arch/s390/crypto/des_s390.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Cryptographic API.
   4  *
   5  * s390 implementation of the DES Cipher Algorithm.
   6  *
   7  * Copyright IBM Corp. 2003, 2011
   8  * Author(s): Thomas Spatzier
   9  *            Jan Glauber (jan.glauber@de.ibm.com)
  10  */
  11
  12 #include <linux/init.h>
  13 #include <linux/module.h>
  14 #include <linux/cpufeature.h>
  15 #include <linux/crypto.h>
  16 #include <linux/fips.h>
  17 #include <linux/mutex.h>
  18 #include <crypto/algapi.h>
  19 #include <crypto/internal/des.h>
  20 #include <crypto/internal/skcipher.h>
  21 #include <asm/cpacf.h>
  22
  23 #define DES3_KEY_SIZE   (3 * DES_KEY_SIZE)
  24
  25 static u8 *ctrblk;
  26 static DEFINE_MUTEX(ctrblk_lock);
  27
  28 static cpacf_mask_t km_functions, kmc_functions, kmctr_functions;
  29
  30 struct s390_des_ctx {
  31         u8 iv[DES_BLOCK_SIZE];
  32         u8 key[DES3_KEY_SIZE];
  33 };
  34
  35 static int des_setkey(struct crypto_tfm *tfm, const u8 *key,
  36                       unsigned int key_len)
  37 {
  38         struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
  39         int err;
  40
  41         err = crypto_des_verify_key(tfm, key);
  42         if (err)
  43                 return err;
  44
  45         memcpy(ctx->key, key, key_len);
  46         return 0;
  47 }
  48
  49 static int des_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
  50                                unsigned int key_len)
  51 {
  52         return des_setkey(crypto_skcipher_tfm(tfm), key, key_len);
  53 }
  54
  55 static void s390_des_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  56 {
  57         struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
  58
  59         cpacf_km(CPACF_KM_DEA, ctx->key, out, in, DES_BLOCK_SIZE);
  60 }
  61
  62 static void s390_des_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  63 {
  64         struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
  65
  66         cpacf_km(CPACF_KM_DEA | CPACF_DECRYPT,
  67                  ctx->key, out, in, DES_BLOCK_SIZE);
  68 }
  69
  70 static struct crypto_alg des_alg = {
  71         .cra_name               =       "des",
  72         .cra_driver_name        =       "des-s390",
  73         .cra_priority           =       300,
  74         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
  75         .cra_blocksize          =       DES_BLOCK_SIZE,
  76         .cra_ctxsize            =       sizeof(struct s390_des_ctx),
  77         .cra_module             =       THIS_MODULE,
  78         .cra_u                  =       {
  79                 .cipher = {
  80                         .cia_min_keysize        =       DES_KEY_SIZE,
  81                         .cia_max_keysize        =       DES_KEY_SIZE,
  82                         .cia_setkey             =       des_setkey,
  83                         .cia_encrypt            =       s390_des_encrypt,
  84                         .cia_decrypt            =       s390_des_decrypt,
  85                 }
  86         }
  87 };
  88
  89 static int ecb_desall_crypt(struct skcipher_request *req, unsigned long fc)
  90 {
  91         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
  92         struct s390_des_ctx *ctx = crypto_skcipher_ctx(tfm);
  93         struct skcipher_walk walk;
  94         unsigned int nbytes, n;
  95         int ret;
  96
  97         ret = skcipher_walk_virt(&walk, req, false);
  98         while ((nbytes = walk.nbytes) != 0) {
  99                 /* only use complete blocks */
 100                 n = nbytes & ~(DES_BLOCK_SIZE - 1);
 101                 cpacf_km(fc, ctx->key, walk.dst.virt.addr,
 102                          walk.src.virt.addr, n);
 103                 ret = skcipher_walk_done(&walk, nbytes - n);
 104         }
 105         return ret;
