| /********************************************************************** |
| * gost2001.c * |
| * Copyright (c) 2005-2006 Cryptocom LTD * |
| * This file is distributed under the same license as OpenSSL * |
| * * |
| * Implementation of GOST R 34.10-2001 * |
| * Requires OpenSSL 0.9.9 for compilation * |
| **********************************************************************/ |
| #include "gost_lcl.h" |
| #include "gost_params.h" |
| #include <string.h> |
| #include <openssl/rand.h> |
| #include <openssl/ecdsa.h> |
| #include <openssl/err.h> |
| #include "e_gost_err.h" |
| #ifdef DEBUG_SIGN |
| extern |
| void dump_signature(const char *message,const unsigned char *buffer,size_t len); |
| void dump_dsa_sig(const char *message, DSA_SIG *sig); |
| #else |
| |
| #define dump_signature(a,b,c) |
| #define dump_dsa_sig(a,b) |
| #endif |
| |
| /* |
| * Fills EC_KEY structure hidden in the app_data field of DSA structure |
| * with parameter information, extracted from parameter array in |
| * params.c file. |
| * |
| * Also fils DSA->q field with copy of EC_GROUP order field to make |
| * DSA_size function work |
| */ |
| int fill_GOST2001_params(EC_KEY *eckey, int nid) |
| { |
| R3410_2001_params *params = R3410_2001_paramset; |
| EC_GROUP *grp=NULL; |
| BIGNUM *p=NULL,*q=NULL,*a=NULL,*b=NULL,*x=NULL,*y=NULL; |
| EC_POINT *P=NULL; |
| BN_CTX *ctx=BN_CTX_new(); |
| int ok=0; |
| |
| BN_CTX_start(ctx); |
| p=BN_CTX_get(ctx); |
| a=BN_CTX_get(ctx); |
| b=BN_CTX_get(ctx); |
| x=BN_CTX_get(ctx); |
| y=BN_CTX_get(ctx); |
| q=BN_CTX_get(ctx); |
| while (params->nid!=NID_undef && params->nid != nid) params++; |
| if (params->nid == NID_undef) |
| { |
| GOSTerr(GOST_F_FILL_GOST2001_PARAMS,GOST_R_UNSUPPORTED_PARAMETER_SET); |
| goto err; |
| } |
| BN_hex2bn(&p,params->p); |
| BN_hex2bn(&a,params->a); |
| BN_hex2bn(&b,params->b); |
| |
| grp = EC_GROUP_new_curve_GFp(p,a,b,ctx); |
| |
| P = EC_POINT_new(grp); |
| |
| BN_hex2bn(&x,params->x); |
| BN_hex2bn(&y,params->y); |
| EC_POINT_set_affine_coordinates_GFp(grp,P,x,y,ctx); |
| BN_hex2bn(&q,params->q); |
| #ifdef DEBUG_KEYS |
| fprintf(stderr,"Set params index %d oid %s\nq=", |
| (params-R3410_2001_paramset),OBJ_nid2sn(params->nid)); |
| BN_print_fp(stderr,q); |
| fprintf(stderr,"\n"); |
| #endif |
| |
| EC_GROUP_set_generator(grp,P,q,NULL); |
| EC_GROUP_set_curve_name(grp,params->nid); |
| |
| EC_KEY_set_group(eckey,grp); |
| ok=1; |
| err: |
| EC_POINT_free(P); |
| EC_GROUP_free(grp); |
| BN_CTX_end(ctx); |
| BN_CTX_free(ctx); |
| return ok; |
| } |
| |
| |
| /* |
| * Computes gost2001 signature as DSA_SIG structure |
| * |
| * |
| */ |
| DSA_SIG *gost2001_do_sign(const unsigned char *dgst,int dlen, EC_KEY *eckey) |
| { |
| DSA_SIG *newsig = NULL; |
| BIGNUM *md = hashsum2bn(dgst); |
| BIGNUM *order = NULL; |
| const EC_GROUP *group; |
| const BIGNUM *priv_key; |
| BIGNUM *r=NULL,*s=NULL,*X=NULL,*tmp=NULL,*tmp2=NULL, *k=NULL,*e=NULL; |
| EC_POINT *C=NULL; |
