gost_grasshopper_cipher.c

   1 /*
   2  * Maxim Tishkov 2016
   3  * This file is distributed under the same license as OpenSSL
   4  */
   5
   6 #if defined(__cplusplus)
   7 extern "C" {
   8 #endif
   9
  10 #include "gost_grasshopper_cipher.h"
  11 #include "gost_grasshopper_defines.h"
  12 #include "gost_grasshopper_math.h"
  13 #include "gost_grasshopper_core.h"
  14
  15 #include <openssl/evp.h>
  16 #include <openssl/rand.h>
  17 #include <openssl/err.h>
  18 #include <string.h>
  19
  20 #include "gost_lcl.h"
  21 #include "e_gost_err.h"
  22
  23 enum GRASSHOPPER_CIPHER_TYPE {
  24     GRASSHOPPER_CIPHER_ECB = 0,
  25     GRASSHOPPER_CIPHER_CBC,
  26     GRASSHOPPER_CIPHER_OFB,
  27     GRASSHOPPER_CIPHER_CFB,
  28     GRASSHOPPER_CIPHER_CTR,
  29     GRASSHOPPER_CIPHER_CTRACPKM,
  30 };
  31
  32 static EVP_CIPHER *gost_grasshopper_ciphers[6] = {
  33     [GRASSHOPPER_CIPHER_ECB] = NULL,
  34     [GRASSHOPPER_CIPHER_CBC] = NULL,
  35     [GRASSHOPPER_CIPHER_OFB] = NULL,
  36     [GRASSHOPPER_CIPHER_CFB] = NULL,
  37     [GRASSHOPPER_CIPHER_CTR] = NULL,
  38     [GRASSHOPPER_CIPHER_CTRACPKM] = 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
  46 struct GRASSHOPPER_CIPHER_PARAMS {
  47     int nid;
  48     grasshopper_init_cipher_func init_cipher;
  49     grasshopper_do_cipher_func do_cipher;
  50     grasshopper_destroy_cipher_func destroy_cipher;
  51     int block_size;
  52     int ctx_size;
  53     int iv_size;
  54     bool padding;
  55 };
  56
  57 static struct GRASSHOPPER_CIPHER_PARAMS gost_cipher_params[6] = {
  58     [GRASSHOPPER_CIPHER_ECB] = {
  59                                 NID_grasshopper_ecb,
  60                                 gost_grasshopper_cipher_init_ecb,
  61                                 gost_grasshopper_cipher_do_ecb,
  62                                 NULL,
  63                                 16,
  64                                 sizeof(gost_grasshopper_cipher_ctx),
  65                                 0,
  66                                 true}
  67     ,
  68     [GRASSHOPPER_CIPHER_CBC] = {
  69                                 NID_grasshopper_cbc,
  70                                 gost_grasshopper_cipher_init_cbc,
  71                                 gost_grasshopper_cipher_do_cbc,
  72                                 NULL,
  73                                 16,
  74                                 sizeof(gost_grasshopper_cipher_ctx),
  75                                 16,
  76                                 true}
  77     ,
  78     [GRASSHOPPER_CIPHER_OFB] = {
  79                                 NID_grasshopper_ofb,
  80                                 gost_grasshopper_cipher_init_ofb,
  81                                 gost_grasshopper_cipher_do_ofb,
  82                                 gost_grasshopper_cipher_destroy_ofb,
  83                                 1,
  84                                 sizeof(gost_grasshopper_cipher_ctx_ofb),
  85                                 16,
  86                                 false}
  87     ,
  88     [GRASSHOPPER_CIPHER_CFB] = {
  89                                 NID_grasshopper_cfb,
  90                                 gost_grasshopper_cipher_init_cfb,
  91                                 gost_grasshopper_cipher_do_cfb,
  92                                 NULL,
  93                                 1,
  94                                 sizeof(gost_grasshopper_cipher_ctx),
  95                                 16,
  96                                 false}
  97     ,
  98     [GRASSHOPPER_CIPHER_CTR] = {
  99                                 NID_grasshopper_ctr,
 100                                 gost_grasshopper_cipher_init_ctr,
 101                                 gost_grasshopper_cipher_do_ctr,
 102                                 gost_grasshopper_cipher_destroy_ctr,
 103                                 1,
 104                                 sizeof(gost_grasshopper_cipher_ctx_ctr),
 105                                 /* IV size is set to match full block, to make it responsibility of
 106                                  * user to assign correct values (IV || 0), and to make naive context
 107                                  * copy possible (for software such as openssh) */
 108                                 16,
 109                                 false}
 110     ,
 111     [GRASSHOPPER_CIPHER_CTRACPKM] = {
 112                                      NID_id_tc26_cipher_gostr3412_2015_kuznyechik_ctracpkm,
 113                                      gost_grasshopper_cipher_init_ctracpkm,
 114                                      gost_grasshopper_cipher_do_ctracpkm,
 115                                      gost_grasshopper_cipher_destroy_ctr,
 116                                      1,
