engines/ccgost/gost2001.c

   1 /**********************************************************************
   2  *                          gost2001.c                                *
   3  *             Copyright (c) 2005-2006 Cryptocom LTD                  *
   4  *         This file is distributed under the same license as OpenSSL *
   5  *                                                                    *
   6  *          Implementation of GOST R 34.10-2001                                   *
   7  *          Requires OpenSSL 0.9.9 for compilation                    *
   8  **********************************************************************/
   9 #include "gost_lcl.h"
  10 #include "gost_params.h"
  11 #include <string.h>
  12 #include <openssl/rand.h>
  13 #include <openssl/ecdsa.h>
  14 #include <openssl/err.h>
  15 #include "e_gost_err.h"
  16 #ifdef DEBUG_SIGN
  17 extern
  18 void dump_signature(const char *message, const unsigned char *buffer,
  19                     size_t len);
  20 void dump_dsa_sig(const char *message, DSA_SIG *sig);
  21 #else
  22
  23 # define dump_signature(a,b,c)
  24 # define dump_dsa_sig(a,b)
  25 #endif
  26
  27 /*
  28  * Fills EC_KEY structure hidden in the app_data field of DSA structure
  29  * with parameter information, extracted from parameter array in
  30  * params.c file.
  31  *
  32  * Also fils DSA->q field with copy of EC_GROUP order field to make
  33  * DSA_size function work
  34  */
  35 int fill_GOST2001_params(EC_KEY *eckey, int nid)
  36 {
  37     R3410_2001_params *params = R3410_2001_paramset;
  38     EC_GROUP *grp = NULL;
  39     BIGNUM *p = NULL, *q = NULL, *a = NULL, *b = NULL, *x = NULL, *y = NULL;
  40     EC_POINT *P = NULL;
  41     BN_CTX *ctx = BN_CTX_new();
  42     int ok = 0;
  43
  44     if(!ctx) {
  45         GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
  46         goto err;
  47     }
  48
  49     BN_CTX_start(ctx);
  50     p = BN_CTX_get(ctx);
  51     a = BN_CTX_get(ctx);
  52     b = BN_CTX_get(ctx);
  53     x = BN_CTX_get(ctx);
  54     y = BN_CTX_get(ctx);
  55     q = BN_CTX_get(ctx);
  56     if(!p || !a || !b || !x || !y || !q) {
  57         GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
  58         goto err;
  59     }
  60     while (params->nid != NID_undef && params->nid != nid)
  61         params++;
  62     if (params->nid == NID_undef) {
  63         GOSTerr(GOST_F_FILL_GOST2001_PARAMS,
  64                 GOST_R_UNSUPPORTED_PARAMETER_SET);
  65         goto err;
  66     }
  67     if(!BN_hex2bn(&p, params->p)
  68         || !BN_hex2bn(&a, params->a)
  69         || !BN_hex2bn(&b, params->b)) {
  70         GOSTerr(GOST_F_FILL_GOST2001_PARAMS,
  71                 ERR_R_INTERNAL_ERROR);
  72         goto err;
  73     }
  74
  75     grp = EC_GROUP_new_curve_GFp(p, a, b, ctx);
  76     if(!grp)  {
  77         GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
  78         goto err;
  79     }
  80
  81     P = EC_POINT_new(grp);
  82     if(!P)  {
  83         GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_MALLOC_FAILURE);
  84         goto err;
  85     }
  86
  87     if(!BN_hex2bn(&x, params->x)
  88         || !BN_hex2bn(&y, params->y)
  89         || !EC_POINT_set_affine_coordinates_GFp(grp, P, x, y, ctx)
  90         || !BN_hex2bn(&q, params->q))  {
  91         GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_INTERNAL_ERROR);
  92         goto err;
  93     }
  94 #ifdef DEBUG_KEYS
  95     fprintf(stderr, "Set params index %d oid %s\nq=",
  96             (params - R3410_2001_paramset), OBJ_nid2sn(params->nid));
  97     BN_print_fp(stderr, q);
  98     fprintf(stderr, "\n");
  99 #endif
 100
 101     if(!EC_GROUP_set_generator(grp, P, q, NULL)) {
 102         GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_INTERNAL_ERROR);
 103         goto err;
 104     }
 105     EC_GROUP_set_curve_name(grp, params->nid);