| BN_CTX *ctx = BN_CTX_new(); |
| BN_CTX_start(ctx); |
| OPENSSL_assert(dlen==32); |
| newsig=DSA_SIG_new(); |
| if (!newsig) |
| { |
| GOSTerr(GOST_F_GOST2001_DO_SIGN,GOST_R_NO_MEMORY); |
| goto err; |
| } |
| group = EC_KEY_get0_group(eckey); |
| order=BN_CTX_get(ctx); |
| EC_GROUP_get_order(group,order,ctx); |
| priv_key = EC_KEY_get0_private_key(eckey); |
| e = BN_CTX_get(ctx); |
| BN_mod(e,md,order,ctx); |
| #ifdef DEBUG_SIGN |
| fprintf(stderr,"digest as bignum="); |
| BN_print_fp(stderr,md); |
| fprintf(stderr,"\ndigest mod q="); |
| BN_print_fp(stderr,e); |
| fprintf(stderr,"\n"); |
| #endif |
| if (BN_is_zero(e)) |
| { |
| BN_one(e); |
| } |
| k =BN_CTX_get(ctx); |
| C=EC_POINT_new(group); |
| do |
| { |
| do |
| { |
| if (!BN_rand_range(k,order)) |
| { |
| GOSTerr(GOST_F_GOST2001_DO_SIGN,GOST_R_RANDOM_NUMBER_GENERATOR_FAILED); |
| DSA_SIG_free(newsig); |
| newsig = NULL; |
| goto err; |
| } |
| if (!EC_POINT_mul(group,C,k,NULL,NULL,ctx)) |
| { |
| GOSTerr(GOST_F_GOST2001_DO_SIGN,ERR_R_EC_LIB); |
| DSA_SIG_free(newsig); |
| newsig = NULL; |
| goto err; |
| } |
| if (!X) X=BN_CTX_get(ctx); |
| if (!EC_POINT_get_affine_coordinates_GFp(group,C,X,NULL,ctx)) |
| { |
| GOSTerr(GOST_F_GOST2001_DO_SIGN,ERR_R_EC_LIB); |
| DSA_SIG_free(newsig); |
| newsig = NULL; |
| goto err; |
| } |
| if (!r) r=BN_CTX_get(ctx); |
| BN_nnmod(r,X,order,ctx); |
| } |
| while (BN_is_zero(r)); |
| /* s = (r*priv_key+k*e) mod order */ |
| if (!tmp) tmp = BN_CTX_get(ctx); |
| BN_mod_mul(tmp,priv_key,r,order,ctx); |
| if (!tmp2) tmp2 = BN_CTX_get(ctx); |
| BN_mod_mul(tmp2,k,e,order,ctx); |
| if (!s) s=BN_CTX_get(ctx); |
| BN_mod_add(s,tmp,tmp2,order,ctx); |
| } |
| while (BN_is_zero(s)); |
| |
| newsig->s=BN_dup(s); |
| newsig->r=BN_dup(r); |
| err: |
| BN_CTX_end(ctx); |
| BN_CTX_free(ctx); |
| EC_POINT_free(C); |
| BN_free(md); |
| return newsig; |
| } |
| /* |
| * Verifies gost 2001 signature |
| * |
| */ |
| int gost2001_do_verify(const unsigned char *dgst,int dgst_len, |
| DSA_SIG *sig, EC_KEY *ec) |
| { |
| BN_CTX *ctx=BN_CTX_new(); |
| const EC_GROUP *group = EC_KEY_get0_group(ec); |
| BIGNUM *order; |
| BIGNUM *md = NULL,*e=NULL,*R=NULL,*v=NULL,*z1=NULL,*z2=NULL; |
| BIGNUM *X=NULL,*tmp=NULL; |
| EC_POINT *C = NULL; |
| const EC_POINT *pub_key=NULL; |
| int ok=0; |
| |
| BN_CTX_start(ctx); |
| order = BN_CTX_get(ctx); |
| e = BN_CTX_get(ctx); |
| z1 = BN_CTX_get(ctx); |
| z2 = BN_CTX_get(ctx); |
| tmp = BN_CTX_get(ctx); |
| X= BN_CTX_get(ctx); |
| R=BN_CTX_get(ctx); |
| v=BN_CTX_get(ctx); |
| |
| EC_GROUP_get_order(group,order,ctx); |
| pub_key = EC_KEY_get0_public_key(ec); |
| if (BN_is_zero(sig->s) || BN_is_zero(sig->r) || |
| (BN_cmp(sig->s,order)>=1) || (BN_cmp(sig->r,order)>=1)) |
| { |
| GOSTerr(GOST_F_GOST2001_DO_VERIFY,GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q); |
| goto err; |
| |
| } |
| md = hashsum2bn(dgst); |
| |
| BN_mod(e,md,order,ctx); |
| #ifdef DEBUG_SIGN |
