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         int ret;
  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         ret = crypto_cipher_setkey(sctx->fallback.cip, in_key, key_len);
  82         if (ret) {
  83                 tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
  84                 tfm->crt_flags |= (sctx->fallback.cip->base.crt_flags &
  85                                 CRYPTO_TFM_RES_MASK);
  86         }
  87         return ret;
  88 }
  89
  90 static int aes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
  91                        unsigned int key_len)
  92 {
  93         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
  94         unsigned long fc;
  95
  96         /* Pick the correct function code based on the key length */
  97         fc = (key_len == 16) ? CPACF_KM_AES_128 :
  98              (key_len == 24) ? CPACF_KM_AES_192 :
  99              (key_len == 32) ? CPACF_KM_AES_256 : 0;
 100
 101         /* Check if the function code is available */
 102         sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
 103         if (!sctx->fc)
 104                 return setkey_fallback_cip(tfm, in_key, key_len);
 105
 106         sctx->key_len = key_len;
 107         memcpy(sctx->key, in_key, key_len);
 108         return 0;
 109 }
 110
 111 static void crypto_aes_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 112 {
 113         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 114
 115         if (unlikely(!sctx->fc)) {
 116                 crypto_cipher_encrypt_one(sctx->fallback.cip, out, in);
 117                 return;
 118         }
 119         cpacf_km(sctx->fc, &sctx->key, out, in, AES_BLOCK_SIZE);
 120 }
 121
 122 static void crypto_aes_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
 123 {
 124         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 125
 126         if (unlikely(!sctx->fc)) {
 127                 crypto_cipher_decrypt_one(sctx->fallback.cip, out, in);
 128                 return;
 129         }
 130         cpacf_km(sctx->fc | CPACF_DECRYPT,
 131                  &sctx->key, out, in, AES_BLOCK_SIZE);
 132 }
 133
 134 static int fallback_init_cip(struct crypto_tfm *tfm)
 135 {
 136         const char *name = tfm->__crt_alg->cra_name;
 137         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 138
 139         sctx->fallback.cip = crypto_alloc_cipher(name, 0,
 140                                                  CRYPTO_ALG_NEED_FALLBACK);
 141
 142         if (IS_ERR(sctx->fallback.cip)) {
 143                 pr_err("Allocating AES fallback algorithm %s failed\n",
 144                        name);
 145                 return PTR_ERR(sctx->fallback.cip);
 146         }
 147
 148         return 0;
 149 }
 150
 151 static void fallback_exit_cip(struct crypto_tfm *tfm)
 152 {
 153         struct s390_aes_ctx *sctx = crypto_tfm_ctx(tfm);
 154
 155         crypto_free_cipher(sctx->fallback.cip);
 156         sctx->fallback.cip = NULL;
 157 }
 158
 159 static struct crypto_alg aes_alg = {
 160         .cra_name               =       "aes",
 161         .cra_driver_name        =       "aes-s390",
 162         .cra_priority           =       300,
 163         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER |
 164                                         CRYPTO_ALG_NEED_FALLBACK,
 165         .cra_blocksize          =       AES_BLOCK_SIZE,
 166         .cra_ctxsize            =       sizeof(struct s390_aes_ctx),
 167         .cra_module             =       THIS_MODULE,
 168         .cra_init               =       fallback_init_cip,
 169         .cra_exit               =       fallback_exit_cip,
 170         .cra_u                  =       {
 171                 .cipher = {
 172                         .cia_min_keysize        =       AES_MIN_KEY_SIZE,
 173                         .cia_max_keysize        =       AES_MAX_KEY_SIZE,
 174                         .cia_setkey             =       aes_set_key,
 175                         .cia_encrypt            =       crypto_aes_encrypt,
 176                         .cia_decrypt            =       crypto_aes_decrypt,
 177                 }
 178         }
 179 };
 180
 181 static int setkey_fallback_skcipher(struct crypto_skcipher *tfm, const u8 *key,
 182                                     unsigned int len)
 183 {
 184         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 185         int ret;
 186
 187         crypto_skcipher_clear_flags(sctx->fallback.skcipher,
 188                                     CRYPTO_TFM_REQ_MASK);
 189         crypto_skcipher_set_flags(sctx->fallback.skcipher,
 190                                   crypto_skcipher_get_flags(tfm) &
 191                                   CRYPTO_TFM_REQ_MASK);
 192         ret = crypto_skcipher_setkey(sctx->fallback.skcipher, key, len);
 193         crypto_skcipher_set_flags(tfm,
 194                                   crypto_skcipher_get_flags(sctx->fallback.skcipher) &
 195                                   CRYPTO_TFM_RES_MASK);
 196         return ret;
 197 }
 198
 199 static int fallback_skcipher_crypt(struct s390_aes_ctx *sctx,
 200                                    struct skcipher_request *req,
 201                                    unsigned long modifier)
 202 {
 203         struct skcipher_request *subreq = skcipher_request_ctx(req);
 204
 205         *subreq = *req;
 206         skcipher_request_set_tfm(subreq, sctx->fallback.skcipher);
 207         return (modifier & CPACF_DECRYPT) ?
