engines/ccgost/gost_crypt.c

   1 /**********************************************************************
   2  *                          gost_crypt.c                              *
   3  *             Copyright (c) 2005-2006 Cryptocom LTD                  *
   4  *         This file is distributed under the same license as OpenSSL *
   5  *                                                                    *
   6  *       OpenSSL interface to GOST 28147-89 cipher functions          *
   7  *          Requires OpenSSL 0.9.9 for compilation                    *
   8  **********************************************************************/
   9 #include <string.h>
  10 #include "gost89.h"
  11 #include <openssl/rand.h>
  12 #include "e_gost_err.h"
  13 #include "gost_lcl.h"
  14 static int gost_cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
  15         const unsigned char *iv, int enc);
  16 static int      gost_cipher_init_cpa(EVP_CIPHER_CTX *ctx, const unsigned char *key,
  17         const unsigned char *iv, int enc);
  18 /* Handles block of data in CFB mode */
  19 static int      gost_cipher_do_cfb(EVP_CIPHER_CTX *ctx, unsigned char *out,
  20         const unsigned char *in, size_t inl);
  21 /* Handles block of data in CNT mode */
  22 static int      gost_cipher_do_cnt(EVP_CIPHER_CTX *ctx, unsigned char *out,
  23         const unsigned char *in, size_t inl);
  24 /* Cleanup function */
  25 static int gost_cipher_cleanup(EVP_CIPHER_CTX *);
  26 /* set/get cipher parameters */
  27 static int gost89_set_asn1_parameters(EVP_CIPHER_CTX *ctx,ASN1_TYPE *params);
  28 static int gost89_get_asn1_parameters(EVP_CIPHER_CTX *ctx,ASN1_TYPE *params);
  29 /* Control function */
  30 static int gost_cipher_ctl(EVP_CIPHER_CTX *ctx,int type,int arg,void *ptr);
  31
  32 EVP_CIPHER cipher_gost =
  33         {
  34         NID_id_Gost28147_89,
  35         1,/*block_size*/
  36         32,/*key_size*/
  37         8,/*iv_len - ñèíõðîïîñûëêà*/
  38         EVP_CIPH_CFB_MODE| EVP_CIPH_NO_PADDING |
  39         EVP_CIPH_CUSTOM_IV| EVP_CIPH_RAND_KEY | EVP_CIPH_ALWAYS_CALL_INIT,
  40         gost_cipher_init,
  41         gost_cipher_do_cfb,
  42         gost_cipher_cleanup,
  43         sizeof(struct ossl_gost_cipher_ctx),/* ctx_size */
  44         gost89_set_asn1_parameters,
  45         gost89_get_asn1_parameters,
  46         gost_cipher_ctl,
  47         NULL,
  48         };
  49
  50 EVP_CIPHER cipher_gost_cpacnt =
  51         {
  52         NID_gost89_cnt,
  53         1,/*block_size*/
  54         32,/*key_size*/
  55         8,/*iv_len - ñèíõðîïîñûëêà*/
  56         EVP_CIPH_OFB_MODE| EVP_CIPH_NO_PADDING |
  57         EVP_CIPH_CUSTOM_IV| EVP_CIPH_RAND_KEY | EVP_CIPH_ALWAYS_CALL_INIT,
  58         gost_cipher_init_cpa,
  59         gost_cipher_do_cnt,
  60         gost_cipher_cleanup,
  61         sizeof(struct ossl_gost_cipher_ctx), /* ctx_size */
  62         gost89_set_asn1_parameters,
  63         gost89_get_asn1_parameters,
  64         gost_cipher_ctl,
  65         NULL,
  66         };
  67
  68 /* Implementation of GOST 28147-89 in MAC (imitovstavka) mode */
  69 /* Init functions which set specific parameters */
  70 static int gost_imit_init_cpa(EVP_MD_CTX *ctx);
  71 /* process block of data */
  72 static int gost_imit_update(EVP_MD_CTX *ctx, const void *data, size_t count);
  73 /* Return computed value */
  74 static int gost_imit_final(EVP_MD_CTX *ctx,unsigned char *md);
  75 /* Copies context */
  76 static int gost_imit_copy(EVP_MD_CTX *to,const EVP_MD_CTX *from);
  77 static int gost_imit_cleanup(EVP_MD_CTX *ctx);
  78 /* Control function, knows how to set MAC key.*/
  79 static int gost_imit_ctrl(EVP_MD_CTX *ctx,int type, int arg, void *ptr);
  80
  81 EVP_MD imit_gost_cpa =
  82         {
  83         NID_id_Gost28147_89_MAC,
  84         NID_undef,
  85         4,
  86         0,
  87         gost_imit_init_cpa,
  88         gost_imit_update,
  89         gost_imit_final,
