gost_grasshopper_cipher.c

   1 /*
   2  * Maxim Tishkov 2016
   3  * This file is distributed under the same license as OpenSSL
   4  */
   5
   6 #include "gost_grasshopper_cipher.h"
   7 #include "gost_grasshopper_defines.h"
   8 #include "gost_grasshopper_math.h"
   9 #include "gost_grasshopper_core.h"
  10
  11 #include <openssl/evp.h>
  12 #include <openssl/rand.h>
  13 #include <openssl/err.h>
  14
  15 #include <string.h>
  16 #include <byteswap.h>
  17
  18 #include "gost_lcl.h"
  19 #include "e_gost_err.h"
  20
  21 enum GRASSHOPPER_CIPHER_TYPE {
  22     GRASSHOPPER_CIPHER_ECB = 0,
  23     GRASSHOPPER_CIPHER_CBC,
  24     GRASSHOPPER_CIPHER_OFB,
  25     GRASSHOPPER_CIPHER_CFB,
  26     GRASSHOPPER_CIPHER_CTR,
  27     GRASSHOPPER_CIPHER_CTRACPKM,
  28     GRASSHOPPER_CIPHER_MGM,
  29 };
  30
  31 static EVP_CIPHER *gost_grasshopper_ciphers[7] = {
  32     [GRASSHOPPER_CIPHER_ECB] = NULL,
  33     [GRASSHOPPER_CIPHER_CBC] = NULL,
  34     [GRASSHOPPER_CIPHER_OFB] = NULL,
  35     [GRASSHOPPER_CIPHER_CFB] = NULL,
  36     [GRASSHOPPER_CIPHER_CTR] = NULL,
  37     [GRASSHOPPER_CIPHER_CTRACPKM] = NULL,
  38     [GRASSHOPPER_CIPHER_MGM] = NULL,
  39 };
  40
  41 static GRASSHOPPER_INLINE void
  42 gost_grasshopper_cipher_destroy_ofb(gost_grasshopper_cipher_ctx * c);
  43 static GRASSHOPPER_INLINE void
  44 gost_grasshopper_cipher_destroy_ctr(gost_grasshopper_cipher_ctx * c);
  45 static GRASSHOPPER_INLINE void
  46 gost_grasshopper_cipher_destroy_mgm(gost_grasshopper_cipher_ctx * c);
  47
  48 struct GRASSHOPPER_CIPHER_PARAMS {
  49     int nid;
  50     grasshopper_init_cipher_func init_cipher;
  51     grasshopper_do_cipher_func do_cipher;
  52     grasshopper_destroy_cipher_func destroy_cipher;
  53     int block_size;
  54     int ctx_size;
  55     int iv_size;
  56     bool padding;
  57 };
  58
  59 static struct GRASSHOPPER_CIPHER_PARAMS gost_cipher_params[7] = {
  60     [GRASSHOPPER_CIPHER_ECB] = {
  61                                 NID_grasshopper_ecb,
  62                                 gost_grasshopper_cipher_init_ecb,
  63                                 gost_grasshopper_cipher_do_ecb,
  64                                 NULL,
  65                                 16,
  66                                 sizeof(gost_grasshopper_cipher_ctx),
  67                                 0,
  68                                 true}
  69     ,
  70     [GRASSHOPPER_CIPHER_CBC] = {
  71                                 NID_grasshopper_cbc,
  72                                 gost_grasshopper_cipher_init_cbc,
  73                                 gost_grasshopper_cipher_do_cbc,
  74                                 NULL,
  75                                 16,
  76                                 sizeof(gost_grasshopper_cipher_ctx),
  77                                 16,
  78                                 true}
  79     ,
  80     [GRASSHOPPER_CIPHER_OFB] = {
  81                                 NID_grasshopper_ofb,
  82                                 gost_grasshopper_cipher_init_ofb,
  83                                 gost_grasshopper_cipher_do_ofb,
  84                                 gost_grasshopper_cipher_destroy_ofb,
  85                                 1,
  86                                 sizeof(gost_grasshopper_cipher_ctx_ofb),
  87                                 16,
  88                                 false}
  89     ,
  90     [GRASSHOPPER_CIPHER_CFB] = {
  91                                 NID_grasshopper_cfb,
  92                                 gost_grasshopper_cipher_init_cfb,
  93                                 gost_grasshopper_cipher_do_cfb,
  94                                 NULL,
  95                                 1,
  96                                 sizeof(gost_grasshopper_cipher_ctx),
  97                                 16,
  98                                 false}
  99     ,
 100     [GRASSHOPPER_CIPHER_CTR] = {
 101                                 NID_grasshopper_ctr,
 102                                 gost_grasshopper_cipher_init_ctr,
 103                                 gost_grasshopper_cipher_do_ctr,
 104                                 gost_grasshopper_cipher_destroy_ctr,
 105                                 1,
 106                                 sizeof(gost_grasshopper_cipher_ctx_ctr),
 107                                 /* IV size is set to match full block, to make it responsibility of
 108                                  * user to assign correct values (IV || 0), and to make naive context
 109                                  * copy possible (for software such as openssh) */
 110                                 16,
 111                                 false}
 112     ,
 113     [GRASSHOPPER_CIPHER_CTRACPKM] = {
 114                                      NID_id_tc26_cipher_gostr3412_2015_kuznyechik_ctracpkm,
 115                                      gost_grasshopper_cipher_init_ctracpkm,
 116                                      gost_grasshopper_cipher_do_ctracpkm,
 117                                      gost_grasshopper_cipher_destroy_ctr,
 118                                      1,
 119                                      sizeof(gost_grasshopper_cipher_ctx_ctr),
 120                                      16,
 121                                      false}
 122     ,
 123 #ifdef NID_kuznyechik_mgm
 124     [GRASSHOPPER_CIPHER_MGM] = {
 125                                 NID_kuznyechik_mgm,
 126                                 gost_grasshopper_cipher_init_mgm,
 127                                 gost_grasshopper_cipher_do_mgm,
 128                                 gost_grasshopper_cipher_destroy_mgm,
 129                                 1,
 130                                 sizeof(gost_grasshopper_cipher_ctx_mgm),
 131                                 16,
 132                                 false}
 133     ,
 134 #else
 135     [GRASSHOPPER_CIPHER_MGM] = {
 136                                 NID_undef,
 137                                 NULL,
 138                                 NULL,
 139                                 NULL,
 140                                 0,
 141                                 0,
 142                                 0,
 143                                 false}
 144     ,
 145 #endif
 146 };
 147
 148 /* first 256 bit of D from draft-irtf-cfrg-re-keying-12 */
 149 static const unsigned char ACPKM_D_2018[] = {
 150     0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /*  64 bit */
 151     0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, /* 128 bit */
 152     0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
 153     0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, /* 256 bit */
 154 };
 155
 156 static void acpkm_next(gost_grasshopper_cipher_ctx * c)
 157 {
 158     unsigned char newkey[GRASSHOPPER_KEY_SIZE];
