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     int encrypting = EVP_CIPHER_CTX_encrypting(ctx);
 704
 705 /* ======== Here we deal with associated data =========== */
 706     if (out == NULL && c->mgm_state == mgm_associated_data) {
 707         if (n == 0) {
 708             grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 709                                       &c->partial_buffer, &c->c.buffer);
 710             memcpy(c->mgm_iv, &c->partial_buffer, GRASSHOPPER_BLOCK_SIZE);
 711             hexdump(stderr, "Tag", c->tag, 16);
 712         }
 713
 714         if (rest_len != 0) {
 715             /* Finalize partial_data */
 716             if (inl + rest_len < GRASSHOPPER_BLOCK_SIZE) {
 717                 memcpy(c->mgm_partial_buffer.b + rest_len, current_in, inl);
 718                 n += inl;
 719                 EVP_CIPHER_CTX_set_num(ctx, n);
 720                 return 1;
 721             } else {
 722                 memcpy(c->mgm_partial_buffer.b + rest_len, current_in,
 723                        GRASSHOPPER_BLOCK_SIZE - rest_len);
 724
 725                 grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 726                                           &h, &c->c.buffer);
 727                 inc_counter(c->mgm_iv->b, 8);
 728
 729                 hexdump(stderr, "Hnext", h.b, 16);
 730                 hexdump(stderr, "Adata", c->mgm_partial_buffer.b, 16);
 731                 /* Galois multiply Hi * Ai */
 732                 gf128_mul_uint64(tmp.q, h.q, c->mgm_partial_buffer.q);
 733
 734                 /* XOR to c->tag */
 735                 grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 736                 grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 737                 hexdump(stderr, "Tag", c->tag, 16);
 738
 739                 current_in += GRASSHOPPER_BLOCK_SIZE - rest_len;
 740                 inl -= (GRASSHOPPER_BLOCK_SIZE - rest_len);
 741                 n += GRASSHOPPER_BLOCK_SIZE - rest_len;
 742             }
 743         }
 744
 745         while (inl >= GRASSHOPPER_BLOCK_SIZE) {
 746             currentInputBlock = (grasshopper_w128_t *) current_in;
 747
 748             grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 749                                       &h, &c->c.buffer);
 750             inc_counter(c->mgm_iv->b, 8);
 751
 752             hexdump(stderr, "Hnext", h.b, 16);
 753             hexdump(stderr, "Adata", currentInputBlock->b, 16);
 754             /* Galois multiply */
 755             gf128_mul_uint64(tmp.q, h.q, currentInputBlock->q);
 756
 757             /* XOR to c->tag */
 758             grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 759             grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 760             hexdump(stderr, "Tag", c->tag, 16);
 761
 762             current_in += GRASSHOPPER_BLOCK_SIZE;
 763             inl -= GRASSHOPPER_BLOCK_SIZE;
 764             n += GRASSHOPPER_BLOCK_SIZE;
 765         }
 766
 767         if (inl > 0) {
 768             memcpy(c->mgm_partial_buffer.b, current_in, inl);
 769             n += inl;
 770         }
 771
 772         EVP_CIPHER_CTX_set_num(ctx, n);
 773         return 1;
 774     }
 775
 776     if (out == NULL && in != NULL && inl != 0 && c->mgm_state == mgm_main_data) {
 777         GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_DO_MGM, GOST_R_BAD_ORDER);
 778         return 0;
 779     }
 780
 781     if (out != NULL && c->mgm_state == mgm_associated_data) {
 782         memset(c->mgm_partial_buffer.b + rest_len, 0,
 783                GRASSHOPPER_BLOCK_SIZE - rest_len);
 784
 785         grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 786                                   &h, &c->c.buffer);
 787         inc_counter(c->mgm_iv->b, 8);
 788
 789         hexdump(stderr, "Hnext", h.b, 16);
 790         hexdump(stderr, "Padded Adata", c->mgm_partial_buffer.b, 16);
 791         /* Galois multiply Hi * Ai */
 792         gf128_mul_uint64(tmp.q, h.q, c->mgm_partial_buffer.q);
 793
 794         /* XOR to c->tag */
