arch/s390/crypto/paes

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This source file includes following definitions.
_copy_key_to_kb
_free_kb_keybuf
__paes_convert_key
__paes_set_key
ecb_paes_init
ecb_paes_exit
ecb_paes_set_key
ecb_paes_crypt
ecb_paes_encrypt
ecb_paes_decrypt
cbc_paes_init
cbc_paes_exit
__cbc_paes_set_key
cbc_paes_set_key
cbc_paes_crypt
cbc_paes_encrypt
cbc_paes_decrypt
xts_paes_init
xts_paes_exit
__xts_paes_set_key
xts_paes_set_key
xts_paes_crypt
xts_paes_encrypt
xts_paes_decrypt
ctr_paes_init
ctr_paes_exit
__ctr_paes_set_key
ctr_paes_set_key
__ctrblk_init
ctr_paes_crypt
ctr_paes_encrypt
ctr_paes_decrypt
__crypto_unregister_alg
paes_s390_fini
paes_s390_init
   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Cryptographic API.
   4  *
   5  * s390 implementation of the AES Cipher Algorithm with protected keys.
   6  *
   7  * s390 Version:
   8  *   Copyright IBM Corp. 2017,2019
   9  *   Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  10  *              Harald Freudenberger <freude@de.ibm.com>
  11  */
  12 
  13 #define KMSG_COMPONENT "paes_s390"
  14 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  15 
  16 #include <crypto/aes.h>
  17 #include <crypto/algapi.h>
  18 #include <linux/bug.h>
  19 #include <linux/err.h>
  20 #include <linux/module.h>
  21 #include <linux/cpufeature.h>
  22 #include <linux/init.h>
  23 #include <linux/spinlock.h>
  24 #include <crypto/xts.h>
  25 #include <asm/cpacf.h>
  26 #include <asm/pkey.h>
  27 
  28 /*
  29  * Key blobs smaller/bigger than these defines are rejected
  30  * by the common code even before the individual setkey function
  31  * is called. As paes can handle different kinds of key blobs
  32  * and padding is also possible, the limits need to be generous.
  33  */
  34 #define PAES_MIN_KEYSIZE 64
  35 #define PAES_MAX_KEYSIZE 256
  36 
  37 static u8 *ctrblk;
  38 static DEFINE_SPINLOCK(ctrblk_lock);
  39 
  40 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
  41 
  42 struct key_blob {
  43         /*
  44          * Small keys will be stored in the keybuf. Larger keys are
  45          * stored in extra allocated memory. In both cases does
  46          * key point to the memory where the key is stored.
  47          * The code distinguishes by checking keylen against
  48          * sizeof(keybuf). See the two following helper functions.
  49          */
  50         u8 *key;
  51         u8 keybuf[128];
  52         unsigned int keylen;
  53 };
  54 
  55 static inline int _copy_key_to_kb(struct key_blob *kb,
  56                                   const u8 *key,
  57                                   unsigned int keylen)
  58 {
  59         if (keylen <= sizeof(kb->keybuf))
  60                 kb->key = kb->keybuf;
  61         else {
  62                 kb->key = kmalloc(keylen, GFP_KERNEL);
  63                 if (!kb->key)
  64                         return -ENOMEM;
  65         }
  66         memcpy(kb->key, key, keylen);
  67         kb->keylen = keylen;
  68 
  69         return 0;
  70 }
  71 
  72 static inline void _free_kb_keybuf(struct key_blob *kb)
  73 {
  74         if (kb->key && kb->key != kb->keybuf
  75             && kb->keylen > sizeof(kb->keybuf)) {
  76                 kfree(kb->key);
  77                 kb->key = NULL;
  78         }
  79 }
  80 
  81 struct s390_paes_ctx {
  82         struct key_blob kb;
  83         struct pkey_protkey pk;
  84         unsigned long fc;
  85 };
  86 
  87 struct s390_pxts_ctx {
  88         struct key_blob kb[2];
  89         struct pkey_protkey pk[2];
  90         unsigned long fc;
  91 };
  92 
  93 static inline int __paes_convert_key(struct key_blob *kb,
  94                                      struct pkey_protkey *pk)
  95 {
  96         int i, ret;
  97 
  98         /* try three times in case of failure */