 159     const int J = GRASSHOPPER_KEY_SIZE / GRASSHOPPER_BLOCK_SIZE;
 160     int n;
 161
 162     for (n = 0; n < J; n++) {
 163         const unsigned char *D_n = &ACPKM_D_2018[n * GRASSHOPPER_BLOCK_SIZE];
 164
 165         grasshopper_encrypt_block(&c->encrypt_round_keys,
 166                                   (grasshopper_w128_t *) D_n,
 167                                   (grasshopper_w128_t *) & newkey[n *
 168                                                                   GRASSHOPPER_BLOCK_SIZE],
 169                                   &c->buffer);
 170     }
 171     gost_grasshopper_cipher_key(c, newkey);
 172 }
 173
 174 /* Set 256 bit  key into context */
 175 GRASSHOPPER_INLINE void
 176 gost_grasshopper_cipher_key(gost_grasshopper_cipher_ctx * c, const uint8_t *k)
 177 {
 178     int i;
 179     for (i = 0; i < 2; i++) {
 180         grasshopper_copy128(&c->key.k.k[i],
 181                             (const grasshopper_w128_t *)(k + i * 16));
 182     }
 183
 184     grasshopper_set_encrypt_key(&c->encrypt_round_keys, &c->key);
 185     grasshopper_set_decrypt_key(&c->decrypt_round_keys, &c->key);
 186 }
 187
 188 /* Set master 256-bit key to be used in TLSTREE calculation into context */
 189 GRASSHOPPER_INLINE void
 190 gost_grasshopper_master_key(gost_grasshopper_cipher_ctx * c, const uint8_t *k)
 191 {
 192     int i;
 193     for (i = 0; i < 2; i++) {
 194         grasshopper_copy128(&c->master_key.k.k[i],
 195                             (const grasshopper_w128_t *)(k + i * 16));
 196     }
 197 }
 198
 199 /* Cleans up key from context */
 200 GRASSHOPPER_INLINE void
 201 gost_grasshopper_cipher_destroy(gost_grasshopper_cipher_ctx * c)
 202 {
 203     int i;
 204     for (i = 0; i < 2; i++) {
 205         grasshopper_zero128(&c->key.k.k[i]);
 206         grasshopper_zero128(&c->master_key.k.k[i]);
 207     }
 208     for (i = 0; i < GRASSHOPPER_ROUND_KEYS_COUNT; i++) {
 209         grasshopper_zero128(&c->encrypt_round_keys.k[i]);
 210     }
 211     for (i = 0; i < GRASSHOPPER_ROUND_KEYS_COUNT; i++) {
 212         grasshopper_zero128(&c->decrypt_round_keys.k[i]);
 213     }
 214     grasshopper_zero128(&c->buffer);
 215 }
 216
 217 static GRASSHOPPER_INLINE void
 218 gost_grasshopper_cipher_destroy_ofb(gost_grasshopper_cipher_ctx * c)
 219 {
 220     gost_grasshopper_cipher_ctx_ofb *ctx =
 221         (gost_grasshopper_cipher_ctx_ofb *) c;
 222
 223     grasshopper_zero128(&ctx->buffer1);
 224 }
 225
 226 static GRASSHOPPER_INLINE void
 227 gost_grasshopper_cipher_destroy_ctr(gost_grasshopper_cipher_ctx * c)
 228 {
 229     gost_grasshopper_cipher_ctx_ctr *ctx =
 230         (gost_grasshopper_cipher_ctx_ctr *) c;
 231
 232     grasshopper_zero128(&ctx->partial_buffer);
 233 }
 234
 235 static GRASSHOPPER_INLINE void
 236 gost_grasshopper_cipher_destroy_mgm(gost_grasshopper_cipher_ctx * c)
 237 {
 238     gost_grasshopper_cipher_ctx_mgm *ctx =
 239         (gost_grasshopper_cipher_ctx_mgm *) c;
 240
 241     grasshopper_zero128(&ctx->partial_buffer);
 242 }
 243
 244 int gost_grasshopper_cipher_init(EVP_CIPHER_CTX *ctx,
 245                                  const unsigned char *key,
 246                                  const unsigned char *iv, int enc)
 247 {
 248     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 249
 250     if (EVP_CIPHER_CTX_get_app_data(ctx) == NULL) {
 251         EVP_CIPHER_CTX_set_app_data(ctx, EVP_CIPHER_CTX_get_cipher_data(ctx));
 252     }
 253
 254     if (key != NULL) {
 255         gost_grasshopper_cipher_key(c, key);
 256         gost_grasshopper_master_key(c, key);
 257     }
 258
 259     if (iv != NULL) {
 260         if (c->type == GRASSHOPPER_CIPHER_MGM) {
 261             gost_grasshopper_cipher_ctx_mgm *m =
 262                 (gost_grasshopper_cipher_ctx_mgm *) c;
 263
 264             /* 1st bit should be 0 */
 265             if (iv[0] > 127) {
 266                 GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_INIT,
 267                         GOST_R_INVALID_IV_LENGTH);
 268                 return 0;
 269             }
 270             memcpy(m->mgm_iv, iv, 16);
 271             *(unsigned char *)(m->mgm_iv) += 128;
 272         }
 273         memcpy((unsigned char *)EVP_CIPHER_CTX_original_iv(ctx), iv,
 274                EVP_CIPHER_CTX_iv_length(ctx));
 275     }
 276
 277     memcpy(EVP_CIPHER_CTX_iv_noconst(ctx),
 278            EVP_CIPHER_CTX_original_iv(ctx), EVP_CIPHER_CTX_iv_length(ctx));
 279
 280     grasshopper_zero128(&c->buffer);
 281
 282     return 1;
 283 }
 284
 285 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ecb(EVP_CIPHER_CTX *ctx, const unsigned char
 286                                                         *key, const unsigned char
 287                                                         *iv, int enc)
 288 {
 289     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 290     c->type = GRASSHOPPER_CIPHER_ECB;
 291     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 292 }
 293
 294 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_cbc(EVP_CIPHER_CTX *ctx, const unsigned char
 295                                                         *key, const unsigned char
 296                                                         *iv, int enc)
 297 {
 298     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 299     c->type = GRASSHOPPER_CIPHER_CBC;
 300     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 301 }
 302
 303 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ofb(EVP_CIPHER_CTX *ctx, const unsigned char
 304                                                         *key, const unsigned char
 305                                                         *iv, int enc)
 306 {
 307     gost_grasshopper_cipher_ctx_ofb *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 308
 309     c->c.type = GRASSHOPPER_CIPHER_OFB;
 310
 311     grasshopper_zero128(&c->buffer1);
 312
 313     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 314 }
 315
 316 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_cfb(EVP_CIPHER_CTX *ctx, const unsigned char
 317                                                         *key, const unsigned char
 318                                                         *iv, int enc)
 319 {
 320     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 321     c->type = GRASSHOPPER_CIPHER_CFB;
 322     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 323 }
 324
 325 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ctr(EVP_CIPHER_CTX *ctx, const unsigned char
 326                                                         *key, const unsigned char
 327                                                         *iv, int enc)
 328 {
 329     gost_grasshopper_cipher_ctx_ctr *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 330
 331     c->c.type = GRASSHOPPER_CIPHER_CTR;
 332     EVP_CIPHER_CTX_set_num(ctx, 0);