 106 }
 107
 108 static int cbc_desall_crypt(struct skcipher_request *req, unsigned long fc)
 109 {
 110         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 111         struct s390_des_ctx *ctx = crypto_skcipher_ctx(tfm);
 112         struct skcipher_walk walk;
 113         unsigned int nbytes, n;
 114         int ret;
 115         struct {
 116                 u8 iv[DES_BLOCK_SIZE];
 117                 u8 key[DES3_KEY_SIZE];
 118         } param;
 119
 120         ret = skcipher_walk_virt(&walk, req, false);
 121         if (ret)
 122                 return ret;
 123         memcpy(param.iv, walk.iv, DES_BLOCK_SIZE);
 124         memcpy(param.key, ctx->key, DES3_KEY_SIZE);
 125         while ((nbytes = walk.nbytes) != 0) {
 126                 /* only use complete blocks */
 127                 n = nbytes & ~(DES_BLOCK_SIZE - 1);
 128                 cpacf_kmc(fc, &param, walk.dst.virt.addr,
 129                           walk.src.virt.addr, n);
 130                 memcpy(walk.iv, param.iv, DES_BLOCK_SIZE);
 131                 ret = skcipher_walk_done(&walk, nbytes - n);
 132         }
 133         return ret;
 134 }
 135
 136 static int ecb_des_encrypt(struct skcipher_request *req)
 137 {
 138         return ecb_desall_crypt(req, CPACF_KM_DEA);
 139 }
 140
 141 static int ecb_des_decrypt(struct skcipher_request *req)
 142 {
 143         return ecb_desall_crypt(req, CPACF_KM_DEA | CPACF_DECRYPT);
 144 }
 145
 146 static struct skcipher_alg ecb_des_alg = {
 147         .base.cra_name          =       "ecb(des)",
 148         .base.cra_driver_name   =       "ecb-des-s390",
 149         .base.cra_priority      =       400,    /* combo: des + ecb */
 150         .base.cra_blocksize     =       DES_BLOCK_SIZE,
 151         .base.cra_ctxsize       =       sizeof(struct s390_des_ctx),
 152         .base.cra_module        =       THIS_MODULE,
 153         .min_keysize            =       DES_KEY_SIZE,
 154         .max_keysize            =       DES_KEY_SIZE,
 155         .setkey                 =       des_setkey_skcipher,
 156         .encrypt                =       ecb_des_encrypt,
 157         .decrypt                =       ecb_des_decrypt,
 158 };
 159
 160 static int cbc_des_encrypt(struct skcipher_request *req)
 161 {
 162         return cbc_desall_crypt(req, CPACF_KMC_DEA);
 163 }
 164
 165 static int cbc_des_decrypt(struct skcipher_request *req)
 166 {
 167         return cbc_desall_crypt(req, CPACF_KMC_DEA | CPACF_DECRYPT);
 168 }
 169
 170 static struct skcipher_alg cbc_des_alg = {
 171         .base.cra_name          =       "cbc(des)",
 172         .base.cra_driver_name   =       "cbc-des-s390",
 173         .base.cra_priority      =       400,    /* combo: des + cbc */
 174         .base.cra_blocksize     =       DES_BLOCK_SIZE,
 175         .base.cra_ctxsize       =       sizeof(struct s390_des_ctx),
 176         .base.cra_module        =       THIS_MODULE,
 177         .min_keysize            =       DES_KEY_SIZE,
 178         .max_keysize            =       DES_KEY_SIZE,
 179         .ivsize                 =       DES_BLOCK_SIZE,
 180         .setkey                 =       des_setkey_skcipher,
 181         .encrypt                =       cbc_des_encrypt,
 182         .decrypt                =       cbc_des_decrypt,
 183 };
 184
 185 /*
 186  * RFC2451:
 187  *
 188  *   For DES-EDE3, there is no known need to reject weak or
 189  *   complementation keys.  Any weakness is obviated by the use of
 190  *   multiple keys.
 191  *
 192  *   However, if the first two or last two independent 64-bit keys are
 193  *   equal (k1 == k2 or k2 == k3), then the DES3 operation is simply the
 194  *   same as DES.  Implementers MUST reject keys that exhibit this
 195  *   property.
 196  *
 197  *   In fips mode additinally check for all 3 keys are unique.