  90         gost_imit_copy,
  91         gost_imit_cleanup,
  92         NULL,
  93         NULL,
  94         {0,0,0,0,0},
  95         8,
  96         sizeof(struct ossl_gost_imit_ctx),
  97         gost_imit_ctrl
  98         };
  99
 100 /*
 101  * Correspondence between gost parameter OIDs and substitution blocks
 102  * NID field is filed by register_gost_NID function in engine.c
 103  * upon engine initialization
 104  */
 105
 106 struct gost_cipher_info gost_cipher_list[]=
 107         {
 108 /* NID */  /* Subst block */          /* Key meshing*/
 109 /*{NID_id_GostR3411_94_CryptoProParamSet,&GostR3411_94_CryptoProParamSet,0},*/
 110         {NID_id_Gost28147_89_cc,&GostR3411_94_CryptoProParamSet,0},
 111         {NID_id_Gost28147_89_CryptoPro_A_ParamSet,&Gost28147_CryptoProParamSetA,1},
 112         {NID_id_Gost28147_89_CryptoPro_B_ParamSet,&Gost28147_CryptoProParamSetB,1},
 113         {NID_id_Gost28147_89_CryptoPro_C_ParamSet,&Gost28147_CryptoProParamSetC,1},
 114         {NID_id_Gost28147_89_CryptoPro_D_ParamSet,&Gost28147_CryptoProParamSetD,1},
 115         {NID_id_Gost28147_89_TestParamSet,&Gost28147_TestParamSet,1},
 116         {NID_undef,NULL,0}
 117         };
 118
 119 /*  get encryption parameters from crypto network settings
 120         FIXME For now we use environment var CRYPT_PARAMS as place to
 121         store these settings. Actually, it is better to use engine control   command, read from configuration file to set them */
 122 const struct gost_cipher_info *get_encryption_params(ASN1_OBJECT *obj)
 123         {
 124         int nid;
 125         struct gost_cipher_info *param;
 126         if (!obj)
 127                 {
 128                 const char * params = get_gost_engine_param(GOST_PARAM_CRYPT_PARAMS);
 129                 if (!params || !strlen(params))
 130                         return &gost_cipher_list[1];
 131
 132                 nid = OBJ_txt2nid(params);
 133                 if (nid == NID_undef)
 134                         {
 135                         GOSTerr(GOST_F_GET_ENCRYPTION_PARAMS,
 136                                 GOST_R_INVALID_CIPHER_PARAM_OID);
 137                         return NULL;
 138                         }
 139                 }
 140         else
 141                 {
 142                 nid= OBJ_obj2nid(obj);
 143                 }
 144         for (param=gost_cipher_list;param->sblock!=NULL && param->nid!=nid;
 145                  param++);
 146         if (!param->sblock)
 147                 {
 148                 GOSTerr(GOST_F_GET_ENCRYPTION_PARAMS,GOST_R_INVALID_CIPHER_PARAMS);
 149                 return NULL;
 150                 }
 151         return param;
 152         }
 153
 154 /* Sets cipher param from paramset NID. */
 155 static int gost_cipher_set_param(struct ossl_gost_cipher_ctx *c,int nid)
 156         {
 157         const struct gost_cipher_info *param;
 158         param=get_encryption_params((nid==NID_undef?NULL:OBJ_nid2obj(nid)));
 159         if (!param) return 0;
 160
 161         c->paramNID = param->nid;
 162         c->key_meshing=param->key_meshing;
 163         c->count=0;
 164         gost_init(&(c->cctx), param->sblock);
 165         return 1;
 166         }
 167
 168 /* Initializes EVP_CIPHER_CTX by paramset NID */
 169 static int gost_cipher_init_param(EVP_CIPHER_CTX *ctx, const unsigned char *key,
 170         const unsigned char *iv, int enc, int paramNID,int mode)
 171         {
 172         struct ossl_gost_cipher_ctx *c=ctx->cipher_data;
 173         if (ctx->app_data == NULL)
 174                 {
 175                 if (!gost_cipher_set_param(c,paramNID)) return 0;
 176                 ctx->app_data = ctx->cipher_data;
 177                 }
 178         if (key) gost_key(&(c->cctx),key);
 179         if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 180         memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 181         return 1;