 333
 334     grasshopper_zero128(&c->partial_buffer);
 335
 336     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 337 }
 338
 339 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ctracpkm(EVP_CIPHER_CTX
 340                                                              *ctx, const unsigned
 341                                                              char *key, const unsigned
 342                                                              char *iv, int enc)
 343 {
 344     gost_grasshopper_cipher_ctx_ctr *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 345
 346     /* NB: setting type makes EVP do_cipher callback useless */
 347     c->c.type = GRASSHOPPER_CIPHER_CTRACPKM;
 348     EVP_CIPHER_CTX_set_num(ctx, 0);
 349     c->section_size = 4096;
 350
 351     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 352 }
 353
 354 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_mgm(EVP_CIPHER_CTX *ctx, const unsigned char
 355                                                         *key, const unsigned char
 356                                                         *iv, int enc)
 357 {
 358     gost_grasshopper_cipher_ctx_mgm *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 359
 360     c->c.type = GRASSHOPPER_CIPHER_MGM;
 361     c->taglen = 16;
 362     EVP_CIPHER_CTX_set_num(ctx, 0);
 363
 364     grasshopper_zero128(&c->partial_buffer);
 365
 366     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 367 }
 368
 369 GRASSHOPPER_INLINE int gost_grasshopper_cipher_do(EVP_CIPHER_CTX *ctx,
 370                                                   unsigned char *out,
 371                                                   const unsigned char *in,
 372                                                   size_t inl)
 373 {
 374     gost_grasshopper_cipher_ctx *c =
 375         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 376     struct GRASSHOPPER_CIPHER_PARAMS *params = &gost_cipher_params[c->type];
 377
 378     return params->do_cipher(ctx, out, in, inl);
 379 }
 380
 381 int gost_grasshopper_cipher_do_ecb(EVP_CIPHER_CTX *ctx, unsigned char *out,
 382                                    const unsigned char *in, size_t inl)
 383 {
 384     gost_grasshopper_cipher_ctx *c =
 385         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 386     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
 387     const unsigned char *current_in = in;
 388     unsigned char *current_out = out;
 389     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 390     size_t i;
 391
 392     for (i = 0; i < blocks;
 393          i++, current_in += GRASSHOPPER_BLOCK_SIZE, current_out +=
 394          GRASSHOPPER_BLOCK_SIZE) {
 395         if (encrypting) {
 396             grasshopper_encrypt_block(&c->encrypt_round_keys,
 397                                       (grasshopper_w128_t *) current_in,
 398                                       (grasshopper_w128_t *) current_out,
 399                                       &c->buffer);
 400         } else {
 401             grasshopper_decrypt_block(&c->decrypt_round_keys,
 402                                       (grasshopper_w128_t *) current_in,
 403                                       (grasshopper_w128_t *) current_out,
 404                                       &c->buffer);
 405         }
 406     }
 407
 408     return 1;
 409 }
 410
 411 int gost_grasshopper_cipher_do_cbc(EVP_CIPHER_CTX *ctx, unsigned char *out,
 412                                    const unsigned char *in, size_t inl)
 413 {
 414     gost_grasshopper_cipher_ctx *c =
 415         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 416     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 417     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
 418     const unsigned char *current_in = in;
 419     unsigned char *current_out = out;
 420     grasshopper_w128_t *currentInputBlock;
 421     grasshopper_w128_t *currentOutputBlock;
 422     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 423     size_t i;
 424     grasshopper_w128_t *currentBlock;
 425
 426     currentBlock = (grasshopper_w128_t *) iv;
 427
 428     for (i = 0; i < blocks;
 429          i++, current_in += GRASSHOPPER_BLOCK_SIZE, current_out +=
 430          GRASSHOPPER_BLOCK_SIZE) {
 431         currentInputBlock = (grasshopper_w128_t *) current_in;
 432         currentOutputBlock = (grasshopper_w128_t *) current_out;
 433         if (encrypting) {
 434             grasshopper_append128(currentBlock, currentInputBlock);
 435             grasshopper_encrypt_block(&c->encrypt_round_keys, currentBlock,
 436                                       currentOutputBlock, &c->buffer);
 437             grasshopper_copy128(currentBlock, currentOutputBlock);
 438         } else {
 439             grasshopper_w128_t tmp;
 440
 441             grasshopper_copy128(&tmp, currentInputBlock);
 442             grasshopper_decrypt_block(&c->decrypt_round_keys,
 443                                       currentInputBlock, currentOutputBlock,
 444                                       &c->buffer);
 445             grasshopper_append128(currentOutputBlock, currentBlock);
 446             grasshopper_copy128(currentBlock, &tmp);
 447         }
 448     }
 449
 450     return 1;
 451 }
 452
 453 void inc_counter(unsigned char *counter, size_t counter_bytes)
 454 {
 455     unsigned char c;
 456     unsigned int n = counter_bytes;
 457
 458     do {
 459         --n;
 460         c = counter[n];
 461         ++c;
 462         counter[n] = c;
 463         if (c)
 464             return;
 465     } while (n);
 466 }
 467
 468 /* increment counter (128-bit int) by 1 */
 469 static void ctr128_inc(unsigned char *counter)
 470 {
 471     inc_counter(counter, 16);
 472 }
 473
 474 int gost_grasshopper_cipher_do_ctr(EVP_CIPHER_CTX *ctx, unsigned char *out,
 475                                    const unsigned char *in, size_t inl)
 476 {
 477     gost_grasshopper_cipher_ctx_ctr *c = (gost_grasshopper_cipher_ctx_ctr *)
 478         EVP_CIPHER_CTX_get_cipher_data(ctx);
 479     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 480     const unsigned char *current_in = in;
 481     unsigned char *current_out = out;
 482     grasshopper_w128_t *currentInputBlock;
 483     grasshopper_w128_t *currentOutputBlock;
 484     unsigned int n = EVP_CIPHER_CTX_num(ctx);
 485     size_t lasted;
 486     size_t i;
 487
 488     while (n && inl) {
 489         *(current_out++) = *(current_in++) ^ c->partial_buffer.b[n];
 490         --inl;
 491         n = (n + 1) % GRASSHOPPER_BLOCK_SIZE;
 492     }
 493     EVP_CIPHER_CTX_set_num(ctx, n);
 494     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 495
 496     grasshopper_w128_t *iv_buffer = (grasshopper_w128_t *) iv;
 497     grasshopper_w128_t tmp;
 498
 499     // full parts