 208                 crypto_skcipher_decrypt(subreq) :
 209                 crypto_skcipher_encrypt(subreq);
 210 }
 211
 212 static int ecb_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 213                            unsigned int key_len)
 214 {
 215         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 216         unsigned long fc;
 217
 218         /* Pick the correct function code based on the key length */
 219         fc = (key_len == 16) ? CPACF_KM_AES_128 :
 220              (key_len == 24) ? CPACF_KM_AES_192 :
 221              (key_len == 32) ? CPACF_KM_AES_256 : 0;
 222
 223         /* Check if the function code is available */
 224         sctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
 225         if (!sctx->fc)
 226                 return setkey_fallback_skcipher(tfm, in_key, key_len);
 227
 228         sctx->key_len = key_len;
 229         memcpy(sctx->key, in_key, key_len);
 230         return 0;
 231 }
 232
 233 static int ecb_aes_crypt(struct skcipher_request *req, unsigned long modifier)
 234 {
 235         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 236         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 237         struct skcipher_walk walk;
 238         unsigned int nbytes, n;
 239         int ret;
 240
 241         if (unlikely(!sctx->fc))
 242                 return fallback_skcipher_crypt(sctx, req, modifier);
 243
 244         ret = skcipher_walk_virt(&walk, req, false);
 245         while ((nbytes = walk.nbytes) != 0) {
 246                 /* only use complete blocks */
 247                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 248                 cpacf_km(sctx->fc | modifier, sctx->key,
 249                          walk.dst.virt.addr, walk.src.virt.addr, n);
 250                 ret = skcipher_walk_done(&walk, nbytes - n);
 251         }
 252         return ret;
 253 }
 254
 255 static int ecb_aes_encrypt(struct skcipher_request *req)
 256 {
 257         return ecb_aes_crypt(req, 0);
 258 }
 259
 260 static int ecb_aes_decrypt(struct skcipher_request *req)
 261 {
 262         return ecb_aes_crypt(req, CPACF_DECRYPT);
 263 }
 264
 265 static int fallback_init_skcipher(struct crypto_skcipher *tfm)
 266 {
 267         const char *name = crypto_tfm_alg_name(&tfm->base);
 268         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 269
 270         sctx->fallback.skcipher = crypto_alloc_skcipher(name, 0,
 271                                 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
 272
 273         if (IS_ERR(sctx->fallback.skcipher)) {
 274                 pr_err("Allocating AES fallback algorithm %s failed\n",
 275                        name);
 276                 return PTR_ERR(sctx->fallback.skcipher);
 277         }
 278
 279         crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
 280                                     crypto_skcipher_reqsize(sctx->fallback.skcipher));
 281         return 0;
 282 }
 283
 284 static void fallback_exit_skcipher(struct crypto_skcipher *tfm)
 285 {
 286         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 287
 288         crypto_free_skcipher(sctx->fallback.skcipher);
 289 }
 290
 291 static struct skcipher_alg ecb_aes_alg = {
 292         .base.cra_name          =       "ecb(aes)",
 293         .base.cra_driver_name   =       "ecb-aes-s390",
 294         .base.cra_priority      =       401,    /* combo: aes + ecb + 1 */
 295         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 296         .base.cra_blocksize     =       AES_BLOCK_SIZE,
 297         .base.cra_ctxsize       =       sizeof(struct s390_aes_ctx),
 298         .base.cra_module        =       THIS_MODULE,
 299         .init                   =       fallback_init_skcipher,
 300         .exit                   =       fallback_exit_skcipher,
 301         .min_keysize            =       AES_MIN_KEY_SIZE,
 302         .max_keysize            =       AES_MAX_KEY_SIZE,
 303         .setkey                 =       ecb_aes_set_key,
 304         .encrypt                =       ecb_aes_encrypt,
 305         .decrypt                =       ecb_aes_decrypt,
 306 };
 307
 308 static int cbc_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 309                            unsigned int key_len)
 310 {
 311         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 312         unsigned long fc;
 313
 314         /* Pick the correct function code based on the key length */
 315         fc = (key_len == 16) ? CPACF_KMC_AES_128 :
 316              (key_len == 24) ? CPACF_KMC_AES_192 :
 317              (key_len == 32) ? CPACF_KMC_AES_256 : 0;
 318
 319         /* Check if the function code is available */
 320         sctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0;
 321         if (!sctx->fc)
 322                 return setkey_fallback_skcipher(tfm, in_key, key_len);
 323
 324         sctx->key_len = key_len;
 325         memcpy(sctx->key, in_key, key_len);
 326         return 0;
 327 }
 328
 329 static int cbc_aes_crypt(struct skcipher_request *req, unsigned long modifier)
 330 {
 331         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 332         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 333         struct skcipher_walk walk;
 334         unsigned int nbytes, n;
 335         int ret;
 336         struct {
 337                 u8 iv[AES_BLOCK_SIZE];
