                 crypto_inc(walk.iv, AES_BLOCK_SIZE);
 596                 ret = skcipher_walk_done(&walk, nbytes - n);
 597         }
 598         if (locked)
 599                 mutex_unlock(&ctrblk_lock);
 600         /*
 601          * final block may be < AES_BLOCK_SIZE, copy only nbytes
 602          */
 603         if (nbytes) {
 604                 cpacf_kmctr(sctx->fc, sctx->key, buf, walk.src.virt.addr,
 605                             AES_BLOCK_SIZE, walk.iv);
 606                 memcpy(walk.dst.virt.addr, buf, nbytes);
 607                 crypto_inc(walk.iv, AES_BLOCK_SIZE);
 608                 ret = skcipher_walk_done(&walk, 0);
 609         }
 610
 611         return ret;
 612 }
 613
 614 static struct skcipher_alg ctr_aes_alg = {
 615         .base.cra_name          =       "ctr(aes)",
 616         .base.cra_driver_name   =       "ctr-aes-s390",
 617         .base.cra_priority      =       402,    /* ecb-aes-s390 + 1 */
 618         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 619         .base.cra_blocksize     =       1,
 620         .base.cra_ctxsize       =       sizeof(struct s390_aes_ctx),
 621         .base.cra_module        =       THIS_MODULE,
 622         .init                   =       fallback_init_skcipher,
 623         .exit                   =       fallback_exit_skcipher,
 624         .min_keysize            =       AES_MIN_KEY_SIZE,
 625         .max_keysize            =       AES_MAX_KEY_SIZE,
 626         .ivsize                 =       AES_BLOCK_SIZE,
 627         .setkey                 =       ctr_aes_set_key,
 628         .encrypt                =       ctr_aes_crypt,
 629         .decrypt                =       ctr_aes_crypt,
 630         .chunksize              =       AES_BLOCK_SIZE,
 631 };
 632
 633 static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *key,
 634                           unsigned int keylen)
 635 {
 636         struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
 637
 638         switch (keylen) {
 639         case AES_KEYSIZE_128:
 640                 ctx->fc = CPACF_KMA_GCM_AES_128;
 641                 break;
 642         case AES_KEYSIZE_192:
 643                 ctx->fc = CPACF_KMA_GCM_AES_192;
 644                 break;
 645         case AES_KEYSIZE_256:
 646                 ctx->fc = CPACF_KMA_GCM_AES_256;
 647                 break;
 648         default:
 649                 return -EINVAL;
 650         }
 651
 652         memcpy(ctx->key, key, keylen);
 653         ctx->key_len = keylen;
 654         return 0;
 655 }
 656
 657 static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
 658 {
 659         switch (authsize) {
 660         case 4:
 661         case 8:
 662         case 12:
 663         case 13:
 664         case 14:
 665         case 15:
 666         case 16:
 667                 break;
 668         default:
 669                 return -EINVAL;
 670         }
 671
 672         return 0;
 673 }
 674
 675 static void gcm_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg,
 676                            unsigned int len)
 677 {
 678         memset(gw, 0, sizeof(*gw));
 679         gw->walk_bytes_remain = len;
 680         scatterwalk_start(&gw->walk, sg);
 681 }
 682
 683 static inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw)
 684 {
 685         struct scatterlist *nextsg;
 686
 687         gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain);
 688         while (!gw->walk_bytes) {
 689                 nextsg = sg_next(gw->walk.sg);
 690                 if (!nextsg)
 691                         return 0;
 692                 scatterwalk_start(&gw->walk, nextsg);
 693                 gw->walk_bytes = scatterwalk_clamp(&gw->walk,
 694                                                    gw->walk_bytes_remain);
 695         }
 696         gw->walk_ptr = scatterwalk_map(&gw->walk);
 697         return gw->walk_bytes;
 698 }
 699
 700 static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw,
 701                                              unsigned int nbytes)
 702 {
 703         gw->walk_bytes_remain -= nbytes;
 704         scatterwalk_unmap(&gw->walk);
 705         scatterwalk_advance(&gw->walk, nbytes);
 706         scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
 707         gw->walk_ptr = NULL;
 708 }
 709
 710 static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
 711 {
 712         int n;
 713
 714         if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) {
 715                 gw->ptr = gw->buf;
 716                 gw->nbytes = gw->buf_bytes;
 717                 goto out;
 718         }
 719
 720         if (gw->walk_bytes_remain == 0) {
 721                 gw->ptr = NULL;
 722                 gw->nbytes = 0;
 723                 goto out;
 724         }
 725
 726         if (!_gcm_sg_clamp_and_map(gw)) {