 500     for (i = 0; i < blocks; i++) {
 501         currentInputBlock = (grasshopper_w128_t *) current_in;
 502         currentOutputBlock = (grasshopper_w128_t *) current_out;
 503         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer,
 504                                   &c->partial_buffer, &c->c.buffer);
 505         grasshopper_plus128(&tmp, &c->partial_buffer, currentInputBlock);
 506         grasshopper_copy128(currentOutputBlock, &tmp);
 507         ctr128_inc(iv_buffer->b);
 508         current_in += GRASSHOPPER_BLOCK_SIZE;
 509         current_out += GRASSHOPPER_BLOCK_SIZE;
 510     }
 511
 512     // last part
 513     lasted = inl - blocks * GRASSHOPPER_BLOCK_SIZE;
 514     if (lasted > 0) {
 515         currentInputBlock = (grasshopper_w128_t *) current_in;
 516         currentOutputBlock = (grasshopper_w128_t *) current_out;
 517         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer,
 518                                   &c->partial_buffer, &c->c.buffer);
 519         for (i = 0; i < lasted; i++) {
 520             currentOutputBlock->b[i] =
 521                 c->partial_buffer.b[i] ^ currentInputBlock->b[i];
 522         }
 523         EVP_CIPHER_CTX_set_num(ctx, i);
 524         ctr128_inc(iv_buffer->b);
 525     }
 526
 527     return 1;
 528 }
 529
 530 #define GRASSHOPPER_BLOCK_MASK (GRASSHOPPER_BLOCK_SIZE - 1)
 531 static inline void apply_acpkm_grasshopper(gost_grasshopper_cipher_ctx_ctr *
 532                                            ctx, unsigned int *num)
 533 {
 534     if (!ctx->section_size || (*num < ctx->section_size))
 535         return;
 536     acpkm_next(&ctx->c);
 537     *num &= GRASSHOPPER_BLOCK_MASK;
 538 }
 539
 540 /* If meshing is not configured via ctrl (setting section_size)
 541  * this function works exactly like plain ctr */
 542 int gost_grasshopper_cipher_do_ctracpkm(EVP_CIPHER_CTX *ctx,
 543                                         unsigned char *out,
 544                                         const unsigned char *in, size_t inl)
 545 {
 546     gost_grasshopper_cipher_ctx_ctr *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 547     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 548     unsigned int num = EVP_CIPHER_CTX_num(ctx);
 549
 550     while ((num & GRASSHOPPER_BLOCK_MASK) && inl) {
 551         *out++ = *in++ ^ c->partial_buffer.b[num & GRASSHOPPER_BLOCK_MASK];
 552         --inl;
 553         num++;
 554     }
 555     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 556     size_t i;
 557     grasshopper_w128_t tmp;
 558
 559     // full parts
 560     for (i = 0; i < blocks; i++) {
 561         apply_acpkm_grasshopper(c, &num);
 562         grasshopper_encrypt_block(&c->c.encrypt_round_keys,
 563                                   (grasshopper_w128_t *) iv,
 564                                   (grasshopper_w128_t *) & c->partial_buffer,
 565                                   &c->c.buffer);
 566         grasshopper_plus128(&tmp, &c->partial_buffer,
 567                             (grasshopper_w128_t *) in);
 568         grasshopper_copy128((grasshopper_w128_t *) out, &tmp);
 569         ctr128_inc(iv);
 570         in += GRASSHOPPER_BLOCK_SIZE;
 571         out += GRASSHOPPER_BLOCK_SIZE;
 572         num += GRASSHOPPER_BLOCK_SIZE;
 573     }
 574
 575     // last part
 576     size_t lasted = inl - blocks * GRASSHOPPER_BLOCK_SIZE;
 577     if (lasted > 0) {
 578         apply_acpkm_grasshopper(c, &num);
 579         grasshopper_encrypt_block(&c->c.encrypt_round_keys,
 580                                   (grasshopper_w128_t *) iv,
 581                                   &c->partial_buffer, &c->c.buffer);
 582         for (i = 0; i < lasted; i++)
 583             out[i] = c->partial_buffer.b[i] ^ in[i];
 584         ctr128_inc(iv);
 585         num += lasted;
 586     }
 587     EVP_CIPHER_CTX_set_num(ctx, num);
 588
 589     return 1;
 590 }
 591
 592 /* ----------------------------------------------------------------------------------------------- */
 593 /*! Функция реализует операцию умножения двух элементов конечного поля \f$ \mathbb F_{2^{128}}\f$,
 594     порожденного неприводимым многочленом
 595     \f$ f(x) = x^{128} + x^7 + x^2 + x + 1 \in \mathbb F_2[x]\f$. Для умножения используется
 596     простейшая реализация, основанная на приведении по модулю после каждого шага алгоритма.        */
 597 /* ----------------------------------------------------------------------------------------------- */
 598 static void gf128_mul_uint64(uint64_t *result, uint64_t *arg1, uint64_t *arg2)
 599 {
 600     int i = 0, n = 0;
 601     uint64_t t, s0, s1;
 602     uint64_t x[2], y[2], z[2];
 603
 604     BUF_reverse((unsigned char *)x, (unsigned char *)arg1, 16);
 605     BUF_reverse((unsigned char *)y, (unsigned char *)arg2, 16);
 606
 607 #ifdef L_ENDIAN
 608     s0 = x[0];
 609     s1 = x[1];
 610 #else
 611     s0 = bswap_64(x[0]);
 612     s1 = bswap_64(x[1]);
 613 #endif
 614
 615     memset(z, 0, sizeof(uint64_t) * 2);
 616
 617     /* lower half */
 618 #ifdef L_ENDIAN
 619     t = y[0];
 620 #else
 621     t = bswap_64(y[0]);
 622 #endif
 623
 624     for (i = 0; i < 64; i++) {
 625         if (t & 0x1) {
 626             z[0] ^= s0;
 627             z[1] ^= s1;
 628         }
 629         t >>= 1;
 630         n = s1 >> 63;
 631         s1 <<= 1;
 632         s1 ^= (s0 >> 63);
 633         s0 <<= 1;
 634         if (n)
 635             s0 ^= 0x87;
 636     }
 637
 638     /* upper half */
 639 #ifdef L_ENDIAN
 640     t = y[1];
 641 #else
 642     t = bswap_64(y[1]);
 643 #endif
 644
 645     for (i = 0; i < 63; i++) {
 646         if (t & 0x1) {
 647             z[0] ^= s0;
 648             z[1] ^= s1;
 649         }
 650         t >>= 1;
 651         n = s1 >> 63;
 652         s1 <<= 1;
 653         s1 ^= (s0 >> 63);
 654         s0 <<= 1;
 655         if (n)
 656             s0 ^= 0x87;
 657     }
 658
 659     if (t & 0x1) {
 660         z[0] ^= s0;
 661         z[1] ^= s1;
 662     }
 663 #ifndef L_ENDIAN
 664     z[0] = bswap_64(z[0]);
 665     z[1] = bswap_64(z[1]);
 666 #endif
 667     BUF_reverse((unsigned char *)result, (unsigned char *)z, 16);
 668 }
 669
 670 static void hexdump(FILE *f, const char *title, const unsigned char *s, int l)
 671 {
 672     int n = 0;
 673
 674     fprintf(f, "%s", title);
 675     for (; n < l; ++n) {
 676         if ((n % 16) == 0)
 677             fprintf(f, "\n%04x", n);
 678         fprintf(f, " %02x", s[n]);
 679     }
 680     fprintf(f, "\n");
 681 }
 682
 683 int gost_grasshopper_cipher_do_mgm(EVP_CIPHER_CTX *ctx, unsigned char *out,
 684                                    const unsigned char *in, size_t inl)
 685 {
 686     gost_grasshopper_cipher_ctx_mgm *c = (gost_grasshopper_cipher_ctx_mgm *)
 687         EVP_CIPHER_CTX_get_cipher_data(ctx);
 688     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 689     const unsigned char *current_in = in;