 338                 u8 key[AES_MAX_KEY_SIZE];
 339         } param;
 340
 341         if (unlikely(!sctx->fc))
 342                 return fallback_skcipher_crypt(sctx, req, modifier);
 343
 344         ret = skcipher_walk_virt(&walk, req, false);
 345         if (ret)
 346                 return ret;
 347         memcpy(param.iv, walk.iv, AES_BLOCK_SIZE);
 348         memcpy(param.key, sctx->key, sctx->key_len);
 349         while ((nbytes = walk.nbytes) != 0) {
 350                 /* only use complete blocks */
 351                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 352                 cpacf_kmc(sctx->fc | modifier, &param,
 353                           walk.dst.virt.addr, walk.src.virt.addr, n);
 354                 memcpy(walk.iv, param.iv, AES_BLOCK_SIZE);
 355                 ret = skcipher_walk_done(&walk, nbytes - n);
 356         }
 357         return ret;
 358 }
 359
 360 static int cbc_aes_encrypt(struct skcipher_request *req)
 361 {
 362         return cbc_aes_crypt(req, 0);
 363 }
 364
 365 static int cbc_aes_decrypt(struct skcipher_request *req)
 366 {
 367         return cbc_aes_crypt(req, CPACF_DECRYPT);
 368 }
 369
 370 static struct skcipher_alg cbc_aes_alg = {
 371         .base.cra_name          =       "cbc(aes)",
 372         .base.cra_driver_name   =       "cbc-aes-s390",
 373         .base.cra_priority      =       402,    /* ecb-aes-s390 + 1 */
 374         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 375         .base.cra_blocksize     =       AES_BLOCK_SIZE,
 376         .base.cra_ctxsize       =       sizeof(struct s390_aes_ctx),
 377         .base.cra_module        =       THIS_MODULE,
 378         .init                   =       fallback_init_skcipher,
 379         .exit                   =       fallback_exit_skcipher,
 380         .min_keysize            =       AES_MIN_KEY_SIZE,
 381         .max_keysize            =       AES_MAX_KEY_SIZE,
 382         .ivsize                 =       AES_BLOCK_SIZE,
 383         .setkey                 =       cbc_aes_set_key,
 384         .encrypt                =       cbc_aes_encrypt,
 385         .decrypt                =       cbc_aes_decrypt,
 386 };
 387
 388 static int xts_fallback_setkey(struct crypto_skcipher *tfm, const u8 *key,
 389                                unsigned int len)
 390 {
 391         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 392         int ret;
 393
 394         crypto_skcipher_clear_flags(xts_ctx->fallback, CRYPTO_TFM_REQ_MASK);
 395         crypto_skcipher_set_flags(xts_ctx->fallback,
 396                                   crypto_skcipher_get_flags(tfm) &
 397                                   CRYPTO_TFM_REQ_MASK);
 398         ret = crypto_skcipher_setkey(xts_ctx->fallback, key, len);
 399         crypto_skcipher_set_flags(tfm,
 400                                   crypto_skcipher_get_flags(xts_ctx->fallback) &
 401                                   CRYPTO_TFM_RES_MASK);
 402         return ret;
 403 }
 404
 405 static int xts_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 406                            unsigned int key_len)
 407 {
 408         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 409         unsigned long fc;
 410         int err;
 411
 412         err = xts_fallback_setkey(tfm, in_key, key_len);
 413         if (err)
 414                 return err;
 415
 416         /* In fips mode only 128 bit or 256 bit keys are valid */
 417         if (fips_enabled && key_len != 32 && key_len != 64) {
 418                 crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
 419                 return -EINVAL;
 420         }
 421
 422         /* Pick the correct function code based on the key length */
 423         fc = (key_len == 32) ? CPACF_KM_XTS_128 :
 424              (key_len == 64) ? CPACF_KM_XTS_256 : 0;
 425
 426         /* Check if the function code is available */
 427         xts_ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
 428         if (!xts_ctx->fc)
 429                 return 0;
 430
 431         /* Split the XTS key into the two subkeys */
 432         key_len = key_len / 2;
 433         xts_ctx->key_len = key_len;
 434         memcpy(xts_ctx->key, in_key, key_len);
 435         memcpy(xts_ctx->pcc_key, in_key + key_len, key_len);
 436         return 0;
 437 }
 438
 439 static int xts_aes_crypt(struct skcipher_request *req, unsigned long modifier)
 440 {
 441         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 442         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 443         struct skcipher_walk walk;
 444         unsigned int offset, nbytes, n;
 445         int ret;
 446         struct {
 447                 u8 key[32];
 448                 u8 tweak[16];
 449                 u8 block[16];
 450                 u8 bit[16];
 451                 u8 xts[16];
 452         } pcc_param;
 453         struct {
 454                 u8 key[32];
 455                 u8 init[16];
 456         } xts_param;
 457
 458         if (req->cryptlen < AES_BLOCK_SIZE)
 459                 return -EINVAL;
 460
 461         if (unlikely(!xts_ctx->fc || (req->cryptlen % AES_BLOCK_SIZE) != 0)) {
 462                 struct skcipher_request *subreq = skcipher_request_ctx(req);
 463
 464                 *subreq = *req;
 465                 skcipher_request_set_tfm(subreq, xts_ctx->fallback);
 466                 return (modifier & CPACF_DECRYPT) ?
