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 gost_grasshopper_cipher_destroy_ofb(gost_grasshopper_cipher_ctx* c);
  42 static GRASSHOPPER_INLINE void gost_grasshopper_cipher_destroy_ctr(gost_grasshopper_cipher_ctx* c);
  43
  44 struct GRASSHOPPER_CIPHER_PARAMS {
  45     int nid;
  46     grasshopper_init_cipher_func init_cipher;
  47     grasshopper_do_cipher_func do_cipher;
  48     grasshopper_destroy_cipher_func destroy_cipher;
  49     int block_size;
  50     int ctx_size;
  51     int iv_size;
  52     bool padding;
  53 };
  54
  55 static struct GRASSHOPPER_CIPHER_PARAMS gost_cipher_params[6] = {
  56         [GRASSHOPPER_CIPHER_ECB] = {
  57                 NID_grasshopper_ecb,
  58                 gost_grasshopper_cipher_init_ecb,
  59                 gost_grasshopper_cipher_do_ecb,
  60                 NULL,
  61                 16,
  62                 sizeof(gost_grasshopper_cipher_ctx),
  63                 0,
  64                 true
  65         },
  66         [GRASSHOPPER_CIPHER_CBC] = {
  67                 NID_grasshopper_cbc,
  68                 gost_grasshopper_cipher_init_cbc,
  69                 gost_grasshopper_cipher_do_cbc,
  70                 NULL,
  71                 16,
  72                 sizeof(gost_grasshopper_cipher_ctx),
  73                 16,
  74                 true
  75         },
  76         [GRASSHOPPER_CIPHER_OFB] = {
  77                 NID_grasshopper_ofb,
  78                 gost_grasshopper_cipher_init_ofb,
  79                 gost_grasshopper_cipher_do_ofb,
  80                 gost_grasshopper_cipher_destroy_ofb,
  81                 1,
  82                 sizeof(gost_grasshopper_cipher_ctx_ofb),
  83                 16,
  84                 false
  85         },
  86         [GRASSHOPPER_CIPHER_CFB] = {
  87                 NID_grasshopper_cfb,
  88                 gost_grasshopper_cipher_init_cfb,
  89                 gost_grasshopper_cipher_do_cfb,
  90                 NULL,
  91                 1,
  92                 sizeof(gost_grasshopper_cipher_ctx),
  93                 16,
  94                 false
  95         },
  96         [GRASSHOPPER_CIPHER_CTR] = {
  97                 NID_grasshopper_ctr,
  98                 gost_grasshopper_cipher_init_ctr,
  99                 gost_grasshopper_cipher_do_ctr,
 100                 gost_grasshopper_cipher_destroy_ctr,
 101                 1,
 102                 sizeof(gost_grasshopper_cipher_ctx_ctr),
 103                 /* IV size is set to match full block, to make it responsibility of
 104                  * user to assign correct values (IV || 0), and to make naive context
 105                  * copy possible (for software such as openssh) */
 106                 16,
 107                 false
 108         },
 109         [GRASSHOPPER_CIPHER_CTRACPKM] = {
 110                 NID_id_tc26_cipher_gostr3412_2015_kuznyechik_ctracpkm,
 111                 gost_grasshopper_cipher_init_ctracpkm,
 112                 gost_grasshopper_cipher_do_ctracpkm,
 113                 gost_grasshopper_cipher_destroy_ctr,
 114                 1,
 115                 sizeof(gost_grasshopper_cipher_ctx_ctr),
 116                 16,
 117                 false
 118         },
 119 };
 120
 121 /* first 256 bit of D from draft-irtf-cfrg-re-keying-12 */
 122 static const unsigned char ACPKM_D_2018[] = {
 123     0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, /*  64 bit */
 124     0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, /* 128 bit */
 125     0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
 126     0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, /* 256 bit */
 127 };
 128
 129 static void acpkm_next(gost_grasshopper_cipher_ctx *c)
 130 {
 131     unsigned char newkey[GRASSHOPPER_KEY_SIZE];
 132     const int J = GRASSHOPPER_KEY_SIZE / GRASSHOPPER_BLOCK_SIZE;