  99         for (i = 0; i < 3; i++) {
 100                 ret = pkey_keyblob2pkey(kb->key, kb->keylen, pk);
 101                 if (ret == 0)
 102                         break;
 103         }
 104 
 105         return ret;
 106 }
 107 
 108 static int __paes_set_key(struct s390_paes_ctx *ctx)
 109 {
 110         unsigned long fc;
 111 
 112         if (__paes_convert_key(&ctx->kb, &ctx->pk))
 113                 return -EINVAL;
 114 
 115         /* Pick the correct function code based on the protected key type */
 116         fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KM_PAES_128 :
 117                 (ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KM_PAES_192 :
 118                 (ctx->pk.type == PKEY_KEYTYPE_AES_256) ? CPACF_KM_PAES_256 : 0;
 119 
 120         /* Check if the function code is available */
 121         ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
 122 
 123         return ctx->fc ? 0 : -EINVAL;
 124 }
 125 
 126 static int ecb_paes_init(struct crypto_tfm *tfm)
 127 {
 128         struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 129 
 130         ctx->kb.key = NULL;
 131 
 132         return 0;
 133 }
 134 
 135 static void ecb_paes_exit(struct crypto_tfm *tfm)
 136 {
 137         struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 138 
 139         _free_kb_keybuf(&ctx->kb);
 140 }
 141 
 142 static int ecb_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 143                             unsigned int key_len)
 144 {
 145         int rc;
 146         struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 147 
 148         _free_kb_keybuf(&ctx->kb);
 149         rc = _copy_key_to_kb(&ctx->kb, in_key, key_len);
 150         if (rc)
 151                 return rc;
 152 
 153         if (__paes_set_key(ctx)) {
 154                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 155                 return -EINVAL;
 156         }
 157         return 0;
 158 }
 159 
 160 static int ecb_paes_crypt(struct blkcipher_desc *desc,
 161                           unsigned long modifier,
 162                           struct blkcipher_walk *walk)
 163 {
 164         struct s390_paes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 165         unsigned int nbytes, n, k;
 166         int ret;
 167 
 168         ret = blkcipher_walk_virt(desc, walk);
 169         while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) {
 170                 /* only use complete blocks */
 171                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 172                 k = cpacf_km(ctx->fc | modifier, ctx->pk.protkey,
 173                              walk->dst.virt.addr, walk->src.virt.addr, n);
 174                 if (k)
 175                         ret = blkcipher_walk_done(desc, walk, nbytes - k);
 176                 if (k < n) {
 177                         if (__paes_set_key(ctx) != 0)
 178                                 return blkcipher_walk_done(desc, walk, -EIO);
 179                 }
 180         }
 181         return ret;
 182 }
 183 
 184 static int ecb_paes_encrypt(struct blkcipher_desc *desc,
 185                             struct scatterlist *dst, struct scatterlist *src,
 186                             unsigned int nbytes)
 187 {
 188         struct blkcipher_walk walk;
 189 
 190         blkcipher_walk_init(&walk, dst, src, nbytes);
 191         return ecb_paes_crypt(desc, CPACF_ENCRYPT, &walk);
 192 }
 193 
 194 static int ecb_paes_decrypt(struct blkcipher_desc *desc,
 195                             struct scatterlist *dst, struct scatterlist *src,
 196                             unsigned int nbytes)
 197 {
 198         struct blkcipher_walk walk;
 199 
 200         blkcipher_walk_init(&walk, dst, src, nbytes);
 201         return ecb_paes_crypt(desc, CPACF_DECRYPT, &walk);
 202 }
 203 
 204 static struct crypto_alg ecb_paes_alg = {