 795         grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 796         grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 797         hexdump(stderr, "Tag", c->tag, 16);
 798
 799         /* We finish processing associated data */
 800         /* Pad rest of mgm_partial_buffer */
 801         /* Process last block */
 802         c->ad_length = n;
 803         n = 0;
 804         rest_len = 0;
 805         EVP_CIPHER_CTX_set_num(ctx, 0);
 806         c->mgm_state = mgm_main_data;
 807
 808         fprintf(stderr, "============= Deal with main data\n");
 809     }
 810
 811 /* ======== Here we deal with main data =========== */
 812     if (n == 0) {
 813         /* actual IV derived from nonce */
 814         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer,
 815                                   &c->partial_buffer, &c->c.buffer);
 816         memcpy(iv, c->partial_buffer.b, GRASSHOPPER_BLOCK_SIZE);
 817         //hexdump(stderr, "Y1", iv, 16);
 818     }
 819
 820     while (rest_len && inl) {
 821         *(current_out++) = *(current_in++) ^ c->partial_buffer.b[rest_len];
 822
 823         if (encrypting)
 824             c->partial_buffer.b[rest_len] = *(current_out - 1);
 825         else
 826             c->partial_buffer.b[rest_len] = *(current_in - 1);
 827
 828         --inl;
 829         n++;
 830         rest_len++;
 831         if (rest_len == GRASSHOPPER_BLOCK_SIZE) {
 832             rest_len = 0;
 833             grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 834                                       &h, &c->c.buffer);
 835             inc_counter(c->mgm_iv->b, 8);
 836             hexdump(stderr, "Hnext", h.b, 16);
 837             hexdump(stderr, "Ciphertext", c->partial_buffer.b, 16);
 838             /* Galois multiply Hi * Ai */
 839             gf128_mul_uint64(tmp.q, h.q, c->partial_buffer.q);
 840
 841             /* XOR to c->tag */
 842             grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 843             grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 844             hexdump(stderr, "Tag", c->tag, 16);
 845         }
 846     }
 847
 848     // full parts
 849     for (i = 0; i < blocks; i++) {
 850         grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 851                                   &h, &c->c.buffer);
 852         inc_counter(c->mgm_iv->b, 8);
 853
 854         currentInputBlock = (grasshopper_w128_t *) current_in;
 855         currentOutputBlock = (grasshopper_w128_t *) current_out;
 856         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer,
 857                                   &c->partial_buffer, &c->c.buffer);
 858         grasshopper_plus128(&tmp, &c->partial_buffer, currentInputBlock);
 859
 860         if (encrypting) {
 861             grasshopper_copy128(currentOutputBlock, &tmp);
 862
 863             hexdump(stderr, "Hnext", h.b, 16);
 864             hexdump(stderr, "Ciphertext", currentOutputBlock->b, 16);
 865             /* Galois multiply Hi * Ai */
 866             gf128_mul_uint64(tmp.q, h.q, currentOutputBlock->q);
 867
 868             /* XOR to c->tag */
 869             grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 870             grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 871             hexdump(stderr, "Tag", c->tag, 16);
 872         } else {
 873             grasshopper_w128_t tmpin;
 874             grasshopper_copy128(&tmpin, currentInputBlock);
 875             grasshopper_copy128(currentOutputBlock, &tmp);
 876
 877             hexdump(stderr, "Hnext", h.b, 16);
 878             hexdump(stderr, "Ciphertext", tmpin.b, 16);
 879             /* Galois multiply Hi * Ai */
 880             gf128_mul_uint64(tmp.q, h.q, tmpin.q);
 881
 882             /* XOR to c->tag */
 883             grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 884             grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 885             hexdump(stderr, "Tag", c->tag, 16);
 886         }
 887
 888         ctr128_inc(iv_buffer->b);
 889         current_in += GRASSHOPPER_BLOCK_SIZE;
 890         current_out += GRASSHOPPER_BLOCK_SIZE;
 891         n += GRASSHOPPER_BLOCK_SIZE;