 182         }
 183
 184 static int gost_cipher_init_cpa(EVP_CIPHER_CTX *ctx, const unsigned char *key,
 185         const unsigned char *iv, int enc)
 186         {
 187         struct ossl_gost_cipher_ctx *c=ctx->cipher_data;
 188         gost_init(&(c->cctx),&Gost28147_CryptoProParamSetA);
 189         c->key_meshing=1;
 190         c->count=0;
 191         if(key) gost_key(&(c->cctx),key);
 192         if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
 193         memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
 194         return 1;
 195         }
 196
 197 /* Initializes EVP_CIPHER_CTX with default values */
 198 int gost_cipher_init(EVP_CIPHER_CTX *ctx, const unsigned char *key,
 199         const unsigned char *iv, int enc)
 200         {
 201         return gost_cipher_init_param(ctx,key,iv,enc,NID_undef,EVP_CIPH_CFB_MODE);
 202         }
 203 /* Wrapper around gostcrypt function from gost89.c which perform
 204  * key meshing when nesseccary
 205  */
 206 static void gost_crypt_mesh (void *ctx,unsigned char *iv,unsigned char *buf)
 207         {
 208         struct ossl_gost_cipher_ctx *c = ctx;
 209         if (c->count&&c->key_meshing && c->count%1024==0)
 210                 {
 211                 cryptopro_key_meshing(&(c->cctx),iv);
 212                 }
 213         gostcrypt(&(c->cctx),iv,buf);
 214         c->count+=8;
 215         }
 216
 217 static void gost_cnt_next (void *ctx, unsigned char *iv, unsigned char *buf)
 218         {
 219         struct ossl_gost_cipher_ctx *c = ctx;
 220         word32 g,go;
 221         unsigned char buf1[8];
 222         if (c->count && c->key_meshing && c->count %1024 ==0)
 223                 {
 224                 cryptopro_key_meshing(&(c->cctx),iv);
 225                 }
 226         if (c->count==0)
 227                 {
 228                 gostcrypt(&(c->cctx),iv,buf1);
 229                 }
 230         else
 231                 {
 232                 memcpy(buf1,iv,8);
 233                 }
 234         g = buf1[0]|(buf1[1]<<8)|(buf1[2]<<16)|(buf1[3]<<24);
 235         g += 0x01010101;
 236         buf1[0]=(unsigned char)(g&0xff);
 237         buf1[1]=(unsigned char)((g>>8)&0xff);
 238         buf1[2]=(unsigned char)((g>>16)&0xff);
 239         buf1[3]=(unsigned char)((g>>24)&0xff);
 240         g = buf1[4]|(buf1[5]<<8)|(buf1[6]<<16)|(buf1[7]<<24);
 241         go = g;
 242         g += 0x01010104;
 243         if (go > g)      /*  overflow*/
 244                 g++;
 245         buf1[4]=(unsigned char)(g&0xff);
 246         buf1[5]=(unsigned char)((g>>8)&0xff);
 247         buf1[6]=(unsigned char)((g>>16)&0xff);
 248         buf1[7]=(unsigned char)((g>>24)&0xff);
 249         memcpy(iv,buf1,8);
 250         gostcrypt(&(c->cctx),buf1,buf);
 251         c->count +=8;
 252         }
 253
 254 /* GOST encryption in CFB mode */
 255 int     gost_cipher_do_cfb(EVP_CIPHER_CTX *ctx, unsigned char *out,
 256         const unsigned char *in, size_t inl)
 257         {
 258         const unsigned char *in_ptr=in;
 259         unsigned char *out_ptr=out;
 260         size_t i=0;
 261         size_t j=0;
 262 /* process partial block if any */
 263         if (ctx->num)
 264                 {
 265                 for (j=ctx->num,i=0;j<8 && i<inl;j++,i++,in_ptr++,out_ptr++)
 266                         {
 267                         if (!ctx->encrypt) ctx->buf[j+8]=*in_ptr;
 268                         *out_ptr=ctx->buf[j]^(*in_ptr);
 269                         if (ctx->encrypt) ctx->buf[j+8]=*out_ptr;
 270                         }
 271                 if (j==8)
 272                         {
 273                         memcpy(ctx->iv,ctx->buf+8,8);
 274                         ctx->num=0;
 275                         }
 276                 else
 277                         {
 278                         ctx->num=j;
 279                         return 1;
 280                         }
 281                 }
 282