 205         .cra_name               =       "ecb(paes)",
 206         .cra_driver_name        =       "ecb-paes-s390",
 207         .cra_priority           =       401,    /* combo: aes + ecb + 1 */
 208         .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER,
 209         .cra_blocksize          =       AES_BLOCK_SIZE,
 210         .cra_ctxsize            =       sizeof(struct s390_paes_ctx),
 211         .cra_type               =       &crypto_blkcipher_type,
 212         .cra_module             =       THIS_MODULE,
 213         .cra_list               =       LIST_HEAD_INIT(ecb_paes_alg.cra_list),
 214         .cra_init               =       ecb_paes_init,
 215         .cra_exit               =       ecb_paes_exit,
 216         .cra_u                  =       {
 217                 .blkcipher = {
 218                         .min_keysize            =       PAES_MIN_KEYSIZE,
 219                         .max_keysize            =       PAES_MAX_KEYSIZE,
 220                         .setkey                 =       ecb_paes_set_key,
 221                         .encrypt                =       ecb_paes_encrypt,
 222                         .decrypt                =       ecb_paes_decrypt,
 223                 }
 224         }
 225 };
 226 
 227 static int cbc_paes_init(struct crypto_tfm *tfm)
 228 {
 229         struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 230 
 231         ctx->kb.key = NULL;
 232 
 233         return 0;
 234 }
 235 
 236 static void cbc_paes_exit(struct crypto_tfm *tfm)
 237 {
 238         struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 239 
 240         _free_kb_keybuf(&ctx->kb);
 241 }
 242 
 243 static int __cbc_paes_set_key(struct s390_paes_ctx *ctx)
 244 {
 245         unsigned long fc;
 246 
 247         if (__paes_convert_key(&ctx->kb, &ctx->pk))
 248                 return -EINVAL;
 249 
 250         /* Pick the correct function code based on the protected key type */
 251         fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KMC_PAES_128 :
 252                 (ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KMC_PAES_192 :
 253                 (ctx->pk.type == PKEY_KEYTYPE_AES_256) ? CPACF_KMC_PAES_256 : 0;
 254 
 255         /* Check if the function code is available */
 256         ctx->fc = (fc && cpacf_test_func(&kmc_functions, fc)) ? fc : 0;
 257 
 258         return ctx->fc ? 0 : -EINVAL;
 259 }
 260 
 261 static int cbc_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 262                             unsigned int key_len)
 263 {
 264         int rc;
 265         struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 266 
 267         _free_kb_keybuf(&ctx->kb);
 268         rc = _copy_key_to_kb(&ctx->kb, in_key, key_len);
 269         if (rc)
 270                 return rc;
 271 
 272         if (__cbc_paes_set_key(ctx)) {
 273                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 274                 return -EINVAL;
 275         }
 276         return 0;
 277 }
 278 
 279 static int cbc_paes_crypt(struct blkcipher_desc *desc, unsigned long modifier,
 280                           struct blkcipher_walk *walk)
 281 {
 282         struct s390_paes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 283         unsigned int nbytes, n, k;
 284         int ret;
 285         struct {
 286                 u8 iv[AES_BLOCK_SIZE];
 287                 u8 key[MAXPROTKEYSIZE];
 288         } param;
 289 
 290         ret = blkcipher_walk_virt(desc, walk);
 291         memcpy(param.iv, walk->iv, AES_BLOCK_SIZE);
 292         memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
 293         while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) {
 294                 /* only use complete blocks */
 295                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 296                 k = cpacf_kmc(ctx->fc | modifier, &param,