 727                 gw->ptr = NULL;
 728                 gw->nbytes = 0;
 729                 goto out;
 730         }
 731
 732         if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) {
 733                 gw->ptr = gw->walk_ptr;
 734                 gw->nbytes = gw->walk_bytes;
 735                 goto out;
 736         }
 737
 738         while (1) {
 739                 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes);
 740                 memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n);
 741                 gw->buf_bytes += n;
 742                 _gcm_sg_unmap_and_advance(gw, n);
 743                 if (gw->buf_bytes >= minbytesneeded) {
 744                         gw->ptr = gw->buf;
 745                         gw->nbytes = gw->buf_bytes;
 746                         goto out;
 747                 }
 748                 if (!_gcm_sg_clamp_and_map(gw)) {
 749                         gw->ptr = NULL;
 750                         gw->nbytes = 0;
 751                         goto out;
 752                 }
 753         }
 754
 755 out:
 756         return gw->nbytes;
 757 }
 758
 759 static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
 760 {
 761         if (gw->walk_bytes_remain == 0) {
 762                 gw->ptr = NULL;
 763                 gw->nbytes = 0;
 764                 goto out;
 765         }
 766
 767         if (!_gcm_sg_clamp_and_map(gw)) {
 768                 gw->ptr = NULL;
 769                 gw->nbytes = 0;
 770                 goto out;
 771         }
 772
 773         if (gw->walk_bytes >= minbytesneeded) {
 774                 gw->ptr = gw->walk_ptr;
 775                 gw->nbytes = gw->walk_bytes;
 776                 goto out;
 777         }
 778
 779         scatterwalk_unmap(&gw->walk);
 780         gw->walk_ptr = NULL;
 781
 782         gw->ptr = gw->buf;
 783         gw->nbytes = sizeof(gw->buf);
 784
 785 out:
 786         return gw->nbytes;
 787 }
 788
 789 static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
 790 {
 791         if (gw->ptr == NULL)
 792                 return 0;
 793
 794         if (gw->ptr == gw->buf) {
 795                 int n = gw->buf_bytes - bytesdone;
 796                 if (n > 0) {
 797                         memmove(gw->buf, gw->buf + bytesdone, n);
 798                         gw->buf_bytes = n;
 799                 } else
 800                         gw->buf_bytes = 0;
 801         } else
 802                 _gcm_sg_unmap_and_advance(gw, bytesdone);
 803
 804         return bytesdone;
 805 }
 806
 807 static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
 808 {
 809         int i, n;
 810
 811         if (gw->ptr == NULL)
 812                 return 0;
 813
 814         if (gw->ptr == gw->buf) {
 815                 for (i = 0; i < bytesdone; i += n) {
 816                         if (!_gcm_sg_clamp_and_map(gw))
 817                                 return i;
 818                         n = min(gw->walk_bytes, bytesdone - i);
 819                         memcpy(gw->walk_ptr, gw->buf + i, n);
 820                         _gcm_sg_unmap_and_advance(gw, n);
 821                 }
 822         } else
 823                 _gcm_sg_unmap_and_advance(gw, bytesdone);
 824
 825         return bytesdone;
 826 }
 827
 828 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags)
 829 {
 830         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 831         struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
 832         unsigned int ivsize = crypto_aead_ivsize(tfm);
 833         unsigned int taglen = crypto_aead_authsize(tfm);
 834         unsigned int aadlen = req->assoclen;
 835         unsigned int pclen = req->cryptlen;
 836         int ret = 0;
 837
 838         unsigned int n, len, in_bytes, out_bytes,
 839                      min_bytes, bytes, aad_bytes, pc_bytes;
 840         struct gcm_sg_walk gw_in, gw_out;
 841         u8 tag[GHASH_DIGEST_SIZE];
 842
 843         struct {
 844                 u32 _[3];               /* reserved */
 845                 u32 cv;                 /* Counter Value */
 846                 u8 t[GHASH_DIGEST_SIZE];/* Tag */
 847                 u8 h[AES_BLOCK_SIZE];   /* Hash-subkey */
 848                 u64 taadl;              /* Total AAD Length */
 849                 u64 tpcl;               /* Total Plain-/Cipher-text Length */
 850                 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */
 851                 u8 k[AES_MAX_KEY_SIZE]; /* Key */
 852         } param;
 853
 854         /*
 855          * encrypt
 856          *   req->src: aad||plaintext
 857          *   req->dst: aad||ciphertext||tag
 858          * decrypt
 859          *   req->src: aad||ciphertext||tag
 860          *   req->dst: aad||plaintext, return 0 or -EBADMSG
 861          * aad, plaintext and ciphertext may be empty.