 690     unsigned char *current_out = out;
 691     grasshopper_w128_t *currentInputBlock;
 692     grasshopper_w128_t *currentOutputBlock;
 693     unsigned int n = EVP_CIPHER_CTX_num(ctx);
 694     size_t lasted;
 695     size_t i;
 696
 697     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 698     int rest_len = n % GRASSHOPPER_BLOCK_SIZE;
 699     grasshopper_w128_t h;
 700
 701     grasshopper_w128_t *iv_buffer = (grasshopper_w128_t *) iv;
 702     grasshopper_w128_t tmp;
 703
 704 /* ======== Here we deal with associated data =========== */
 705     if (out == NULL && c->mgm_state == mgm_associated_data) {
 706         if (n == 0) {
 707             grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 708                                       &c->partial_buffer, &c->c.buffer);
 709             memcpy(c->mgm_iv, &c->partial_buffer, GRASSHOPPER_BLOCK_SIZE);
 710             hexdump(stderr, "Tag", c->tag, 16);
 711         }
 712
 713         if (rest_len != 0) {
 714             /* Finalize partial_data */
 715             if (inl + rest_len < GRASSHOPPER_BLOCK_SIZE) {
 716                 memcpy(c->mgm_partial_buffer.b + rest_len, current_in, inl);
 717                 n += inl;
 718                 EVP_CIPHER_CTX_set_num(ctx, n);
 719                 return 1;
 720             } else {
 721                 memcpy(c->mgm_partial_buffer.b + rest_len, current_in,
 722                        GRASSHOPPER_BLOCK_SIZE - rest_len);
 723
 724                 grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 725                                           &h, &c->c.buffer);
 726                 inc_counter(c->mgm_iv->b, 8);
 727
 728                 hexdump(stderr, "Hnext", h.b, 16);
 729                 hexdump(stderr, "Adata", c->mgm_partial_buffer.b, 16);
 730                 /* Galois multiply Hi * Ai */
 731                 gf128_mul_uint64(tmp.q, h.q, c->mgm_partial_buffer.q);
 732
 733                 /* XOR to c->tag */
 734                 grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 735                 grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 736                 hexdump(stderr, "Tag", c->tag, 16);
 737
 738                 current_in += GRASSHOPPER_BLOCK_SIZE - rest_len;
 739                 inl -= (GRASSHOPPER_BLOCK_SIZE - rest_len);
 740                 n += GRASSHOPPER_BLOCK_SIZE - rest_len;
 741             }
 742         }
 743
 744         while (inl >= GRASSHOPPER_BLOCK_SIZE) {
 745             currentInputBlock = (grasshopper_w128_t *) current_in;
 746
 747             grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 748                                       &h, &c->c.buffer);
 749             inc_counter(c->mgm_iv->b, 8);
 750
 751             hexdump(stderr, "Hnext", h.b, 16);
 752             hexdump(stderr, "Adata", currentInputBlock->b, 16);
 753             /* Galois multiply */
 754             gf128_mul_uint64(tmp.q, h.q, currentInputBlock->q);
 755
 756             /* XOR to c->tag */
 757             grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 758             grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 759             hexdump(stderr, "Tag", c->tag, 16);
 760
 761             current_in += GRASSHOPPER_BLOCK_SIZE;
 762             inl -= GRASSHOPPER_BLOCK_SIZE;
 763             n += GRASSHOPPER_BLOCK_SIZE;
 764         }
 765
 766         if (inl > 0) {
 767             memcpy(c->mgm_partial_buffer.b, current_in, inl);
 768             n += inl;
 769         }
 770
 771         EVP_CIPHER_CTX_set_num(ctx, n);
 772         return 1;
 773     }
 774
 775     if (out == NULL && in != NULL && inl != 0 && c->mgm_state == mgm_main_data) {
 776         GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_DO_MGM, GOST_R_BAD_ORDER);
 777         return 0;
 778     }
 779
 780     if (out != NULL && c->mgm_state == mgm_associated_data) {
 781         memset(c->mgm_partial_buffer.b + rest_len, 0,
 782                GRASSHOPPER_BLOCK_SIZE - rest_len);
 783
 784         grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 785                                   &h, &c->c.buffer);
 786         inc_counter(c->mgm_iv->b, 8);
 787
 788         hexdump(stderr, "Hnext", h.b, 16);
 789         hexdump(stderr, "Padded Adata", c->mgm_partial_buffer.b, 16);
 790         /* Galois multiply Hi * Ai */
 791         gf128_mul_uint64(tmp.q, h.q, c->mgm_partial_buffer.q);
 792
 793         /* XOR to c->tag */
 794         grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 795         grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 796         hexdump(stderr, "Tag", c->tag, 16);
 797
 798         /* We finish processing associated data */
 799         /* Pad rest of mgm_partial_buffer */
 800         /* Process last block */
 801         c->ad_length = n;
 802         n = 0;
 803         rest_len = 0;
 804         EVP_CIPHER_CTX_set_num(ctx, 0);
 805         c->mgm_state = mgm_main_data;
 806
 807         fprintf(stderr, "============= Deal with main data\n");
 808     }
 809
 810 /* ======== Here we deal with main data =========== */
 811     if (n == 0) {
 812         /* actual IV derived from nonce */
 813         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer,
 814                                   &c->partial_buffer, &c->c.buffer);
 815         memcpy(iv, c->partial_buffer.b, GRASSHOPPER_BLOCK_SIZE);
 816         //hexdump(stderr, "Y1", iv, 16);
 817     }
 818
 819     while (rest_len && inl) {
 820         *(current_out++) = *(current_in++) ^ c->partial_buffer.b[rest_len];
 821         c->partial_buffer.b[rest_len] = *(current_out - 1);
 822
 823         --inl;
 824         n++;
 825         rest_len++;
 826         if (rest_len == GRASSHOPPER_BLOCK_SIZE) {
 827             rest_len = 0;
 828             grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 829                                       &h, &c->c.buffer);
 830             inc_counter(c->mgm_iv->b, 8);
 831             hexdump(stderr, "Hnext", h.b, 16);
 832             hexdump(stderr, "Ciphertext", c->partial_buffer.b, 16);
 833             /* Galois multiply Hi * Ai */
 834             gf128_mul_uint64(tmp.q, h.q, c->partial_buffer.q);
 835
 836             /* XOR to c->tag */
 837             grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 838             grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 839             hexdump(stderr, "Tag", c->tag, 16);
 840         }
 841     }
 842
 843     // full parts
 844     for (i = 0; i < blocks; i++) {
 845         currentInputBlock = (grasshopper_w128_t *) current_in;
 846         currentOutputBlock = (grasshopper_w128_t *) current_out;
 847         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer,
 848                                   &c->partial_buffer, &c->c.buffer);