 133     int n;
 134
 135     for (n = 0; n < J; n++) {
 136         const unsigned char *D_n = &ACPKM_D_2018[n * GRASSHOPPER_BLOCK_SIZE];
 137
 138         grasshopper_encrypt_block(&c->encrypt_round_keys,
 139             (grasshopper_w128_t *)D_n,
 140             (grasshopper_w128_t *)&newkey[n * GRASSHOPPER_BLOCK_SIZE],
 141             &c->buffer);
 142     }
 143     gost_grasshopper_cipher_key(c, newkey);
 144 }
 145
 146 /* Set 256 bit  key into context */
 147 GRASSHOPPER_INLINE void gost_grasshopper_cipher_key(gost_grasshopper_cipher_ctx* c, const uint8_t* k) {
 148                 int i;
 149     for (i = 0; i < 2; i++) {
 150         grasshopper_copy128(&c->key.k.k[i], (const grasshopper_w128_t*) (k + i * 16));
 151     }
 152     grasshopper_set_encrypt_key(&c->encrypt_round_keys, &c->key);
 153     grasshopper_set_decrypt_key(&c->decrypt_round_keys, &c->key);
 154 }
 155
 156 /* Cleans up key from context */
 157 GRASSHOPPER_INLINE void gost_grasshopper_cipher_destroy(gost_grasshopper_cipher_ctx* c) {
 158                 int i;
 159     for (i = 0; i < 2; i++) {
 160         grasshopper_zero128(&c->key.k.k[i]);
 161     }
 162     for (i = 0; i < GRASSHOPPER_ROUND_KEYS_COUNT; i++) {
 163         grasshopper_zero128(&c->encrypt_round_keys.k[i]);
 164     }
 165     for (i = 0; i < GRASSHOPPER_ROUND_KEYS_COUNT; i++) {
 166         grasshopper_zero128(&c->decrypt_round_keys.k[i]);
 167     }
 168     grasshopper_zero128(&c->buffer);
 169 }
 170
 171 static GRASSHOPPER_INLINE void gost_grasshopper_cipher_destroy_ofb(gost_grasshopper_cipher_ctx* c) {
 172     gost_grasshopper_cipher_ctx_ofb* ctx = (gost_grasshopper_cipher_ctx_ofb*) c;
 173
 174     grasshopper_zero128(&ctx->buffer1);
 175 }
 176
 177 static GRASSHOPPER_INLINE void gost_grasshopper_cipher_destroy_ctr(gost_grasshopper_cipher_ctx* c) {
 178     gost_grasshopper_cipher_ctx_ctr* ctx = (gost_grasshopper_cipher_ctx_ctr*) c;
 179
 180     grasshopper_zero128(&ctx->partial_buffer);
 181 }
 182
 183 int gost_grasshopper_cipher_init(EVP_CIPHER_CTX* ctx, const unsigned char* key,
 184                                         const unsigned char* iv, int enc) {
 185     gost_grasshopper_cipher_ctx* c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 186
 187     if (EVP_CIPHER_CTX_get_app_data(ctx) == NULL) {
 188         EVP_CIPHER_CTX_set_app_data(ctx, EVP_CIPHER_CTX_get_cipher_data(ctx));
 189     }
 190
 191     if (key != NULL) {
 192         gost_grasshopper_cipher_key(c, key);
 193     }
 194
 195     if (iv != NULL) {
 196         memcpy((unsigned char*) EVP_CIPHER_CTX_original_iv(ctx), iv,
 197                EVP_CIPHER_CTX_iv_length(ctx));
 198     }
 199
 200     memcpy(EVP_CIPHER_CTX_iv_noconst(ctx),
 201            EVP_CIPHER_CTX_original_iv(ctx),
 202            EVP_CIPHER_CTX_iv_length(ctx));
 203
 204     grasshopper_zero128(&c->buffer);
 205
 206     return 1;
 207 }
 208
 209 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ecb(EVP_CIPHER_CTX* ctx, const unsigned char* key,
 210                                                                const unsigned char* iv,
 211                                                                int enc) {
 212     gost_grasshopper_cipher_ctx* c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 213     c->type = GRASSHOPPER_CIPHER_ECB;
 214     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 215 }
 216
 217 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_cbc(EVP_CIPHER_CTX* ctx, const unsigned char* key,
 218                                                                const unsigned char* iv,
 219                                                                int enc) {
 220     gost_grasshopper_cipher_ctx* c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 221     c->type = GRASSHOPPER_CIPHER_CBC;
 222     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 223 }