 892     }
 893
 894     EVP_CIPHER_CTX_set_num(ctx, n);
 895
 896     // last part
 897     lasted = inl - blocks * GRASSHOPPER_BLOCK_SIZE;
 898     if (lasted > 0) {
 899         currentInputBlock = (grasshopper_w128_t *) current_in;
 900         currentOutputBlock = (grasshopper_w128_t *) current_out;
 901         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer,
 902                                   &c->partial_buffer, &c->c.buffer);
 903         for (i = 0; i < lasted; i++) {
 904             if (encrypting) {
 905                 currentOutputBlock->b[i] =
 906                     c->partial_buffer.b[i] ^ currentInputBlock->b[i];
 907                 c->partial_buffer.b[i] = currentOutputBlock->b[i];
 908             } else {
 909                 unsigned char in = currentInputBlock->b[i];
 910                 currentOutputBlock->b[i] =
 911                     c->partial_buffer.b[i] ^ currentInputBlock->b[i];
 912                 c->partial_buffer.b[i] = in;
 913             }
 914         }
 915         EVP_CIPHER_CTX_set_num(ctx, n + i);
 916         ctr128_inc(iv_buffer->b);
 917     }
 918
 919     /* Final step */
 920     if (in == NULL && inl == 0) {
 921         unsigned char len_buf[16];
 922         uint64_t a_len = 0, p_len = 0;
 923
 924         if (rest_len != 0) {
 925             memset(c->partial_buffer.b + rest_len, 0,
 926                    GRASSHOPPER_BLOCK_SIZE - rest_len);
 927             grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv, &h,
 928                                       &c->c.buffer);
 929             inc_counter(c->mgm_iv->b, 8);
 930             hexdump(stderr, "Hnext", h.b, 16);
 931             hexdump(stderr, "Padded ciphertext", c->partial_buffer.b, 16);
 932             /* Galois multiply Hi * Ai */
 933             gf128_mul_uint64(tmp.q, h.q, c->partial_buffer.q);
 934
 935             /* XOR to c->tag */
 936             grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 937             grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 938             hexdump(stderr, "Tag", c->tag, 16);
 939         }
 940
 941         a_len = c->ad_length << 3;
 942         p_len = (c->mgm_state == mgm_associated_data) ? 0 : n << 3;
 943
 944 #ifdef L_ENDIAN
 945         a_len = bswap_64(a_len);
 946         p_len = bswap_64(p_len);
 947 #endif
 948         memset(len_buf, 0, 16);
 949
 950         memcpy(len_buf, &a_len, sizeof(a_len));
 951         memcpy(len_buf + sizeof(a_len), &p_len, sizeof(p_len));
 952         grasshopper_encrypt_block(&c->c.encrypt_round_keys, c->mgm_iv,
 953                                   &h, &c->c.buffer);
 954
 955         hexdump(stderr, "Hlast", h.b, 16);
 956         hexdump(stderr, "Lenbuf", len_buf, 16);
 957         /* Galois multiply Hi * Ai */
 958         gf128_mul_uint64(tmp.q, h.q, (uint64_t *)len_buf);
 959
 960         /* XOR to c->tag */
 961         grasshopper_plus128(&h, (grasshopper_w128_t *) c->tag, &tmp);
 962         grasshopper_copy128((grasshopper_w128_t *) c->tag, &h);
 963         hexdump(stderr, "Tag", c->tag, 16);
 964
 965         /* Final tag calculation */
 966         if (encrypting) {
 967             grasshopper_encrypt_block(&c->c.encrypt_round_keys,
 968                                       (grasshopper_w128_t *) c->tag,
 969                                       (grasshopper_w128_t *) c->final_tag,
 970                                       &c->c.buffer);
 971             return 1;
 972         } else {
 973             grasshopper_w128_t decrypt_tag;
 974             grasshopper_encrypt_block(&c->c.encrypt_round_keys,
 975                                       (grasshopper_w128_t *) c->tag,
 976                                       &decrypt_tag, &c->c.buffer);
 977             if (memcmp(decrypt_tag.b, c->final_tag, 16)) {
 978                 hexdump(stderr, "Bad final tag", decrypt_tag.b, 16);
 979                 return 0;
 980             } else
 981                 return 1;
 982         }
 983     }
 984
 985     return 1;
 986 }
 987
 988 /*
 989  * Fixed 128-bit IV implementation make shift regiser redundant.