 117                                      sizeof
 118                                      (gost_grasshopper_cipher_ctx_ctr),
 119                                      16,
 120                                      false}
 121     ,
 122 };
 123
 124 /* first 256 bit of D from draft-irtf-cfrg-re-keying-12 */
 125 static const unsigned char ACPKM_D_2018[] = {
 126     0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /*  64 bit */
 127     0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, /* 128 bit */
 128     0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
 129     0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, /* 256 bit */
 130 };
 131
 132 static void acpkm_next(gost_grasshopper_cipher_ctx * c) {
 133     unsigned char newkey[GRASSHOPPER_KEY_SIZE];
 134     const int J = GRASSHOPPER_KEY_SIZE / GRASSHOPPER_BLOCK_SIZE;
 135     int n;
 136
 137     for (n = 0; n < J; n++) {
 138         const unsigned char *D_n =
 139             &ACPKM_D_2018[n * GRASSHOPPER_BLOCK_SIZE];
 140
 141         grasshopper_encrypt_block(&c->encrypt_round_keys,
 142                                   (grasshopper_w128_t *) D_n,
 143                                   (grasshopper_w128_t *) & newkey[n *
 144                                                                   GRASSHOPPER_BLOCK_SIZE],
 145                                   &c->buffer);
 146     }
 147     gost_grasshopper_cipher_key(c, newkey);
 148 }
 149
 150 /* Set 256 bit  key into context */
 151 GRASSHOPPER_INLINE void
 152     gost_grasshopper_cipher_key(gost_grasshopper_cipher_ctx * c,
 153                                 const uint8_t *k) {
 154     int i;
 155     for (i = 0; i < 2; i++) {
 156         grasshopper_copy128(&c->key.k.k[i],
 157                             (const grasshopper_w128_t *)(k + i * 16));
 158     }
 159
 160     grasshopper_set_encrypt_key(&c->encrypt_round_keys, &c->key);
 161     grasshopper_set_decrypt_key(&c->decrypt_round_keys, &c->key);
 162 }
 163
 164 /* Set master 256-bit key to be used in TLSTREE calculation into context */
 165 GRASSHOPPER_INLINE void
 166     gost_grasshopper_master_key(gost_grasshopper_cipher_ctx * c,
 167                                 const uint8_t *k) {
 168     int i;
 169     for (i = 0; i < 2; i++) {
 170         grasshopper_copy128(&c->master_key.k.k[i],
 171                             (const grasshopper_w128_t *)(k + i * 16));
 172     }
 173 }
 174
 175 /* Cleans up key from context */
 176 GRASSHOPPER_INLINE void
 177     gost_grasshopper_cipher_destroy(gost_grasshopper_cipher_ctx * c) {
 178     int i;
 179     for (i = 0; i < 2; i++) {
 180         grasshopper_zero128(&c->key.k.k[i]);
 181                                 grasshopper_zero128(&c->master_key.k.k[i]);
 182     }
 183     for (i = 0; i < GRASSHOPPER_ROUND_KEYS_COUNT; i++) {
 184         grasshopper_zero128(&c->encrypt_round_keys.k[i]);
 185     }
 186     for (i = 0; i < GRASSHOPPER_ROUND_KEYS_COUNT; i++) {
 187         grasshopper_zero128(&c->decrypt_round_keys.k[i]);
 188     }
 189     grasshopper_zero128(&c->buffer);
 190 }
 191
 192 static GRASSHOPPER_INLINE void
 193     gost_grasshopper_cipher_destroy_ofb(gost_grasshopper_cipher_ctx * c) {
 194     gost_grasshopper_cipher_ctx_ofb *ctx =
 195         (gost_grasshopper_cipher_ctx_ofb *) c;
 196
 197     grasshopper_zero128(&ctx->buffer1);
 198 }
 199
 200 static GRASSHOPPER_INLINE void
 201     gost_grasshopper_cipher_destroy_ctr(gost_grasshopper_cipher_ctx * c) {
 202     gost_grasshopper_cipher_ctx_ctr *ctx =
 203         (gost_grasshopper_cipher_ctx_ctr *) c;
 204
 205     grasshopper_zero128(&ctx->partial_buffer);
 206 }
 207
 208 int gost_grasshopper_cipher_init(EVP_CIPHER_CTX *ctx,
 209                                  const unsigned char *key,
 210                                  const unsigned char *iv, int enc) {
 211     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 212
 213     if (EVP_CIPHER_CTX_get_app_data(ctx) == NULL) {
 214         EVP_CIPHER_CTX_set_app_data(ctx,
 215                                     EVP_CIPHER_CTX_get_cipher_data(ctx));
 216     }
 217
 218     if (key != NULL) {
 219         gost_grasshopper_cipher_key(c, key);
 220         gost_grasshopper_master_key(c, key);
 221     }
 222
 223     if (iv != NULL) {
 224         memcpy((unsigned char *)EVP_CIPHER_CTX_original_iv(ctx), iv,
 225                EVP_CIPHER_CTX_iv_length(ctx));
 226     }
 227
 228     memcpy(EVP_CIPHER_CTX_iv_noconst(ctx),
 229            EVP_CIPHER_CTX_original_iv(ctx), EVP_CIPHER_CTX_iv_length(ctx));
 230
 231     grasshopper_zero128(&c->buffer);
 232
 233     return 1;
 234 }
 235
 236 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ecb(EVP_CIPHER_CTX *ctx,
 237                                                         const unsigned char
 238                                                         *key,