 467                         crypto_skcipher_decrypt(subreq) :
 468                         crypto_skcipher_encrypt(subreq);
 469         }
 470
 471         ret = skcipher_walk_virt(&walk, req, false);
 472         if (ret)
 473                 return ret;
 474         offset = xts_ctx->key_len & 0x10;
 475         memset(pcc_param.block, 0, sizeof(pcc_param.block));
 476         memset(pcc_param.bit, 0, sizeof(pcc_param.bit));
 477         memset(pcc_param.xts, 0, sizeof(pcc_param.xts));
 478         memcpy(pcc_param.tweak, walk.iv, sizeof(pcc_param.tweak));
 479         memcpy(pcc_param.key + offset, xts_ctx->pcc_key, xts_ctx->key_len);
 480         cpacf_pcc(xts_ctx->fc, pcc_param.key + offset);
 481
 482         memcpy(xts_param.key + offset, xts_ctx->key, xts_ctx->key_len);
 483         memcpy(xts_param.init, pcc_param.xts, 16);
 484
 485         while ((nbytes = walk.nbytes) != 0) {
 486                 /* only use complete blocks */
 487                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 488                 cpacf_km(xts_ctx->fc | modifier, xts_param.key + offset,
 489                          walk.dst.virt.addr, walk.src.virt.addr, n);
 490                 ret = skcipher_walk_done(&walk, nbytes - n);
 491         }
 492         return ret;
 493 }
 494
 495 static int xts_aes_encrypt(struct skcipher_request *req)
 496 {
 497         return xts_aes_crypt(req, 0);
 498 }
 499
 500 static int xts_aes_decrypt(struct skcipher_request *req)
 501 {
 502         return xts_aes_crypt(req, CPACF_DECRYPT);
 503 }
 504
 505 static int xts_fallback_init(struct crypto_skcipher *tfm)
 506 {
 507         const char *name = crypto_tfm_alg_name(&tfm->base);
 508         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 509
 510         xts_ctx->fallback = crypto_alloc_skcipher(name, 0,
 511                                 CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ASYNC);
 512
 513         if (IS_ERR(xts_ctx->fallback)) {
 514                 pr_err("Allocating XTS fallback algorithm %s failed\n",
 515                        name);
 516                 return PTR_ERR(xts_ctx->fallback);
 517         }
 518         crypto_skcipher_set_reqsize(tfm, sizeof(struct skcipher_request) +
 519                                     crypto_skcipher_reqsize(xts_ctx->fallback));
 520         return 0;
 521 }
 522
 523 static void xts_fallback_exit(struct crypto_skcipher *tfm)
 524 {
 525         struct s390_xts_ctx *xts_ctx = crypto_skcipher_ctx(tfm);
 526
 527         crypto_free_skcipher(xts_ctx->fallback);
 528 }
 529
 530 static struct skcipher_alg xts_aes_alg = {
 531         .base.cra_name          =       "xts(aes)",
 532         .base.cra_driver_name   =       "xts-aes-s390",
 533         .base.cra_priority      =       402,    /* ecb-aes-s390 + 1 */
 534         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 535         .base.cra_blocksize     =       AES_BLOCK_SIZE,
 536         .base.cra_ctxsize       =       sizeof(struct s390_xts_ctx),
 537         .base.cra_module        =       THIS_MODULE,
 538         .init                   =       xts_fallback_init,
 539         .exit                   =       xts_fallback_exit,
 540         .min_keysize            =       2 * AES_MIN_KEY_SIZE,
 541         .max_keysize            =       2 * AES_MAX_KEY_SIZE,
 542         .ivsize                 =       AES_BLOCK_SIZE,
 543         .setkey                 =       xts_aes_set_key,
 544         .encrypt                =       xts_aes_encrypt,
 545         .decrypt                =       xts_aes_decrypt,
 546 };
 547
 548 static int ctr_aes_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
 549                            unsigned int key_len)
 550 {
 551         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 552         unsigned long fc;
 553
 554         /* Pick the correct function code based on the key length */
 555         fc = (key_len == 16) ? CPACF_KMCTR_AES_128 :
 556              (key_len == 24) ? CPACF_KMCTR_AES_192 :
 557              (key_len == 32) ? CPACF_KMCTR_AES_256 : 0;
 558
 559         /* Check if the function code is available */
 560         sctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0;
 561         if (!sctx->fc)
 562                 return setkey_fallback_skcipher(tfm, in_key, key_len);
 563
 564         sctx->key_len = key_len;
 565         memcpy(sctx->key, in_key, key_len);
 566         return 0;
 567 }
 568
 569 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
 570 {
 571         unsigned int i, n;
 572
 573         /* only use complete blocks, max. PAGE_SIZE */
 574         memcpy(ctrptr, iv, AES_BLOCK_SIZE);
 575         n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1);
 576         for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) {