 224
 225 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ofb(EVP_CIPHER_CTX* ctx, const unsigned char* key,
 226                                                                const unsigned char* iv,
 227                                                                int enc) {
 228     gost_grasshopper_cipher_ctx_ofb* c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 229
 230     c->c.type = GRASSHOPPER_CIPHER_OFB;
 231
 232     grasshopper_zero128(&c->buffer1);
 233
 234     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 235 }
 236
 237 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_cfb(EVP_CIPHER_CTX* ctx, const unsigned char* key,
 238                                                                const unsigned char* iv,
 239                                                                int enc) {
 240     gost_grasshopper_cipher_ctx* c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 241     c->type = GRASSHOPPER_CIPHER_CFB;
 242     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 243 }
 244
 245 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ctr(EVP_CIPHER_CTX* ctx, const unsigned char* key,
 246                                                                const unsigned char* iv,
 247                                                                int enc) {
 248     gost_grasshopper_cipher_ctx_ctr* c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 249
 250     c->c.type = GRASSHOPPER_CIPHER_CTR;
 251     EVP_CIPHER_CTX_set_num(ctx, 0);
 252
 253     grasshopper_zero128(&c->partial_buffer);
 254
 255     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 256 }
 257
 258 GRASSHOPPER_INLINE int gost_grasshopper_cipher_init_ctracpkm(EVP_CIPHER_CTX *ctx, const unsigned char *key,
 259                                                                const unsigned char *iv,
 260                                                                int enc) {
 261     gost_grasshopper_cipher_ctx_ctr *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 262
 263     /* NB: setting type makes EVP do_cipher callback useless */
 264     c->c.type = GRASSHOPPER_CIPHER_CTRACPKM;
 265     EVP_CIPHER_CTX_set_num(ctx, 0);
 266     c->section_size  = 4096;
 267
 268     return gost_grasshopper_cipher_init(ctx, key, iv, enc);
 269 }
 270
 271 GRASSHOPPER_INLINE int gost_grasshopper_cipher_do(EVP_CIPHER_CTX* ctx, unsigned char* out,
 272                                                          const unsigned char* in, size_t inl) {
 273     gost_grasshopper_cipher_ctx* c = (gost_grasshopper_cipher_ctx*) EVP_CIPHER_CTX_get_cipher_data(ctx);
 274     struct GRASSHOPPER_CIPHER_PARAMS* params = &gost_cipher_params[c->type];
 275
 276     return params->do_cipher(ctx, out, in, inl);
 277 }
 278
 279 int gost_grasshopper_cipher_do_ecb(EVP_CIPHER_CTX* ctx, unsigned char* out,
 280                                           const unsigned char* in, size_t inl) {
 281     gost_grasshopper_cipher_ctx* c = (gost_grasshopper_cipher_ctx*) EVP_CIPHER_CTX_get_cipher_data(ctx);
 282     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
 283     const unsigned char* current_in = in;
 284     unsigned char* current_out = out;
 285     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 286     size_t i;
 287
 288     for (i = 0; i < blocks; i++, current_in += GRASSHOPPER_BLOCK_SIZE, current_out += GRASSHOPPER_BLOCK_SIZE) {
 289         if (encrypting) {
 290             grasshopper_encrypt_block(&c->encrypt_round_keys, (grasshopper_w128_t*) current_in,
 291                                       (grasshopper_w128_t*) current_out,
 292                                       &c->buffer);
 293         } else {
 294             grasshopper_decrypt_block(&c->decrypt_round_keys, (grasshopper_w128_t*) current_in,
 295                                       (grasshopper_w128_t*) current_out,