 239                                                         const unsigned char
 240                                                         *iv, int enc) {
 241     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 242     c->type = GRASSHOPPER_CIPHER_ECB;
 243     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 244 }
 245
 246 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_cbc(EVP_CIPHER_CTX *ctx,
 247                                                         const unsigned char
 248                                                         *key,
 249                                                         const unsigned char
 250                                                         *iv, int enc) {
 251     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 252     c->type = GRASSHOPPER_CIPHER_CBC;
 253     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 254 }
 255
 256 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ofb(EVP_CIPHER_CTX *ctx,
 257                                                         const unsigned char
 258                                                         *key,
 259                                                         const unsigned char
 260                                                         *iv, int enc) {
 261     gost_grasshopper_cipher_ctx_ofb *c =
 262         EVP_CIPHER_CTX_get_cipher_data(ctx);
 263
 264     c->c.type = GRASSHOPPER_CIPHER_OFB;
 265
 266     grasshopper_zero128(&c->buffer1);
 267
 268     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 269 }
 270
 271 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_cfb(EVP_CIPHER_CTX *ctx,
 272                                                         const unsigned char
 273                                                         *key,
 274                                                         const unsigned char
 275                                                         *iv, int enc) {
 276     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 277     c->type = GRASSHOPPER_CIPHER_CFB;
 278     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 279 }
 280
 281 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ctr(EVP_CIPHER_CTX *ctx,
 282                                                         const unsigned char
 283                                                         *key,
 284                                                         const unsigned char
 285                                                         *iv, int enc) {
 286     gost_grasshopper_cipher_ctx_ctr *c =
 287         EVP_CIPHER_CTX_get_cipher_data(ctx);
 288
 289     c->c.type = GRASSHOPPER_CIPHER_CTR;
 290     EVP_CIPHER_CTX_set_num(ctx, 0);
 291
 292     grasshopper_zero128(&c->partial_buffer);
 293
 294     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 295 }
 296
 297 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ctracpkm(EVP_CIPHER_CTX
 298                                                              *ctx,
 299                                                              const unsigned
 300                                                              char *key,
 301                                                              const unsigned
 302                                                              char *iv,
 303                                                              int enc) {
 304     gost_grasshopper_cipher_ctx_ctr *c =
 305         EVP_CIPHER_CTX_get_cipher_data(ctx);
 306
 307     /* NB: setting type makes EVP do_cipher callback useless */
 308     c->c.type = GRASSHOPPER_CIPHER_CTRACPKM;
 309     EVP_CIPHER_CTX_set_num(ctx, 0);
 310     c->section_size = 4096;
 311
 312     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 313 }
 314
 315 GRASSHOPPER_INLINE int gost_grasshopper_cipher_do(EVP_CIPHER_CTX *ctx,
 316                                                   unsigned char *out,
 317                                                   const unsigned char *in,
 318                                                   size_t inl) {
 319     gost_grasshopper_cipher_ctx *c =
 320         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 321     struct GRASSHOPPER_CIPHER_PARAMS *params = &gost_cipher_params[c->type];
 322
 323     return params->do_cipher(ctx, out, in, inl);
 324 }
 325
 326 int gost_grasshopper_cipher_do_ecb(EVP_CIPHER_CTX *ctx, unsigned char *out,
 327                                    const unsigned char *in, size_t inl) {
 328     gost_grasshopper_cipher_ctx *c =
 329         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 330     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
 331     const unsigned char *current_in = in;
 332     unsigned char *current_out = out;
 333     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 334     size_t i;