 297                               walk->dst.virt.addr, walk->src.virt.addr, n);
 298                 if (k)
 299                         ret = blkcipher_walk_done(desc, walk, nbytes - k);
 300                 if (k < n) {
 301                         if (__cbc_paes_set_key(ctx) != 0)
 302                                 return blkcipher_walk_done(desc, walk, -EIO);
 303                         memcpy(param.key, ctx->pk.protkey, MAXPROTKEYSIZE);
 304                 }
 305         }
 306         memcpy(walk->iv, param.iv, AES_BLOCK_SIZE);
 307         return ret;
 308 }
 309 
 310 static int cbc_paes_encrypt(struct blkcipher_desc *desc,
 311                             struct scatterlist *dst, struct scatterlist *src,
 312                             unsigned int nbytes)
 313 {
 314         struct blkcipher_walk walk;
 315 
 316         blkcipher_walk_init(&walk, dst, src, nbytes);
 317         return cbc_paes_crypt(desc, 0, &walk);
 318 }
 319 
 320 static int cbc_paes_decrypt(struct blkcipher_desc *desc,
 321                             struct scatterlist *dst, struct scatterlist *src,
 322                             unsigned int nbytes)
 323 {
 324         struct blkcipher_walk walk;
 325 
 326         blkcipher_walk_init(&walk, dst, src, nbytes);
 327         return cbc_paes_crypt(desc, CPACF_DECRYPT, &walk);
 328 }
 329 
 330 static struct crypto_alg cbc_paes_alg = {
 331         .cra_name               =       "cbc(paes)",
 332         .cra_driver_name        =       "cbc-paes-s390",
 333         .cra_priority           =       402,    /* ecb-paes-s390 + 1 */
 334         .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER,
 335         .cra_blocksize          =       AES_BLOCK_SIZE,
 336         .cra_ctxsize            =       sizeof(struct s390_paes_ctx),
 337         .cra_type               =       &crypto_blkcipher_type,
 338         .cra_module             =       THIS_MODULE,
 339         .cra_list               =       LIST_HEAD_INIT(cbc_paes_alg.cra_list),
 340         .cra_init               =       cbc_paes_init,
 341         .cra_exit               =       cbc_paes_exit,
 342         .cra_u                  =       {
 343                 .blkcipher = {
 344                         .min_keysize            =       PAES_MIN_KEYSIZE,
 345                         .max_keysize            =       PAES_MAX_KEYSIZE,
 346                         .ivsize                 =       AES_BLOCK_SIZE,
 347                         .setkey                 =       cbc_paes_set_key,
 348                         .encrypt                =       cbc_paes_encrypt,
 349                         .decrypt                =       cbc_paes_decrypt,
 350                 }
 351         }
 352 };
 353 
 354 static int xts_paes_init(struct crypto_tfm *tfm)
 355 {
 356         struct s390_pxts_ctx *ctx = crypto_tfm_ctx(tfm);
 357 
 358         ctx->kb[0].key = NULL;
 359         ctx->kb[1].key = NULL;
 360 
 361         return 0;
 362 }
 363 
 364 static void xts_paes_exit(struct crypto_tfm *tfm)
 365 {
 366         struct s390_pxts_ctx *ctx = crypto_tfm_ctx(tfm);
 367 
 368         _free_kb_keybuf(&ctx->kb[0]);
 369         _free_kb_keybuf(&ctx->kb[1]);
 370 }
 371 
 372 static int __xts_paes_set_key(struct s390_pxts_ctx *ctx)
 373 {
 374         unsigned long fc;
 375 
 376         if (__paes_convert_key(&ctx->kb[0], &ctx->pk[0]) ||
 377             __paes_convert_key(&ctx->kb[1], &ctx->pk[1]))
 378                 return -EINVAL;
 379 
 380         if (ctx->pk[0].type != ctx->pk[1].type)
 381                 return -EINVAL;
 382 
 383         /* Pick the correct function code based on the protected key type */
 384         fc = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? CPACF_KM_PXTS_128 :
 385                 (ctx->pk[0].type == PKEY_KEYTYPE_AES_256) ?
