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     grasshopper_set_encrypt_key(&c->encrypt_round_keys, &c->key);
 160     grasshopper_set_decrypt_key(&c->decrypt_round_keys, &c->key);
 161 }
 162
 163 /* Cleans up key from context */
 164 GRASSHOPPER_INLINE void
 165     gost_grasshopper_cipher_destroy(gost_grasshopper_cipher_ctx * c) {
 166     int i;
 167     for (i = 0; i < 2; i++) {
 168         grasshopper_zero128(&c->key.k.k[i]);
 169     }
 170     for (i = 0; i < GRASSHOPPER_ROUND_KEYS_COUNT; i++) {
 171         grasshopper_zero128(&c->encrypt_round_keys.k[i]);
 172     }
 173     for (i = 0; i < GRASSHOPPER_ROUND_KEYS_COUNT; i++) {
 174         grasshopper_zero128(&c->decrypt_round_keys.k[i]);
 175     }
 176     grasshopper_zero128(&c->buffer);
 177 }
 178
 179 static GRASSHOPPER_INLINE void
 180     gost_grasshopper_cipher_destroy_ofb(gost_grasshopper_cipher_ctx * c) {
 181     gost_grasshopper_cipher_ctx_ofb *ctx =
 182         (gost_grasshopper_cipher_ctx_ofb *) c;
 183
 184     grasshopper_zero128(&ctx->buffer1);
 185 }
 186
 187 static GRASSHOPPER_INLINE void
 188     gost_grasshopper_cipher_destroy_ctr(gost_grasshopper_cipher_ctx * c) {
 189     gost_grasshopper_cipher_ctx_ctr *ctx =
 190         (gost_grasshopper_cipher_ctx_ctr *) c;
 191
 192     grasshopper_zero128(&ctx->partial_buffer);
 193 }
 194
 195 int gost_grasshopper_cipher_init(EVP_CIPHER_CTX *ctx,
 196                                  const unsigned char *key,
 197                                  const unsigned char *iv, int enc) {
 198     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 199
 200     if (EVP_CIPHER_CTX_get_app_data(ctx) == NULL) {
 201         EVP_CIPHER_CTX_set_app_data(ctx,
 202                                     EVP_CIPHER_CTX_get_cipher_data(ctx));
 203     }
 204
 205     if (key != NULL) {
 206         gost_grasshopper_cipher_key(c, key);
 207     }
 208
 209     if (iv != NULL) {
 210         memcpy((unsigned char *)EVP_CIPHER_CTX_original_iv(ctx), iv,
 211                EVP_CIPHER_CTX_iv_length(ctx));
 212     }
 213
 214     memcpy(EVP_CIPHER_CTX_iv_noconst(ctx),
 215            EVP_CIPHER_CTX_original_iv(ctx), EVP_CIPHER_CTX_iv_length(ctx));
 216
 217     grasshopper_zero128(&c->buffer);
 218
 219     return 1;
 220 }
 221
 222 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ecb(EVP_CIPHER_CTX *ctx,
 223                                                         const unsigned char
 224                                                         *key,
 225                                                         const unsigned char
 226                                                         *iv, int enc) {
 227     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 228     c->type = GRASSHOPPER_CIPHER_ECB;
 229     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 230 }
 231
 232 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_cbc(EVP_CIPHER_CTX *ctx,
 233                                                         const unsigned char
 234                                                         *key,
 235                                                         const unsigned char
 236                                                         *iv, int enc) {
 237     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 238     c->type = GRASSHOPPER_CIPHER_CBC;
 239     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 240 }
 241
 242 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ofb(EVP_CIPHER_CTX *ctx,
 243                                                         const unsigned char
 244                                                         *key,
 245                                                         const unsigned char
 246                                                         *iv, int enc) {
 247     gost_grasshopper_cipher_ctx_ofb *c =
 248         EVP_CIPHER_CTX_get_cipher_data(ctx);
 249
 250     c->c.type = GRASSHOPPER_CIPHER_OFB;
 251
 252     grasshopper_zero128(&c->buffer1);
 253
 254     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 255 }
 256
 257 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_cfb(EVP_CIPHER_CTX *ctx,