 577                 memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE);
 578                 crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE);
 579                 ctrptr += AES_BLOCK_SIZE;
 580         }
 581         return n;
 582 }
 583
 584 static int ctr_aes_crypt(struct skcipher_request *req)
 585 {
 586         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 587         struct s390_aes_ctx *sctx = crypto_skcipher_ctx(tfm);
 588         u8 buf[AES_BLOCK_SIZE], *ctrptr;
 589         struct skcipher_walk walk;
 590         unsigned int n, nbytes;
 591         int ret, locked;
 592
 593         if (unlikely(!sctx->fc))
 594                 return fallback_skcipher_crypt(sctx, req, 0);
 595
 596         locked = mutex_trylock(&ctrblk_lock);
 597
 598         ret = skcipher_walk_virt(&walk, req, false);
 599         while ((nbytes = walk.nbytes) >= AES_BLOCK_SIZE) {
 600                 n = AES_BLOCK_SIZE;
 601
 602                 if (nbytes >= 2*AES_BLOCK_SIZE && locked)
 603                         n = __ctrblk_init(ctrblk, walk.iv, nbytes);
 604                 ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk.iv;
 605                 cpacf_kmctr(sctx->fc, sctx->key, walk.dst.virt.addr,
 606                             walk.src.virt.addr, n, ctrptr);
 607                 if (ctrptr == ctrblk)
 608                         memcpy(walk.iv, ctrptr + n - AES_BLOCK_SIZE,
 609                                AES_BLOCK_SIZE);
 610                 crypto_inc(walk.iv, AES_BLOCK_SIZE);
 611                 ret = skcipher_walk_done(&walk, nbytes - n);
 612         }
 613         if (locked)
 614                 mutex_unlock(&ctrblk_lock);
 615         /*
 616          * final block may be < AES_BLOCK_SIZE, copy only nbytes
 617          */
 618         if (nbytes) {
 619                 cpacf_kmctr(sctx->fc, sctx->key, buf, walk.src.virt.addr,
 620                             AES_BLOCK_SIZE, walk.iv);
 621                 memcpy(walk.dst.virt.addr, buf, nbytes);
 622                 crypto_inc(walk.iv, AES_BLOCK_SIZE);
 623                 ret = skcipher_walk_done(&walk, 0);
 624         }
 625
 626         return ret;
 627 }
 628
 629 static struct skcipher_alg ctr_aes_alg = {
 630         .base.cra_name          =       "ctr(aes)",
 631         .base.cra_driver_name   =       "ctr-aes-s390",
 632         .base.cra_priority      =       402,    /* ecb-aes-s390 + 1 */
 633         .base.cra_flags         =       CRYPTO_ALG_NEED_FALLBACK,
 634         .base.cra_blocksize     =       1,
 635         .base.cra_ctxsize       =       sizeof(struct s390_aes_ctx),
 636         .base.cra_module        =       THIS_MODULE,
 637         .init                   =       fallback_init_skcipher,
 638         .exit                   =       fallback_exit_skcipher,
 639         .min_keysize            =       AES_MIN_KEY_SIZE,
 640         .max_keysize            =       AES_MAX_KEY_SIZE,
 641         .ivsize                 =       AES_BLOCK_SIZE,
 642         .setkey                 =       ctr_aes_set_key,
 643         .encrypt                =       ctr_aes_crypt,
 644         .decrypt                =       ctr_aes_crypt,
 645         .chunksize              =       AES_BLOCK_SIZE,
 646 };
 647
 648 static int gcm_aes_setkey(struct crypto_aead *tfm, const u8 *key,
 649                           unsigned int keylen)
 650 {
 651         struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
 652
 653         switch (keylen) {
 654         case AES_KEYSIZE_128:
 655                 ctx->fc = CPACF_KMA_GCM_AES_128;
 656                 break;
 657         case AES_KEYSIZE_192:
 658                 ctx->fc = CPACF_KMA_GCM_AES_192;
 659                 break;
 660         case AES_KEYSIZE_256:
 661                 ctx->fc = CPACF_KMA_GCM_AES_256;
 662                 break;
 663         default:
 664                 return -EINVAL;
 665         }
 666
 667         memcpy(ctx->key, key, keylen);
 668         ctx->key_len = keylen;
 669         return 0;
 670 }
 671
 672 static int gcm_aes_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
 673 {
 674         switch (authsize) {
 675         case 4:
 676         case 8:
 677         case 12:
 678         case 13:
 679         case 14:
 680         case 15:
 681         case 16:
 682                 break;
 683         default:
 684                 return -EINVAL;
 685         }
 686
 687         return 0;
 688 }
 689
 690 static void gcm_walk_start(struct gcm_sg_walk *gw, struct scatterlist *sg,
 691                            unsigned int len)
 692 {
 693         memset(gw, 0, sizeof(*gw));
 694         gw->walk_bytes_remain = len;
 695         scatterwalk_start(&gw->walk, sg);
 696 }
 697
 698 static inline unsigned int _gcm_sg_clamp_and_map(struct gcm_sg_walk *gw)