 296                                       &c->buffer);
 297         }
 298     }
 299
 300     return 1;
 301 }
 302
 303 int gost_grasshopper_cipher_do_cbc(EVP_CIPHER_CTX* ctx, unsigned char* out,
 304                                           const unsigned char* in, size_t inl) {
 305     gost_grasshopper_cipher_ctx* c = (gost_grasshopper_cipher_ctx*) EVP_CIPHER_CTX_get_cipher_data(ctx);
 306     unsigned char* iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 307     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
 308     const unsigned char* current_in = in;
 309     unsigned char* current_out = out;
 310     grasshopper_w128_t* currentInputBlock;
 311     grasshopper_w128_t* currentOutputBlock;
 312     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 313     size_t i;
 314     grasshopper_w128_t* currentBlock;
 315
 316     currentBlock = (grasshopper_w128_t*) iv;
 317
 318     for (i = 0; i < blocks; i++, current_in += GRASSHOPPER_BLOCK_SIZE, current_out += GRASSHOPPER_BLOCK_SIZE) {
 319         currentInputBlock = (grasshopper_w128_t*) current_in;
 320         currentOutputBlock = (grasshopper_w128_t*) current_out;
 321         if (encrypting) {
 322             grasshopper_append128(currentBlock, currentInputBlock);
 323             grasshopper_encrypt_block(&c->encrypt_round_keys, currentBlock, currentOutputBlock, &c->buffer);
 324             grasshopper_copy128(currentBlock, currentOutputBlock);
 325         } else {
 326             grasshopper_decrypt_block(&c->decrypt_round_keys, currentInputBlock, currentOutputBlock, &c->buffer);
 327             grasshopper_append128(currentOutputBlock, currentBlock);
 328             grasshopper_copy128(currentBlock, currentInputBlock);
 329         }
 330     }
 331
 332     return 1;
 333 }
 334
 335 void inc_counter(unsigned char* counter, size_t counter_bytes)
 336 {
 337     unsigned char c;
 338     unsigned int n = counter_bytes;
 339
 340     do {
 341         --n;
 342         c = counter[n];
 343         ++c;
 344         counter[n] = c;
 345         if (c) return;
 346     } while (n);
 347 }
 348
 349 /* increment counter (128-bit int) by 1 */
 350 static void ctr128_inc(unsigned char *counter)
 351 {
 352         inc_counter(counter, 16);
 353 }
 354
 355 int gost_grasshopper_cipher_do_ctr(EVP_CIPHER_CTX* ctx, unsigned char* out,
 356                                           const unsigned char* in, size_t inl) {
 357     gost_grasshopper_cipher_ctx_ctr* c = (gost_grasshopper_cipher_ctx_ctr*) EVP_CIPHER_CTX_get_cipher_data(ctx);
 358     unsigned char* iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 359     const unsigned char* current_in = in;
 360     unsigned char* current_out = out;
 361     grasshopper_w128_t* currentInputBlock;
 362     grasshopper_w128_t* currentOutputBlock;
 363     unsigned int n = EVP_CIPHER_CTX_num(ctx);
 364     size_t lasted;
 365     size_t i;
 366
 367     while (n && inl) {
 368         *(current_out++) = *(current_in++) ^ c->partial_buffer.b[n];
 369         --inl;
 370         n = (n + 1) % GRASSHOPPER_BLOCK_SIZE;
 371     }
 372     EVP_CIPHER_CTX_set_num(ctx, n);
 373     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 374
 375     grasshopper_w128_t* iv_buffer = (grasshopper_w128_t*) iv;
 376
 377     // full parts
 378     for (i = 0; i < blocks; i++) {
 379         currentInputBlock = (grasshopper_w128_t*) current_in;
 380         currentOutputBlock = (grasshopper_w128_t*) current_out;
 381         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer, currentOutputBlock, &c->c.buffer);
 382         grasshopper_append128(currentOutputBlock, currentInputBlock);
 383         ctr128_inc(iv_buffer->b);
 384         current_in += GRASSHOPPER_BLOCK_SIZE;
 385         current_out += GRASSHOPPER_BLOCK_SIZE;
 386     }
 387
 388     // last part