 283         for (;i+8<inl;i+=8,in_ptr+=8,out_ptr+=8)
 284                 {
 285                 /*block cipher current iv */
 286                 gost_crypt_mesh(ctx->cipher_data,ctx->iv,ctx->buf);
 287                 /*xor next block of input text with it and output it*/
 288                 /*output this block */
 289                 if (!ctx->encrypt) memcpy(ctx->iv,in_ptr,8);
 290                 for (j=0;j<8;j++)
 291                         {
 292                         out_ptr[j]=ctx->buf[j]^in_ptr[j];
 293                         }
 294                 /* Encrypt */
 295                 /* Next iv is next block of cipher text*/
 296                 if (ctx->encrypt) memcpy(ctx->iv,out_ptr,8);
 297                 }
 298 /* Process rest of buffer */
 299         if (i<inl)
 300                 {
 301                 gost_crypt_mesh(ctx->cipher_data,ctx->iv,ctx->buf);
 302                 if (!ctx->encrypt) memcpy(ctx->buf+8,in_ptr,j);
 303                 for (j=0;i<inl;j++,i++)
 304                         {
 305                         out_ptr[j]=ctx->buf[j]^in_ptr[j];
 306                         }
 307                 ctx->num = j;
 308                 if (ctx->encrypt) memcpy(ctx->buf+8,out_ptr,j);
 309                 }
 310         else
 311                 {
 312                 ctx->num = 0;
 313                 }
 314         return 1;
 315         }
 316
 317 static int gost_cipher_do_cnt(EVP_CIPHER_CTX *ctx, unsigned char *out,
 318         const unsigned char *in, size_t inl)
 319         {
 320         const unsigned char *in_ptr=in;
 321         unsigned char *out_ptr=out;
 322         size_t i=0;
 323         size_t j;
 324 /* process partial block if any */
 325         if (ctx->num)
 326                 {
 327                 for (j=ctx->num,i=0;j<8 && i<inl;j++,i++,in_ptr++,out_ptr++)
 328                         {
 329                         *out_ptr=ctx->buf[j]^(*in_ptr);
 330                         }
 331                 if (j==8)
 332                         {
 333                         ctx->num=0;
 334                         }
 335                 else
 336                         {
 337                         ctx->num=j;
 338                         return 1;
 339                         }
 340                 }
 341
 342         for (;i+8<inl;i+=8,in_ptr+=8,out_ptr+=8)
 343                 {
 344                 /*block cipher current iv */
 345                 /* Encrypt */
 346                 gost_cnt_next(ctx->cipher_data,ctx->iv,ctx->buf);
 347                 /*xor next block of input text with it and output it*/
 348                 /*output this block */
 349                 for (j=0;j<8;j++)
 350                         {
 351                         out_ptr[j]=ctx->buf[j]^in_ptr[j];
 352                         }
 353                 }
 354 /* Process rest of buffer */
 355         if (i<inl)
 356                 {
 357                 gost_cnt_next(ctx->cipher_data,ctx->iv,ctx->buf);
 358                 for (j=0;i<inl;j++,i++)
 359                         {
 360                         out_ptr[j]=ctx->buf[j]^in_ptr[j];
 361                         }
 362                 ctx->num = j;
 363                 }
 364         else
 365                 {
 366                 ctx->num = 0;
 367                 }
 368         return 1;
 369         }
 370
 371 /* Cleaning up of EVP_CIPHER_CTX */
 372 int gost_cipher_cleanup(EVP_CIPHER_CTX *ctx)
 373         {
 374         gost_destroy((gost_ctx *)ctx->cipher_data);
 375         ctx->app_data = NULL;
 376         return 1;
 377         }
 378
 379 /* Control function for gost cipher */
 380 int gost_cipher_ctl(EVP_CIPHER_CTX *ctx,int type,int arg,void *ptr)
 381         {
 382         switch (type)
 383                 {
 384                 case EVP_CTRL_RAND_KEY:
 385                 {
 386                 if (RAND_bytes((unsigned char *)ptr,ctx->key_len)<=0)
 387                         {