 862          */
 863         if (flags & CPACF_DECRYPT)
 864                 pclen -= taglen;
 865         len = aadlen + pclen;
 866
 867         memset(&param, 0, sizeof(param));
 868         param.cv = 1;
 869         param.taadl = aadlen * 8;
 870         param.tpcl = pclen * 8;
 871         memcpy(param.j0, req->iv, ivsize);
 872         *(u32 *)(param.j0 + ivsize) = 1;
 873         memcpy(param.k, ctx->key, ctx->key_len);
 874
 875         gcm_walk_start(&gw_in, req->src, len);
 876         gcm_walk_start(&gw_out, req->dst, len);
 877
 878         do {
 879                 min_bytes = min_t(unsigned int,
 880                                   aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE);
 881                 in_bytes = gcm_in_walk_go(&gw_in, min_bytes);
 882                 out_bytes = gcm_out_walk_go(&gw_out, min_bytes);
 883                 bytes = min(in_bytes, out_bytes);
 884
 885                 if (aadlen + pclen <= bytes) {
 886                         aad_bytes = aadlen;
 887                         pc_bytes = pclen;
 888                         flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC;
 889                 } else {
 890                         if (aadlen <= bytes) {
 891                                 aad_bytes = aadlen;
 892                                 pc_bytes = (bytes - aadlen) &
 893                                            ~(AES_BLOCK_SIZE - 1);
 894                                 flags |= CPACF_KMA_LAAD;
 895                         } else {
 896                                 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1);
 897                                 pc_bytes = 0;
 898                         }
 899                 }
 900
 901                 if (aad_bytes > 0)
 902                         memcpy(gw_out.ptr, gw_in.ptr, aad_bytes);
 903
 904                 cpacf_kma(ctx->fc | flags, &param,
 905                           gw_out.ptr + aad_bytes,
 906                           gw_in.ptr + aad_bytes, pc_bytes,
 907                           gw_in.ptr, aad_bytes);
 908
 909                 n = aad_bytes + pc_bytes;
 910                 if (gcm_in_walk_done(&gw_in, n) != n)
 911                         return -ENOMEM;
 912                 if (gcm_out_walk_done(&gw_out, n) != n)
 913                         return -ENOMEM;
 914                 aadlen -= aad_bytes;
 915                 pclen -= pc_bytes;
 916         } while (aadlen + pclen > 0);
 917
 918         if (flags & CPACF_DECRYPT) {
 919                 scatterwalk_map_and_copy(tag, req->src, len, taglen, 0);
 920                 if (crypto_memneq(tag, param.t, taglen))
 921                         ret = -EBADMSG;
 922         } else
 923                 scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1);
 924
 925         memzero_explicit(&param, sizeof(param));
 926         return ret;
 927 }
 928
 929 static int gcm_aes_encrypt(struct aead_request *req)
 930 {
 931         return gcm_aes_crypt(req, CPACF_ENCRYPT);
 932 }
 933
 934 static int gcm_aes_decrypt(struct aead_request *req)
 935 {
 936         return gcm_aes_crypt(req, CPACF_DECRYPT);
 937 }
 938
 939 static struct aead_alg gcm_aes_aead = {
 940         .setkey                 = gcm_aes_setkey,
 941         .setauthsize            = gcm_aes_setauthsize,
 942         .encrypt                = gcm_aes_encrypt,
 943         .decrypt                = gcm_aes_decrypt,
 944
 945         .ivsize                 = GHASH_BLOCK_SIZE - sizeof(u32),
 946         .maxauthsize            = GHASH_DIGEST_SIZE,
 947         .chunksize              = AES_BLOCK_SIZE,
 948
 949         .base                   = {
 950                 .cra_blocksize          = 1,
 951                 .cra_ctxsize            = sizeof(struct s390_aes_ctx),
 952                 .cra_priority           = 900,
 953                 .cra_name               = "gcm(aes)",
 954                 .cra_driver_name        = "gcm-aes-s390",
 955                 .cra_module             = THIS_MODULE,