 258                                                         const unsigned char
 259                                                         *key,
 260                                                         const unsigned char
 261                                                         *iv, int enc) {
 262     gost_grasshopper_cipher_ctx *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 263     c->type = GRASSHOPPER_CIPHER_CFB;
 264     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 265 }
 266
 267 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ctr(EVP_CIPHER_CTX *ctx,
 268                                                         const unsigned char
 269                                                         *key,
 270                                                         const unsigned char
 271                                                         *iv, int enc) {
 272     gost_grasshopper_cipher_ctx_ctr *c =
 273         EVP_CIPHER_CTX_get_cipher_data(ctx);
 274
 275     c->c.type = GRASSHOPPER_CIPHER_CTR;
 276     EVP_CIPHER_CTX_set_num(ctx, 0);
 277
 278     grasshopper_zero128(&c->partial_buffer);
 279
 280     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 281 }
 282
 283 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ctracpkm(EVP_CIPHER_CTX
 284                                                              *ctx,
 285                                                              const unsigned
 286                                                              char *key,
 287                                                              const unsigned
 288                                                              char *iv,
 289                                                              int enc) {
 290     gost_grasshopper_cipher_ctx_ctr *c =
 291         EVP_CIPHER_CTX_get_cipher_data(ctx);
 292
 293     /* NB: setting type makes EVP do_cipher callback useless */
 294     c->c.type = GRASSHOPPER_CIPHER_CTRACPKM;
 295     EVP_CIPHER_CTX_set_num(ctx, 0);
 296     c->section_size = 4096;
 297
 298     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 299 }
 300
 301 GRASSHOPPER_INLINE int gost_grasshopper_cipher_do(EVP_CIPHER_CTX *ctx,
 302                                                   unsigned char *out,
 303                                                   const unsigned char *in,
 304                                                   size_t inl) {
 305     gost_grasshopper_cipher_ctx *c =
 306         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 307     struct GRASSHOPPER_CIPHER_PARAMS *params = &gost_cipher_params[c->type];
 308
 309     return params->do_cipher(ctx, out, in, inl);
 310 }
 311
 312 int gost_grasshopper_cipher_do_ecb(EVP_CIPHER_CTX *ctx, unsigned char *out,
 313                                    const unsigned char *in, size_t inl) {
 314     gost_grasshopper_cipher_ctx *c =
 315         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 316     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
 317     const unsigned char *current_in = in;
 318     unsigned char *current_out = out;
 319     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 320     size_t i;
 321
 322     for (i = 0; i < blocks;
 323          i++, current_in += GRASSHOPPER_BLOCK_SIZE, current_out +=
 324          GRASSHOPPER_BLOCK_SIZE) {
 325         if (encrypting) {
 326             grasshopper_encrypt_block(&c->encrypt_round_keys,
 327                                       (grasshopper_w128_t *) current_in,
 328                                       (grasshopper_w128_t *) current_out,
 329                                       &c->buffer);
 330         } else {
 331             grasshopper_decrypt_block(&c->decrypt_round_keys,
 332                                       (grasshopper_w128_t *) current_in,
 333                                       (grasshopper_w128_t *) current_out,
 334                                       &c->buffer);
 335         }
 336     }
 337
 338     return 1;
 339 }
 340
 341 int gost_grasshopper_cipher_do_cbc(EVP_CIPHER_CTX *ctx, unsigned char *out,
 342                                    const unsigned char *in, size_t inl) {
 343     gost_grasshopper_cipher_ctx *c =
