crypto/external/bsd/openssl/dist/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,size_t len);
  19 void dump_dsa_sig(const char *message, DSA_SIG *sig);
  20 #else
  21
  22 #define dump_signature(a,b,c)
  23 #define dump_dsa_sig(a,b)
  24 #endif
  25
  26 /*
  27  * Fills EC_KEY structure hidden in the app_data field of DSA structure
  28  * with parameter information, extracted from parameter array in
  29  * params.c file.
  30  *
  31  * Also fils DSA->q field with copy of EC_GROUP order field to make
  32  * DSA_size function work
  33  */
  34 int fill_GOST2001_params(EC_KEY *eckey, int nid)
  35         {
  36         R3410_2001_params *params = R3410_2001_paramset;
  37         EC_GROUP *grp=NULL;
  38         BIGNUM *p=NULL,*q=NULL,*a=NULL,*b=NULL,*x=NULL,*y=NULL;
  39         EC_POINT *P=NULL;
  40         BN_CTX *ctx=BN_CTX_new();
  41         int ok=0;
  42
  43         BN_CTX_start(ctx);
  44         p=BN_CTX_get(ctx);
  45         a=BN_CTX_get(ctx);
  46         b=BN_CTX_get(ctx);
  47         x=BN_CTX_get(ctx);
  48         y=BN_CTX_get(ctx);
  49         q=BN_CTX_get(ctx);
  50         while (params->nid!=NID_undef && params->nid != nid) params++;
  51         if (params->nid == NID_undef)
  52                 {
  53                 GOSTerr(GOST_F_FILL_GOST2001_PARAMS,GOST_R_UNSUPPORTED_PARAMETER_SET);
  54                 goto err;
  55                 }
  56         BN_hex2bn(&p,params->p);
  57         BN_hex2bn(&a,params->a);
  58         BN_hex2bn(&b,params->b);
  59
  60         grp = EC_GROUP_new_curve_GFp(p,a,b,ctx);
  61
  62         P = EC_POINT_new(grp);
  63
  64         BN_hex2bn(&x,params->x);
  65         BN_hex2bn(&y,params->y);
  66         EC_POINT_set_affine_coordinates_GFp(grp,P,x,y,ctx);
  67         BN_hex2bn(&q,params->q);
  68 #ifdef DEBUG_KEYS
  69         fprintf(stderr,"Set params index %d oid %s\nq=",
  70                 (params-R3410_2001_paramset),OBJ_nid2sn(params->nid));
  71         BN_print_fp(stderr,q);
  72         fprintf(stderr,"\n");
  73 #endif
  74
  75         EC_GROUP_set_generator(grp,P,q,NULL);
  76         EC_GROUP_set_curve_name(grp,params->nid);
  77
  78         EC_KEY_set_group(eckey,grp);
  79         ok=1;
  80         err:
  81         EC_POINT_free(P);
  82         EC_GROUP_free(grp);
  83         BN_CTX_end(ctx);
  84         BN_CTX_free(ctx);
  85         return ok;
  86         }
  87
  88
  89 /*
  90  * Computes gost2001 signature as DSA_SIG structure
  91  *
  92  *
  93  */
  94 DSA_SIG *gost2001_do_sign(const unsigned char *dgst,int dlen, EC_KEY *eckey)
  95         {
  96         DSA_SIG *newsig = NULL;
  97         BIGNUM *md = hashsum2bn(dgst);
  98         BIGNUM *order = NULL;
  99         const EC_GROUP *group;
 100         const BIGNUM *priv_key;
 101         BIGNUM *r=NULL,*s=NULL,*X=NULL,*tmp=NULL,*tmp2=NULL, *k=NULL,*e=NULL;
 102         EC_POINT *C=NULL;
 103         BN_CTX *ctx = BN_CTX_new();
 104         BN_CTX_start(ctx);
 105         OPENSSL_assert(dlen==32);
 106         newsig=DSA_SIG_new();
 107         if (!newsig)
 108                 {
 109                 GOSTerr(GOST_F_GOST2001_DO_SIGN,GOST_R_NO_MEMORY);
 110                 goto err;
 111                 }
 112         group = EC_KEY_get0_group(eckey);
 113         order=BN_CTX_get(ctx);
 114         EC_GROUP_get_order(group,order,ctx);
 115         priv_key = EC_KEY_get0_private_key(eckey);
 116         e = BN_CTX_get(ctx);
 117         BN_mod(e,md,order,ctx);
 118 #ifdef DEBUG_SIGN
 119         fprintf(stderr,"digest as bignum=");
 120         BN_print_fp(stderr,md);
 121         fprintf(stderr,"\ndigest mod q=");
 122         BN_print_fp(stderr,e);
 123         fprintf(stderr,"\n");
 124 #endif
 125         if (BN_is_zero(e))
 126                 {
 127                 BN_one(e);
 128                 }
 129         k =BN_CTX_get(ctx);
 130         C=EC_POINT_new(group);