 106     if(!EC_KEY_set_group(eckey, grp)) {
 107         GOSTerr(GOST_F_FILL_GOST2001_PARAMS, ERR_R_INTERNAL_ERROR);
 108         goto err;
 109     }
 110     ok = 1;
 111  err:
 112     if (P) EC_POINT_free(P);
 113     if (grp) EC_GROUP_free(grp);
 114     if (ctx) {
 115         BN_CTX_end(ctx);
 116         BN_CTX_free(ctx);
 117     }
 118     return ok;
 119 }
 120
 121 /*
 122  * Computes gost2001 signature as DSA_SIG structure
 123  *
 124  *
 125  */
 126 DSA_SIG *gost2001_do_sign(const unsigned char *dgst, int dlen, EC_KEY *eckey)
 127 {
 128     DSA_SIG *newsig = NULL, *ret = NULL;
 129     BIGNUM *md = hashsum2bn(dgst);
 130     BIGNUM *order = NULL;
 131     const EC_GROUP *group;
 132     const BIGNUM *priv_key;
 133     BIGNUM *r = NULL, *s = NULL, *X = NULL, *tmp = NULL, *tmp2 = NULL, *k =
 134         NULL, *e = NULL;
 135     EC_POINT *C = NULL;
 136     BN_CTX *ctx = BN_CTX_new();
 137     if(!ctx || !md) {
 138         GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
 139         goto err;
 140     }
 141     BN_CTX_start(ctx);
 142     OPENSSL_assert(dlen == 32);
 143     newsig = DSA_SIG_new();
 144     if (!newsig) {
 145         GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
 146         goto err;
 147     }
 148     group = EC_KEY_get0_group(eckey);
 149     if(!group) {
 150         GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
 151         goto err;
 152     }
 153     order = BN_CTX_get(ctx);
 154     if(!order || !EC_GROUP_get_order(group, order, ctx)) {
 155         GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
 156         goto err;
 157     }
 158     priv_key = EC_KEY_get0_private_key(eckey);
 159     if(!priv_key) {
 160         GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
 161         goto err;
 162     }
 163     e = BN_CTX_get(ctx);
 164     if(!e || !BN_mod(e, md, order, ctx)) {
 165         GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
 166         goto err;
 167     }
 168 #ifdef DEBUG_SIGN
 169     fprintf(stderr, "digest as bignum=");
 170     BN_print_fp(stderr, md);
 171     fprintf(stderr, "\ndigest mod q=");
 172     BN_print_fp(stderr, e);
 173     fprintf(stderr, "\n");
 174 #endif
 175     if (BN_is_zero(e)) {
 176         BN_one(e);
 177     }
 178     k = BN_CTX_get(ctx);
 179     C = EC_POINT_new(group);
 180     if(!k || !C) {
 181         GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
 182         goto err;
 183     }
 184     do {
 185         do {
 186             if (!BN_rand_range(k, order)) {
 187                 GOSTerr(GOST_F_GOST2001_DO_SIGN,
 188                         GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
 189                 goto err;
 190             }
 191             if (!EC_POINT_mul(group, C, k, NULL, NULL, ctx)) {
 192                 GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_EC_LIB);
 193                 goto err;
 194             }
 195             if (!X)
 196                 X = BN_CTX_get(ctx);
 197             if (!r)
 198                 r = BN_CTX_get(ctx);
 199             if (!X || !r) {
 200                 GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
 201                 goto err;
 202             }
 203             if (!EC_POINT_get_affine_coordinates_GFp(group, C, X, NULL, ctx)) {
 204                 GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_EC_LIB);
 205                 goto err;
 206             }
 207
 208             if(!BN_nnmod(r, X, order, ctx)) {
 209                 GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
 210                 goto err;
 211             }
 212         }
 213         while (BN_is_zero(r));
 214         /* s =  (r*priv_key+k*e) mod order */
 215         if (!tmp)
 216             tmp = BN_CTX_get(ctx);
 217         if (!tmp2)
 218             tmp2 = BN_CTX_get(ctx);
 219         if (!s)