 198  *
 199  */
 200 static int des3_setkey(struct crypto_tfm *tfm, const u8 *key,
 201                        unsigned int key_len)
 202 {
 203         struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
 204         int err;
 205
 206         err = crypto_des3_ede_verify_key(tfm, key);
 207         if (err)
 208                 return err;
 209
 210         memcpy(ctx->key, key, key_len);
 211         return 0;
 212 }
 213
 214 static int des3_setkey_skcipher(struct crypto_skcipher *tfm, const u8 *key,
 215                                 unsigned int key_len)
 216 {
 217         return des3_setkey(crypto_skcipher_tfm(tfm), key, key_len);
 218 }
 219
 220 static void des3_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
 221 {
 222         struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
 223
 224         cpacf_km(CPACF_KM_TDEA_192, ctx->key, dst, src, DES_BLOCK_SIZE);
 225 }
 226
 227 static void des3_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
 228 {
 229         struct s390_des_ctx *ctx = crypto_tfm_ctx(tfm);
 230
 231         cpacf_km(CPACF_KM_TDEA_192 | CPACF_DECRYPT,
 232                  ctx->key, dst, src, DES_BLOCK_SIZE);
 233 }
 234
 235 static struct crypto_alg des3_alg = {
 236         .cra_name               =       "des3_ede",
 237         .cra_driver_name        =       "des3_ede-s390",
 238         .cra_priority           =       300,
 239         .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
 240         .cra_blocksize          =       DES_BLOCK_SIZE,
 241         .cra_ctxsize            =       sizeof(struct s390_des_ctx),
 242         .cra_module             =       THIS_MODULE,
 243         .cra_u                  =       {
 244                 .cipher = {
 245                         .cia_min_keysize        =       DES3_KEY_SIZE,
 246                         .cia_max_keysize        =       DES3_KEY_SIZE,
 247                         .cia_setkey             =       des3_setkey,
 248                         .cia_encrypt            =       des3_encrypt,
 249                         .cia_decrypt            =       des3_decrypt,
 250                 }
 251         }
 252 };
 253
 254 static int ecb_des3_encrypt(struct skcipher_request *req)
 255 {
 256         return ecb_desall_crypt(req, CPACF_KM_TDEA_192);
 257 }
 258
 259 static int ecb_des3_decrypt(struct skcipher_request *req)
 260 {
 261         return ecb_desall_crypt(req, CPACF_KM_TDEA_192 | CPACF_DECRYPT);
 262 }
 263
 264 static struct skcipher_alg ecb_des3_alg = {
 265         .base.cra_name          =       "ecb(des3_ede)",
 266         .base.cra_driver_name   =       "ecb-des3_ede-s390",
 267         .base.cra_priority      =       400,    /* combo: des3 + ecb */
 268         .base.cra_blocksize     =       DES_BLOCK_SIZE,
 269         .base.cra_ctxsize       =       sizeof(struct s390_des_ctx),
 270         .base.cra_module        =       THIS_MODULE,
 271         .min_keysize            =       DES3_KEY_SIZE,
 272         .max_keysize            =       DES3_KEY_SIZE,
 273         .setkey                 =       des3_setkey_skcipher,
 274         .encrypt                =       ecb_des3_encrypt,
 275         .decrypt                =       ecb_des3_decrypt,
 276 };
 277
 278 static int cbc_des3_encrypt(struct skcipher_request *req)
 279 {
 280         return cbc_desall_crypt(req, CPACF_KMC_TDEA_192);
 281 }
 282
 283 static int cbc_des3_decrypt(struct skcipher_request *req)
 284 {
 285         return cbc_desall_crypt(req, CPACF_KMC_TDEA_192 | CPACF_DECRYPT);
 286 }
 287
 288 static struct skcipher_alg cbc_des3_alg = {
 289         .base.cra_name          =       "cbc(des3_ede)",
 290         .base.cra_driver_name   =       "cbc-des3_ede-s390",
 291         .base.cra_priority      =       400,    /* combo: des3 + cbc */
 292         .base.cra_blocksize     =       DES_BLOCK_SIZE,
 293         .base.cra_ctxsize       =       sizeof(struct s390_des_ctx),
 294         .base.cra_module        =       THIS_MODULE,
 295         .min_keysize            =       DES3_KEY_SIZE,
 296         .max_keysize            =       DES3_KEY_SIZE,
 297         .ivsize                 =       DES_BLOCK_SIZE,
 298         .setkey                 =       des3_setkey_skcipher,