 131         do
 132                 {
 133                 do
 134                         {
 135                         if (!BN_rand_range(k,order))
 136                                 {
 137                                 GOSTerr(GOST_F_GOST2001_DO_SIGN,GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
 138                                 DSA_SIG_free(newsig);
 139                                 goto err;
 140                                 }
 141                         if (!EC_POINT_mul(group,C,k,NULL,NULL,ctx))
 142                                 {
 143                                 GOSTerr(GOST_F_GOST2001_DO_SIGN,ERR_R_EC_LIB);
 144                                 DSA_SIG_free(newsig);
 145                                 goto err;
 146                                 }
 147                         if (!X) X=BN_CTX_get(ctx);
 148                         if (!EC_POINT_get_affine_coordinates_GFp(group,C,X,NULL,ctx))
 149                                 {
 150                                 GOSTerr(GOST_F_GOST2001_DO_SIGN,ERR_R_EC_LIB);
 151                                 DSA_SIG_free(newsig);
 152                                 goto err;
 153                                 }
 154                         if (!r) r=BN_CTX_get(ctx);
 155                         BN_nnmod(r,X,order,ctx);
 156                         }
 157                 while (BN_is_zero(r));
 158                 /* s =  (r*priv_key+k*e) mod order */
 159                 if (!tmp) tmp = BN_CTX_get(ctx);
 160                 BN_mod_mul(tmp,priv_key,r,order,ctx);
 161                 if (!tmp2) tmp2 = BN_CTX_get(ctx);
 162                 BN_mod_mul(tmp2,k,e,order,ctx);
 163                 if (!s) s=BN_CTX_get(ctx);
 164                 BN_mod_add(s,tmp,tmp2,order,ctx);
 165                 }
 166         while (BN_is_zero(s));
 167
 168         newsig->s=BN_dup(s);
 169         newsig->r=BN_dup(r);
 170         err:
 171         BN_CTX_end(ctx);
 172         BN_CTX_free(ctx);
 173         EC_POINT_free(C);
 174         BN_free(md);
 175         return newsig;
 176         }
 177 /*
 178  * Verifies gost 2001 signature
 179  *
 180  */
 181 int gost2001_do_verify(const unsigned char *dgst,int dgst_len,
 182         DSA_SIG *sig, EC_KEY *ec)
 183         {
 184         BN_CTX *ctx=BN_CTX_new();
 185         const EC_GROUP *group = EC_KEY_get0_group(ec);
 186         BIGNUM *order;
 187         BIGNUM *md = NULL,*e=NULL,*R=NULL,*v=NULL,*z1=NULL,*z2=NULL;
 188         BIGNUM *X=NULL,*tmp=NULL;
 189         EC_POINT *C = NULL;
 190         const EC_POINT *pub_key=NULL;
 191         int ok=0;
 192
 193         BN_CTX_start(ctx);
 194         order = BN_CTX_get(ctx);
 195         e = BN_CTX_get(ctx);
 196         z1 = BN_CTX_get(ctx);
 197         z2 = BN_CTX_get(ctx);
 198         tmp = BN_CTX_get(ctx);
 199         X= BN_CTX_get(ctx);
 200         R=BN_CTX_get(ctx);
 201         v=BN_CTX_get(ctx);
 202
 203         EC_GROUP_get_order(group,order,ctx);
 204         pub_key = EC_KEY_get0_public_key(ec);
 205         if (BN_is_zero(sig->s) || BN_is_zero(sig->r) ||
 206                 (BN_cmp(sig->s,order)>=1) || (BN_cmp(sig->r,order)>=1))
 207                 {
 208                 GOSTerr(GOST_F_GOST2001_DO_VERIFY,GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q);
 209                 goto err;
 210
 211                 }
 212         md = hashsum2bn(dgst);
 213
 214         BN_mod(e,md,order,ctx);
 215 #ifdef DEBUG_SIGN
 216         fprintf(stderr,"digest as bignum: ");
 217         BN_print_fp(stderr,md);
 218         fprintf(stderr,"\ndigest mod q: ");
 219         BN_print_fp(stderr,e);
 220 #endif
 221         if (BN_is_zero(e)) BN_one(e);
 222         v=BN_mod_inverse(v,e,order,ctx);
 223         BN_mod_mul(z1,sig->s,v,order,ctx);
 224         BN_sub(tmp,order,sig->r);
 225         BN_mod_mul(z2,tmp,v,order,ctx);