 389     lasted = inl - blocks * GRASSHOPPER_BLOCK_SIZE;
 390     if (lasted > 0) {
 391         currentInputBlock = (grasshopper_w128_t*) current_in;
 392         currentOutputBlock = (grasshopper_w128_t*) current_out;
 393         grasshopper_encrypt_block(&c->c.encrypt_round_keys, iv_buffer, &c->partial_buffer, &c->c.buffer);
 394         for (i = 0; i < lasted; i++) {
 395             currentOutputBlock->b[i] = c->partial_buffer.b[i] ^ currentInputBlock->b[i];
 396         }
 397         EVP_CIPHER_CTX_set_num(ctx, i);
 398         ctr128_inc(iv_buffer->b);
 399     }
 400
 401     return 1;
 402 }
 403
 404 #define GRASSHOPPER_BLOCK_MASK (GRASSHOPPER_BLOCK_SIZE - 1)
 405 static inline void apply_acpkm_grasshopper(gost_grasshopper_cipher_ctx_ctr *ctx, unsigned int *num)
 406 {
 407     if (!ctx->section_size ||
 408         (*num < ctx->section_size))
 409         return;
 410     acpkm_next(&ctx->c);
 411     *num &= GRASSHOPPER_BLOCK_MASK;
 412 }
 413
 414 /* If meshing is not configured via ctrl (setting section_size)
 415  * this function works exactly like plain ctr */
 416 int gost_grasshopper_cipher_do_ctracpkm(EVP_CIPHER_CTX *ctx, unsigned char *out,
 417     const unsigned char *in, size_t inl) {
 418     gost_grasshopper_cipher_ctx_ctr *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 419     unsigned char *iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 420     unsigned int num = EVP_CIPHER_CTX_num(ctx);
 421
 422     while ((num & GRASSHOPPER_BLOCK_MASK) && inl) {
 423         *out++ = *in++ ^ c->partial_buffer.b[num & GRASSHOPPER_BLOCK_MASK];
 424         --inl;
 425         num++;
 426     }
 427     size_t blocks = inl / GRASSHOPPER_BLOCK_SIZE;
 428     size_t i;
 429
 430     // full parts
 431     for (i = 0; i < blocks; i++) {
 432         apply_acpkm_grasshopper(c, &num);
 433         grasshopper_encrypt_block(&c->c.encrypt_round_keys,
 434             (grasshopper_w128_t *)iv, (grasshopper_w128_t *)out, &c->c.buffer);
 435         grasshopper_append128((grasshopper_w128_t *)out, (grasshopper_w128_t *)in);
 436         ctr128_inc(iv);
 437         in  += GRASSHOPPER_BLOCK_SIZE;
 438         out += GRASSHOPPER_BLOCK_SIZE;
 439         num += GRASSHOPPER_BLOCK_SIZE;
 440     }
 441
 442     // last part
 443     size_t lasted = inl - blocks * GRASSHOPPER_BLOCK_SIZE;
 444     if (lasted > 0) {
 445         apply_acpkm_grasshopper(c, &num);
 446         grasshopper_encrypt_block(&c->c.encrypt_round_keys,
 447             (grasshopper_w128_t *)iv, &c->partial_buffer, &c->c.buffer);
 448         for (i = 0; i < lasted; i++)
 449             out[i] = c->partial_buffer.b[i] ^ in[i];
 450         ctr128_inc(iv);
 451         num += lasted;
 452     }
 453     EVP_CIPHER_CTX_set_num(ctx, num);
 454
 455     return 1;
 456 }
 457
 458 /*
 459  * Fixed 128-bit IV implementation make shift regiser redundant.
 460  */
 461 static void gost_grasshopper_cnt_next(gost_grasshopper_cipher_ctx_ofb* ctx, grasshopper_w128_t* iv,
 462                                       grasshopper_w128_t* buf) {
 463     memcpy(&ctx->buffer1, iv, 16);
 464     grasshopper_encrypt_block(&ctx->c.encrypt_round_keys, &ctx->buffer1, buf, &ctx->c.buffer);
 465     memcpy(iv, buf, 16);
 466 }
 467
 468 int gost_grasshopper_cipher_do_ofb(EVP_CIPHER_CTX* ctx, unsigned char* out,
 469                                           const unsigned char* in, size_t inl) {
 470     gost_grasshopper_cipher_ctx_ofb* c = (gost_grasshopper_cipher_ctx_ofb*) EVP_CIPHER_CTX_get_cipher_data(ctx);
 471     const unsigned char* in_ptr = in;
 472     unsigned char* out_ptr = out;
 473     unsigned char* buf = EVP_CIPHER_CTX_buf_noconst(ctx);
 474     unsigned char* iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 475     int num = EVP_CIPHER_CTX_num(ctx);
 476     size_t i = 0;
 477     size_t j;
 478
 479     /* process partial block if any */