 335
 336     for (i = 0; i < blocks;
 337          i++, current_in += GRASSHOPPER_BLOCK_SIZE, current_out +=
 338          GRASSHOPPER_BLOCK_SIZE) {
 339         if (encrypting) {
 340             grasshopper_encrypt_block(&c->encrypt_round_keys,
 341                                       (grasshopper_w128_t *) current_in,
 342                                       (grasshopper_w128_t *) current_out,
 343                                       &c->buffer);
 344         } else {
 345             grasshopper_decrypt_block(&c->decrypt_round_keys,
 346                                       (grasshopper_w128_t *) current_in,
 347                                       (grasshopper_w128_t *) current_out,
 348                                       &c->buffer);
 349         }
 350     }
 351
 352     return 1;
 353 }
 354
 355 int gost_grasshopper_cipher_do_cbc(EVP_CIPHER_CTX *ctx, unsigned char *out,
 356                                    const unsigned char *in, size_t inl) {
 357     gost_grasshopper_cipher_ctx *c =
 358         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 359     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 360     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
 361     const unsigned char *current_in = in;
 362     unsigned char *current_out = out;
 363     grasshopper_w128_t *currentInputBlock;
 364     grasshopper_w128_t *currentOutputBlock;
 365     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 366     size_t i;
 367     grasshopper_w128_t *currentBlock;
 368
 369     currentBlock = (grasshopper_w128_t *) iv;
 370
 371     for (i = 0; i < blocks;
 372          i++, current_in += GRASSHOPPER_BLOCK_SIZE, current_out +=
 373          GRASSHOPPER_BLOCK_SIZE) {
 374         currentInputBlock = (grasshopper_w128_t *) current_in;
 375         currentOutputBlock = (grasshopper_w128_t *) current_out;
 376         if (encrypting) {
 377             grasshopper_append128(currentBlock, currentInputBlock);
 378             grasshopper_encrypt_block(&c->encrypt_round_keys, currentBlock,
 379                                       currentOutputBlock, &c->buffer);
 380             grasshopper_copy128(currentBlock, currentOutputBlock);
 381         } else {
 382             grasshopper_w128_t tmp;
 383
 384             grasshopper_copy128(&tmp, currentInputBlock);
 385             grasshopper_decrypt_block(&c->decrypt_round_keys,
 386                                       currentInputBlock, currentOutputBlock,
 387                                       &c->buffer);
 388             grasshopper_append128(currentOutputBlock, currentBlock);
 389             grasshopper_copy128(currentBlock, &tmp);
 390         }
 391     }
 392
 393     return 1;
 394 }
 395
 396 void inc_counter(unsigned char *counter, size_t counter_bytes) {
 397     unsigned char c;
 398     unsigned int n = counter_bytes;
 399
 400     do {
 401         --n;
 402         c = counter[n];
 403         ++c;
 404         counter[n] = c;
 405         if (c)
 406             return;
 407     } while (n);
 408 }
 409
 410 /* increment counter (128-bit int) by 1 */
 411 static void ctr128_inc(unsigned char *counter) {
 412     inc_counter(counter, 16);
 413 }
 414
 415 int gost_grasshopper_cipher_do_ctr(EVP_CIPHER_CTX *ctx, unsigned char *out,
 416                                    const unsigned char *in, size_t inl) {
 417     gost_grasshopper_cipher_ctx_ctr *c =
 418         (gost_grasshopper_cipher_ctx_ctr *)
 419         EVP_CIPHER_CTX_get_cipher_data(ctx);
 420     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 421     const unsigned char *current_in = in;
 422     unsigned char *current_out = out;
 423     grasshopper_w128_t *currentInputBlock;
 424     grasshopper_w128_t *currentOutputBlock;
 425     unsigned int n = EVP_CIPHER_CTX_num(ctx);
 426     size_t lasted;
 427     size_t i;
 428
 429     while (n && inl) {
 430         *(current_out++) = *(current_in++) ^ c->partial_buffer.b[n];
 431         --inl;
 432         n = (n + 1) % GRASSHOPPER_BLOCK_SIZE;
 433     }
 434     EVP_CIPHER_CTX_set_num(ctx, n);
 435     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 436
 437     grasshopper_w128_t *iv_buffer = (grasshopper_w128_t *) iv;
 438     grasshopper_w128_t tmp;
 439
 440     // full parts
 441     for (i = 0; i < blocks; i++) {
 442         currentInputBlock = (grasshopper_w128_t *) current_in;
 443         currentOutputBlock = (grasshopper_w128_t *) current_out;
 444         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer,
 445                                   &c->partial_buffer, &c->c.buffer);
 446         grasshopper_plus128(&tmp, &c->partial_buffer, currentInputBlock);
 447         grasshopper_copy128(currentOutputBlock, &tmp);
 448         ctr128_inc(iv_buffer->b);
