diff options
Diffstat (limited to 'engines/ccgost/gost2001.c')
| -rw-r--r-- | engines/ccgost/gost2001.c | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/engines/ccgost/gost2001.c b/engines/ccgost/gost2001.c new file mode 100644 index 0000000..dacd82d --- /dev/null +++ b/engines/ccgost/gost2001.c @@ -0,0 +1,343 @@ +/********************************************************************** + * 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); + } + |