 386                 CPACF_KM_PXTS_256 : 0;
 387 
 388         /* Check if the function code is available */
 389         ctx->fc = (fc && cpacf_test_func(&km_functions, fc)) ? fc : 0;
 390 
 391         return ctx->fc ? 0 : -EINVAL;
 392 }
 393 
 394 static int xts_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 395                             unsigned int xts_key_len)
 396 {
 397         int rc;
 398         struct s390_pxts_ctx *ctx = crypto_tfm_ctx(tfm);
 399         u8 ckey[2 * AES_MAX_KEY_SIZE];
 400         unsigned int ckey_len, key_len;
 401 
 402         if (xts_key_len % 2)
 403                 return -EINVAL;
 404 
 405         key_len = xts_key_len / 2;
 406 
 407         _free_kb_keybuf(&ctx->kb[0]);
 408         _free_kb_keybuf(&ctx->kb[1]);
 409         rc = _copy_key_to_kb(&ctx->kb[0], in_key, key_len);
 410         if (rc)
 411                 return rc;
 412         rc = _copy_key_to_kb(&ctx->kb[1], in_key + key_len, key_len);
 413         if (rc)
 414                 return rc;
 415 
 416         if (__xts_paes_set_key(ctx)) {
 417                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 418                 return -EINVAL;
 419         }
 420 
 421         /*
 422          * xts_check_key verifies the key length is not odd and makes
 423          * sure that the two keys are not the same. This can be done
 424          * on the two protected keys as well
 425          */
 426         ckey_len = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ?
 427                 AES_KEYSIZE_128 : AES_KEYSIZE_256;
 428         memcpy(ckey, ctx->pk[0].protkey, ckey_len);
 429         memcpy(ckey + ckey_len, ctx->pk[1].protkey, ckey_len);
 430         return xts_check_key(tfm, ckey, 2*ckey_len);
 431 }
 432 
 433 static int xts_paes_crypt(struct blkcipher_desc *desc, unsigned long modifier,
 434                           struct blkcipher_walk *walk)
 435 {
 436         struct s390_pxts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 437         unsigned int keylen, offset, nbytes, n, k;
 438         int ret;
 439         struct {
 440                 u8 key[MAXPROTKEYSIZE]; /* key + verification pattern */
 441                 u8 tweak[16];
 442                 u8 block[16];
 443                 u8 bit[16];
 444                 u8 xts[16];
 445         } pcc_param;
 446         struct {
 447                 u8 key[MAXPROTKEYSIZE]; /* key + verification pattern */
 448                 u8 init[16];
 449         } xts_param;
 450 
 451         ret = blkcipher_walk_virt(desc, walk);
 452         keylen = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 48 : 64;
 453         offset = (ctx->pk[0].type == PKEY_KEYTYPE_AES_128) ? 16 : 0;
 454 retry:
 455         memset(&pcc_param, 0, sizeof(pcc_param));
 456         memcpy(pcc_param.tweak, walk->iv, sizeof(pcc_param.tweak));
 457         memcpy(pcc_param.key + offset, ctx->pk[1].protkey, keylen);
 458         cpacf_pcc(ctx->fc, pcc_param.key + offset);
 459 
 460         memcpy(xts_param.key + offset, ctx->pk[0].protkey, keylen);
 461         memcpy(xts_param.init, pcc_param.xts, 16);
 462 
 463         while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) {
 464                 /* only use complete blocks */
 465                 n = nbytes & ~(AES_BLOCK_SIZE - 1);
 466                 k = cpacf_km(ctx->fc | modifier, xts_param.key + offset,
 467                              walk->dst.virt.addr, walk->src.virt.addr, n);
 468                 if (k)
 469                         ret = blkcipher_walk_done(desc, walk, nbytes - k);
 470                 if (k < n) {
 471                         if (__xts_paes_set_key(ctx) != 0)
 472                                 return blkcipher_walk_done(desc, walk, -EIO);
 473                         goto retry;
 474                 }
 475         }
 476         return ret;
 477 }
 478 
 479 static int xts_paes_encrypt(struct blkcipher_desc *desc,
 480                             struct scatterlist *dst, struct scatterlist *src,
 481                             unsigned int nbytes)