 449         current_in += GRASSHOPPER_BLOCK_SIZE;
 450         current_out += GRASSHOPPER_BLOCK_SIZE;
 451     }
 452
 453     // last part
 454     lasted = inl - blocks * GRASSHOPPER_BLOCK_SIZE;
 455     if (lasted > 0) {
 456         currentInputBlock = (grasshopper_w128_t *) current_in;
 457         currentOutputBlock = (grasshopper_w128_t *) current_out;
 458         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer,
 459                                   &c->partial_buffer, &c->c.buffer);
 460         for (i = 0; i < lasted; i++) {
 461             currentOutputBlock->b[i] =
 462                 c->partial_buffer.b[i] ^ currentInputBlock->b[i];
 463         }
 464         EVP_CIPHER_CTX_set_num(ctx, i);
 465         ctr128_inc(iv_buffer->b);
 466     }
 467
 468     return 1;
 469 }
 470
 471 #define GRASSHOPPER_BLOCK_MASK (GRASSHOPPER_BLOCK_SIZE - 1)
 472 static inline void apply_acpkm_grasshopper(gost_grasshopper_cipher_ctx_ctr *
 473                                            ctx, unsigned int *num) {
 474     if (!ctx->section_size || (*num < ctx->section_size))
 475         return;
 476     acpkm_next(&ctx->c);
 477     *num &= GRASSHOPPER_BLOCK_MASK;
 478 }
 479
 480 /* If meshing is not configured via ctrl (setting section_size)
 481  * this function works exactly like plain ctr */
 482 int gost_grasshopper_cipher_do_ctracpkm(EVP_CIPHER_CTX *ctx,
 483                                         unsigned char *out,
 484                                         const unsigned char *in,
 485                                         size_t inl) {
 486     gost_grasshopper_cipher_ctx_ctr *c =
 487         EVP_CIPHER_CTX_get_cipher_data(ctx);
 488     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 489     unsigned int num = EVP_CIPHER_CTX_num(ctx);
 490
 491     while ((num & GRASSHOPPER_BLOCK_MASK) && inl) {
 492         *out++ = *in++ ^ c->partial_buffer.b[num & GRASSHOPPER_BLOCK_MASK];
 493         --inl;
 494         num++;
 495     }
 496     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 497     size_t i;
 498     grasshopper_w128_t tmp;
 499
 500     // full parts
 501     for (i = 0; i < blocks; i++) {
 502         apply_acpkm_grasshopper(c, &num);
 503         grasshopper_encrypt_block(&c->c.encrypt_round_keys,
 504                                   (grasshopper_w128_t *) iv,
 505                                   (grasshopper_w128_t *) &c->partial_buffer, &c->c.buffer);
 506         grasshopper_plus128(&tmp, &c->partial_buffer, (grasshopper_w128_t *) in);
 507         grasshopper_copy128((grasshopper_w128_t *) out, &tmp);
 508         ctr128_inc(iv);
 509         in += GRASSHOPPER_BLOCK_SIZE;
 510         out += GRASSHOPPER_BLOCK_SIZE;
 511         num += GRASSHOPPER_BLOCK_SIZE;
 512     }
 513
 514     // last part
 515     size_t lasted = inl - blocks * GRASSHOPPER_BLOCK_SIZE;
 516     if (lasted > 0) {
 517         apply_acpkm_grasshopper(c, &num);
 518         grasshopper_encrypt_block(&c->c.encrypt_round_keys,
 519                                   (grasshopper_w128_t *) iv,
 520                                   &c->partial_buffer, &c->c.buffer);
 521         for (i = 0; i < lasted; i++)
 522             out[i] = c->partial_buffer.b[i] ^ in[i];
 523         ctr128_inc(iv);
 524         num += lasted;
 525     }
 526     EVP_CIPHER_CTX_set_num(ctx, num);
 527
 528     return 1;
 529 }
 530
 531 /*
 532  * Fixed 128-bit IV implementation make shift regiser redundant.
 533  */
 534 static void gost_grasshopper_cnt_next(gost_grasshopper_cipher_ctx_ofb * ctx,
 535                                       grasshopper_w128_t * iv,
 536                                       grasshopper_w128_t * buf) {
 537     memcpy(&ctx->buffer1, iv, 16);
 538     grasshopper_encrypt_block(&ctx->c.encrypt_round_keys, &ctx->buffer1,
 539                               buf, &ctx->c.buffer);
 540     memcpy(iv, buf, 16);
 541 }
 542
 543 int gost_grasshopper_cipher_do_ofb(EVP_CIPHER_CTX *ctx, unsigned char *out,
 544                                    const unsigned char *in, size_t inl) {
 545     gost_grasshopper_cipher_ctx_ofb *c =
 546         (gost_grasshopper_cipher_ctx_ofb *)
 547         EVP_CIPHER_CTX_get_cipher_data(ctx);
 548     const unsigned char *in_ptr = in;
 549     unsigned char *out_ptr = out;
 550     unsigned char *buf = EVP_CIPHER_CTX_buf_noconst(ctx);
 551     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 552     int num = EVP_CIPHER_CTX_num(ctx);
 553     size_t i = 0;
 554     size_t j;
 555
 556     /* process partial block if any */
 557     if (num > 0) {
 558         for (j = (size_t)num, i = 0; j < GRASSHOPPER_BLOCK_SIZE && i < inl;
 559              j++, i++, in_ptr++, out_ptr++) {
 560             *out_ptr = buf[j] ^ (*in_ptr);
 561         }
 562         if (j == GRASSHOPPER_BLOCK_SIZE) {