 480     if (num > 0) {
 481         for (j = (size_t) num, i = 0; j < GRASSHOPPER_BLOCK_SIZE && i < inl;
 482              j++, i++, in_ptr++, out_ptr++) {
 483             *out_ptr = buf[j] ^ (*in_ptr);
 484         }
 485         if (j == GRASSHOPPER_BLOCK_SIZE) {
 486             EVP_CIPHER_CTX_set_num(ctx, 0);
 487         } else {
 488             EVP_CIPHER_CTX_set_num(ctx, (int) j);
 489             return 1;
 490         }
 491     }
 492
 493     for (; i + GRASSHOPPER_BLOCK_SIZE <
 494            inl; i += GRASSHOPPER_BLOCK_SIZE, in_ptr += GRASSHOPPER_BLOCK_SIZE, out_ptr += GRASSHOPPER_BLOCK_SIZE) {
 495         /*
 496          * block cipher current iv
 497          */
 498         /* Encrypt */
 499         gost_grasshopper_cnt_next(c, (grasshopper_w128_t*) iv, (grasshopper_w128_t*) buf);
 500
 501         /*
 502          * xor next block of input text with it and output it
 503          */
 504         /*
 505          * output this block
 506          */
 507         for (j = 0; j < GRASSHOPPER_BLOCK_SIZE; j++) {
 508             out_ptr[j] = buf[j] ^ in_ptr[j];
 509         }
 510     }
 511
 512     /* Process rest of buffer */
 513     if (i < inl) {
 514         gost_grasshopper_cnt_next(c, (grasshopper_w128_t*) iv, (grasshopper_w128_t*) buf);
 515         for (j = 0; i < inl; j++, i++) {
 516             out_ptr[j] = buf[j] ^ in_ptr[j];
 517         }
 518         EVP_CIPHER_CTX_set_num(ctx, (int) j);
 519     } else {
 520         EVP_CIPHER_CTX_set_num(ctx, 0);
 521     }
 522
 523     return 1;
 524 }
 525
 526 int gost_grasshopper_cipher_do_cfb(EVP_CIPHER_CTX* ctx, unsigned char* out,
 527                                           const unsigned char* in, size_t inl) {
 528     gost_grasshopper_cipher_ctx* c = (gost_grasshopper_cipher_ctx*) EVP_CIPHER_CTX_get_cipher_data(ctx);
 529     const unsigned char* in_ptr = in;
 530     unsigned char* out_ptr = out;
 531     unsigned char* buf = EVP_CIPHER_CTX_buf_noconst(ctx);
 532     unsigned char* iv = EVP_CIPHER_CTX_iv_noconst(ctx);
 533     bool encrypting = (bool) EVP_CIPHER_CTX_encrypting(ctx);
 534     int num = EVP_CIPHER_CTX_num(ctx);
 535     size_t i = 0;
 536     size_t j = 0;
 537
 538     /* process partial block if any */
 539     if (num > 0) {
 540         for (j = (size_t) num, i = 0; j < GRASSHOPPER_BLOCK_SIZE && i < inl; j++, i++, in_ptr++, out_ptr++) {
 541             if (!encrypting) {
 542                 buf[j + GRASSHOPPER_BLOCK_SIZE] = *in_ptr;
 543             }
 544             *out_ptr = buf[j] ^ (*in_ptr);
 545             if (encrypting) {
 546                 buf[j + GRASSHOPPER_BLOCK_SIZE] = *out_ptr;
 547             }
 548         }
 549         if (j == GRASSHOPPER_BLOCK_SIZE) {
 550             memcpy(iv, buf + GRASSHOPPER_BLOCK_SIZE, GRASSHOPPER_BLOCK_SIZE);
 551             EVP_CIPHER_CTX_set_num(ctx, 0);
 552         } else {
 553             EVP_CIPHER_CTX_set_num(ctx, (int) j);
 554             return 1;
 555         }
 556     }
 557
 558     for (; i + GRASSHOPPER_BLOCK_SIZE <
 559            inl; i += GRASSHOPPER_BLOCK_SIZE, in_ptr += GRASSHOPPER_BLOCK_SIZE, out_ptr += GRASSHOPPER_BLOCK_SIZE) {
 560         /*
 561          * block cipher current iv
 562          */
 563         grasshopper_encrypt_block(&c->encrypt_round_keys, (grasshopper_w128_t*) iv, (grasshopper_w128_t*) buf,
 564                                   &c->buffer);
 565         /*
 566          * xor next block of input text with it and output it
 567          */
 568         /*
 569          * output this block
 570          */
 571         if (!encrypting) {
 572             memcpy(iv, in_ptr, GRASSHOPPER_BLOCK_SIZE);
 573         }
 574         for (j = 0; j < GRASSHOPPER_BLOCK_SIZE; j++) {
 575             out_ptr[j] = buf[j] ^ in_ptr[j];
 576         }
 577         /* Encrypt */