 299         .encrypt                =       cbc_des3_encrypt,
 300         .decrypt                =       cbc_des3_decrypt,
 301 };
 302
 303 static unsigned int __ctrblk_init(u8 *ctrptr, u8 *iv, unsigned int nbytes)
 304 {
 305         unsigned int i, n;
 306
 307         /* align to block size, max. PAGE_SIZE */
 308         n = (nbytes > PAGE_SIZE) ? PAGE_SIZE : nbytes & ~(DES_BLOCK_SIZE - 1);
 309         memcpy(ctrptr, iv, DES_BLOCK_SIZE);
 310         for (i = (n / DES_BLOCK_SIZE) - 1; i > 0; i--) {
 311                 memcpy(ctrptr + DES_BLOCK_SIZE, ctrptr, DES_BLOCK_SIZE);
 312                 crypto_inc(ctrptr + DES_BLOCK_SIZE, DES_BLOCK_SIZE);
 313                 ctrptr += DES_BLOCK_SIZE;
 314         }
 315         return n;
 316 }
 317
 318 static int ctr_desall_crypt(struct skcipher_request *req, unsigned long fc)
 319 {
 320         struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
 321         struct s390_des_ctx *ctx = crypto_skcipher_ctx(tfm);
 322         u8 buf[DES_BLOCK_SIZE], *ctrptr;
 323         struct skcipher_walk walk;
 324         unsigned int n, nbytes;
 325         int ret, locked;
 326
 327         locked = mutex_trylock(&ctrblk_lock);
 328
 329         ret = skcipher_walk_virt(&walk, req, false);
 330         while ((nbytes = walk.nbytes) >= DES_BLOCK_SIZE) {
 331                 n = DES_BLOCK_SIZE;
 332                 if (nbytes >= 2*DES_BLOCK_SIZE && locked)
 333                         n = __ctrblk_init(ctrblk, walk.iv, nbytes);
 334                 ctrptr = (n > DES_BLOCK_SIZE) ? ctrblk : walk.iv;
 335                 cpacf_kmctr(fc, ctx->key, walk.dst.virt.addr,
 336                             walk.src.virt.addr, n, ctrptr);
 337                 if (ctrptr == ctrblk)
 338                         memcpy(walk.iv, ctrptr + n - DES_BLOCK_SIZE,
 339                                 DES_BLOCK_SIZE);
 340                 crypto_inc(walk.iv, DES_BLOCK_SIZE);
 341                 ret = skcipher_walk_done(&walk, nbytes - n);
 342         }
 343         if (locked)
 344                 mutex_unlock(&ctrblk_lock);
 345         /* final block may be < DES_BLOCK_SIZE, copy only nbytes */
 346         if (nbytes) {
 347                 cpacf_kmctr(fc, ctx->key, buf, walk.src.virt.addr,
 348                             DES_BLOCK_SIZE, walk.iv);
 349                 memcpy(walk.dst.virt.addr, buf, nbytes);
 350                 crypto_inc(walk.iv, DES_BLOCK_SIZE);
 351                 ret = skcipher_walk_done(&walk, 0);
 352         }
 353         return ret;
 354 }
 355
 356 static int ctr_des_crypt(struct skcipher_request *req)
 357 {
 358         return ctr_desall_crypt(req, CPACF_KMCTR_DEA);
 359 }
 360
 361 static struct skcipher_alg ctr_des_alg = {
 362         .base.cra_name          =       "ctr(des)",
 363         .base.cra_driver_name   =       "ctr-des-s390",
 364         .base.cra_priority      =       400,    /* combo: des + ctr */
 365         .base.cra_blocksize     =       1,
 366         .base.cra_ctxsize       =       sizeof(struct s390_des_ctx),
 367         .base.cra_module        =       THIS_MODULE,
 368         .min_keysize            =       DES_KEY_SIZE,
 369         .max_keysize            =       DES_KEY_SIZE,
 370         .ivsize                 =       DES_BLOCK_SIZE,
 371         .setkey                 =       des_setkey_skcipher,
 372         .encrypt                =       ctr_des_crypt,
 373         .decrypt                =       ctr_des_crypt,
 374         .chunksize              =       DES_BLOCK_SIZE,
 375 };
 376
 377 static int ctr_des3_crypt(struct skcipher_request *req)
 378 {
 379         return ctr_desall_crypt(req, CPACF_KMCTR_TDEA_192);
 380 }
 381
 382 static struct skcipher_alg ctr_des3_alg = {
 383         .base.cra_name          =       "ctr(des3_ede)",
 384         .base.cra_driver_name   =       "ctr-des3_ede-s390",
 385         .base.cra_priority      =       400,    /* combo: des3 + ede */
 386         .base.cra_blocksize     =       1,
 387         .base.cra_ctxsize       =       sizeof(struct s390_des_ctx),
 388         .base.cra_module        =       THIS_MODULE,
 389         .min_keysize            =       DES3_KEY_SIZE,