 563             EVP_CIPHER_CTX_set_num(ctx, 0);
 564         } else {
 565             EVP_CIPHER_CTX_set_num(ctx, (int)j);
 566             return 1;
 567         }
 568     }
 569
 570     for (; i + GRASSHOPPER_BLOCK_SIZE <
 571          inl;
 572          i += GRASSHOPPER_BLOCK_SIZE, in_ptr +=
 573          GRASSHOPPER_BLOCK_SIZE, out_ptr += GRASSHOPPER_BLOCK_SIZE) {
 574         /*
 575          * block cipher current iv
 576          */
 577         /* Encrypt */
 578         gost_grasshopper_cnt_next(c, (grasshopper_w128_t *) iv,
 579                                   (grasshopper_w128_t *) buf);
 580
 581         /*
 582          * xor next block of input text with it and output it
 583          */
 584         /*
 585          * output this block
 586          */
 587         for (j = 0; j < GRASSHOPPER_BLOCK_SIZE; j++) {
 588             out_ptr[j] = buf[j] ^ in_ptr[j];
 589         }
 590     }
 591
 592     /* Process rest of buffer */
 593     if (i < inl) {
 594         gost_grasshopper_cnt_next(c, (grasshopper_w128_t *) iv,
 595                                   (grasshopper_w128_t *) buf);
 596         for (j = 0; i < inl; j++, i++) {
 597             out_ptr[j] = buf[j] ^ in_ptr[j];
 598         }
 599         EVP_CIPHER_CTX_set_num(ctx, (int)j);
 600     } else {
 601         EVP_CIPHER_CTX_set_num(ctx, 0);
 602     }
 603
 604     return 1;
 605 }
 606
 607 int gost_grasshopper_cipher_do_cfb(EVP_CIPHER_CTX *ctx, unsigned char *out,
 608                                    const unsigned char *in, size_t inl) {
 609     gost_grasshopper_cipher_ctx *c =
 610         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 611     const unsigned char *in_ptr = in;
 612     unsigned char *out_ptr = out;
 613     unsigned char *buf = EVP_CIPHER_CTX_buf_noconst(ctx);
 614     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 615     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
 616     int num = EVP_CIPHER_CTX_num(ctx);
 617     size_t i = 0;
 618     size_t j = 0;
 619
 620     /* process partial block if any */
 621     if (num > 0) {
 622         for (j = (size_t)num, i = 0; j < GRASSHOPPER_BLOCK_SIZE && i < inl;
 623              j++, i++, in_ptr++, out_ptr++) {
 624             if (!encrypting) {
 625                 buf[j + GRASSHOPPER_BLOCK_SIZE] = *in_ptr;
 626             }
 627             *out_ptr = buf[j] ^ (*in_ptr);
 628             if (encrypting) {
 629                 buf[j + GRASSHOPPER_BLOCK_SIZE] = *out_ptr;
 630             }
 631         }
 632         if (j == GRASSHOPPER_BLOCK_SIZE) {
 633             memcpy(iv, buf + GRASSHOPPER_BLOCK_SIZE,
 634                    GRASSHOPPER_BLOCK_SIZE);
 635             EVP_CIPHER_CTX_set_num(ctx, 0);
 636         } else {
 637             EVP_CIPHER_CTX_set_num(ctx, (int)j);
 638             return 1;
 639         }
 640     }
 641
 642     for (; i + GRASSHOPPER_BLOCK_SIZE <
 643          inl;
 644          i += GRASSHOPPER_BLOCK_SIZE, in_ptr +=
 645          GRASSHOPPER_BLOCK_SIZE, out_ptr += GRASSHOPPER_BLOCK_SIZE) {
 646         /*
 647          * block cipher current iv
 648          */
 649         grasshopper_encrypt_block(&c->encrypt_round_keys,
 650                                   (grasshopper_w128_t *) iv,
 651                                   (grasshopper_w128_t *) buf, &c->buffer);
 652         /*
 653          * xor next block of input text with it and output it
 654          */
 655         /*
 656          * output this block
 657          */
 658         if (!encrypting) {
 659             memcpy(iv, in_ptr, GRASSHOPPER_BLOCK_SIZE);
 660         }
 661         for (j = 0; j < GRASSHOPPER_BLOCK_SIZE; j++) {
 662             out_ptr[j] = buf[j] ^ in_ptr[j];
 663         }
 664         /* Encrypt */
 665         /* Next iv is next block of cipher text */
 666         if (encrypting) {
 667             memcpy(iv, out_ptr, GRASSHOPPER_BLOCK_SIZE);
 668         }
 669     }
 670
 671     /* Process rest of buffer */
 672     if (i < inl) {
 673         grasshopper_encrypt_block(&c->encrypt_round_keys,
 674                                   (grasshopper_w128_t *) iv,
 675                                   (grasshopper_w128_t *) buf, &c->buffer);
 676         if (!encrypting) {
 677             memcpy(buf + GRASSHOPPER_BLOCK_SIZE, in_ptr, inl - i);
 678         }
 679         for (j = 0; i < inl; j++, i++) {
 680             out_ptr[j] = buf[j] ^ in_ptr[j];
 681         }
 682         EVP_CIPHER_CTX_set_num(ctx, (int)j);
 683         if (encrypting) {
 684             memcpy(buf + GRASSHOPPER_BLOCK_SIZE, out_ptr, j);
 685         }
 686     } else {
 687         EVP_CIPHER_CTX_set_num(ctx, 0);
 688     }
 689
 690     return 1;
 691 }
 692
 693 int gost_grasshopper_cipher_cleanup(EVP_CIPHER_CTX *ctx) {
 694     gost_grasshopper_cipher_ctx *c =