 990  */
 991 static void gost_grasshopper_cnt_next(gost_grasshopper_cipher_ctx_ofb * ctx,
 992                                       grasshopper_w128_t * iv,
 993                                       grasshopper_w128_t * buf)
 994 {
 995     memcpy(&ctx->buffer1, iv, 16);
 996     grasshopper_encrypt_block(&ctx->c.encrypt_round_keys, &ctx->buffer1,
 997                               buf, &ctx->c.buffer);
 998     memcpy(iv, buf, 16);
 999 }
1000
1001 int gost_grasshopper_cipher_do_ofb(EVP_CIPHER_CTX *ctx, unsigned char *out,
1002                                    const unsigned char *in, size_t inl)
1003 {
1004     gost_grasshopper_cipher_ctx_ofb *c = (gost_grasshopper_cipher_ctx_ofb *)
1005         EVP_CIPHER_CTX_get_cipher_data(ctx);
1006     const unsigned char *in_ptr = in;
1007     unsigned char *out_ptr = out;
1008     unsigned char *buf = EVP_CIPHER_CTX_buf_noconst(ctx);
1009     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
1010     int num = EVP_CIPHER_CTX_num(ctx);
1011     size_t i = 0;
1012     size_t j;
1013
1014     /* process partial block if any */
1015     if (num > 0) {
1016         for (j = (size_t)num, i = 0; j < GRASSHOPPER_BLOCK_SIZE && i < inl;
1017              j++, i++, in_ptr++, out_ptr++) {
1018             *out_ptr = buf[j] ^ (*in_ptr);
1019         }
1020         if (j == GRASSHOPPER_BLOCK_SIZE) {
1021             EVP_CIPHER_CTX_set_num(ctx, 0);
1022         } else {
1023             EVP_CIPHER_CTX_set_num(ctx, (int)j);
1024             return 1;
1025         }
1026     }
1027
1028     for (; i + GRASSHOPPER_BLOCK_SIZE <
1029          inl;
1030          i += GRASSHOPPER_BLOCK_SIZE, in_ptr +=
1031          GRASSHOPPER_BLOCK_SIZE, out_ptr += GRASSHOPPER_BLOCK_SIZE) {
1032         /*
1033          * block cipher current iv
1034          */
1035         /* Encrypt */
1036         gost_grasshopper_cnt_next(c, (grasshopper_w128_t *) iv,
1037                                   (grasshopper_w128_t *) buf);
1038
1039         /*
1040          * xor next block of input text with it and output it
1041          */
1042         /*
1043          * output this block
1044          */
1045         for (j = 0; j < GRASSHOPPER_BLOCK_SIZE; j++) {
1046             out_ptr[j] = buf[j] ^ in_ptr[j];
1047         }
1048     }
1049
1050     /* Process rest of buffer */
1051     if (i < inl) {
1052         gost_grasshopper_cnt_next(c, (grasshopper_w128_t *) iv,
1053                                   (grasshopper_w128_t *) buf);
1054         for (j = 0; i < inl; j++, i++) {
1055             out_ptr[j] = buf[j] ^ in_ptr[j];
1056         }
1057         EVP_CIPHER_CTX_set_num(ctx, (int)j);
1058     } else {
1059         EVP_CIPHER_CTX_set_num(ctx, 0);
1060     }
1061
1062     return 1;
1063 }
1064
1065 int gost_grasshopper_cipher_do_cfb(EVP_CIPHER_CTX *ctx, unsigned char *out,
1066                                    const unsigned char *in, size_t inl)
1067 {
1068     gost_grasshopper_cipher_ctx *c =
1069         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
1070     const unsigned char *in_ptr = in;
1071     unsigned char *out_ptr = out;