 699 {
 700         struct scatterlist *nextsg;
 701
 702         gw->walk_bytes = scatterwalk_clamp(&gw->walk, gw->walk_bytes_remain);
 703         while (!gw->walk_bytes) {
 704                 nextsg = sg_next(gw->walk.sg);
 705                 if (!nextsg)
 706                         return 0;
 707                 scatterwalk_start(&gw->walk, nextsg);
 708                 gw->walk_bytes = scatterwalk_clamp(&gw->walk,
 709                                                    gw->walk_bytes_remain);
 710         }
 711         gw->walk_ptr = scatterwalk_map(&gw->walk);
 712         return gw->walk_bytes;
 713 }
 714
 715 static inline void _gcm_sg_unmap_and_advance(struct gcm_sg_walk *gw,
 716                                              unsigned int nbytes)
 717 {
 718         gw->walk_bytes_remain -= nbytes;
 719         scatterwalk_unmap(&gw->walk);
 720         scatterwalk_advance(&gw->walk, nbytes);
 721         scatterwalk_done(&gw->walk, 0, gw->walk_bytes_remain);
 722         gw->walk_ptr = NULL;
 723 }
 724
 725 static int gcm_in_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
 726 {
 727         int n;
 728
 729         if (gw->buf_bytes && gw->buf_bytes >= minbytesneeded) {
 730                 gw->ptr = gw->buf;
 731                 gw->nbytes = gw->buf_bytes;
 732                 goto out;
 733         }
 734
 735         if (gw->walk_bytes_remain == 0) {
 736                 gw->ptr = NULL;
 737                 gw->nbytes = 0;
 738                 goto out;
 739         }
 740
 741         if (!_gcm_sg_clamp_and_map(gw)) {
 742                 gw->ptr = NULL;
 743                 gw->nbytes = 0;
 744                 goto out;
 745         }
 746
 747         if (!gw->buf_bytes && gw->walk_bytes >= minbytesneeded) {
 748                 gw->ptr = gw->walk_ptr;
 749                 gw->nbytes = gw->walk_bytes;
 750                 goto out;
 751         }
 752
 753         while (1) {
 754                 n = min(gw->walk_bytes, AES_BLOCK_SIZE - gw->buf_bytes);
 755                 memcpy(gw->buf + gw->buf_bytes, gw->walk_ptr, n);
 756                 gw->buf_bytes += n;
 757                 _gcm_sg_unmap_and_advance(gw, n);
 758                 if (gw->buf_bytes >= minbytesneeded) {
 759                         gw->ptr = gw->buf;
 760                         gw->nbytes = gw->buf_bytes;
 761                         goto out;
 762                 }
 763                 if (!_gcm_sg_clamp_and_map(gw)) {
 764                         gw->ptr = NULL;
 765                         gw->nbytes = 0;
 766                         goto out;
 767                 }
 768         }
 769
 770 out:
 771         return gw->nbytes;
 772 }
 773
 774 static int gcm_out_walk_go(struct gcm_sg_walk *gw, unsigned int minbytesneeded)
 775 {
 776         if (gw->walk_bytes_remain == 0) {
 777                 gw->ptr = NULL;
 778                 gw->nbytes = 0;
 779                 goto out;
 780         }
 781
 782         if (!_gcm_sg_clamp_and_map(gw)) {
 783                 gw->ptr = NULL;
 784                 gw->nbytes = 0;
 785                 goto out;
 786         }
 787
 788         if (gw->walk_bytes >= minbytesneeded) {
 789                 gw->ptr = gw->walk_ptr;
 790                 gw->nbytes = gw->walk_bytes;
 791                 goto out;
 792         }
 793
 794         scatterwalk_unmap(&gw->walk);
 795         gw->walk_ptr = NULL;
 796
 797         gw->ptr = gw->buf;
 798         gw->nbytes = sizeof(gw->buf);
 799
 800 out:
 801         return gw->nbytes;
 802 }
 803
 804 static int gcm_in_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
 805 {
 806         if (gw->ptr == NULL)
 807                 return 0;
 808
 809         if (gw->ptr == gw->buf) {
 810                 int n = gw->buf_bytes - bytesdone;
 811                 if (n > 0) {
 812                         memmove(gw->buf, gw->buf + bytesdone, n);
 813                         gw->buf_bytes = n;
 814                 } else
 815                         gw->buf_bytes = 0;
 816         } else
 817                 _gcm_sg_unmap_and_advance(gw, bytesdone);
 818
 819         return bytesdone;
 820 }
 821
 822 static int gcm_out_walk_done(struct gcm_sg_walk *gw, unsigned int bytesdone)
 823 {
 824         int i, n;
 825
 826         if (gw->ptr == NULL)
 827                 return 0;
 828
 829         if (gw->ptr == gw->buf) {
 830                 for (i = 0; i < bytesdone; i += n) {
 831                         if (!_gcm_sg_clamp_and_map(gw))
 832                                 return i;
 833                         n = min(gw->walk_bytes, bytesdone - i);
 834                         memcpy(gw->walk_ptr, gw->buf + i, n);
 835                         _gcm_sg_unmap_and_advance(gw, n);
 836                 }
 837         } else