 482 {
 483         struct blkcipher_walk walk;
 484 
 485         blkcipher_walk_init(&walk, dst, src, nbytes);
 486         return xts_paes_crypt(desc, 0, &walk);
 487 }
 488 
 489 static int xts_paes_decrypt(struct blkcipher_desc *desc,
 490                             struct scatterlist *dst, struct scatterlist *src,
 491                             unsigned int nbytes)
 492 {
 493         struct blkcipher_walk walk;
 494 
 495         blkcipher_walk_init(&walk, dst, src, nbytes);
 496         return xts_paes_crypt(desc, CPACF_DECRYPT, &walk);
 497 }
 498 
 499 static struct crypto_alg xts_paes_alg = {
 500         .cra_name               =       "xts(paes)",
 501         .cra_driver_name        =       "xts-paes-s390",
 502         .cra_priority           =       402,    /* ecb-paes-s390 + 1 */
 503         .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER,
 504         .cra_blocksize          =       AES_BLOCK_SIZE,
 505         .cra_ctxsize            =       sizeof(struct s390_pxts_ctx),
 506         .cra_type               =       &crypto_blkcipher_type,
 507         .cra_module             =       THIS_MODULE,
 508         .cra_list               =       LIST_HEAD_INIT(xts_paes_alg.cra_list),
 509         .cra_init               =       xts_paes_init,
 510         .cra_exit               =       xts_paes_exit,
 511         .cra_u                  =       {
 512                 .blkcipher = {
 513                         .min_keysize            =       2 * PAES_MIN_KEYSIZE,
 514                         .max_keysize            =       2 * PAES_MAX_KEYSIZE,
 515                         .ivsize                 =       AES_BLOCK_SIZE,
 516                         .setkey                 =       xts_paes_set_key,
 517                         .encrypt                =       xts_paes_encrypt,
 518                         .decrypt                =       xts_paes_decrypt,
 519                 }
 520         }
 521 };
 522 
 523 static int ctr_paes_init(struct crypto_tfm *tfm)
 524 {
 525         struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 526 
 527         ctx->kb.key = NULL;
 528 
 529         return 0;
 530 }
 531 
 532 static void ctr_paes_exit(struct crypto_tfm *tfm)
 533 {
 534         struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 535 
 536         _free_kb_keybuf(&ctx->kb);
 537 }
 538 
 539 static int __ctr_paes_set_key(struct s390_paes_ctx *ctx)
 540 {
 541         unsigned long fc;
 542 
 543         if (__paes_convert_key(&ctx->kb, &ctx->pk))
 544                 return -EINVAL;
 545 
 546         /* Pick the correct function code based on the protected key type */
 547         fc = (ctx->pk.type == PKEY_KEYTYPE_AES_128) ? CPACF_KMCTR_PAES_128 :
 548                 (ctx->pk.type == PKEY_KEYTYPE_AES_192) ? CPACF_KMCTR_PAES_192 :
 549                 (ctx->pk.type == PKEY_KEYTYPE_AES_256) ?
 550                 CPACF_KMCTR_PAES_256 : 0;
 551 
 552         /* Check if the function code is available */
 553         ctx->fc = (fc && cpacf_test_func(&kmctr_functions, fc)) ? fc : 0;
 554 
 555         return ctx->fc ? 0 : -EINVAL;
 556 }
 557 
 558 static int ctr_paes_set_key(struct crypto_tfm *tfm, const u8 *in_key,
 559                             unsigned int key_len)
 560 {
 561         int rc;
 562         struct s390_paes_ctx *ctx = crypto_tfm_ctx(tfm);
 563 
 564         _free_kb_keybuf(&ctx->kb);
 565         rc = _copy_key_to_kb(&ctx->kb, in_key, key_len);
 566         if (rc)
 567                 return rc;
 568 
 569         if (__ctr_paes_set_key(ctx)) {
 570                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
 571                 return -EINVAL;
 572         }
 573         return 0;
 574 }
 575 
 576 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
 577 {
 578         unsigned int i, n;
 579 
 580         /* only use complete blocks, max. PAGE_SIZE */
 581         memcpy(ctrptr, iv, AES_BLOCK_SIZE);
 582         n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(AES_BLOCK_SIZE - 1);