 695         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 696
 697     if (!c)
 698         return 1;
 699
 700     struct GRASSHOPPER_CIPHER_PARAMS *params = &gost_cipher_params[c->type];
 701
 702     gost_grasshopper_cipher_destroy(c);
 703     if (params->destroy_cipher != NULL) {
 704         params->destroy_cipher(c);
 705     }
 706
 707     EVP_CIPHER_CTX_set_app_data(ctx, NULL);
 708
 709     return 1;
 710 }
 711
 712 int gost_grasshopper_set_asn1_parameters(EVP_CIPHER_CTX *ctx,
 713                                          ASN1_TYPE *params) {
 714     int len = 0;
 715     unsigned char *buf = NULL;
 716     ASN1_OCTET_STRING *os = NULL;
 717
 718     os = ASN1_OCTET_STRING_new();
 719
 720     if (!os || !ASN1_OCTET_STRING_set(os, buf, len)) {
 721         OPENSSL_free(buf);
 722         GOSTerr(GOST_F_GOST_GRASSHOPPER_SET_ASN1_PARAMETERS,
 723                 ERR_R_MALLOC_FAILURE);
 724         return 0;
 725     }
 726     OPENSSL_free(buf);
 727
 728     ASN1_TYPE_set(params, V_ASN1_SEQUENCE, os);
 729     return 1;
 730 }
 731
 732 GRASSHOPPER_INLINE int gost_grasshopper_get_asn1_parameters(EVP_CIPHER_CTX
 733                                                             *ctx,
 734                                                             ASN1_TYPE
 735                                                             *params) {
 736     int ret = -1;
 737
 738     if (ASN1_TYPE_get(params) != V_ASN1_SEQUENCE) {
 739         return ret;
 740     }
 741
 742     return 1;
 743 }
 744
 745 int gost_grasshopper_cipher_ctl(EVP_CIPHER_CTX *ctx, int type, int arg,
 746                                 void *ptr) {
 747     switch (type) {
 748     case EVP_CTRL_RAND_KEY:{
 749             if (RAND_bytes
 750                 ((unsigned char *)ptr,
 751                  EVP_CIPHER_CTX_key_length(ctx)) <= 0) {
 752                 GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL,
 753                         GOST_R_RNG_ERROR);
 754                 return -1;
 755             }
 756             break;
 757         }
 758     case EVP_CTRL_KEY_MESH:{
 759             gost_grasshopper_cipher_ctx_ctr *c =
 760                 EVP_CIPHER_CTX_get_cipher_data(ctx);
 761             if (c->c.type != GRASSHOPPER_CIPHER_CTRACPKM || !arg
 762                 || (arg % GRASSHOPPER_BLOCK_SIZE))
 763                 return -1;
 764             c->section_size = arg;
 765             break;
 766         }
 767 #ifdef EVP_CTRL_TLS1_2_TLSTREE
 768     case EVP_CTRL_TLS1_2_TLSTREE:
 769                         {
 770                                 unsigned char newkey[32];
 771                                 int mode = EVP_CIPHER_CTX_mode(ctx);
 772                                 gost_grasshopper_cipher_ctx_ctr *ctr_ctx = NULL;
 773                                 gost_grasshopper_cipher_ctx *c = NULL;
 774
 775                                 if (mode != EVP_CIPH_CTR_MODE)
 776                                         return -1;
 777
 778                                 ctr_ctx =
 779                                 (gost_grasshopper_cipher_ctx_ctr *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 780                                 c = &(ctr_ctx->c);
 781
 782                                 if (gost_tlstree(NID_grasshopper_cbc, c->master_key.k.b, newkey,
 783                                                                 (const unsigned char *)ptr) )
 784                                         {
 785                                                 gost_grasshopper_cipher_key(c, newkey);
 786                                                 return 1;
 787                                         }
 788                         }
 789     return -1;
 790 #endif
 791     default:
 792         GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL,
 793                 GOST_R_UNSUPPORTED_CIPHER_CTL_COMMAND);
 794         return -1;
 795     }
 796     return 1;
 797 }
 798
 799 GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_create(int
 800                                                               cipher_type,
 801                                                               int
 802                                                               block_size) {
 803     return EVP_CIPHER_meth_new(cipher_type, block_size /* block_size */ ,
 804                                GRASSHOPPER_KEY_SIZE /* key_size */ );
 805 }
 806
 807 const int cipher_gost_grasshopper_setup(EVP_CIPHER *cipher, uint8_t mode,
 808                                         int iv_size, bool padding) {
 809     return EVP_CIPHER_meth_set_iv_length(cipher, iv_size)
 810         && EVP_CIPHER_meth_set_flags(cipher,
 811                                      (unsigned long)(mode |
 812                                                      ((!padding) ?