 578         /* Next iv is next block of cipher text */
 579         if (encrypting) {
 580             memcpy(iv, out_ptr, GRASSHOPPER_BLOCK_SIZE);
 581         }
 582     }
 583
 584     /* Process rest of buffer */
 585     if (i < inl) {
 586         grasshopper_encrypt_block(&c->encrypt_round_keys, (grasshopper_w128_t*) iv, (grasshopper_w128_t*) buf,
 587                                   &c->buffer);
 588         if (!encrypting) {
 589             memcpy(buf + GRASSHOPPER_BLOCK_SIZE, in_ptr, inl - i);
 590         }
 591         for (j = 0; i < inl; j++, i++) {
 592             out_ptr[j] = buf[j] ^ in_ptr[j];
 593         }
 594         EVP_CIPHER_CTX_set_num(ctx, (int) j);
 595         if (encrypting) {
 596             memcpy(buf + GRASSHOPPER_BLOCK_SIZE, out_ptr, j);
 597         }
 598     } else {
 599         EVP_CIPHER_CTX_set_num(ctx, 0);
 600     }
 601
 602     return 1;
 603 }
 604
 605 int gost_grasshopper_cipher_cleanup(EVP_CIPHER_CTX* ctx) {
 606     gost_grasshopper_cipher_ctx* c = (gost_grasshopper_cipher_ctx*) EVP_CIPHER_CTX_get_cipher_data(ctx);
 607
 608     if (!c)
 609         return 1;
 610
 611     struct GRASSHOPPER_CIPHER_PARAMS* params = &gost_cipher_params[c->type];
 612
 613     gost_grasshopper_cipher_destroy(c);
 614     if (params->destroy_cipher != NULL) {
 615         params->destroy_cipher(c);
 616     }
 617
 618     EVP_CIPHER_CTX_set_app_data(ctx, NULL);
 619
 620     return 1;
 621 }
 622
 623 int gost_grasshopper_set_asn1_parameters(EVP_CIPHER_CTX* ctx, ASN1_TYPE* params) {
 624     int len = 0;
 625     unsigned char* buf = NULL;
 626     ASN1_OCTET_STRING* os = NULL;
 627
 628     os = ASN1_OCTET_STRING_new();
 629
 630     if (!os || !ASN1_OCTET_STRING_set(os, buf, len)) {
 631         OPENSSL_free(buf);
 632         GOSTerr(GOST_F_GOST_GRASSHOPPER_SET_ASN1_PARAMETERS, ERR_R_MALLOC_FAILURE);
 633         return 0;
 634     }
 635     OPENSSL_free(buf);
 636
 637     ASN1_TYPE_set(params, V_ASN1_SEQUENCE, os);
 638     return 1;
 639 }
 640
 641 GRASSHOPPER_INLINE int gost_grasshopper_get_asn1_parameters(EVP_CIPHER_CTX* ctx, ASN1_TYPE* params) {
 642     int ret = -1;
 643
 644     if (ASN1_TYPE_get(params) != V_ASN1_SEQUENCE) {
 645         return ret;
 646     }
 647
 648     return 1;
 649 }
 650
 651 int gost_grasshopper_cipher_ctl(EVP_CIPHER_CTX* ctx, int type, int arg, void* ptr) {
 652     switch (type) {
 653         case EVP_CTRL_RAND_KEY: {
 654             if (RAND_bytes((unsigned char*) ptr, EVP_CIPHER_CTX_key_length(ctx)) <= 0) {
 655                 GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL, GOST_R_RNG_ERROR);
 656                 return -1;
 657             }
 658             break;
 659         }
 660         case EVP_CTRL_KEY_MESH: {
 661             gost_grasshopper_cipher_ctx_ctr *c = EVP_CIPHER_CTX_get_cipher_data(ctx);
 662             if (c->c.type != GRASSHOPPER_CIPHER_CTRACPKM ||
 663                 !arg || (arg % GRASSHOPPER_BLOCK_SIZE))
 664                 return -1;
 665             c->section_size = arg;
 666             break;
 667         }
 668         default:
 669             GOSTerr(GOST_F_GOST_GRASSHOPPER_CIPHER_CTL, GOST_R_UNSUPPORTED_CIPHER_CTL_COMMAND);
 670             return -1;
 671     }
 672     return 1;
 673 }
 674
 675 GRASSHOPPER_INLINE EVP_CIPHER* cipher_gost_grasshopper_create(int cipher_type, int block_size) {
 676     return EVP_CIPHER_meth_new(cipher_type,
 677                                block_size  /* block_size */,
 678                                GRASSHOPPER_KEY_SIZE /* key_size */);
 679 }
 680
 681 const int cipher_gost_grasshopper_setup(EVP_CIPHER* cipher, uint8_t mode, int iv_size, bool padding) {
 682     return EVP_CIPHER_meth_set_iv_length(cipher, iv_size) &&
 683            EVP_CIPHER_meth_set_flags(cipher, (unsigned long) (
 684                    mode |
 685                    ((!padding) ? EVP_CIPH_NO_PADDING : 0) |
