| Index: openssl/engines/ccgost/gost_sign.c
|
| ===================================================================
|
| --- openssl/engines/ccgost/gost_sign.c (revision 0)
|
| +++ openssl/engines/ccgost/gost_sign.c (revision 0)
|
| @@ -0,0 +1,321 @@
|
| +/**********************************************************************
|
| + * gost_sign.c *
|
| + * Copyright (c) 2005-2006 Cryptocom LTD *
|
| + * This file is distributed under the same license as OpenSSL *
|
| + * *
|
| + * Implementation of GOST R 34.10-94 signature algorithm *
|
| + * for OpenSSL *
|
| + * Requires OpenSSL 0.9.9 for compilation *
|
| + **********************************************************************/
|
| +#include <string.h>
|
| +#include <openssl/rand.h>
|
| +#include <openssl/bn.h>
|
| +#include <openssl/dsa.h>
|
| +#include <openssl/evp.h>
|
| +
|
| +#include "gost_params.h"
|
| +#include "gost_lcl.h"
|
| +#include "e_gost_err.h"
|
| +
|
| +#ifdef DEBUG_SIGN
|
| +void dump_signature(const char *message,const unsigned char *buffer,size_t len)
|
| + {
|
| + size_t i;
|
| + fprintf(stderr,"signature %s Length=%d",message,len);
|
| + for (i=0; i<len; i++)
|
| + {
|
| + if (i% 16 ==0) fputc('\n',stderr);
|
| + fprintf (stderr," %02x",buffer[i]);
|
| + }
|
| + fprintf(stderr,"\nEnd of signature\n");
|
| + }
|
| +
|
| +void dump_dsa_sig(const char *message, DSA_SIG *sig)
|
| + {
|
| + fprintf(stderr,"%s\nR=",message);
|
| + BN_print_fp(stderr,sig->r);
|
| + fprintf(stderr,"\nS=");
|
| + BN_print_fp(stderr,sig->s);
|
| + fprintf(stderr,"\n");
|
| + }
|
| +
|
| +#else
|
| +
|
| +#define dump_signature(a,b,c)
|
| +#define dump_dsa_sig(a,b)
|
| +#endif
|
| +
|
| +/*
|
| + * Computes signature and returns it as DSA_SIG structure
|
| + */
|
| +DSA_SIG *gost_do_sign(const unsigned char *dgst,int dlen, DSA *dsa)
|
| + {
|
| + BIGNUM *k=NULL,*tmp=NULL,*tmp2=NULL;
|
| + DSA_SIG *newsig = DSA_SIG_new();
|
| + BIGNUM *md = hashsum2bn(dgst);
|
| + /* check if H(M) mod q is zero */
|
| + BN_CTX *ctx=BN_CTX_new();
|
| + BN_CTX_start(ctx);
|
| + if (!newsig)
|
| + {
|
| + GOSTerr(GOST_F_GOST_DO_SIGN,GOST_R_NO_MEMORY);
|
| + goto err;
|
| + }
|
| + tmp=BN_CTX_get(ctx);
|
| + k = BN_CTX_get(ctx);
|
| + tmp2 = BN_CTX_get(ctx);
|
| + BN_mod(tmp,md,dsa->q,ctx);
|
| + if (BN_is_zero(tmp))
|
| + {
|
| + BN_one(md);
|
| + }
|
| + do
|
| + {
|
| + do
|
| + {
|
| + /*Generate random number k less than q*/
|
| + BN_rand_range(k,dsa->q);
|
| + /* generate r = (a^x mod p) mod q */
|
| + BN_mod_exp(tmp,dsa->g, k, dsa->p,ctx);
|
| + if (!(newsig->r)) newsig->r=BN_new();
|
| + BN_mod(newsig->r,tmp,dsa->q,ctx);
|
| + }
|
| + while (BN_is_zero(newsig->r));
|
| + /* generate s = (xr + k(Hm)) mod q */
|
| + BN_mod_mul(tmp,dsa->priv_key,newsig->r,dsa->q,ctx);
|
| + BN_mod_mul(tmp2,k,md,dsa->q,ctx);
|
| + if (!newsig->s) newsig->s=BN_new();
|
| + BN_mod_add(newsig->s,tmp,tmp2,dsa->q,ctx);
|
| + }
|
| + while (BN_is_zero(newsig->s));
|
| + err:
|
| + BN_free(md);