 344         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 345     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 346     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
 347     const unsigned char *current_in = in;
 348     unsigned char *current_out = out;
 349     grasshopper_w128_t *currentInputBlock;
 350     grasshopper_w128_t *currentOutputBlock;
 351     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 352     size_t i;
 353     grasshopper_w128_t *currentBlock;
 354
 355     currentBlock = (grasshopper_w128_t *) iv;
 356
 357     for (i = 0; i < blocks;
 358          i++, current_in += GRASSHOPPER_BLOCK_SIZE, current_out +=
 359          GRASSHOPPER_BLOCK_SIZE) {
 360         currentInputBlock = (grasshopper_w128_t *) current_in;
 361         currentOutputBlock = (grasshopper_w128_t *) current_out;
 362         if (encrypting) {
 363             grasshopper_append128(currentBlock, currentInputBlock);
 364             grasshopper_encrypt_block(&c->encrypt_round_keys, currentBlock,
 365                                       currentOutputBlock, &c->buffer);
 366             grasshopper_copy128(currentBlock, currentOutputBlock);
 367         } else {
 368             grasshopper_w128_t tmp;
 369
 370             grasshopper_copy128(&tmp, currentInputBlock);
 371             grasshopper_decrypt_block(&c->decrypt_round_keys,
 372                                       currentInputBlock, currentOutputBlock,
 373                                       &c->buffer);
 374             grasshopper_append128(currentOutputBlock, currentBlock);
 375             grasshopper_copy128(currentBlock, &tmp);
 376         }
 377     }
 378
 379     return 1;
 380 }
 381
 382 void inc_counter(unsigned char *counter, size_t counter_bytes) {
 383     unsigned char c;
 384     unsigned int n = counter_bytes;
 385
 386     do {
 387         --n;
 388         c = counter[n];
 389         ++c;
 390         counter[n] = c;
 391         if (c)
 392             return;
 393     } while (n);
 394 }
 395
 396 /* increment counter (128-bit int) by 1 */
 397 static void ctr128_inc(unsigned char *counter) {
 398     inc_counter(counter, 16);
 399 }
 400
 401 int gost_grasshopper_cipher_do_ctr(EVP_CIPHER_CTX *ctx, unsigned char *out,
 402                                    const unsigned char *in, size_t inl) {
 403     gost_grasshopper_cipher_ctx_ctr *c =
 404         (gost_grasshopper_cipher_ctx_ctr *)
 405         EVP_CIPHER_CTX_get_cipher_data(ctx);
 406     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 407     const unsigned char *current_in = in;
 408     unsigned char *current_out = out;
 409     grasshopper_w128_t *currentInputBlock;
 410     grasshopper_w128_t *currentOutputBlock;
 411     unsigned int n = EVP_CIPHER_CTX_num(ctx);
 412     size_t lasted;
 413     size_t i;
 414
 415     while (n && inl) {
 416         *(current_out++) = *(current_in++) ^ c->partial_buffer.b[n];
 417         --inl;
 418         n = (n + 1) % GRASSHOPPER_BLOCK_SIZE;
 419     }
 420     EVP_CIPHER_CTX_set_num(ctx, n);
 421     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 422
 423     grasshopper_w128_t *iv_buffer = (grasshopper_w128_t *) iv;
 424     grasshopper_w128_t tmp;
 425
 426     // full parts
 427     for (i = 0; i < blocks; i++) {
 428         currentInputBlock = (grasshopper_w128_t *) current_in;
 429         currentOutputBlock = (grasshopper_w128_t *) current_out;
 430         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer,
 431                                   &c->partial_buffer, &c->c.buffer);
 432         grasshopper_plus128(&tmp, &c->partial_buffer, currentInputBlock);
 433         grasshopper_copy128(currentOutputBlock, &tmp);
 434         ctr128_inc(iv_buffer->b);
 435         current_in += GRASSHOPPER_BLOCK_SIZE;
 436         current_out += GRASSHOPPER_BLOCK_SIZE;
 437     }
 438
 439     // last part
 440     lasted = inl - blocks * GRASSHOPPER_BLOCK_SIZE;
 441     if (lasted > 0) {
 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         for (i = 0; i < lasted; i++) {
 447             currentOutputBlock->b[i] =
 448                 c->partial_buffer.b[i] ^ currentInputBlock->b[i];