 956         },
 957 };
 958
 959 static struct crypto_alg *aes_s390_alg;
 960 static struct skcipher_alg *aes_s390_skcipher_algs[4];
 961 static int aes_s390_skciphers_num;
 962 static struct aead_alg *aes_s390_aead_alg;
 963
 964 static int aes_s390_register_skcipher(struct skcipher_alg *alg)
 965 {
 966         int ret;
 967
 968         ret = crypto_register_skcipher(alg);
 969         if (!ret)
 970                 aes_s390_skcipher_algs[aes_s390_skciphers_num++] = alg;
 971         return ret;
 972 }
 973
 974 static void aes_s390_fini(void)
 975 {
 976         if (aes_s390_alg)
 977                 crypto_unregister_alg(aes_s390_alg);
 978         while (aes_s390_skciphers_num--)
 979                 crypto_unregister_skcipher(aes_s390_skcipher_algs[aes_s390_skciphers_num]);
 980         if (ctrblk)
 981                 free_page((unsigned long) ctrblk);
 982
 983         if (aes_s390_aead_alg)
 984                 crypto_unregister_aead(aes_s390_aead_alg);
 985 }
 986
 987 static int __init aes_s390_init(void)
 988 {
 989         int ret;
 990
 991         /* Query available functions for KM, KMC, KMCTR and KMA */
 992         cpacf_query(CPACF_KM, &km_functions);
 993         cpacf_query(CPACF_KMC, &kmc_functions);
 994         cpacf_query(CPACF_KMCTR, &kmctr_functions);
 995         cpacf_query(CPACF_KMA, &kma_functions);
 996
 997         if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) ||
 998             cpacf_test_func(&km_functions, CPACF_KM_AES_192) ||
 999             cpacf_test_func(&km_functions, CPACF_KM_AES_256)) {
1000                 ret = crypto_register_alg(&aes_alg);
1001                 if (ret)
1002                         goto out_err;
1003                 aes_s390_alg = &aes_alg;
1004                 ret = aes_s390_register_skcipher(&ecb_aes_alg);
1005                 if (ret)
1006                         goto out_err;
1007         }
1008
1009         if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) ||
1010             cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) ||
1011             cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) {
1012                 ret = aes_s390_register_skcipher(&cbc_aes_alg);
1013                 if (ret)
1014                         goto out_err;
1015         }
1016
1017         if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) ||
1018             cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) {
1019                 ret = aes_s390_register_skcipher(&xts_aes_alg);
1020                 if (ret)
1021                         goto out_err;
1022         }
1023
1024         if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) ||
1025             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) ||
1026             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) {
1027                 ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
1028                 if (!ctrblk) {
1029                         ret = -ENOMEM;
1030                         goto out_err;
1031                 }
1032                 ret = aes_s390_register_skcipher(&ctr_aes_alg);
1033                 if (ret)
1034                         goto out_err;
1035         }
1036
1037         if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) ||
1038             cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) ||
1039             cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) {
1040                 ret = crypto_register_aead(&gcm_aes_aead);
1041                 if (ret)
1042                         goto out_err;
1043                 aes_s390_aead_alg = &gcm_aes_aead;
1044         }
1045
1046         return 0;
1047 out_err:
1048         aes_s390_fini();
1049         return ret;
1050 }
1051
1052 module_cpu_feature_match(MSA, aes_s390_init);
1053 module_exit(aes_s390_fini);
1054
1055 MODULE_ALIAS_CRYPTO("aes-all");
1056
1057 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
1058 MODULE_LICENSE("GPL");
1059 MODULE_IMPORT_NS(CRYPTO_INTERNAL);