 849         grasshopper_plus128(&tmp, &c->partial_buffer, currentInputBlock);
 850         grasshopper_copy128(currentOutputBlock, &tmp);
 851         //hexdump(stderr, "Ciphertext", currentOutputBlock->b, 16);
 852
 853         grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 854                                   &h, &c->c.buffer);
 855         inc_counter(c->mgm_iv->b, 8);
 856         hexdump(stderr, "Hnext", h.b, 16);
 857         hexdump(stderr, "Ciphertext", currentOutputBlock->b, 16);
 858         /* Galois multiply Hi * Ai */
 859         gf128_mul_uint64(tmp.q, h.q, currentOutputBlock->q);
 860
 861         /* XOR to c->tag */
 862         grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 863         grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 864         hexdump(stderr, "Tag", c->tag, 16);
 865
 866         ctr128_inc(iv_buffer->b);
 867         current_in += GRASSHOPPER_BLOCK_SIZE;
 868         current_out += GRASSHOPPER_BLOCK_SIZE;
 869         n += GRASSHOPPER_BLOCK_SIZE;
 870     }
 871
 872     EVP_CIPHER_CTX_set_num(ctx, n);
 873
 874     // last part
 875     lasted = inl - blocks * GRASSHOPPER_BLOCK_SIZE;
 876     if (lasted > 0) {
 877         currentInputBlock = (grasshopper_w128_t *) current_in;
 878         currentOutputBlock = (grasshopper_w128_t *) current_out;
 879         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer,
 880                                   &c->partial_buffer, &c->c.buffer);
 881         for (i = 0; i < lasted; i++) {
 882             currentOutputBlock->b[i] =
 883                 c->partial_buffer.b[i] ^ currentInputBlock->b[i];
 884             c->partial_buffer.b[i] = currentOutputBlock->b[i];
 885         }
 886         EVP_CIPHER_CTX_set_num(ctx, n + i);
 887         ctr128_inc(iv_buffer->b);
 888     }
 889
 890     /* Final step */
 891     if (in == NULL && inl == 0) {
 892         unsigned char len_buf[16];
 893         uint64_t a_len = 0, p_len = 0;
 894
 895         if (rest_len != 0) {
 896             memset(c->partial_buffer.b + rest_len, 0,
 897                    GRASSHOPPER_BLOCK_SIZE - rest_len);
 898             grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv, &h,
 899                                       &c->c.buffer);
 900             inc_counter(c->mgm_iv->b, 8);
 901             hexdump(stderr, "Hnext", h.b, 16);
 902             hexdump(stderr, "Padded ciphertext", c->partial_buffer.b, 16);
 903             /* Galois multiply Hi * Ai */
 904             gf128_mul_uint64(tmp.q, h.q, c->partial_buffer.q);
 905
 906             /* XOR to c->tag */
 907             grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 908             grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 909             hexdump(stderr, "Tag", c->tag, 16);
 910         }
 911
 912         a_len = c->ad_length << 3;
 913         p_len = (c->mgm_state == mgm_associated_data) ? 0 : n << 3;
 914
 915 #ifdef L_ENDIAN
 916         a_len = bswap_64(a_len);
 917         p_len = bswap_64(p_len);
 918 #endif
 919         memset(len_buf, 0, 16);
 920
 921         memcpy(len_buf, &a_len, sizeof(a_len));
 922         memcpy(len_buf + sizeof(a_len), &p_len, sizeof(p_len));
 923         grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 924                                   &h, &c->c.buffer);
 925
 926         hexdump(stderr, "Hlast", h.b, 16);
 927         hexdump(stderr, "Lenbuf", len_buf, 16);
 928         /* Galois multiply Hi * Ai */
 929         gf128_mul_uint64(tmp.q, h.q, (uint64_t *)len_buf);
 930
 931         /* XOR to c->tag */
 932         grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 933         grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 934         hexdump(stderr, "Tag", c->tag, 16);
 935
 936         /* Final tag calculation */
 937         grasshopper_encrypt_block(&c->c.encrypt_round_keys,
 938                                   (grasshopper_w128_t *) c->tag,
 939                                   (grasshopper_w128_t *) c->final_tag,
 940                                   &c->c.buffer);
 941     }
 942
 943     return 1;
 944 }
 945
 946 /*
 947  * Fixed 128-bit IV implementation make shift regiser redundant.
 948  */
 949 static void gost_grasshopper_cnt_next(gost_grasshopper_cipher_ctx_ofb * ctx,
 950                                       grasshopper_w128_t * iv,
 951                                       grasshopper_w128_t * buf)
 952 {
 953     memcpy(&ctx->buffer1, iv, 16);
 954     grasshopper_encrypt_block(&ctx->c.encrypt_round_keys, &ctx->buffer1,
 955                               buf, &ctx->c.buffer);
 956     memcpy(iv, buf, 16);
 957 }
 958
 959 int gost_grasshopper_cipher_do_ofb(EVP_CIPHER_CTX *ctx, unsigned char *out,
 960                                    const unsigned char *in, size_t inl)
 961 {
 962     gost_grasshopper_cipher_ctx_ofb *c = (gost_grasshopper_cipher_ctx_ofb *)
 963         EVP_CIPHER_CTX_get_cipher_data(ctx);
 964     const unsigned char *in_ptr = in;
 965     unsigned char *out_ptr = out;
 966     unsigned char *buf = EVP_CIPHER_CTX_buf_noconst(ctx);
 967     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 968     int num = EVP_CIPHER_CTX_num(ctx);
 969     size_t i = 0;
 970     size_t j;
 971
 972     /* process partial block if any */
 973     if (num > 0) {
 974         for (j = (size_t)num, i = 0; j < GRASSHOPPER_BLOCK_SIZE && i < inl;
 975              j++, i++, in_ptr++, out_ptr++) {
 976             *out_ptr = buf[j] ^ (*in_ptr);
 977         }
 978         if (j == GRASSHOPPER_BLOCK_SIZE) {
 979             EVP_CIPHER_CTX_set_num(ctx, 0);
 980         } else {
 981             EVP_CIPHER_CTX_set_num(ctx, (int)j);
 982             return 1;
 983         }
 984     }
 985
 986     for (; i + GRASSHOPPER_BLOCK_SIZE <
 987          inl;
 988          i += GRASSHOPPER_BLOCK_SIZE, in_ptr +=
 989          GRASSHOPPER_BLOCK_SIZE, out_ptr += GRASSHOPPER_BLOCK_SIZE) {
 990         /*
 991          * block cipher current iv
 992          */
 993         /* Encrypt */
 994         gost_grasshopper_cnt_next(c, (grasshopper_w128_t *) iv,
 995                                   (grasshopper_w128_t *) buf);
 996
 997         /*
 998          * xor next block of input text with it and output it
 999          */
1000         /*
1001          * output this block
1002          */
1003         for (j = 0; j < GRASSHOPPER_BLOCK_SIZE; j++) {
1004             out_ptr[j] = buf[j] ^ in_ptr[j];
1005         }
1006     }
1007
1008     /* Process rest of buffer */
1009     if (i < inl) {
1010         gost_grasshopper_cnt_next(c, (grasshopper_w128_t *) iv,
1011                                   (grasshopper_w128_t *) buf);
1012         for (j = 0; i < inl; j++, i++) {
1013             out_ptr[j] = buf[j] ^ in_ptr[j];
1014         }
1015         EVP_CIPHER_CTX_set_num(ctx, (int)j);
1016     } else {