 813                                                       EVP_CIPH_NO_PADDING :
 814                                                       0) | ((iv_size >
 815                                                              0) ?
 816                                                             EVP_CIPH_CUSTOM_IV
 817                                                             : 0) |
 818                                                      EVP_CIPH_RAND_KEY |
 819                                                      EVP_CIPH_ALWAYS_CALL_INIT)
 820         )
 821         && EVP_CIPHER_meth_set_cleanup(cipher,
 822                                        gost_grasshopper_cipher_cleanup)
 823         && EVP_CIPHER_meth_set_set_asn1_params(cipher,
 824                                                gost_grasshopper_set_asn1_parameters)
 825         && EVP_CIPHER_meth_set_get_asn1_params(cipher,
 826                                                gost_grasshopper_get_asn1_parameters)
 827         && EVP_CIPHER_meth_set_ctrl(cipher, gost_grasshopper_cipher_ctl)
 828         && EVP_CIPHER_meth_set_do_cipher(cipher,
 829                                          gost_grasshopper_cipher_do);
 830 }
 831
 832 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper(uint8_t mode,
 833                                                              uint8_t num) {
 834     EVP_CIPHER **cipher;
 835     struct GRASSHOPPER_CIPHER_PARAMS *params;
 836
 837     cipher = &gost_grasshopper_ciphers[num];
 838
 839     if (*cipher == NULL) {
 840         params = &gost_cipher_params[num];
 841
 842         int nid = params->nid;
 843         grasshopper_init_cipher_func init_cipher = params->init_cipher;
 844         int block_size = params->block_size;
 845         int ctx_size = params->ctx_size;
 846         int iv_size = params->iv_size;
 847         bool padding = params->padding;
 848
 849         *cipher = cipher_gost_grasshopper_create(nid, block_size);
 850         if (*cipher == NULL) {
 851             return NULL;
 852         }
 853
 854         if (!cipher_gost_grasshopper_setup(*cipher, mode, iv_size, padding)
 855             || !EVP_CIPHER_meth_set_init(*cipher, init_cipher)
 856             || !EVP_CIPHER_meth_set_impl_ctx_size(*cipher, ctx_size)) {
 857             EVP_CIPHER_meth_free(*cipher);
 858             *cipher = NULL;
 859         }
 860     }
 861
 862     return *cipher;
 863 }
 864
 865 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ecb() {
 866     return cipher_gost_grasshopper(EVP_CIPH_ECB_MODE,
 867                                    GRASSHOPPER_CIPHER_ECB);
 868 }
 869
 870 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_cbc() {
 871     return cipher_gost_grasshopper(EVP_CIPH_CBC_MODE,
 872                                    GRASSHOPPER_CIPHER_CBC);
 873 }
 874
 875 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ofb() {
 876     return cipher_gost_grasshopper(EVP_CIPH_OFB_MODE,
 877                                    GRASSHOPPER_CIPHER_OFB);
 878 }
 879
 880 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_cfb() {
 881     return cipher_gost_grasshopper(EVP_CIPH_CFB_MODE,
 882                                    GRASSHOPPER_CIPHER_CFB);
 883 }
 884
 885 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ctr() {
 886     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE,
 887                                    GRASSHOPPER_CIPHER_CTR);
 888 }
 889
 890 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ctracpkm() {
 891     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE,
 892                                    GRASSHOPPER_CIPHER_CTRACPKM);
 893 }
 894
 895 void cipher_gost_grasshopper_destroy(void) {
 896     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_ECB]);
 897     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_ECB] = NULL;
 898     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CBC]);
 899     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CBC] = NULL;
 900     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_OFB]);
 901     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_OFB] = NULL;
 902     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CFB]);
 903     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CFB] = NULL;
 904     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTR]);
 905     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTR] = NULL;
 906     EVP_CIPHER_meth_free(gost_grasshopper_ciphers
 907                          [GRASSHOPPER_CIPHER_CTRACPKM]);
 908     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKM] = NULL;
 909 }
 910
 911 #if defined(__cplusplus)
 912 }
 913 #endif