 390         .max_keysize            =       DES3_KEY_SIZE,
 391         .ivsize                 =       DES_BLOCK_SIZE,
 392         .setkey                 =       des3_setkey_skcipher,
 393         .encrypt                =       ctr_des3_crypt,
 394         .decrypt                =       ctr_des3_crypt,
 395         .chunksize              =       DES_BLOCK_SIZE,
 396 };
 397
 398 static struct crypto_alg *des_s390_algs_ptr[2];
 399 static int des_s390_algs_num;
 400 static struct skcipher_alg *des_s390_skciphers_ptr[6];
 401 static int des_s390_skciphers_num;
 402
 403 static int des_s390_register_alg(struct crypto_alg *alg)
 404 {
 405         int ret;
 406
 407         ret = crypto_register_alg(alg);
 408         if (!ret)
 409                 des_s390_algs_ptr[des_s390_algs_num++] = alg;
 410         return ret;
 411 }
 412
 413 static int des_s390_register_skcipher(struct skcipher_alg *alg)
 414 {
 415         int ret;
 416
 417         ret = crypto_register_skcipher(alg);
 418         if (!ret)
 419                 des_s390_skciphers_ptr[des_s390_skciphers_num++] = alg;
 420         return ret;
 421 }
 422
 423 static void des_s390_exit(void)
 424 {
 425         while (des_s390_algs_num--)
 426                 crypto_unregister_alg(des_s390_algs_ptr[des_s390_algs_num]);
 427         while (des_s390_skciphers_num--)
 428                 crypto_unregister_skcipher(des_s390_skciphers_ptr[des_s390_skciphers_num]);
 429         if (ctrblk)
 430                 free_page((unsigned long) ctrblk);
 431 }
 432
 433 static int __init des_s390_init(void)
 434 {
 435         int ret;
 436
 437         /* Query available functions for KM, KMC and KMCTR */
 438         cpacf_query(CPACF_KM, &km_functions);
 439         cpacf_query(CPACF_KMC, &kmc_functions);
 440         cpacf_query(CPACF_KMCTR, &kmctr_functions);
 441
 442         if (cpacf_test_func(&km_functions, CPACF_KM_DEA)) {
 443                 ret = des_s390_register_alg(&des_alg);
 444                 if (ret)
 445                         goto out_err;
 446                 ret = des_s390_register_skcipher(&ecb_des_alg);
 447                 if (ret)
 448                         goto out_err;
 449         }
 450         if (cpacf_test_func(&kmc_functions, CPACF_KMC_DEA)) {
 451                 ret = des_s390_register_skcipher(&cbc_des_alg);
 452                 if (ret)
 453                         goto out_err;
 454         }
 455         if (cpacf_test_func(&km_functions, CPACF_KM_TDEA_192)) {
 456                 ret = des_s390_register_alg(&des3_alg);
 457                 if (ret)
 458                         goto out_err;
 459                 ret = des_s390_register_skcipher(&ecb_des3_alg);
 460                 if (ret)
 461                         goto out_err;
 462         }
 463         if (cpacf_test_func(&kmc_functions, CPACF_KMC_TDEA_192)) {
 464                 ret = des_s390_register_skcipher(&cbc_des3_alg);
 465                 if (ret)
 466                         goto out_err;
 467         }
 468
 469         if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_DEA) ||
 470             cpacf_test_func(&kmctr_functions, CPACF_KMCTR_TDEA_192)) {
 471                 ctrblk = (u8 *) __get_free_page(GFP_KERNEL);
 472                 if (!ctrblk) {
 473                         ret = -ENOMEM;
 474                         goto out_err;
 475                 }
 476         }
 477
 478         if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_DEA)) {
 479                 ret = des_s390_register_skcipher(&ctr_des_alg);
 480                 if (ret)
 481                         goto out_err;
 482         }
 483         if (cpacf_test_func(&kmctr_functions, CPACF_KMCTR_TDEA_192)) {
 484                 ret = des_s390_register_skcipher(&ctr_des3_alg);
 485                 if (ret)
 486                         goto out_err;
 487         }
 488
 489         return 0;
 490 out_err:
 491         des_s390_exit();
 492         return ret;
 493 }
 494
 495 module_cpu_feature_match(MSA, des_s390_init);
 496 module_exit(des_s390_exit);
 497
 498 MODULE_ALIAS_CRYPTO("des");
 499 MODULE_ALIAS_CRYPTO("des3_ede");
 500
 501 MODULE_LICENSE("GPL");
 502 MODULE_DESCRIPTION("DES & Triple DES EDE Cipher Algorithms");