|
| + BN_CTX_end(ctx);
|
| + BN_CTX_free(ctx);
|
| + return newsig;
|
| + }
|
| +
|
| +
|
| +/*
|
| + * Packs signature according to Cryptocom rules
|
| + * and frees up DSA_SIG structure
|
| + */
|
| +/*
|
| +int pack_sign_cc(DSA_SIG *s,int order,unsigned char *sig, size_t *siglen)
|
| + {
|
| + *siglen = 2*order;
|
| + memset(sig,0,*siglen);
|
| + store_bignum(s->r, sig,order);
|
| + store_bignum(s->s, sig + order,order);
|
| + dump_signature("serialized",sig,*siglen);
|
| + DSA_SIG_free(s);
|
| + return 1;
|
| + }
|
| +*/
|
| +/*
|
| + * Packs signature according to Cryptopro rules
|
| + * and frees up DSA_SIG structure
|
| + */
|
| +int pack_sign_cp(DSA_SIG *s,int order,unsigned char *sig, size_t *siglen)
|
| + {
|
| + *siglen = 2*order;
|
| + memset(sig,0,*siglen);
|
| + store_bignum(s->s, sig, order);
|
| + store_bignum(s->r, sig+order,order);
|
| + dump_signature("serialized",sig,*siglen);
|
| + DSA_SIG_free(s);
|
| + return 1;
|
| + }
|
| +
|
| +/*
|
| + * Verifies signature passed as DSA_SIG structure
|
| + *
|
| + */
|
| +
|
| +int gost_do_verify(const unsigned char *dgst, int dgst_len,
|
| + DSA_SIG *sig, DSA *dsa)
|
| + {
|
| + BIGNUM *md, *tmp=NULL;
|
| + BIGNUM *q2=NULL;
|
| + BIGNUM *u=NULL,*v=NULL,*z1=NULL,*z2=NULL;
|
| + BIGNUM *tmp2=NULL,*tmp3=NULL;
|
| + int ok;
|
| + BN_CTX *ctx = BN_CTX_new();
|
| +
|
| + BN_CTX_start(ctx);
|
| + if (BN_cmp(sig->s,dsa->q)>=1||
|
| + BN_cmp(sig->r,dsa->q)>=1)
|
| + {
|
| + GOSTerr(GOST_F_GOST_DO_VERIFY,GOST_R_SIGNATURE_PARTS_GREATER_THAN_Q);
|
| + return 0;
|
| + }
|
| + md=hashsum2bn(dgst);
|
| +
|
| + tmp=BN_CTX_get(ctx);
|
| + v=BN_CTX_get(ctx);
|
| + q2=BN_CTX_get(ctx);
|
| + z1=BN_CTX_get(ctx);
|
| + z2=BN_CTX_get(ctx);
|
| + tmp2=BN_CTX_get(ctx);
|
| + tmp3=BN_CTX_get(ctx);
|
| + u = BN_CTX_get(ctx);
|
| +
|
| + BN_mod(tmp,md,dsa->q,ctx);
|
| + if (BN_is_zero(tmp))
|
| + {
|
| + BN_one(md);
|
| + }
|
| + BN_copy(q2,dsa->q);
|
| + BN_sub_word(q2,2);
|
| + BN_mod_exp(v,md,q2,dsa->q,ctx);
|
| + BN_mod_mul(z1,sig->s,v,dsa->q,ctx);
|
| + BN_sub(tmp,dsa->q,sig->r);
|
| + BN_mod_mul(z2,tmp,v,dsa->p,ctx);
|
| + BN_mod_exp(tmp,dsa->g,z1,dsa->p,ctx);
|
| + BN_mod_exp(tmp2,dsa->pub_key,z2,dsa->p,ctx);
|
| + BN_mod_mul(tmp3,tmp,tmp2,dsa->p,ctx);
|
| + BN_mod(u,tmp3,dsa->q,ctx);
|
| + ok= BN_cmp(u,sig->r);
|
| +
|
| + BN_free(md);
|
| + BN_CTX_end(ctx);
|
| + BN_CTX_free(ctx);
|
| + if (ok!=0)
|
| + {
|
| + GOSTerr(GOST_F_GOST_DO_VERIFY,GOST_R_SIGNATURE_MISMATCH);
|
| + }
|
| + return (ok==0);
|
| + }
|
| +
|
| +/*
|
| + * Computes public keys for GOST R 34.10-94 algorithm
|
| + *
|
| + */
|
| +int gost94_compute_public(DSA *dsa)
|
| + {
|
| + /* Now fill algorithm parameters with correct values */
|
| + BN_CTX *ctx = BN_CTX_new();
|
| + if (!dsa->g)
|
| + {
|
| + GOSTerr(GOST_F_GOST94_COMPUTE_PUBLIC,GOST_R_KEY_IS_NOT_INITALIZED);
|
| + return 0;
|
| + }
|
| + /* Compute public key y = a^x mod p */
|
| + dsa->pub_key=BN_new();
|