 449         }
 450         EVP_CIPHER_CTX_set_num(ctx, i);
 451         ctr128_inc(iv_buffer->b);
 452     }
 453
 454     return 1;
 455 }
 456
 457 #define GRASSHOPPER_BLOCK_MASK (GRASSHOPPER_BLOCK_SIZE - 1)
 458 static inline void apply_acpkm_grasshopper(gost_grasshopper_cipher_ctx_ctr *
 459                                            ctx, unsigned int *num) {
 460     if (!ctx->section_size || (*num < ctx->section_size))
 461         return;
 462     acpkm_next(&ctx->c);
 463     *num &= GRASSHOPPER_BLOCK_MASK;
 464 }
 465
 466 /* If meshing is not configured via ctrl (setting section_size)
 467  * this function works exactly like plain ctr */
 468 int gost_grasshopper_cipher_do_ctracpkm(EVP_CIPHER_CTX *ctx,
 469                                         unsigned char *out,
 470                                         const unsigned char *in,
 471                                         size_t inl) {
 472     gost_grasshopper_cipher_ctx_ctr *c =
 473         EVP_CIPHER_CTX_get_cipher_data(ctx);
 474     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 475     unsigned int num = EVP_CIPHER_CTX_num(ctx);
 476
 477     while ((num & GRASSHOPPER_BLOCK_MASK) && inl) {
 478         *out++ = *in++ ^ c->partial_buffer.b[num & GRASSHOPPER_BLOCK_MASK];
 479         --inl;
 480         num++;
 481     }
 482     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 483     size_t i;
 484     grasshopper_w128_t tmp;
 485
 486     // full parts
 487     for (i = 0; i < blocks; i++) {
 488         apply_acpkm_grasshopper(c, &num);
 489         grasshopper_encrypt_block(&c->c.encrypt_round_keys,
 490                                   (grasshopper_w128_t *) iv,
 491                                   (grasshopper_w128_t *) &c->partial_buffer, &c->c.buffer);
 492         grasshopper_plus128(&tmp, &c->partial_buffer, (grasshopper_w128_t *) in);
 493         grasshopper_copy128((grasshopper_w128_t *) out, &tmp);
 494         ctr128_inc(iv);
 495         in += GRASSHOPPER_BLOCK_SIZE;
 496         out += GRASSHOPPER_BLOCK_SIZE;
 497         num += GRASSHOPPER_BLOCK_SIZE;
 498     }
 499
 500     // last part
 501     size_t lasted = inl - blocks * GRASSHOPPER_BLOCK_SIZE;
 502     if (lasted > 0) {
 503         apply_acpkm_grasshopper(c, &num);
 504         grasshopper_encrypt_block(&c->c.encrypt_round_keys,
 505                                   (grasshopper_w128_t *) iv,
 506                                   &c->partial_buffer, &c->c.buffer);
 507         for (i = 0; i < lasted; i++)
 508             out[i] = c->partial_buffer.b[i] ^ in[i];
 509         ctr128_inc(iv);
 510         num += lasted;
 511     }
 512     EVP_CIPHER_CTX_set_num(ctx, num);
 513
 514     return 1;
 515 }
 516
 517 /*
 518  * Fixed 128-bit IV implementation make shift regiser redundant.
 519  */
 520 static void gost_grasshopper_cnt_next(gost_grasshopper_cipher_ctx_ofb * ctx,
 521                                       grasshopper_w128_t * iv,
 522                                       grasshopper_w128_t * buf) {
 523     memcpy(&ctx->buffer1, iv, 16);
 524     grasshopper_encrypt_block(&ctx->c.encrypt_round_keys, &ctx->buffer1,
 525                               buf, &ctx->c.buffer);
 526     memcpy(iv, buf, 16);
 527 }
 528
 529 int gost_grasshopper_cipher_do_ofb(EVP_CIPHER_CTX *ctx, unsigned char *out,
 530                                    const unsigned char *in, size_t inl) {
 531     gost_grasshopper_cipher_ctx_ofb *c =
 532         (gost_grasshopper_cipher_ctx_ofb *)
 533         EVP_CIPHER_CTX_get_cipher_data(ctx);
 534     const unsigned char *in_ptr = in;
 535     unsigned char *out_ptr = out;
 536     unsigned char *buf = EVP_CIPHER_CTX_buf_noconst(ctx);
 537     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 538     int num = EVP_CIPHER_CTX_num(ctx);
 539     size_t i = 0;
 540     size_t j;
 541
 542     /* process partial block if any */
 543     if (num > 0) {
 544         for (j = (size_t)num, i = 0; j < GRASSHOPPER_BLOCK_SIZE && i < inl;
 545              j++, i++, in_ptr++, out_ptr++) {
 546             *out_ptr = buf[j] ^ (*in_ptr);
 547         }
 548         if (j == GRASSHOPPER_BLOCK_SIZE) {