1017         EVP_CIPHER_CTX_set_num(ctx, 0);
1018     }
1019
1020     return 1;
1021 }
1022
1023 int gost_grasshopper_cipher_do_cfb(EVP_CIPHER_CTX *ctx, unsigned char *out,
1024                                    const unsigned char *in, size_t inl)
1025 {
1026     gost_grasshopper_cipher_ctx *c =
1027         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
1028     const unsigned char *in_ptr = in;
1029     unsigned char *out_ptr = out;
1030     unsigned char *buf = EVP_CIPHER_CTX_buf_noconst(ctx);
1031     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
1032     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
1033     int num = EVP_CIPHER_CTX_num(ctx);
1034     size_t i = 0;
1035     size_t j = 0;
1036
1037     /* process partial block if any */
1038     if (num > 0) {
1039         for (j = (size_t)num, i = 0; j < GRASSHOPPER_BLOCK_SIZE && i < inl;
1040              j++, i++, in_ptr++, out_ptr++) {
1041             if (!encrypting) {
1042                 buf[j + GRASSHOPPER_BLOCK_SIZE] = *in_ptr;
1043             }
1044             *out_ptr = buf[j] ^ (*in_ptr);
1045             if (encrypting) {
1046                 buf[j + GRASSHOPPER_BLOCK_SIZE] = *out_ptr;
1047             }
1048         }
1049         if (j == GRASSHOPPER_BLOCK_SIZE) {
1050             memcpy(iv, buf + GRASSHOPPER_BLOCK_SIZE, GRASSHOPPER_BLOCK_SIZE);
1051             EVP_CIPHER_CTX_set_num(ctx, 0);
1052         } else {
1053             EVP_CIPHER_CTX_set_num(ctx, (int)j);
1054             return 1;
1055         }
1056     }
1057
1058     for (; i + GRASSHOPPER_BLOCK_SIZE <
1059          inl;
1060          i += GRASSHOPPER_BLOCK_SIZE, in_ptr +=
1061          GRASSHOPPER_BLOCK_SIZE, out_ptr += GRASSHOPPER_BLOCK_SIZE) {
1062         /*
1063          * block cipher current iv
1064          */
1065         grasshopper_encrypt_block(&c->encrypt_round_keys,
1066                                   (grasshopper_w128_t *) iv,
1067                                   (grasshopper_w128_t *) buf, &c->buffer);
1068         /*
1069          * xor next block of input text with it and output it
1070          */
1071         /*
1072          * output this block
1073          */
1074         if (!encrypting) {
1075             memcpy(iv, in_ptr, GRASSHOPPER_BLOCK_SIZE);
1076         }
1077         for (j = 0; j < GRASSHOPPER_BLOCK_SIZE; j++) {
1078             out_ptr[j] = buf[j] ^ in_ptr[j];
1079         }
1080         /* Encrypt */
1081         /* Next iv is next block of cipher text */
1082         if (encrypting) {
1083             memcpy(iv, out_ptr, GRASSHOPPER_BLOCK_SIZE);
1084         }
1085     }
1086
1087     /* Process rest of buffer */
1088     if (i < inl) {
1089         grasshopper_encrypt_block(&c->encrypt_round_keys,
1090                                   (grasshopper_w128_t *) iv,
1091                                   (grasshopper_w128_t *) buf, &c->buffer);
1092         if (!encrypting) {
1093             memcpy(buf + GRASSHOPPER_BLOCK_SIZE, in_ptr, inl - i);
1094         }
1095         for (j = 0; i < inl; j++, i++) {
1096             out_ptr[j] = buf[j] ^ in_ptr[j];
1097         }
1098         EVP_CIPHER_CTX_set_num(ctx, (int)j);
1099         if (encrypting) {
1100             memcpy(buf + GRASSHOPPER_BLOCK_SIZE, out_ptr, j);
1101         }
1102     } else {
1103         EVP_CIPHER_CTX_set_num(ctx, 0);
1104     }
1105
1106     return 1;
1107 }
1108
1109 int gost_grasshopper_cipher_cleanup(EVP_CIPHER_CTX *ctx)
1110 {
1111     gost_grasshopper_cipher_ctx *c =
1112         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
1113
1114     if (!c)
1115         return 1;
1116
1117     struct GRASSHOPPER_CIPHER_PARAMS *params = &gost_cipher_params[c->type];
1118
1119     gost_grasshopper_cipher_destroy(c);
1120     if (params->destroy_cipher != NULL) {
1121         params->destroy_cipher(c);
1122     }
1123
1124     EVP_CIPHER_CTX_set_app_data(ctx, NULL);
1125
1126     return 1;
1127 }
1128
1129 int gost_grasshopper_set_asn1_parameters(EVP_CIPHER_CTX *ctx, ASN1_TYPE *params)
1130 {
1131     int len = 0;
1132     unsigned char *buf = NULL;
1133     ASN1_OCTET_STRING *os = NULL;
1134
1135     os = ASN1_OCTET_STRING_new();
1136
1137     if (!os || !ASN1_OCTET_STRING_set(os, buf, len)) {
1138         OPENSSL_free(buf);
1139         GOSTerr(GOST_F_GOST_GRASSHOPPER_SET_ASN1_PARAMETERS,
1140                 ERR_R_MALLOC_FAILURE);
1141         return 0;
1142     }
1143     OPENSSL_free(buf);
1144
1145     ASN1_TYPE_set(params, V_ASN1_SEQUENCE, os);
1146     return 1;
1147 }
1148
1149 GRASSHOPPER_INLINE int gost_grasshopper_get_asn1_parameters(EVP_CIPHER_CTX
1150                                                             *ctx, ASN1_TYPE
1151                                                             *params)
1152 {
1153     int ret = -1;
1154
1155     if (ASN1_TYPE_get(params) != V_ASN1_SEQUENCE) {
1156         return ret;
1157     }
1158
1159     return 1;
1160 }
1161
1162 int gost_grasshopper_cipher_ctl(EVP_CIPHER_CTX *ctx, int type, int arg,
1163                                 void *ptr)
1164 {
1165     switch (type) {
1166     case EVP_CTRL_RAND_KEY:{
1167             if (RAND_bytes
1168                 ((unsigned char *)ptr, EVP_CIPHER_CTX_key_length(ctx)) <= 0) {
1169                 GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL, GOST_R_RNG_ERROR);
1170                 return -1;
1171             }
1172             break;
1173         }
1174     case EVP_CTRL_KEY_MESH:{
1175             gost_grasshopper_cipher_ctx_ctr *c =
1176                 EVP_CIPHER_CTX_get_cipher_data(ctx);
1177             if (c->c.type != GRASSHOPPER_CIPHER_CTRACPKM || !arg
1178                 || (arg % GRASSHOPPER_BLOCK_SIZE))
1179                 return -1;
1180             c->section_size = arg;
1181             break;
1182         }
1183 #ifdef EVP_CTRL_TLS1_2_TLSTREE
1184     case EVP_CTRL_TLS1_2_TLSTREE:
1185         {
1186             unsigned char newkey[32];
1187             int mode = EVP_CIPHER_CTX_mode(ctx);
1188             static const unsigned char zeroseq[8];
1189             gost_grasshopper_cipher_ctx_ctr *ctr_ctx = NULL;
1190             gost_grasshopper_cipher_ctx *c = NULL;
1191
1192             unsigned char adjusted_iv[16];
1193             unsigned char seq[8];
1194             int j;
1195             if (mode != EVP_CIPH_CTR_MODE)
1196                 return -1;
1197
1198             ctr_ctx = (gost_grasshopper_cipher_ctx_ctr *)
1199                 EVP_CIPHER_CTX_get_cipher_data(ctx);
1200             c = &(ctr_ctx->c);
1201
1202             memcpy(seq, ptr, 8);
1203             if (EVP_CIPHER_CTX_encrypting(ctx)) {
1204                 /*
1205                  * OpenSSL increments seq after mac calculation.
1206                  * As we have Mac-Then-Encrypt, we need decrement it here on encryption
1207                  * to derive the key correctly.