1072     unsigned char *buf = EVP_CIPHER_CTX_buf_noconst(ctx);
1073     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
1074     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
1075     int num = EVP_CIPHER_CTX_num(ctx);
1076     size_t i = 0;
1077     size_t j = 0;
1078
1079     /* process partial block if any */
1080     if (num > 0) {
1081         for (j = (size_t)num, i = 0; j < GRASSHOPPER_BLOCK_SIZE && i < inl;
1082              j++, i++, in_ptr++, out_ptr++) {
1083             if (!encrypting) {
1084                 buf[j + GRASSHOPPER_BLOCK_SIZE] = *in_ptr;
1085             }
1086             *out_ptr = buf[j] ^ (*in_ptr);
1087             if (encrypting) {
1088                 buf[j + GRASSHOPPER_BLOCK_SIZE] = *out_ptr;
1089             }
1090         }
1091         if (j == GRASSHOPPER_BLOCK_SIZE) {
1092             memcpy(iv, buf + GRASSHOPPER_BLOCK_SIZE, GRASSHOPPER_BLOCK_SIZE);
1093             EVP_CIPHER_CTX_set_num(ctx, 0);
1094         } else {
1095             EVP_CIPHER_CTX_set_num(ctx, (int)j);
1096             return 1;
1097         }
1098     }
1099
1100     for (; i + GRASSHOPPER_BLOCK_SIZE <
1101          inl;
1102          i += GRASSHOPPER_BLOCK_SIZE, in_ptr +=
1103          GRASSHOPPER_BLOCK_SIZE, out_ptr += GRASSHOPPER_BLOCK_SIZE) {
1104         /*
1105          * block cipher current iv
1106          */
1107         grasshopper_encrypt_block(&c->encrypt_round_keys,
1108                                   (grasshopper_w128_t *) iv,
1109                                   (grasshopper_w128_t *) buf, &c->buffer);
1110         /*
1111          * xor next block of input text with it and output it
1112          */
1113         /*
1114          * output this block
1115          */
1116         if (!encrypting) {
1117             memcpy(iv, in_ptr, GRASSHOPPER_BLOCK_SIZE);
1118         }
1119         for (j = 0; j < GRASSHOPPER_BLOCK_SIZE; j++) {
1120             out_ptr[j] = buf[j] ^ in_ptr[j];
1121         }
1122         /* Encrypt */
1123         /* Next iv is next block of cipher text */
1124         if (encrypting) {
1125             memcpy(iv, out_ptr, GRASSHOPPER_BLOCK_SIZE);
1126         }
1127     }
1128
1129     /* Process rest of buffer */
1130     if (i < inl) {
1131         grasshopper_encrypt_block(&c->encrypt_round_keys,
1132                                   (grasshopper_w128_t *) iv,
1133                                   (grasshopper_w128_t *) buf, &c->buffer);
1134         if (!encrypting) {
1135             memcpy(buf + GRASSHOPPER_BLOCK_SIZE, in_ptr, inl - i);
1136         }
1137         for (j = 0; i < inl; j++, i++) {
1138             out_ptr[j] = buf[j] ^ in_ptr[j];
1139         }
1140         EVP_CIPHER_CTX_set_num(ctx, (int)j);
1141         if (encrypting) {
1142             memcpy(buf + GRASSHOPPER_BLOCK_SIZE, out_ptr, j);
1143         }
1144     } else {
1145         EVP_CIPHER_CTX_set_num(ctx, 0);
1146     }
1147
1148     return 1;
1149 }
1150
1151 int gost_grasshopper_cipher_cleanup(EVP_CIPHER_CTX *ctx)
1152 {
1153     gost_grasshopper_cipher_ctx *c =
1154         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