 226 #ifdef DEBUG_SIGN
 227         fprintf(stderr,"\nInverted digest value: ");
 228         BN_print_fp(stderr,v);
 229         fprintf(stderr,"\nz1: ");
 230         BN_print_fp(stderr,z1);
 231         fprintf(stderr,"\nz2: ");
 232         BN_print_fp(stderr,z2);
 233 #endif
 234         C = EC_POINT_new(group);
 235         if (!EC_POINT_mul(group,C,z1,pub_key,z2,ctx))
 236                 {
 237                 GOSTerr(GOST_F_GOST2001_DO_VERIFY,ERR_R_EC_LIB);
 238                 goto err;
 239                 }
 240         if (!EC_POINT_get_affine_coordinates_GFp(group,C,X,NULL,ctx))
 241                 {
 242                 GOSTerr(GOST_F_GOST2001_DO_VERIFY,ERR_R_EC_LIB);
 243                 goto err;
 244                 }
 245         BN_mod(R,X,order,ctx);
 246 #ifdef DEBUG_SIGN
 247         fprintf(stderr,"\nX=");
 248         BN_print_fp(stderr,X);
 249         fprintf(stderr,"\nX mod q=");
 250         BN_print_fp(stderr,R);
 251         fprintf(stderr,"\n");
 252 #endif
 253         if (BN_cmp(R,sig->r)!=0)
 254                 {
 255                 GOSTerr(GOST_F_GOST2001_DO_VERIFY,GOST_R_SIGNATURE_MISMATCH);
 256                 }
 257         else
 258                 {
 259                 ok = 1;
 260                 }
 261         err:
 262         EC_POINT_free(C);
 263         BN_CTX_end(ctx);
 264         BN_CTX_free(ctx);
 265         BN_free(md);
 266         return ok;
 267         }
 268 /*
 269  * Computes GOST R 34.10-2001 public key
 270  *
 271  *
 272  */
 273 int gost2001_compute_public(EC_KEY *ec)
 274         {
 275         const EC_GROUP *group = EC_KEY_get0_group(ec);
 276         EC_POINT *pub_key=NULL;
 277         const BIGNUM *priv_key=NULL;
 278         BN_CTX *ctx=NULL;
 279         int ok=0;
 280
 281         if (!group)
 282                 {
 283                 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,GOST_R_KEY_IS_NOT_INITIALIZED);
 284                 return 0;
 285                 }
 286         ctx=BN_CTX_new();
 287         BN_CTX_start(ctx);
 288         if (!(priv_key=EC_KEY_get0_private_key(ec)))
 289                 {
 290                 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,ERR_R_EC_LIB);
 291                 goto err;
 292                 }
 293
 294         pub_key = EC_POINT_new(group);
 295         if (!EC_POINT_mul(group,pub_key,priv_key,NULL,NULL,ctx))
 296                 {
 297                 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,ERR_R_EC_LIB);
 298                 goto err;
 299                 }
 300         if (!EC_KEY_set_public_key(ec,pub_key))
 301                 {
 302                 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,ERR_R_EC_LIB);
 303                 goto err;
 304                 }
 305         ok = 256;
 306         err:
 307         BN_CTX_end(ctx);
 308         EC_POINT_free(pub_key);
 309         BN_CTX_free(ctx);
 310         return ok;
 311         }
 312 /*
 313  *
 314  * Generates GOST R 34.10-2001 keypair
 315  *
 316  *
 317  */
 318 int gost2001_keygen(EC_KEY *ec)
 319         {
 320         BIGNUM *order = BN_new(),*d=BN_new();
 321         const EC_GROUP *group = EC_KEY_get0_group(ec);
 322         EC_GROUP_get_order(group,order,NULL);
 323
 324         do
 325                 {
 326                 if (!BN_rand_range(d,order))
 327                         {
 328                         GOSTerr(GOST_F_GOST2001_KEYGEN,GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
 329                         BN_free(d);
 330                         BN_free(order);
 331                         return 0;
 332                         }
 333                 }
 334         while (BN_is_zero(d));
 335         EC_KEY_set_private_key(ec,d);
 336         BN_free(d);
 337         BN_free(order);
 338         return gost2001_compute_public(ec);
 339         }
 340