1208                  * */
1209                 if (memcmp(seq, zeroseq, 8) != 0) {
1210                     for (j = 7; j >= 0; j--) {
1211                         if (seq[j] != 0) {
1212                             seq[j]--;
1213                             break;
1214                         } else
1215                             seq[j] = 0xFF;
1216                     }
1217                 }
1218             }
1219             if (gost_tlstree(NID_grasshopper_cbc, c->master_key.k.b, newkey,
1220                              (const unsigned char *)seq) > 0) {
1221                 memset(adjusted_iv, 0, 16);
1222                 memcpy(adjusted_iv, EVP_CIPHER_CTX_original_iv(ctx), 8);
1223                 for (j = 7; j >= 0; j--) {
1224                     int adj_byte, carry = 0;
1225                     adj_byte = adjusted_iv[j] + seq[j] + carry;
1226                     carry = (adj_byte > 255) ? 1 : 0;
1227                     adjusted_iv[j] = adj_byte & 0xFF;
1228                 }
1229                 EVP_CIPHER_CTX_set_num(ctx, 0);
1230                 memcpy(EVP_CIPHER_CTX_iv_noconst(ctx), adjusted_iv, 16);
1231
1232                 gost_grasshopper_cipher_key(c, newkey);
1233                 return 1;
1234             }
1235         }
1236         return -1;
1237 #endif
1238     case EVP_CTRL_AEAD_GET_TAG:
1239     case EVP_CTRL_AEAD_SET_TAG:
1240         {
1241             gost_grasshopper_cipher_ctx_mgm *mgm_ctx = NULL;
1242             gost_grasshopper_cipher_ctx *c = NULL;
1243             int taglen = arg;
1244             unsigned char *tag = ptr;
1245
1246             mgm_ctx = (gost_grasshopper_cipher_ctx_mgm *)
1247                 EVP_CIPHER_CTX_get_cipher_data(ctx);
1248             c = (gost_grasshopper_cipher_ctx *) mgm_ctx;
1249
1250             if (c->type != GRASSHOPPER_CIPHER_MGM)
1251                 return -1;
1252
1253             if (taglen > 16) {
1254                 GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL,
1255                         GOST_R_INVALID_TAG_LENGTH);
1256                 return -1;
1257             }
1258
1259             if (type == EVP_CTRL_AEAD_GET_TAG)
1260                 memcpy(tag, mgm_ctx->final_tag, taglen);
1261             else
1262                 memcpy(mgm_ctx->final_tag, tag, taglen);
1263
1264             return 1;
1265         }
1266     default:
1267         GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL,
1268                 GOST_R_UNSUPPORTED_CIPHER_CTL_COMMAND);
1269         return -1;
1270     }
1271     return 1;
1272 }
1273
1274 GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_create(int
1275                                                               cipher_type, int
1276                                                               block_size)
1277 {
1278     return EVP_CIPHER_meth_new(cipher_type, block_size /* block_size */ ,
1279                                GRASSHOPPER_KEY_SIZE /* key_size */ );
1280 }
1281
1282 const int cipher_gost_grasshopper_setup(EVP_CIPHER *cipher, uint8_t mode,
1283                                         int iv_size, bool padding,
1284                                         int extra_flags)
1285 {
1286     return EVP_CIPHER_meth_set_iv_length(cipher, iv_size)
1287         && EVP_CIPHER_meth_set_flags(cipher,
1288                                      (unsigned long)(mode |
1289                                                      ((!padding) ?
1290                                                       EVP_CIPH_NO_PADDING :
1291                                                       0) | ((iv_size >
1292                                                              0) ?
1293                                                             EVP_CIPH_CUSTOM_IV
1294                                                             : 0) |
1295                                                      EVP_CIPH_RAND_KEY |
1296                                                      EVP_CIPH_ALWAYS_CALL_INIT |
1297                                                      extra_flags)
1298         )
1299         && EVP_CIPHER_meth_set_cleanup(cipher, gost_grasshopper_cipher_cleanup)
1300         && EVP_CIPHER_meth_set_set_asn1_params(cipher,
1301                                                gost_grasshopper_set_asn1_parameters)
1302         && EVP_CIPHER_meth_set_get_asn1_params(cipher,
1303                                                gost_grasshopper_get_asn1_parameters)
1304         && EVP_CIPHER_meth_set_ctrl(cipher, gost_grasshopper_cipher_ctl)
1305         && EVP_CIPHER_meth_set_do_cipher(cipher, gost_grasshopper_cipher_do);
1306 }
1307
1308 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper(uint8_t mode,
1309                                                              uint8_t num)
1310 {
1311     EVP_CIPHER **cipher;
1312     struct GRASSHOPPER_CIPHER_PARAMS *params;
1313
1314     cipher = &gost_grasshopper_ciphers[num];
1315
1316     if (*cipher == NULL) {
1317         params = &gost_cipher_params[num];
1318
1319         int nid = params->nid;
1320         grasshopper_init_cipher_func init_cipher = params->init_cipher;
1321         int block_size = params->block_size;
1322         int ctx_size = params->ctx_size;
1323         int iv_size = params->iv_size;
1324         bool padding = params->padding;
1325
1326         int extra_flags = (num == GRASSHOPPER_CIPHER_MGM) ?
1327             EVP_CIPH_FLAG_CUSTOM_CIPHER | EVP_CIPH_FLAG_AEAD_CIPHER : 0;
1328
1329         *cipher = cipher_gost_grasshopper_create(nid, block_size);
1330         if (*cipher == NULL) {
1331             return NULL;
1332         }
1333
1334         if (!cipher_gost_grasshopper_setup
1335             (*cipher, mode, iv_size, padding, extra_flags)
1336             || !EVP_CIPHER_meth_set_init(*cipher, init_cipher)
1337             || !EVP_CIPHER_meth_set_impl_ctx_size(*cipher, ctx_size)) {
1338             EVP_CIPHER_meth_free(*cipher);
1339             *cipher = NULL;
1340         }
1341     }
1342
1343     return *cipher;
1344 }
1345
1346 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ecb()
1347 {
1348     return cipher_gost_grasshopper(EVP_CIPH_ECB_MODE, GRASSHOPPER_CIPHER_ECB);
1349 }
1350
1351 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_cbc()
1352 {
1353     return cipher_gost_grasshopper(EVP_CIPH_CBC_MODE, GRASSHOPPER_CIPHER_CBC);
1354 }
1355
1356 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ofb()
1357 {
1358     return cipher_gost_grasshopper(EVP_CIPH_OFB_MODE, GRASSHOPPER_CIPHER_OFB);
1359 }
1360
1361 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_cfb()
1362 {
1363     return cipher_gost_grasshopper(EVP_CIPH_CFB_MODE, GRASSHOPPER_CIPHER_CFB);
1364 }
1365
1366 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ctr()
1367 {
1368     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE, GRASSHOPPER_CIPHER_CTR);
1369 }
1370
1371 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ctracpkm()
1372 {
1373     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE,
1374                                    GRASSHOPPER_CIPHER_CTRACPKM);
1375 }
1376
1377 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_mgm()
1378 {
1379 #ifndef NID_kuznyechik_mgm
1380     return NULL;
1381 #else
1382     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE, GRASSHOPPER_CIPHER_MGM);
1383 #endif
1384 }
1385
1386 void cipher_gost_grasshopper_destroy(void)
1387 {
1388     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_ECB]);
1389     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_ECB] = NULL;
1390     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CBC]);
1391     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CBC] = NULL;
1392     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_OFB]);
1393     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_OFB] = NULL;
1394     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CFB]);
1395     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CFB] = NULL;
1396     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTR]);
1397     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTR] = NULL;
1398     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKM]);
1399     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKM] = NULL;
1400     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_MGM]);
1401     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_MGM] = NULL;
1402 }