| fprintf(stderr,"digest as bignum: "); |
| BN_print_fp(stderr,md); |
| fprintf(stderr,"\ndigest mod q: "); |
| BN_print_fp(stderr,e); |
| #endif |
| if (BN_is_zero(e)) BN_one(e); |
| v=BN_mod_inverse(v,e,order,ctx); |
| BN_mod_mul(z1,sig->s,v,order,ctx); |
| BN_sub(tmp,order,sig->r); |
| BN_mod_mul(z2,tmp,v,order,ctx); |
| #ifdef DEBUG_SIGN |
| fprintf(stderr,"\nInverted digest value: "); |
| BN_print_fp(stderr,v); |
| fprintf(stderr,"\nz1: "); |
| BN_print_fp(stderr,z1); |
| fprintf(stderr,"\nz2: "); |
| BN_print_fp(stderr,z2); |
| #endif |
| C = EC_POINT_new(group); |
| if (!EC_POINT_mul(group,C,z1,pub_key,z2,ctx)) |
| { |
| GOSTerr(GOST_F_GOST2001_DO_VERIFY,ERR_R_EC_LIB); |
| goto err; |
| } |
| if (!EC_POINT_get_affine_coordinates_GFp(group,C,X,NULL,ctx)) |
| { |
| GOSTerr(GOST_F_GOST2001_DO_VERIFY,ERR_R_EC_LIB); |
| goto err; |
| } |
| BN_mod(R,X,order,ctx); |
| #ifdef DEBUG_SIGN |
| fprintf(stderr,"\nX="); |
| BN_print_fp(stderr,X); |
| fprintf(stderr,"\nX mod q="); |
| BN_print_fp(stderr,R); |
| fprintf(stderr,"\n"); |
| #endif |
| if (BN_cmp(R,sig->r)!=0) |
| { |
| GOSTerr(GOST_F_GOST2001_DO_VERIFY,GOST_R_SIGNATURE_MISMATCH); |
| } |
| else |
| { |
| ok = 1; |
| } |
| err: |
| EC_POINT_free(C); |
| BN_CTX_end(ctx); |
| BN_CTX_free(ctx); |
| BN_free(md); |
| return ok; |
| } |
| /* |
| * Computes GOST R 34.10-2001 public key |
| * |
| * |
| */ |
| int gost2001_compute_public(EC_KEY *ec) |
| { |
| const EC_GROUP *group = EC_KEY_get0_group(ec); |
| EC_POINT *pub_key=NULL; |
| const BIGNUM *priv_key=NULL; |
| BN_CTX *ctx=NULL; |
| int ok=0; |
| |
| if (!group) |
| { |
| GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,GOST_R_KEY_IS_NOT_INITIALIZED); |
| return 0; |
| } |
| ctx=BN_CTX_new(); |
| BN_CTX_start(ctx); |
| if (!(priv_key=EC_KEY_get0_private_key(ec))) |
| { |
| GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,ERR_R_EC_LIB); |
| goto err; |
| } |
| |
| pub_key = EC_POINT_new(group); |
| if (!EC_POINT_mul(group,pub_key,priv_key,NULL,NULL,ctx)) |
| { |
| GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,ERR_R_EC_LIB); |
| goto err; |
| } |
| if (!EC_KEY_set_public_key(ec,pub_key)) |
| { |
| GOSTerr(GOST_F_GOST2001_COMPUTE_PUBLIC,ERR_R_EC_LIB); |
| goto err; |
| } |
| ok = 256; |
| err: |
| BN_CTX_end(ctx); |
| EC_POINT_free(pub_key); |
| BN_CTX_free(ctx); |
| return ok; |
| } |
| /* |
| * |
| * Generates GOST R 34.10-2001 keypair |
| * |
| * |
| */ |
| int gost2001_keygen(EC_KEY *ec) |
| { |
| BIGNUM *order = BN_new(),*d=BN_new(); |
| const EC_GROUP *group = EC_KEY_get0_group(ec); |
| EC_GROUP_get_order(group,order,NULL); |
| |
| do |
| { |
| if (!BN_rand_range(d,order)) |
| { |
| GOSTerr(GOST_F_GOST2001_KEYGEN,GOST_R_RANDOM_NUMBER_GENERATOR_FAILED); |
| BN_free(d); |
| BN_free(order); |
| return 0; |
| } |
| } |
| while (BN_is_zero(d)); |
| EC_KEY_set_private_key(ec,d); |
| BN_free(d); |
| BN_free(order); |
| return gost2001_compute_public(ec); |
| } |
| |