1155
1156     if (!c)
1157         return 1;
1158
1159     struct GRASSHOPPER_CIPHER_PARAMS *params = &gost_cipher_params[c->type];
1160
1161     gost_grasshopper_cipher_destroy(c);
1162     if (params->destroy_cipher != NULL) {
1163         params->destroy_cipher(c);
1164     }
1165
1166     EVP_CIPHER_CTX_set_app_data(ctx, NULL);
1167
1168     return 1;
1169 }
1170
1171 int gost_grasshopper_set_asn1_parameters(EVP_CIPHER_CTX *ctx, ASN1_TYPE *params)
1172 {
1173     int len = 0;
1174     unsigned char *buf = NULL;
1175     ASN1_OCTET_STRING *os = NULL;
1176
1177     os = ASN1_OCTET_STRING_new();
1178
1179     if (!os || !ASN1_OCTET_STRING_set(os, buf, len)) {
1180         OPENSSL_free(buf);
1181         GOSTerr(GOST_F_GOST_GRASSHOPPER_SET_ASN1_PARAMETERS,
1182                 ERR_R_MALLOC_FAILURE);
1183         return 0;
1184     }
1185     OPENSSL_free(buf);
1186
1187     ASN1_TYPE_set(params, V_ASN1_SEQUENCE, os);
1188     return 1;
1189 }
1190
1191 GRASSHOPPER_INLINE int gost_grasshopper_get_asn1_parameters(EVP_CIPHER_CTX
1192                                                             *ctx, ASN1_TYPE
1193                                                             *params)
1194 {
1195     int ret = -1;
1196
1197     if (ASN1_TYPE_get(params) != V_ASN1_SEQUENCE) {
1198         return ret;
1199     }
1200
1201     return 1;
1202 }
1203
1204 int gost_grasshopper_cipher_ctl(EVP_CIPHER_CTX *ctx, int type, int arg,
1205                                 void *ptr)
1206 {
1207     switch (type) {
1208     case EVP_CTRL_RAND_KEY:{
1209             if (RAND_bytes
1210                 ((unsigned char *)ptr, EVP_CIPHER_CTX_key_length(ctx)) <= 0) {
1211                 GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL, GOST_R_RNG_ERROR);
1212                 return -1;
1213             }
1214             break;
1215         }
1216     case EVP_CTRL_KEY_MESH:{
1217             gost_grasshopper_cipher_ctx_ctr *c =
1218                 EVP_CIPHER_CTX_get_cipher_data(ctx);
1219             if (c->c.type != GRASSHOPPER_CIPHER_CTRACPKM || !arg
1220                 || (arg % GRASSHOPPER_BLOCK_SIZE))
1221                 return -1;
1222             c->section_size = arg;
1223             break;
1224         }
1225 #ifdef EVP_CTRL_TLS1_2_TLSTREE
1226     case EVP_CTRL_TLS1_2_TLSTREE:
1227         {
1228           unsigned char newkey[32];
1229           int mode = EVP_CIPHER_CTX_mode(ctx);
1230           static const unsigned char zeroseq[8];
1231           gost_grasshopper_cipher_ctx_ctr *ctr_ctx = NULL;
1232           gost_grasshopper_cipher_ctx *c = NULL;
1233
1234           unsigned char adjusted_iv[16];
1235           unsigned char seq[8];
1236           int j, carry;
1237           if (mode != EVP_CIPH_CTR_MODE)
1238             return -1;
1239
1240           ctr_ctx = (gost_grasshopper_cipher_ctx_ctr *)
1241             EVP_CIPHER_CTX_get_cipher_data(ctx);
1242           c = &(ctr_ctx->c);
1243
1244           memcpy(seq, ptr, 8);
1245           if (EVP_CIPHER_CTX_encrypting(ctx)) {
1246             /*
1247              * OpenSSL increments seq after mac calculation.