 220             s = BN_CTX_get(ctx);
 221         if (!tmp || !tmp2 || !s) {
 222             GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
 223             goto err;
 224         }
 225
 226         if(!BN_mod_mul(tmp, priv_key, r, order, ctx)
 227             || !BN_mod_mul(tmp2, k, e, order, ctx)
 228             || !BN_mod_add(s, tmp, tmp2, order, ctx)) {
 229             GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_INTERNAL_ERROR);
 230             goto err;
 231         }
 232     }
 233     while (BN_is_zero(s));
 234
 235     newsig->s = BN_dup(s);
 236     newsig->r = BN_dup(r);
 237     if(!newsig->s || !newsig->r) {
 238         GOSTerr(GOST_F_GOST2001_DO_SIGN, ERR_R_MALLOC_FAILURE);
 239         goto err;
 240     }
 241
 242     ret = newsig;
 243  err:
 244     if(ctx) {
 245         BN_CTX_end(ctx);
 246         BN_CTX_free(ctx);
 247     }
 248     if (C) EC_POINT_free(C);
 249     if (md) BN_free(md);
 250     if (!ret && newsig) {
 251         DSA_SIG_free(newsig);
 252     }
 253     return ret;
 254 }
 255
 256 /*
 257  * Verifies gost 2001 signature
 258  *
 259  */
 260 int gost2001_do_verify(const unsigned char *dgst, int dgst_len,
 261                        DSA_SIG *sig, EC_KEY *ec)
 262 {
 263     BN_CTX *ctx = BN_CTX_new();
 264     const EC_GROUP *group = EC_KEY_get0_group(ec);
 265     BIGNUM *order;
 266     BIGNUM *md = NULL, *e = NULL, *R = NULL, *v = NULL, *z1 = NULL, *z2 =
 267         NULL;
 268     BIGNUM *X = NULL, *tmp = NULL;
 269     EC_POINT *C = NULL;
 270     const EC_POINT *pub_key = NULL;
 271     int ok = 0;
 272
 273     if(!ctx || !group) {
 274         GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
 275         goto err;
 276     }
 277
 278     BN_CTX_start(ctx);
 279     order = BN_CTX_get(ctx);
 280     e = BN_CTX_get(ctx);
 281     z1 = BN_CTX_get(ctx);
 282     z2 = BN_CTX_get(ctx);
 283     tmp = BN_CTX_get(ctx);
 284     X = BN_CTX_get(ctx);
 285     R = BN_CTX_get(ctx);
 286     v = BN_CTX_get(ctx);
 287     if(!order || !e || !z1 || !z2 || !tmp || !X || !R || !v) {
 288         GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_MALLOC_FAILURE);
 289         goto err;
 290     }
 291
 292     pub_key = EC_KEY_get0_public_key(ec);
 293     if(!pub_key || !EC_GROUP_get_order(group, order, ctx)) {
 294         GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
 295         goto err;
 296     }
 297
 298     if (BN_is_zero(sig->s) || BN_is_zero(sig->r) ||
 299         (BN_cmp(sig->s, order) >= 1) || (BN_cmp(sig->r, order) >= 1)) {
 300         GOSTerr(GOST_F_GOST2001_DO_VERIFY,
 301                 GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q);
 302         goto err;
 303
 304     }
 305     md = hashsum2bn(dgst);
 306
 307     if(!md || !BN_mod(e, md, order, ctx)) {
 308         GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
 309         goto err;
 310     }
 311 #ifdef DEBUG_SIGN
 312     fprintf(stderr, "digest as bignum: ");
 313     BN_print_fp(stderr, md);
 314     fprintf(stderr, "\ndigest mod q: ");
 315     BN_print_fp(stderr, e);
 316 #endif
 317     if (BN_is_zero(e) && !BN_one(e)) {
 318         GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
 319         goto err;
 320     }
 321     v = BN_mod_inverse(v, e, order, ctx);
 322     if(!v
 323         || !BN_mod_mul(z1, sig->s, v, order, ctx)
 324         || !BN_sub(tmp, order, sig->r)
 325         || !BN_mod_mul(z2, tmp, v, order, ctx)) {
 326         GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
 327         goto err;
 328     }
 329 #ifdef DEBUG_SIGN
 330     fprintf(stderr, "\nInverted digest value: ");
 331     BN_print_fp(stderr, v);
 332     fprintf(stderr, "\nz1: ");
 333     BN_print_fp(stderr, z1);
 334     fprintf(stderr, "\nz2: ");
 335     BN_print_fp(stderr, z2);
 336 #endif
 337     C = EC_POINT_new(group);
 338     if (!C) {