 838                 _gcm_sg_unmap_and_advance(gw, bytesdone);
 839
 840         return bytesdone;
 841 }
 842
 843 static int gcm_aes_crypt(struct aead_request *req, unsigned int flags)
 844 {
 845         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 846         struct s390_aes_ctx *ctx = crypto_aead_ctx(tfm);
 847         unsigned int ivsize = crypto_aead_ivsize(tfm);
 848         unsigned int taglen = crypto_aead_authsize(tfm);
 849         unsigned int aadlen = req->assoclen;
 850         unsigned int pclen = req->cryptlen;
 851         int ret = 0;
 852
 853         unsigned int n, len, in_bytes, out_bytes,
 854                      min_bytes, bytes, aad_bytes, pc_bytes;
 855         struct gcm_sg_walk gw_in, gw_out;
 856         u8 tag[GHASH_DIGEST_SIZE];
 857
 858         struct {
 859                 u32 _[3];               /* reserved */
 860                 u32 cv;                 /* Counter Value */
 861                 u8 t[GHASH_DIGEST_SIZE];/* Tag */
 862                 u8 h[AES_BLOCK_SIZE];   /* Hash-subkey */
 863                 u64 taadl;              /* Total AAD Length */
 864                 u64 tpcl;               /* Total Plain-/Cipher-text Length */
 865                 u8 j0[GHASH_BLOCK_SIZE];/* initial counter value */
 866                 u8 k[AES_MAX_KEY_SIZE]; /* Key */
 867         } param;
 868
 869         /*
 870          * encrypt
 871          *   req->src: aad||plaintext
 872          *   req->dst: aad||ciphertext||tag
 873          * decrypt
 874          *   req->src: aad||ciphertext||tag
 875          *   req->dst: aad||plaintext, return 0 or -EBADMSG
 876          * aad, plaintext and ciphertext may be empty.
 877          */
 878         if (flags & CPACF_DECRYPT)
 879                 pclen -= taglen;
 880         len = aadlen + pclen;
 881
 882         memset(&param, 0, sizeof(param));
 883         param.cv = 1;
 884         param.taadl = aadlen * 8;
 885         param.tpcl = pclen * 8;
 886         memcpy(param.j0, req->iv, ivsize);
 887         *(u32 *)(param.j0 + ivsize) = 1;
 888         memcpy(param.k, ctx->key, ctx->key_len);
 889
 890         gcm_walk_start(&gw_in, req->src, len);
 891         gcm_walk_start(&gw_out, req->dst, len);
 892
 893         do {
 894                 min_bytes = min_t(unsigned int,
 895                                   aadlen > 0 ? aadlen : pclen, AES_BLOCK_SIZE);
 896                 in_bytes = gcm_in_walk_go(&gw_in, min_bytes);
 897                 out_bytes = gcm_out_walk_go(&gw_out, min_bytes);
 898                 bytes = min(in_bytes, out_bytes);
 899
 900                 if (aadlen + pclen <= bytes) {
 901                         aad_bytes = aadlen;
 902                         pc_bytes = pclen;
 903                         flags |= CPACF_KMA_LAAD | CPACF_KMA_LPC;
 904                 } else {
 905                         if (aadlen <= bytes) {
 906                                 aad_bytes = aadlen;
 907                                 pc_bytes = (bytes - aadlen) &
 908                                            ~(AES_BLOCK_SIZE - 1);
 909                                 flags |= CPACF_KMA_LAAD;
 910                         } else {
 911                                 aad_bytes = bytes & ~(AES_BLOCK_SIZE - 1);
 912                                 pc_bytes = 0;
 913                         }
 914                 }
 915
 916                 if (aad_bytes > 0)
 917                         memcpy(gw_out.ptr, gw_in.ptr, aad_bytes);
 918
 919                 cpacf_kma(ctx->fc | flags, &param,
 920                           gw_out.ptr + aad_bytes,
 921                           gw_in.ptr + aad_bytes, pc_bytes,
 922                           gw_in.ptr, aad_bytes);
 923
 924                 n = aad_bytes + pc_bytes;
 925                 if (gcm_in_walk_done(&gw_in, n) != n)
 926                         return -ENOMEM;
 927                 if (gcm_out_walk_done(&gw_out, n) != n)
 928                         return -ENOMEM;
 929                 aadlen -= aad_bytes;
 930                 pclen -= pc_bytes;
 931         } while (aadlen + pclen > 0);
 932
 933         if (flags & CPACF_DECRYPT) {
 934                 scatterwalk_map_and_copy(tag, req->src, len, taglen, 0);
 935                 if (crypto_memneq(tag, param.t, taglen))
 936                         ret = -EBADMSG;
 937         } else
 938                 scatterwalk_map_and_copy(param.t, req->dst, len, taglen, 1);
 939
 940         memzero_explicit(&param, sizeof(param));
 941         return ret;
 942 }
 943
 944 static int gcm_aes_encrypt(struct aead_request *req)
 945 {
 946         return gcm_aes_crypt(req, CPACF_ENCRYPT);
 947 }
 948
 949 static int gcm_aes_decrypt(struct aead_request *req)
 950 {
 951         return gcm_aes_crypt(req, CPACF_DECRYPT);
 952 }
 953
 954 static struct aead_alg gcm_aes_aead = {