1248              * As we have Mac-Then-Encrypt, we need decrement it here on encryption
1249              * to derive the key correctly.
1250              * */
1251             if (memcmp(seq, zeroseq, 8) != 0)
1252             {
1253               for(j=7; j>=0; j--)
1254               {
1255                 if (seq[j] != 0) {seq[j]--; break;}
1256                 else seq[j]  = 0xFF;
1257               }
1258             }
1259           }
1260           if (gost_tlstree(NID_grasshopper_cbc, c->master_key.k.b, newkey,
1261                 (const unsigned char *)seq) > 0) {
1262             memset(adjusted_iv, 0, 16);
1263             memcpy(adjusted_iv, EVP_CIPHER_CTX_original_iv(ctx), 8);
1264             for(j=7,carry=0; j>=0; j--)
1265             {
1266               int adj_byte = adjusted_iv[j]+seq[j]+carry;
1267               carry = (adj_byte > 255) ? 1 : 0;
1268               adjusted_iv[j] = adj_byte & 0xFF;
1269             }
1270         }
1271         return -1;
1272 #endif
1273     case EVP_CTRL_AEAD_GET_TAG:
1274     case EVP_CTRL_AEAD_SET_TAG:
1275         {
1276             gost_grasshopper_cipher_ctx_mgm *mgm_ctx = NULL;
1277             gost_grasshopper_cipher_ctx *c = NULL;
1278             int taglen = arg;
1279             unsigned char *tag = ptr;
1280
1281             mgm_ctx = (gost_grasshopper_cipher_ctx_mgm *)
1282                 EVP_CIPHER_CTX_get_cipher_data(ctx);
1283             c = (gost_grasshopper_cipher_ctx *) mgm_ctx;
1284
1285             if (c->type != GRASSHOPPER_CIPHER_MGM)
1286                 return -1;
1287
1288             if (taglen > 16) {
1289                 GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL,
1290                         GOST_R_INVALID_TAG_LENGTH);
1291                 return -1;
1292             }
1293
1294             if (type == EVP_CTRL_AEAD_GET_TAG)
1295                 memcpy(tag, mgm_ctx->final_tag, taglen);
1296             else
1297                 memcpy(mgm_ctx->final_tag, tag, taglen);
1298
1299             return 1;
1300         }
1301     default:
1302         GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL,
1303                 GOST_R_UNSUPPORTED_CIPHER_CTL_COMMAND);
1304         return -1;
1305     }
1306     return 1;
1307 }
1308
1309 GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_create(int
1310                                                               cipher_type, int
1311                                                               block_size)
1312 {
1313     return EVP_CIPHER_meth_new(cipher_type, block_size /* block_size */ ,
1314                                GRASSHOPPER_KEY_SIZE /* key_size */ );
1315 }
1316
1317 const int cipher_gost_grasshopper_setup(EVP_CIPHER *cipher, uint8_t mode,
1318                                         int iv_size, bool padding,
1319                                         int extra_flags)
1320 {
1321     return EVP_CIPHER_meth_set_iv_length(cipher, iv_size)
1322         && EVP_CIPHER_meth_set_flags(cipher,
1323                                      (unsigned long)(mode |
1324                                                      ((!padding) ?
1325                                                       EVP_CIPH_NO_PADDING :
1326                                                       0) | ((iv_size >
1327                                                              0) ?