 388                         GOSTerr(GOST_F_GOST_CIPHER_CTL,GOST_R_RANDOM_GENERATOR_ERROR);
 389                         return -1;
 390                         }
 391                 break;
 392                 }
 393                 default:
 394                         GOSTerr(GOST_F_GOST_CIPHER_CTL,GOST_R_UNSUPPORTED_CIPHER_CTL_COMMAND);
 395                         return -1;
 396                 }
 397         return 1;
 398         }
 399
 400 /* Set cipher parameters from ASN1 structure */
 401 int gost89_set_asn1_parameters(EVP_CIPHER_CTX *ctx,ASN1_TYPE *params)
 402         {
 403         int len=0;
 404         unsigned char *buf=NULL;
 405         unsigned char *p=NULL;
 406         struct ossl_gost_cipher_ctx *c = ctx->cipher_data;
 407         GOST_CIPHER_PARAMS *gcp = GOST_CIPHER_PARAMS_new();
 408         ASN1_OCTET_STRING *os = NULL;
 409         if (!gcp)
 410                 {
 411                 GOSTerr(GOST_F_GOST89_SET_ASN1_PARAMETERS, GOST_R_NO_MEMORY);
 412                 return 0;
 413                 }
 414         if (!ASN1_OCTET_STRING_set(gcp->iv, ctx->iv, ctx->cipher->iv_len))
 415                 {
 416                 GOST_CIPHER_PARAMS_free(gcp);
 417                 GOSTerr(GOST_F_GOST89_SET_ASN1_PARAMETERS, GOST_R_NO_MEMORY);
 418                 return 0;
 419                 }
 420         ASN1_OBJECT_free(gcp->enc_param_set);
 421         gcp->enc_param_set = OBJ_nid2obj(c->paramNID);
 422
 423         len = i2d_GOST_CIPHER_PARAMS(gcp, NULL);
 424         p = buf = (unsigned char*)OPENSSL_malloc(len);
 425         if (!buf)
 426                 {
 427                 GOST_CIPHER_PARAMS_free(gcp);
 428                 GOSTerr(GOST_F_GOST89_SET_ASN1_PARAMETERS, GOST_R_NO_MEMORY);
 429                 return 0;
 430                 }
 431         i2d_GOST_CIPHER_PARAMS(gcp, &p);
 432         GOST_CIPHER_PARAMS_free(gcp);
 433
 434         os = ASN1_OCTET_STRING_new();
 435
 436         if(!os || !ASN1_OCTET_STRING_set(os, buf, len))
 437                 {
 438                 OPENSSL_free(buf);
 439                 GOSTerr(GOST_F_GOST89_SET_ASN1_PARAMETERS, GOST_R_NO_MEMORY);
 440                 return 0;
 441                 }
 442         OPENSSL_free(buf);
 443
 444         ASN1_TYPE_set(params, V_ASN1_SEQUENCE, os);
 445         return 1;
 446         }
 447
 448 /* Store parameters into ASN1 structure */
 449 int  gost89_get_asn1_parameters(EVP_CIPHER_CTX *ctx,ASN1_TYPE *params)
 450         {
 451         int ret = -1;
 452         int len;
 453         GOST_CIPHER_PARAMS *gcp = NULL;
 454         unsigned char *p = params->value.sequence->data;
 455         struct ossl_gost_cipher_ctx *c=ctx->cipher_data;
 456         if (ASN1_TYPE_get(params) != V_ASN1_SEQUENCE)
 457                 {
 458                 return ret;
 459                 }
 460
 461         gcp = d2i_GOST_CIPHER_PARAMS(NULL, (const unsigned char **)&p,
 462                 params->value.sequence->length);
 463
 464         len = gcp->iv->length;
 465         if (len != ctx->cipher->iv_len)
 466                 {
 467                 GOST_CIPHER_PARAMS_free(gcp);
 468                 GOSTerr(GOST_F_GOST89_GET_ASN1_PARAMETERS,
 469                         GOST_R_INVALID_IV_LENGTH);
 470                 return -1;
 471                 }
 472         if (!gost_cipher_set_param(c,OBJ_obj2nid(gcp->enc_param_set)))
 473                 {
 474                 GOST_CIPHER_PARAMS_free(gcp);
 475                 return -1;
 476                 }
 477         memcpy(ctx->oiv, gcp->iv->data, len);
 478
 479         GOST_CIPHER_PARAMS_free(gcp);
 480
 481         return 1;
 482         }
 483
 484
 485 int gost_imit_init_cpa(EVP_MD_CTX *ctx)
 486         {
 487         struct ossl_gost_imit_ctx *c = ctx->md_data;
 488         memset(c->buffer,0,16);
 489         c->count = 0;
 490         c->bytes_left=0;
 491         c->key_meshing=1;
 492         gost_init(&(c->cctx),&Gost28147_CryptoProParamSetA);