 583         for (i = (n / AES_BLOCK_SIZE) - 1; i > 0; i--) {
 584                 memcpy(ctrptr + AES_BLOCK_SIZE, ctrptr, AES_BLOCK_SIZE);
 585                 crypto_inc(ctrptr + AES_BLOCK_SIZE, AES_BLOCK_SIZE);
 586                 ctrptr += AES_BLOCK_SIZE;
 587         }
 588         return n;
 589 }
 590 
 591 static int ctr_paes_crypt(struct blkcipher_desc *desc, unsigned long modifier,
 592                           struct blkcipher_walk *walk)
 593 {
 594         struct s390_paes_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
 595         u8 buf[AES_BLOCK_SIZE], *ctrptr;
 596         unsigned int nbytes, n, k;
 597         int ret, locked;
 598 
 599         locked = spin_trylock(&ctrblk_lock);
 600 
 601         ret = blkcipher_walk_virt_block(desc, walk, AES_BLOCK_SIZE);
 602         while ((nbytes = walk->nbytes) >= AES_BLOCK_SIZE) {
 603                 n = AES_BLOCK_SIZE;
 604                 if (nbytes >= 2*AES_BLOCK_SIZE && locked)
 605                         n = __ctrblk_init(ctrblk, walk->iv, nbytes);
 606                 ctrptr = (n > AES_BLOCK_SIZE) ? ctrblk : walk->iv;
 607                 k = cpacf_kmctr(ctx->fc | modifier, ctx->pk.protkey,
 608                                 walk->dst.virt.addr, walk->src.virt.addr,
 609                                 n, ctrptr);
 610                 if (k) {
 611                         if (ctrptr == ctrblk)
 612                                 memcpy(walk->iv, ctrptr + k - AES_BLOCK_SIZE,
 613                                        AES_BLOCK_SIZE);
 614                         crypto_inc(walk->iv, AES_BLOCK_SIZE);
 615                         ret = blkcipher_walk_done(desc, walk, nbytes - n);
 616                 }
 617                 if (k < n) {
 618                         if (__ctr_paes_set_key(ctx) != 0) {
 619                                 if (locked)
 620                                         spin_unlock(&ctrblk_lock);
 621                                 return blkcipher_walk_done(desc, walk, -EIO);
 622                         }
 623                 }
 624         }
 625         if (locked)
 626                 spin_unlock(&ctrblk_lock);
 627         /*
 628          * final block may be < AES_BLOCK_SIZE, copy only nbytes
 629          */
 630         if (nbytes) {
 631                 while (1) {
 632                         if (cpacf_kmctr(ctx->fc | modifier,
 633                                         ctx->pk.protkey, buf,
 634                                         walk->src.virt.addr, AES_BLOCK_SIZE,
 635                                         walk->iv) == AES_BLOCK_SIZE)
 636                                 break;
 637                         if (__ctr_paes_set_key(ctx) != 0)
 638                                 return blkcipher_walk_done(desc, walk, -EIO);
 639                 }
 640                 memcpy(walk->dst.virt.addr, buf, nbytes);
 641                 crypto_inc(walk->iv, AES_BLOCK_SIZE);
 642                 ret = blkcipher_walk_done(desc, walk, 0);
 643         }
 644 
 645         return ret;
 646 }
 647 
 648 static int ctr_paes_encrypt(struct blkcipher_desc *desc,
 649                             struct scatterlist *dst, struct scatterlist *src,
 650                             unsigned int nbytes)
 651 {
 652         struct blkcipher_walk walk;
 653 
 654         blkcipher_walk_init(&walk, dst, src, nbytes);
 655         return ctr_paes_crypt(desc, 0, &walk);
 656 }
 657 
 658 static int ctr_paes_decrypt(struct blkcipher_desc *desc,
 659                             struct scatterlist *dst, struct scatterlist *src,
 660                             unsigned int nbytes)
 661 {
 662         struct blkcipher_walk walk;
 663 
 664         blkcipher_walk_init(&walk, dst, src, nbytes);
 665         return ctr_paes_crypt(desc, CPACF_DECRYPT, &walk);
 666 }
 667 
 668 static struct crypto_alg ctr_paes_alg = {
 669         .cra_name               =       "ctr(paes)",
 670         .cra_driver_name        =       "ctr-paes-s390",
 671         .cra_priority           =       402,    /* ecb-paes-s390 + 1 */