1328                                                             EVP_CIPH_CUSTOM_IV
1329                                                             : 0) |
1330                                                      EVP_CIPH_RAND_KEY |
1331                                                      EVP_CIPH_ALWAYS_CALL_INIT |
1332                                                      extra_flags)
1333         )
1334         && EVP_CIPHER_meth_set_cleanup(cipher, gost_grasshopper_cipher_cleanup)
1335         && EVP_CIPHER_meth_set_set_asn1_params(cipher,
1336                                                gost_grasshopper_set_asn1_parameters)
1337         && EVP_CIPHER_meth_set_get_asn1_params(cipher,
1338                                                gost_grasshopper_get_asn1_parameters)
1339         && EVP_CIPHER_meth_set_ctrl(cipher, gost_grasshopper_cipher_ctl)
1340         && EVP_CIPHER_meth_set_do_cipher(cipher, gost_grasshopper_cipher_do);
1341 }
1342
1343 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper(uint8_t mode,
1344                                                              uint8_t num)
1345 {
1346     EVP_CIPHER **cipher;
1347     struct GRASSHOPPER_CIPHER_PARAMS *params;
1348
1349     cipher = &gost_grasshopper_ciphers[num];
1350
1351     if (*cipher == NULL) {
1352         params = &gost_cipher_params[num];
1353
1354         int nid = params->nid;
1355         grasshopper_init_cipher_func init_cipher = params->init_cipher;
1356         int block_size = params->block_size;
1357         int ctx_size = params->ctx_size;
1358         int iv_size = params->iv_size;
1359         bool padding = params->padding;
1360
1361         int extra_flags = (num == GRASSHOPPER_CIPHER_MGM) ?
1362             EVP_CIPH_FLAG_CUSTOM_CIPHER | EVP_CIPH_FLAG_AEAD_CIPHER : 0;
1363
1364         *cipher = cipher_gost_grasshopper_create(nid, block_size);
1365         if (*cipher == NULL) {
1366             return NULL;
1367         }
1368
1369         if (!cipher_gost_grasshopper_setup
1370             (*cipher, mode, iv_size, padding, extra_flags)
1371             || !EVP_CIPHER_meth_set_init(*cipher, init_cipher)
1372             || !EVP_CIPHER_meth_set_impl_ctx_size(*cipher, ctx_size)) {
1373             EVP_CIPHER_meth_free(*cipher);
1374             *cipher = NULL;
1375         }
1376     }
1377
1378     return *cipher;
1379 }
1380
1381 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ecb()
1382 {
1383     return cipher_gost_grasshopper(EVP_CIPH_ECB_MODE, GRASSHOPPER_CIPHER_ECB);
1384 }
1385
1386 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_cbc()
1387 {
1388     return cipher_gost_grasshopper(EVP_CIPH_CBC_MODE, GRASSHOPPER_CIPHER_CBC);
1389 }
1390
1391 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ofb()
1392 {
1393     return cipher_gost_grasshopper(EVP_CIPH_OFB_MODE, GRASSHOPPER_CIPHER_OFB);
1394 }
1395
1396 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_cfb()
1397 {
1398     return cipher_gost_grasshopper(EVP_CIPH_CFB_MODE, GRASSHOPPER_CIPHER_CFB);
1399 }
1400
1401 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ctr()
1402 {
1403     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE, GRASSHOPPER_CIPHER_CTR);
1404 }
1405
1406 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ctracpkm()
1407 {
1408     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE,
1409                                    GRASSHOPPER_CIPHER_CTRACPKM);
1410 }
1411
1412 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_mgm()
1413 {
1414 #ifndef NID_kuznyechik_mgm
1415     return NULL;
1416 #else
1417     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE, GRASSHOPPER_CIPHER_MGM);
1418 #endif
1419 }
1420
1421 void cipher_gost_grasshopper_destroy(void)
1422 {
1423     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_ECB]);
1424     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_ECB] = NULL;
1425     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CBC]);
1426     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CBC] = NULL;
1427     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_OFB]);
1428     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_OFB] = NULL;
1429     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CFB]);
1430     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CFB] = NULL;
1431     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTR]);
1432     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTR] = NULL;
1433     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKM]);
1434     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKM] = NULL;
1435     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_MGM]);
1436     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_MGM] = NULL;
1437 }