 493         return 1;
 494         }
 495
 496 static void mac_block_mesh(struct ossl_gost_imit_ctx *c,const unsigned char *data)
 497         {
 498         unsigned char buffer[8];
 499         /* We are using local buffer for iv because CryptoPro doesn't
 500          * interpret internal state of MAC algorithm as iv during keymeshing
 501          * (but does initialize internal state from iv in key transport
 502          */
 503         if (c->key_meshing&& c->count && c->count %1024 ==0)
 504                 {
 505                 cryptopro_key_meshing(&(c->cctx),buffer);
 506                 }
 507         mac_block(&(c->cctx),c->buffer,data);
 508         c->count +=8;
 509         }
 510
 511 int gost_imit_update(EVP_MD_CTX *ctx, const void *data, size_t count)
 512         {
 513         struct ossl_gost_imit_ctx *c = ctx->md_data;
 514         const unsigned char *p = data;
 515         size_t bytes = count,i;
 516         if (!(c->key_set)) {
 517                 GOSTerr(GOST_F_GOST_IMIT_UPDATE, GOST_R_MAC_KEY_NOT_SET);
 518                 return 0;
 519         }
 520         if (c->bytes_left)
 521                 {
 522                 for (i=c->bytes_left;i<8&&bytes>0;bytes--,i++,p++)
 523                         {
 524                         c->partial_block[i]=*p;
 525                         }
 526                 if (i==8)
 527                         {
 528                         mac_block_mesh(c,c->partial_block);
 529                         }
 530                 else
 531                         {
 532                         c->bytes_left = i;
 533                         return 1;
 534                         }
 535                 }
 536         while (bytes>8)
 537                 {
 538                 mac_block_mesh(c,p);
 539                 p+=8;
 540                 bytes-=8;
 541                 }
 542         if (bytes>0)
 543                 {
 544                 memcpy(c->partial_block,p,bytes);
 545                 }
 546         c->bytes_left=bytes;
 547         return 1;
 548         }
 549
 550 int gost_imit_final(EVP_MD_CTX *ctx,unsigned char *md)
 551         {
 552         struct ossl_gost_imit_ctx *c = ctx->md_data;
 553         if (!c->key_set) return 0;
 554         if (c->bytes_left)
 555                 {
 556                 int i;
 557                 for (i=c->bytes_left;i<8;i++)
 558                         {
 559                         c->partial_block[i]=0;
 560                         }
 561                 mac_block_mesh(c,c->partial_block);
 562                 }
 563         get_mac(c->buffer,32,md);
 564         return 1;
 565         }
 566
 567 int gost_imit_ctrl(EVP_MD_CTX *ctx,int type, int arg, void *ptr)
 568         {
 569         switch (type)
 570                 {
 571                 case EVP_MD_CTRL_KEY_LEN:
 572                         *((unsigned int*)(ptr)) = 32;
 573                         return 1;
 574                 case EVP_MD_CTRL_SET_KEY:
 575                 {
 576                 if (arg!=32) {
 577                         GOSTerr(GOST_F_GOST_IMIT_CTRL, GOST_R_INVALID_MAC_KEY_LENGTH);
 578                         return 0;
 579                 }
 580
 581                 gost_key(&(((struct ossl_gost_imit_ctx*)(ctx->md_data))->cctx),ptr)     ;
 582                 ((struct ossl_gost_imit_ctx*)(ctx->md_data))->key_set = 1;
 583                 return 1;
 584
 585                 }
 586                 default:
 587                         return 0;
 588                 }
 589         }
 590
 591 int gost_imit_copy(EVP_MD_CTX *to,const EVP_MD_CTX *from)
 592         {
 593         memcpy(to->md_data,from->md_data,sizeof(struct ossl_gost_imit_ctx));
 594         return 1;
 595         }
 596
 597 /* Clean up imit ctx */
 598 int gost_imit_cleanup(EVP_MD_CTX *ctx)
 599         {
 600         memset(ctx->md_data,0,sizeof(struct ossl_gost_imit_ctx));
 601         return 1;
 602         }
 603