void sign(int argc, char **argv) {
ecc_int256_t secret, hash, k, krecip, r, s, tmp;
ecc_25519_work_t kG;
if (argc != 2)
exit_error(1, 0, "Usage: ecdsautil sign file (secret is read from stdin)");
if (!sha256_file(argv[1], tmp.p))
exit_error(1, 0, "Error while hashing file");
char secret_string[65];
if (fgets(secret_string, sizeof(secret_string), stdin) == NULL)
exit_error(1, 0, "Error reading secret");
if (!parsehex(secret.p, secret_string, 32))
exit_error(1, 0, "Error reading secret");
// Reduce hash (instead of clearing 3 bits)
ecc_25519_gf_reduce(&hash, &tmp);
// Generate k
generate_k(k.p, secret.p, tmp.p);
ecc_25519_gf_sanitize_secret(&k, &k);
// calculate k^(-1)
ecc_25519_gf_recip(&krecip, &k);
// calculate kG = k * base point
ecc_25519_scalarmult_base(&kG, &k);
// store x coordinate of kG in r
ecc_25519_store_xy(&tmp, NULL, &kG);
ecc_25519_gf_reduce(&r, &tmp);
if (ecc_25519_gf_is_zero(&r))
exit_error(1, 0, "Error: r is zero (this should never happen)");
// tmp = r * secret
ecc_25519_gf_mult(&tmp, &r, &secret);
// s = hash + tmp = hash + r * secret
ecc_25519_gf_add(&s, &hash, &tmp);
// tmp = krecip * s = k^(-1) * s
ecc_25519_gf_mult(&tmp, &krecip, &s);
// mod n (order of G)
ecc_25519_gf_reduce(&s, &tmp);
if (ecc_25519_gf_is_zero(&s))
exit_error(1, 0, "Error: s is zero (this should never happen)");
hexdump(stdout, r.p, 32);
hexdump(stdout, s.p, 32);
puts("");
}
int main(int argc, char** argv){
int cases, case_no;
long a, b, c, r, k, n;
node* k_list, *tail;
long output;
float start_time, end_time;
char* filename = "sample.txt";
if(argc>=2){
filename = argv[1];
}
FILE* infile = fopen(filename,"r");
FILE* outfile = fopen("out.txt","w");
fscanf(infile,"%d",&cases);
for(case_no=1;case_no<=cases;case_no++){
//input
fscanf(infile,"%ld %ld",&n,&k);
fscanf(infile,"%ld %ld %ld %ld",&a,&b,&c,&r);
printf("Case #%d: %ld/%ld: %ld %ld %ld %ld\n",case_no,k,n,a,b,c,r);
start_time = (float) clock()/CLOCKS_PER_SEC;
//generate first k-values
k_list = generate_k(a,b,c,r,k);
//print_arr(k_list,k);
//execution
k_list = solve(k_list, a, b, c, r, k, n);
tail=get_tail(k_list,k);
output = tail->val;
//print_arr(k_list,k);
//post-execution
clean_list(k_list,k);
end_time = (float) clock()/CLOCKS_PER_SEC;
printf("Case #%d: Output: %ld\n",case_no,output);
fprintf(outfile,"Case #%d: %ld\n",case_no,output);
printf("Time %f sec\n",end_time-start_time);
}
fclose(infile);
fclose(outfile);
return 0;
}