 549             EVP_CIPHER_CTX_set_num(ctx, 0);
 550         } else {
 551             EVP_CIPHER_CTX_set_num(ctx, (int)j);
 552             return 1;
 553         }
 554     }
 555
 556     for (; i + GRASSHOPPER_BLOCK_SIZE <
 557          inl;
 558          i += GRASSHOPPER_BLOCK_SIZE, in_ptr +=
 559          GRASSHOPPER_BLOCK_SIZE, out_ptr += GRASSHOPPER_BLOCK_SIZE) {
 560         /*
 561          * block cipher current iv
 562          */
 563         /* Encrypt */
 564         gost_grasshopper_cnt_next(c, (grasshopper_w128_t *) iv,
 565                                   (grasshopper_w128_t *) buf);
 566
 567         /*
 568          * xor next block of input text with it and output it
 569          */
 570         /*
 571          * output this block
 572          */
 573         for (j = 0; j < GRASSHOPPER_BLOCK_SIZE; j++) {
 574             out_ptr[j] = buf[j] ^ in_ptr[j];
 575         }
 576     }
 577
 578     /* Process rest of buffer */
 579     if (i < inl) {
 580         gost_grasshopper_cnt_next(c, (grasshopper_w128_t *) iv,
 581                                   (grasshopper_w128_t *) buf);
 582         for (j = 0; i < inl; j++, i++) {
 583             out_ptr[j] = buf[j] ^ in_ptr[j];
 584         }
 585         EVP_CIPHER_CTX_set_num(ctx, (int)j);
 586     } else {
 587         EVP_CIPHER_CTX_set_num(ctx, 0);
 588     }
 589
 590     return 1;
 591 }
 592
 593 int gost_grasshopper_cipher_do_cfb(EVP_CIPHER_CTX *ctx, unsigned char *out,
 594                                    const unsigned char *in, size_t inl) {
 595     gost_grasshopper_cipher_ctx *c =
 596         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 597     const unsigned char *in_ptr = in;
 598     unsigned char *out_ptr = out;
 599     unsigned char *buf = EVP_CIPHER_CTX_buf_noconst(ctx);
 600     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 601     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
 602     int num = EVP_CIPHER_CTX_num(ctx);
 603     size_t i = 0;
 604     size_t j = 0;
 605
 606     /* process partial block if any */
 607     if (num > 0) {
 608         for (j = (size_t)num, i = 0; j < GRASSHOPPER_BLOCK_SIZE && i < inl;
 609              j++, i++, in_ptr++, out_ptr++) {
 610             if (!encrypting) {
 611                 buf[j + GRASSHOPPER_BLOCK_SIZE] = *in_ptr;
 612             }
 613             *out_ptr = buf[j] ^ (*in_ptr);
 614             if (encrypting) {
 615                 buf[j + GRASSHOPPER_BLOCK_SIZE] = *out_ptr;
 616             }
 617         }
 618         if (j == GRASSHOPPER_BLOCK_SIZE) {
 619             memcpy(iv, buf + GRASSHOPPER_BLOCK_SIZE,
 620                    GRASSHOPPER_BLOCK_SIZE);
 621             EVP_CIPHER_CTX_set_num(ctx, 0);
 622         } else {
 623             EVP_CIPHER_CTX_set_num(ctx, (int)j);
 624             return 1;
 625         }
 626     }
 627
 628     for (; i + GRASSHOPPER_BLOCK_SIZE <
 629          inl;
 630          i += GRASSHOPPER_BLOCK_SIZE, in_ptr +=
 631          GRASSHOPPER_BLOCK_SIZE, out_ptr += GRASSHOPPER_BLOCK_SIZE) {
 632         /*
 633          * block cipher current iv
 634          */
 635         grasshopper_encrypt_block(&c->encrypt_round_keys,
 636                                   (grasshopper_w128_t *) iv,
 637                                   (grasshopper_w128_t *) buf, &c->buffer);
 638         /*
 639          * xor next block of input text with it and output it
 640          */
 641         /*
 642          * output this block
 643          */
 644         if (!encrypting) {
 645             memcpy(iv, in_ptr, GRASSHOPPER_BLOCK_SIZE);
 646         }
 647         for (j = 0; j < GRASSHOPPER_BLOCK_SIZE; j++) {
 648             out_ptr[j] = buf[j] ^ in_ptr[j];
 649         }
 650         /* Encrypt */
 651         /* Next iv is next block of cipher text */
 652         if (encrypting) {
 653             memcpy(iv, out_ptr, GRASSHOPPER_BLOCK_SIZE);
 654         }
 655     }
 656
 657     /* Process rest of buffer */
 658     if (i < inl) {
 659         grasshopper_encrypt_block(&c->encrypt_round_keys,
 660                                   (grasshopper_w128_t *) iv,
 661                                   (grasshopper_w128_t *) buf, &c->buffer);