| + BN_mod_exp(dsa->pub_key, dsa->g,dsa->priv_key,dsa->p,ctx);
|
| + BN_CTX_free(ctx);
|
| + return 1;
|
| + }
|
| +
|
| +/*
|
| + * Fill GOST 94 params, searching them in R3410_paramset array
|
| + * by nid of paramset
|
| + *
|
| + */
|
| +int fill_GOST94_params(DSA *dsa,int nid)
|
| + {
|
| + R3410_params *params=R3410_paramset;
|
| + while (params->nid!=NID_undef && params->nid !=nid) params++;
|
| + if (params->nid == NID_undef)
|
| + {
|
| + GOSTerr(GOST_F_FILL_GOST94_PARAMS,GOST_R_UNSUPPORTED_PARAMETER_SET);
|
| + return 0;
|
| + }
|
| +#define dump_signature(a,b,c)
|
| + if (dsa->p) { BN_free(dsa->p); }
|
| + dsa->p=NULL;
|
| + BN_dec2bn(&(dsa->p),params->p);
|
| + if (dsa->q) { BN_free(dsa->q); }
|
| + dsa->q=NULL;
|
| + BN_dec2bn(&(dsa->q),params->q);
|
| + if (dsa->g) { BN_free(dsa->g); }
|
| + dsa->g=NULL;
|
| + BN_dec2bn(&(dsa->g),params->a);
|
| + return 1;
|
| + }
|
| +
|
| +/*
|
| + * Generate GOST R 34.10-94 keypair
|
| + *
|
| + *
|
| + */
|
| +int gost_sign_keygen(DSA *dsa)
|
| + {
|
| + dsa->priv_key = BN_new();
|
| + BN_rand_range(dsa->priv_key,dsa->q);
|
| + return gost94_compute_public( dsa);
|
| + }
|
| +
|
| +/* Unpack signature according to cryptocom rules */
|
| +/*
|
| +DSA_SIG *unpack_cc_signature(const unsigned char *sig,size_t siglen)
|
| + {
|
| + DSA_SIG *s;
|
| + s = DSA_SIG_new();
|
| + if (s == NULL)
|
| + {
|
| + GOSTerr(GOST_F_UNPACK_CC_SIGNATURE,GOST_R_NO_MEMORY);
|
| + return(NULL);
|
| + }
|
| + s->r = getbnfrombuf(sig, siglen/2);
|
| + s->s = getbnfrombuf(sig + siglen/2, siglen/2);
|
| + return s;
|
| + }
|
| +*/
|
| +/* Unpack signature according to cryptopro rules */
|
| +DSA_SIG *unpack_cp_signature(const unsigned char *sig,size_t siglen)
|
| + {
|
| + DSA_SIG *s;
|
| +
|
| + s = DSA_SIG_new();
|
| + if (s == NULL)
|
| + {
|
| + GOSTerr(GOST_F_UNPACK_CP_SIGNATURE,GOST_R_NO_MEMORY);
|
| + return NULL;
|
| + }
|
| + s->s = getbnfrombuf(sig , siglen/2);
|
| + s->r = getbnfrombuf(sig + siglen/2, siglen/2);
|
| + return s;
|
| + }
|
| +
|
| +/* Convert little-endian byte array into bignum */
|
| +BIGNUM *hashsum2bn(const unsigned char *dgst)
|
| + {
|
| + unsigned char buf[32];
|
| + int i;
|
| + for (i=0;i<32;i++)
|
| + {
|
| + buf[31-i]=dgst[i];
|
| + }
|
| + return getbnfrombuf(buf,32);
|
| + }
|
| +
|
| +/* Convert byte buffer to bignum, skipping leading zeros*/
|
| +BIGNUM *getbnfrombuf(const unsigned char *buf,size_t len)
|
| + {
|
| + while (*buf==0&&len>0)
|
| + {
|
| + buf++; len--;
|
| + }
|
| + if (len)
|
| + {
|
| + return BN_bin2bn(buf,len,NULL);
|
| + }
|
| + else
|
| + {
|
| + BIGNUM *b=BN_new();
|
| + BN_zero(b);
|
| + return b;
|
| + }
|
| + }
|
| +
|
| +/* Pack bignum into byte buffer of given size, filling all leading bytes
|
| + * by zeros */
|
| +int store_bignum(BIGNUM *bn, unsigned char *buf,int len)
|
| + {
|
| + int bytes = BN_num_bytes(bn);
|
| + if (bytes>len) return 0;
|
| + memset(buf,0,len);
|
| + BN_bn2bin(bn,buf+len-bytes);
|
| + return 1;
|
| + }
|
|
|