1 /**********************************************************************
3 * Copyright (c) 2005-2006 Cryptocom LTD *
4 * This file is distributed under the same license as OpenSSL *
6 * Implementation of GOST R 34.10-2001 *
7 * Requires OpenSSL 0.9.9 for compilation *
8 **********************************************************************/
13 #include <openssl/rand.h>
14 #include <openssl/ecdsa.h>
15 #include <openssl/err.h>
16 #include "e_gost_err.h"
19 void dump_signature(const char *message,const unsigned char *buffer,size_t len);
20 void dump_dsa_sig(const char *message, DSA_SIG *sig);
23 #define dump_signature(a,b,c)
24 #define dump_dsa_sig(a,b)
28 * Fills EC_KEY structure hidden in the app_data field of DSA structure
29 * with parameter information, extracted from parameter array in
32 * Also fils DSA->q field with copy of EC_GROUP order field to make
33 * DSA_size function work
35 int fill_GOST2001_params(EC_KEY *eckey, int nid) {
36 R3410_2001_params *params = R3410_2001_paramset;
38 BIGNUM *p=NULL,*q=NULL,*a=NULL,*b=NULL,*x=NULL,*y=NULL;
40 BN_CTX *ctx=BN_CTX_new();
50 while (params->nid!=NID_undef && params->nid != nid) params++;
51 if (params->nid == NID_undef) {
52 GOSTerr(GOST_F_FILL_GOST2001_PARAMS,GOST_R_UNSUPPORTED_PARAMETER_SET);
55 BN_hex2bn(&p,params->p);
56 BN_hex2bn(&a,params->a);
57 BN_hex2bn(&b,params->b);
59 grp = EC_GROUP_new_curve_GFp(p,a,b,ctx);
61 P = EC_POINT_new(grp);
63 BN_hex2bn(&x,params->x);
64 BN_hex2bn(&y,params->y);
65 EC_POINT_set_affine_coordinates_GFp(grp,P,x,y,ctx);
66 BN_hex2bn(&q,params->q);
68 fprintf(stderr,"Set params index %d oid %s\nq=",
69 (params-R3410_2001_paramset),OBJ_nid2sn(params->nid));
70 BN_print_fp(stderr,q);
74 EC_GROUP_set_generator(grp,P,q,NULL);
75 EC_GROUP_set_curve_name(grp,params->nid);
77 EC_KEY_set_group(eckey,grp);
90 * Computes gost2001 signature as DSA_SIG structure
94 DSA_SIG *gost2001_do_sign(const unsigned char *dgst,int dlen, EC_KEY *eckey) {
95 DSA_SIG *newsig = NULL;
96 BIGNUM *md = hashsum2bn(dgst);
98 const EC_GROUP *group;
99 const BIGNUM *priv_key;
100 BIGNUM *r=NULL,*s=NULL,*X=NULL,*tmp=NULL,*tmp2=NULL, *k=NULL,*e=NULL;
102 BN_CTX *ctx = BN_CTX_new();
104 OPENSSL_assert(dlen==32);
105 newsig=DSA_SIG_new();
108 GOSTerr(GOST_F_GOST2001_DO_SIGN,GOST_R_NO_MEMORY);
111 group = EC_KEY_get0_group(eckey);
112 order=BN_CTX_get(ctx);
113 EC_GROUP_get_order(group,order,ctx);
114 priv_key = EC_KEY_get0_private_key(eckey);
116 BN_mod(e,md,order,ctx);
118 fprintf(stderr,"digest as bignum=");
119 BN_print_fp(stderr,md);
120 fprintf(stderr,"\ndigest mod q=");
121 BN_print_fp(stderr,e);
122 fprintf(stderr,"\n");
129 C=EC_POINT_new(group);
132 if (!BN_rand_range(k,order))
134 GOSTerr(GOST_F_GOST2001_DO_SIGN,GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
135 DSA_SIG_free(newsig);
138 if (!EC_POINT_mul(group,C,k,NULL,NULL,ctx)) {
139 GOSTerr(GOST_F_GOST2001_DO_SIGN,ERR_R_EC_LIB);
140 DSA_SIG_free(newsig);
143 if (!X) X=BN_CTX_get(ctx);
144 if (!EC_POINT_get_affine_coordinates_GFp(group,C,X,NULL,ctx)) {
145 GOSTerr(GOST_F_GOST2001_DO_SIGN,ERR_R_EC_LIB);
146 DSA_SIG_free(newsig);
149 if (!r) r=BN_CTX_get(ctx);
150 BN_nnmod(r,X,order,ctx);
151 } while (BN_is_zero(r));
152 /* s = (r*priv_key+k*e) mod order */