 686                    ((iv_size > 0) ? EVP_CIPH_CUSTOM_IV : 0) |
 687                    EVP_CIPH_RAND_KEY |
 688                    EVP_CIPH_ALWAYS_CALL_INIT)
 689            ) &&
 690            EVP_CIPHER_meth_set_cleanup(cipher, gost_grasshopper_cipher_cleanup) &&
 691            EVP_CIPHER_meth_set_set_asn1_params(cipher, gost_grasshopper_set_asn1_parameters) &&
 692            EVP_CIPHER_meth_set_get_asn1_params(cipher, gost_grasshopper_get_asn1_parameters) &&
 693            EVP_CIPHER_meth_set_ctrl(cipher, gost_grasshopper_cipher_ctl) &&
 694            EVP_CIPHER_meth_set_do_cipher(cipher, gost_grasshopper_cipher_do);
 695 }
 696
 697 const GRASSHOPPER_INLINE EVP_CIPHER* cipher_gost_grasshopper(uint8_t mode, uint8_t num) {
 698     EVP_CIPHER** cipher;
 699     struct GRASSHOPPER_CIPHER_PARAMS* params;
 700
 701     cipher = &gost_grasshopper_ciphers[num];
 702
 703     if (*cipher == NULL) {
 704         params = &gost_cipher_params[num];
 705
 706         int nid = params->nid;
 707         grasshopper_init_cipher_func init_cipher = params->init_cipher;
 708         int block_size = params->block_size;
 709         int ctx_size = params->ctx_size;
 710         int iv_size = params->iv_size;
 711         bool padding = params->padding;
 712
 713         *cipher = cipher_gost_grasshopper_create(nid, block_size);
 714         if (*cipher == NULL) {
 715             return NULL;
 716         }
 717
 718         if (!cipher_gost_grasshopper_setup(*cipher, mode, iv_size, padding) ||
 719             !EVP_CIPHER_meth_set_init(*cipher, init_cipher) ||
 720             !EVP_CIPHER_meth_set_impl_ctx_size(*cipher, ctx_size)) {
 721             EVP_CIPHER_meth_free(*cipher);
 722             *cipher = NULL;
 723         }
 724     }
 725
 726     return *cipher;
 727 }
 728
 729 const GRASSHOPPER_INLINE EVP_CIPHER* cipher_gost_grasshopper_ecb() {
 730     return cipher_gost_grasshopper(EVP_CIPH_ECB_MODE, GRASSHOPPER_CIPHER_ECB);
 731 }
 732
 733 const GRASSHOPPER_INLINE EVP_CIPHER* cipher_gost_grasshopper_cbc() {
 734     return cipher_gost_grasshopper(EVP_CIPH_CBC_MODE, GRASSHOPPER_CIPHER_CBC);
 735 }
 736
 737 const GRASSHOPPER_INLINE EVP_CIPHER* cipher_gost_grasshopper_ofb() {
 738     return cipher_gost_grasshopper(EVP_CIPH_OFB_MODE, GRASSHOPPER_CIPHER_OFB);
 739 }
 740
 741 const GRASSHOPPER_INLINE EVP_CIPHER* cipher_gost_grasshopper_cfb() {
 742     return cipher_gost_grasshopper(EVP_CIPH_CFB_MODE, GRASSHOPPER_CIPHER_CFB);
 743 }
 744
 745 const GRASSHOPPER_INLINE EVP_CIPHER* cipher_gost_grasshopper_ctr() {
 746     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE, GRASSHOPPER_CIPHER_CTR);
 747 }
 748
 749 const GRASSHOPPER_INLINE EVP_CIPHER* cipher_gost_grasshopper_ctracpkm() {
 750     return cipher_gost_grasshopper(EVP_CIPH_CTR_MODE, GRASSHOPPER_CIPHER_CTRACPKM);
 751 }
 752
 753 void cipher_gost_grasshopper_destroy(void)
 754 {
 755     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_ECB]);
 756     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_ECB] = NULL;
 757     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CBC]);
 758     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CBC] = NULL;
 759     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_OFB]);
 760     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_OFB] = NULL;
 761     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CFB]);
 762     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CFB] = NULL;
 763     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTR]);
 764     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTR] = NULL;
 765     EVP_CIPHER_meth_free(gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKM]);
 766     gost_grasshopper_ciphers[GRASSHOPPER_CIPHER_CTRACPKM] = NULL;
 767 }
 768
 769 #if defined(__cplusplus)
 770 }
 771 #endif