 339         GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_MALLOC_FAILURE);
 340         goto err;
 341     }
 342     if (!EC_POINT_mul(group, C, z1, pub_key, z2, ctx)) {
 343         GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_EC_LIB);
 344         goto err;
 345     }
 346     if (!EC_POINT_get_affine_coordinates_GFp(group, C, X, NULL, ctx)) {
 347         GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_EC_LIB);
 348         goto err;
 349     }
 350     if(!BN_mod(R, X, order, ctx)) {
 351         GOSTerr(GOST_F_GOST2001_DO_VERIFY, ERR_R_INTERNAL_ERROR);
 352         goto err;
 353     }
 354 #ifdef DEBUG_SIGN
 355     fprintf(stderr, "\nX=");
 356     BN_print_fp(stderr, X);
 357     fprintf(stderr, "\nX mod q=");
 358     BN_print_fp(stderr, R);
 359     fprintf(stderr, "\n");
 360 #endif
 361     if (BN_cmp(R, sig->r) != 0) {
 362         GOSTerr(GOST_F_GOST2001_DO_VERIFY, GOST_R_SIGNATURE_MISMATCH);
 363     } else {
 364         ok = 1;
 365     }
 366  err:
 367     if (C) EC_POINT_free(C);
 368     if (ctx) {
 369         BN_CTX_end(ctx);
 370         BN_CTX_free(ctx);
 371     }
 372     if (md) BN_free(md);
 373     return ok;
 374 }
 375
 376 /*
 377  * Computes GOST R 34.10-2001 public key
 378  *
 379  *
 380  */
 381 int gost2001_compute_public(EC_KEY *ec)
 382 {
 383     const EC_GROUP *group = EC_KEY_get0_group(ec);
 384     EC_POINT *pub_key = NULL;
 385     const BIGNUM *priv_key = NULL;
 386     BN_CTX *ctx = NULL;
 387     int ok = 0;
 388
 389     if (!group) {
 390         GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,
 391                 GOST_R_KEY_IS_NOT_INITIALIZED);
 392         return 0;
 393     }
 394     ctx = BN_CTX_new();
 395     if(!ctx) {
 396         GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC, ERR_R_MALLOC_FAILURE);
 397         goto err;
 398     }
 399     BN_CTX_start(ctx);
 400     if (!(priv_key = EC_KEY_get0_private_key(ec))) {
 401         GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC, ERR_R_EC_LIB);
 402         goto err;
 403     }
 404
 405     pub_key = EC_POINT_new(group);
 406     if(!pub_key) {
 407         GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC, ERR_R_MALLOC_FAILURE);
 408         goto err;
 409     }
 410     if (!EC_POINT_mul(group, pub_key, priv_key, NULL, NULL, ctx)) {
 411         GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC, ERR_R_EC_LIB);
 412         goto err;
 413     }
 414     if (!EC_KEY_set_public_key(ec, pub_key)) {
 415         GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC, ERR_R_EC_LIB);
 416         goto err;
 417     }
 418     ok = 256;
 419  err:
 420     if (pub_key) EC_POINT_free(pub_key);
 421     if (ctx) {
 422         BN_CTX_end(ctx);
 423         BN_CTX_free(ctx);
 424     }
 425     return ok;
 426 }
 427
 428 /*
 429  *
 430  * Generates GOST R 34.10-2001 keypair
 431  *
 432  *
 433  */
 434 int gost2001_keygen(EC_KEY *ec)
 435 {
 436     BIGNUM *order = BN_new(), *d = BN_new();
 437     const EC_GROUP *group = EC_KEY_get0_group(ec);
 438
 439     if(!group || !EC_GROUP_get_order(group, order, NULL)) {
 440         GOSTerr(GOST_F_GOST2001_KEYGEN, ERR_R_INTERNAL_ERROR);
 441         BN_free(d);
 442         BN_free(order);
 443         return 0;
 444     }
 445
 446     do {
 447         if (!BN_rand_range(d, order)) {
 448             GOSTerr(GOST_F_GOST2001_KEYGEN,
 449                     GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
 450             BN_free(d);
 451             BN_free(order);
 452             return 0;
 453         }
 454     }
 455     while (BN_is_zero(d));
 456
 457     if(!EC_KEY_set_private_key(ec, d)) {
 458         GOSTerr(GOST_F_GOST2001_KEYGEN, ERR_R_INTERNAL_ERROR);
 459         BN_free(d);
 460         BN_free(order);
 461         return 0;
 462     }
 463     BN_free(d);
 464     BN_free(order);
 465     return gost2001_compute_public(ec);
 466 }