 955         .setkey                 = gcm_aes_setkey,
 956         .setauthsize            = gcm_aes_setauthsize,
 957         .encrypt                = gcm_aes_encrypt,
 958         .decrypt                = gcm_aes_decrypt,
 959
 960         .ivsize                 = GHASH_BLOCK_SIZE - sizeof(u32),
 961         .maxauthsize            = GHASH_DIGEST_SIZE,
 962         .chunksize              = AES_BLOCK_SIZE,
 963
 964         .base                   = {
 965                 .cra_blocksize          = 1,
 966                 .cra_ctxsize            = sizeof(struct s390_aes_ctx),
 967                 .cra_priority           = 900,
 968                 .cra_name               = "gcm(aes)",
 969                 .cra_driver_name        = "gcm-aes-s390",
 970                 .cra_module             = THIS_MODULE,
 971         },
 972 };
 973
 974 static struct crypto_alg *aes_s390_alg;
 975 static struct skcipher_alg *aes_s390_skcipher_algs[4];
 976 static int aes_s390_skciphers_num;
 977 static struct aead_alg *aes_s390_aead_alg;
 978
 979 static int aes_s390_register_skcipher(struct skcipher_alg *alg)
 980 {
 981         int ret;
 982
 983         ret = crypto_register_skcipher(alg);
 984         if (!ret)
 985                 aes_s390_skcipher_algs[aes_s390_skciphers_num++] = alg;
 986         return ret;
 987 }
 988
 989 static void aes_s390_fini(void)
 990 {
 991         if (aes_s390_alg)
 992                 crypto_unregister_alg(aes_s390_alg);
 993         while (aes_s390_skciphers_num--)
 994                 crypto_unregister_skcipher(aes_s390_skcipher_algs[aes_s390_skciphers_num]);
 995         if (ctrblk)
 996                 free_page((unsigned long) ctrblk);
 997
 998         if (aes_s390_aead_alg)
 999                 crypto_unregister_aead(aes_s390_aead_alg);
1000 }
1001
1002 static int __init aes_s390_init(void)
1003 {
1004         int ret;
1005
1006         /* Query available functions for KM, KMC, KMCTR and KMA */
1007         cpacf_query(CPACF_KM, &km_functions);
1008         cpacf_query(CPACF_KMC, &kmc_functions);
1009         cpacf_query(CPACF_KMCTR, &kmctr_functions);
1010         cpacf_query(CPACF_KMA, &kma_functions);
1011
1012         if (cpacf_test_func(&km_functions, CPACF_KM_AES_128) ||
1013             cpacf_test_func(&km_functions, CPACF_KM_AES_192) ||
1014             cpacf_test_func(&km_functions, CPACF_KM_AES_256)) {
1015                 ret = crypto_register_alg(&aes_alg);
1016                 if (ret)
1017                         goto out_err;
1018                 aes_s390_alg = &aes_alg;
1019                 ret = aes_s390_register_skcipher(&ecb_aes_alg);
1020                 if (ret)
1021                         goto out_err;
1022         }
1023
1024         if (cpacf_test_func(&kmc_functions, CPACF_KMC_AES_128) ||
1025             cpacf_test_func(&kmc_functions, CPACF_KMC_AES_192) ||
1026             cpacf_test_func(&kmc_functions, CPACF_KMC_AES_256)) {
1027                 ret = aes_s390_register_skcipher(&cbc_aes_alg);
1028                 if (ret)
1029                         goto out_err;
1030         }
1031
1032         if (cpacf_test_func(&km_functions, CPACF_KM_XTS_128) ||
1033             cpacf_test_func(&km_functions, CPACF_KM_XTS_256)) {
1034                 ret = aes_s390_register_skcipher(&xts_aes_alg);
1035                 if (ret)
1036                         goto out_err;
1037         }
1038
1039         if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_128) ||
1040             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_192) ||
1041             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_AES_256)) {
1042                 ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
1043                 if (!ctrblk) {
1044                         ret = -ENOMEM;
1045                         goto out_err;
1046                 }
1047                 ret = aes_s390_register_skcipher(&ctr_aes_alg);
1048                 if (ret)
1049                         goto out_err;
1050         }
1051
1052         if (cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_128) ||
1053             cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_192) ||
1054             cpacf_test_func(&kma_functions, CPACF_KMA_GCM_AES_256)) {
1055                 ret = crypto_register_aead(&gcm_aes_aead);
1056                 if (ret)
1057                         goto out_err;
1058                 aes_s390_aead_alg = &gcm_aes_aead;
1059         }
1060
1061         return 0;
1062 out_err:
1063         aes_s390_fini();
1064         return ret;
1065 }
1066
1067 module_cpu_feature_match(MSA, aes_s390_init);
1068 module_exit(aes_s390_fini);
1069
1070 MODULE_ALIAS_CRYPTO("aes-all");
1071
1072 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm");
1073 MODULE_LICENSE("GPL");