 672         .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER,
 673         .cra_blocksize          =       1,
 674         .cra_ctxsize            =       sizeof(struct s390_paes_ctx),
 675         .cra_type               =       &crypto_blkcipher_type,
 676         .cra_module             =       THIS_MODULE,
 677         .cra_list               =       LIST_HEAD_INIT(ctr_paes_alg.cra_list),
 678         .cra_init               =       ctr_paes_init,
 679         .cra_exit               =       ctr_paes_exit,
 680         .cra_u                  =       {
 681                 .blkcipher = {
 682                         .min_keysize            =       PAES_MIN_KEYSIZE,
 683                         .max_keysize            =       PAES_MAX_KEYSIZE,
 684                         .ivsize                 =       AES_BLOCK_SIZE,
 685                         .setkey                 =       ctr_paes_set_key,
 686                         .encrypt                =       ctr_paes_encrypt,
 687                         .decrypt                =       ctr_paes_decrypt,
 688                 }
 689         }
 690 };
 691 
 692 static inline void __crypto_unregister_alg(struct crypto_alg *alg)
 693 {
 694         if (!list_empty(&alg->cra_list))
 695                 crypto_unregister_alg(alg);
 696 }
 697 
 698 static void paes_s390_fini(void)
 699 {
 700         if (ctrblk)
 701                 free_page((unsigned long) ctrblk);
 702         __crypto_unregister_alg(&ctr_paes_alg);
 703         __crypto_unregister_alg(&xts_paes_alg);
 704         __crypto_unregister_alg(&cbc_paes_alg);
 705         __crypto_unregister_alg(&ecb_paes_alg);
 706 }
 707 
 708 static int __init paes_s390_init(void)
 709 {
 710         int ret;
 711 
 712         /* Query available functions for KM, KMC and KMCTR */
 713         cpacf_query(CPACF_KM, &km_functions);
 714         cpacf_query(CPACF_KMC, &kmc_functions);
 715         cpacf_query(CPACF_KMCTR, &kmctr_functions);
 716 
 717         if (cpacf_test_func(&km_functions, CPACF_KM_PAES_128) ||
 718             cpacf_test_func(&km_functions, CPACF_KM_PAES_192) ||
 719             cpacf_test_func(&km_functions, CPACF_KM_PAES_256)) {
 720                 ret = crypto_register_alg(&ecb_paes_alg);
 721                 if (ret)
 722                         goto out_err;
 723         }
 724 
 725         if (cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_128) ||
 726             cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_192) ||
 727             cpacf_test_func(&kmc_functions, CPACF_KMC_PAES_256)) {
 728                 ret = crypto_register_alg(&cbc_paes_alg);
 729                 if (ret)
 730                         goto out_err;
 731         }
 732 
 733         if (cpacf_test_func(&km_functions, CPACF_KM_PXTS_128) ||
 734             cpacf_test_func(&km_functions, CPACF_KM_PXTS_256)) {
 735                 ret = crypto_register_alg(&xts_paes_alg);
 736                 if (ret)
 737                         goto out_err;
 738         }
 739 
 740         if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_128) ||
 741             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_192) ||
 742             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_PAES_256)) {
 743                 ret = crypto_register_alg(&ctr_paes_alg);
 744                 if (ret)
 745                         goto out_err;
 746                 ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
 747                 if (!ctrblk) {
 748                         ret = -ENOMEM;
 749                         goto out_err;
 750                 }
 751         }
 752 
 753         return 0;
 754 out_err:
 755         paes_s390_fini();
 756         return ret;
 757 }
 758 
 759 module_init(paes_s390_init);
 760 module_exit(paes_s390_fini);
 761 
 762 MODULE_ALIAS_CRYPTO("paes");
 763 
 764 MODULE_DESCRIPTION("Rijndael (AES) Cipher Algorithm with protected keys");
 765 MODULE_LICENSE("GPL");
/* [<][>][^][v][top][bottom][index][help] */
root/arch/s390/crypto/paes_s390.c

DEFINITIONS