 662         if (!encrypting) {
 663             memcpy(buf + GRASSHOPPER_BLOCK_SIZE, in_ptr, inl - i);
 664         }
 665         for (j = 0; i < inl; j++, i++) {
 666             out_ptr[j] = buf[j] ^ in_ptr[j];
 667         }
 668         EVP_CIPHER_CTX_set_num(ctx, (int)j);
 669         if (encrypting) {
 670             memcpy(buf + GRASSHOPPER_BLOCK_SIZE, out_ptr, j);
 671         }
 672     } else {
 673         EVP_CIPHER_CTX_set_num(ctx, 0);
 674     }
 675
 676     return 1;
 677 }
 678
 679 int gost_grasshopper_cipher_cleanup(EVP_CIPHER_CTX *ctx) {
 680     gost_grasshopper_cipher_ctx *c =
 681         (gost_grasshopper_cipher_ctx *) EVP_CIPHER_CTX_get_cipher_data(ctx);
 682
 683     if (!c)
 684         return 1;
 685
 686     struct GRASSHOPPER_CIPHER_PARAMS *params = &gost_cipher_params[c->type];
 687
 688     gost_grasshopper_cipher_destroy(c);
 689     if (params->destroy_cipher != NULL) {
 690         params->destroy_cipher(c);
 691     }
 692
 693     EVP_CIPHER_CTX_set_app_data(ctx, NULL);
 694
 695     return 1;
 696 }
 697
 698 int gost_grasshopper_set_asn1_parameters(EVP_CIPHER_CTX *ctx,
 699                                          ASN1_TYPE *params) {
 700     int len = 0;
 701     unsigned char *buf = NULL;
 702     ASN1_OCTET_STRING *os = NULL;
 703
 704     os = ASN1_OCTET_STRING_new();
 705
 706     if (!os || !ASN1_OCTET_STRING_set(os, buf, len)) {
 707         OPENSSL_free(buf);
 708         GOSTerr(GOST_F_GOST_GRASSHOPPER_SET_ASN1_PARAMETERS,
 709                 ERR_R_MALLOC_FAILURE);
 710         return 0;
 711     }
 712     OPENSSL_free(buf);
 713
 714     ASN1_TYPE_set(params, V_ASN1_SEQUENCE, os);
 715     return 1;
 716 }
 717
 718 GRASSHOPPER_INLINE int gost_grasshopper_get_asn1_parameters(EVP_CIPHER_CTX
 719                                                             *ctx,
 720                                                             ASN1_TYPE
 721                                                             *params) {
 722     int ret = -1;
 723
 724     if (ASN1_TYPE_get(params) != V_ASN1_SEQUENCE) {
 725         return ret;
 726     }
 727
 728     return 1;
 729 }
 730
 731 int gost_grasshopper_cipher_ctl(EVP_CIPHER_CTX *ctx, int type, int arg,
 732                                 void *ptr) {
 733     switch (type) {
 734     case EVP_CTRL_RAND_KEY:{
 735             if (RAND_bytes
 736                 ((unsigned char *)ptr,
 737                  EVP_CIPHER_CTX_key_length(ctx)) <= 0) {
 738                 GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL,
 739                         GOST_R_RNG_ERROR);
 740                 return -1;
 741             }
 742             break;
 743         }
 744     case EVP_CTRL_KEY_MESH:{
 745             gost_grasshopper_cipher_ctx_ctr *c =
 746                 EVP_CIPHER_CTX_get_cipher_data(ctx);
 747             if (c->c.type != GRASSHOPPER_CIPHER_CTRACPKM || !arg
 748                 || (arg % GRASSHOPPER_BLOCK_SIZE))
 749                 return -1;
 750             c->section_size = arg;
 751             break;
 752         }
 753     default:
 754         GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL,
 755                 GOST_R_UNSUPPORTED_CIPHER_CTL_COMMAND);
 756         return -1;
 757     }
 758     return 1;
 759 }
 760
 761 GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_create(int
 762                                                               cipher_type,
 763                                                               int
 764                                                               block_size) {
 765     return EVP_CIPHER_meth_new(cipher_type, block_size /* block_size */ ,
 766                                GRASSHOPPER_KEY_SIZE /* key_size */ );
 767 }
 768
 769 const int cipher_gost_grasshopper_setup(EVP_CIPHER *cipher, uint8_t mode,
 770                                         int iv_size, bool padding) {
 771     return EVP_CIPHER_meth_set_iv_length(cipher, iv_size)
 772         && EVP_CIPHER_meth_set_flags(cipher,
 773                                      (unsigned long)(mode |
 774                                                      ((!padding) ?