153 if (!tmp) tmp = BN_CTX_get(ctx);
154 BN_mod_mul(tmp,priv_key,r,order,ctx);
155 if (!tmp2) tmp2 = BN_CTX_get(ctx);
156 BN_mod_mul(tmp2,k,e,order,ctx);
157 if (!s) s=BN_CTX_get(ctx);
158 BN_mod_add(s,tmp,tmp2,order,ctx);
159 } while (BN_is_zero(s));
171 * Verifies gost 2001 signature
174 int gost2001_do_verify(const unsigned char *dgst,int dgst_len,
175 DSA_SIG *sig, EC_KEY *ec) {
176 BN_CTX *ctx=BN_CTX_new();
177 const EC_GROUP *group = EC_KEY_get0_group(ec);
179 BIGNUM *md = NULL,*e=NULL,*R=NULL,*v=NULL,*z1=NULL,*z2=NULL;
180 BIGNUM *X=NULL,*tmp=NULL;
182 const EC_POINT *pub_key=NULL;
186 order = BN_CTX_get(ctx);
188 z1 = BN_CTX_get(ctx);
189 z2 = BN_CTX_get(ctx);
190 tmp = BN_CTX_get(ctx);
195 EC_GROUP_get_order(group,order,ctx);
196 pub_key = EC_KEY_get0_public_key(ec);
197 if (BN_is_zero(sig->s) || BN_is_zero(sig->r) ||
198 (BN_cmp(sig->s,order)>=1) || (BN_cmp(sig->r,order)>=1))
200 GOSTerr(GOST_F_GOST_DO_VERIFY,GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q);
204 md = hashsum2bn(dgst);
206 BN_mod(e,md,order,ctx);
208 fprintf(stderr,"digest as bignum: ");
209 BN_print_fp(stderr,md);
210 fprintf(stderr,"\ndigest mod q: ");
211 BN_print_fp(stderr,e);
213 if (BN_is_zero(e)) BN_one(e);
214 v=BN_mod_inverse(v,e,order,ctx);
215 BN_mod_mul(z1,sig->s,v,order,ctx);
216 BN_sub(tmp,order,sig->r);
217 BN_mod_mul(z2,tmp,v,order,ctx);
219 fprintf(stderr,"\nInverted digest value: ");
220 BN_print_fp(stderr,v);
221 fprintf(stderr,"\nz1: ");
222 BN_print_fp(stderr,z1);
223 fprintf(stderr,"\nz2: ");
224 BN_print_fp(stderr,z2);
226 C = EC_POINT_new(group);
227 if (!EC_POINT_mul(group,C,z1,pub_key,z2,ctx))
229 GOSTerr(GOST_F_GOST2001_DO_VERIFY,ERR_R_EC_LIB);
232 if (!EC_POINT_get_affine_coordinates_GFp(group,C,X,NULL,ctx))
234 GOSTerr(GOST_F_GOST2001_DO_VERIFY,ERR_R_EC_LIB);
237 BN_mod(R,X,order,ctx);
239 fprintf(stderr,"\nX=");
240 BN_print_fp(stderr,X);
241 fprintf(stderr,"\nX mod q=");
242 BN_print_fp(stderr,R);
243 fprintf(stderr,"\n");
245 if (BN_cmp(R,sig->r)!=0) {
246 GOSTerr(GOST_F_GOST2001_DO_VERIFY,GOST_R_SIGNATURE_MISMATCH);
258 * Computes GOST R 34.10-2001 public key
262 int gost2001_compute_public(EC_KEY *ec)
264 const EC_GROUP *group = EC_KEY_get0_group(ec);
265 EC_POINT *pub_key=NULL;
266 const BIGNUM *priv_key=NULL;
271 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,GOST_R_KEY_IS_NOT_INITIALIZED);
276 if (!(priv_key=EC_KEY_get0_private_key(ec)))
278 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,ERR_R_EC_LIB);
282 pub_key = EC_POINT_new(group);
283 if (!EC_POINT_mul(group,pub_key,priv_key,NULL,NULL,ctx))
285 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,ERR_R_EC_LIB);
288 if (!EC_KEY_set_public_key(ec,pub_key)) {
289 GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,ERR_R_EC_LIB);
295 EC_POINT_free(pub_key);
301 * Generates GOST R 34.10-2001 keypair
305 int gost2001_keygen(EC_KEY *ec) {
306 BIGNUM *order = BN_new(),*d=BN_new();
307 const EC_GROUP *group = EC_KEY_get0_group(ec);
308 EC_GROUP_get_order(group,order,NULL);
311 if (!BN_rand_range(d,order))
313 GOSTerr(GOST_F_GOST2001_DO_SIGN,GOST_R_RANDOM_NUMBER_GENERATOR_FAILED);
318 } while (BN_is_zero(d));
319 EC_KEY_set_private_key(ec,d);
322 return gost2001_compute_public(ec);