 775                                                       EVP_CIPH_NO_PADDING :
 776                                                       0) | ((iv_size >
 777                                                              0) ?
 778                                                             EVP_CIPH_CUSTOM_IV
 779                                                             : 0) |
 780                                                      EVP_CIPH_RAND_KEY |
 781                                                      EVP_CIPH_ALWAYS_CALL_INIT)
 782         )
 783         && EVP_CIPHER_meth_set_cleanup(cipher,
 784                                        gost_grasshopper_cipher_cleanup)
 785         && EVP_CIPHER_meth_set_set_asn1_params(cipher,
 786                                                gost_grasshopper_set_asn1_parameters)
 787         && EVP_CIPHER_meth_set_get_asn1_params(cipher,
 788                                                gost_grasshopper_get_asn1_parameters)
 789         && EVP_CIPHER_meth_set_ctrl(cipher, gost_grasshopper_cipher_ctl)
 790         && EVP_CIPHER_meth_set_do_cipher(cipher,
 791                                          gost_grasshopper_cipher_do);
 792 }
 793
 794 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper(uint8_t mode,
 795                                                              uint8_t num) {
 796     EVP_CIPHER **cipher;
 797     struct GRASSHOPPER_CIPHER_PARAMS *params;
 798
 799     cipher = &gost_grasshopper_ciphers[num];
 800
 801     if (*cipher == NULL) {
 802         params = &gost_cipher_params[num];
 803
 804         int nid = params->nid;
 805         grasshopper_init_cipher_func init_cipher = params->init_cipher;
 806         int block_size = params->block_size;
 807         int ctx_size = params->ctx_size;
 808         int iv_size = params->iv_size;
 809         bool padding = params->padding;
 810
 811         *cipher = cipher_gost_grasshopper_create(nid, block_size);
 812         if (*cipher == NULL) {
 813             return NULL;
 814         }
 815
 816         if (!cipher_gost_grasshopper_setup(*cipher, mode, iv_size, padding)
 817             || !EVP_CIPHER_meth_set_init(*cipher, init_cipher)
 818             || !EVP_CIPHER_meth_set_impl_ctx_size(*cipher, ctx_size)) {
 819             EVP_CIPHER_meth_free(*cipher);
 820             *cipher = NULL;
 821         }
 822     }
 823
 824     return *cipher;
 825 }
 826
 827 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ecb() {
 828     return cipher_gost_grasshopper(EVP_CIPH_ECB_MODE,
 829                                    GRASSHOPPER_CIPHER_ECB);
 830 }
 831
 832 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_cbc() {
 833     return cipher_gost_grasshopper(EVP_CIPH_CBC_MODE,
 834                                    GRASSHOPPER_CIPHER_CBC);
 835 }
 836
 837 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ofb() {
 838     return cipher_gost_grasshopper(EVP_CIPH_OFB_MODE,
 839                                    GRASSHOPPER_CIPHER_OFB);
 840 }
 841
 842 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_cfb() {
 843     return cipher_gost_grasshopper(EVP_CIPH_CFB_MODE,
 844                                    GRASSHOPPER_CIPHER_CFB);
 845 }
 846
 847 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ctr() {
 848     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE,
 849                                    GRASSHOPPER_CIPHER_CTR);
 850 }
 851
 852 const GRASSHOPPER_INLINE EVP_CIPHER *cipher_gost_grasshopper_ctracpkm() {
 853     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE,
 854                                    GRASSHOPPER_CIPHER_CTRACPKM);
 855 }
 856
 857 void cipher_gost_grasshopper_destroy(void) {
 858     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_ECB]);
 859     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_ECB] = NULL;
 860     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CBC]);
 861     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CBC] = NULL;
 862     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_OFB]);
 863     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_OFB] = NULL;
 864     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CFB]);
 865     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CFB] = NULL;
 866     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTR]);
 867     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTR] = NULL;
 868     EVP_CIPHER_meth_free(gost_grasshopper_ciphers
 869                          [GRASSHOPPER_CIPHER_CTRACPKM]);
 870     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKM] = NULL;
 871 }
 872
 873 #if defined(__cplusplus)
 874 }
 875 #endif