// return random prime p
// length of p is bits
// p = 3 mod 4
// generate safe prime that is: p = 2*q + 1, q is prime too
Integer Commiter::gen_prime(unsigned bits) {
PrimeAndGenerator gen_p(1, common::rng(), bits);
Integer res = gen_p.Prime();
// sanity check p = 3 mod 4
if (res % 4 != 3) {
throw SanityException("gen prime");
}
return res;
}
int main(int argc, char *argv[]){
int keybits = 0;
int choice = 0;
int mod = 0;
int txtpos = argc - 1; // argc-1 is because argc is base 1, argv is base 0...and we don't know how many arguments we'll get.
char *text = NULL;
if((strlen(argv[txtpos]) < 1) || (argc == 1)){
printf("Usage:\n%s -h\n", argv[0]);
return 0;
}
text = (char*)malloc(sizeof(char) * strlen(argv[txtpos]) + 1);
while((choice = getopt(argc, argv, "k:m:h")) != -1){
switch(choice){
case 'k':
keybits = atoi(optarg);
break;
case 'm':
mod = atoi(optarg);
break;
case 'h':
default:
printf("\t ZKEY v0.1\n\n");
printf("Usage: %s <args> <text>\n\n", argv[0]);
printf("ARGS:\n");
printf("-k ###: Key length in bits for encryption\n");
printf("-m ###: Key length for cipher encrypting and decrypting\n");
printf("text: Any text that you want encrypted and sent to someone else\n\n");
printf("For -k, valid values are 1024, 4096 and 8192\n");
printf("For -m, valid values are 26, 52 and 94\n\n");
printf("Program is released as is.\n");
break;
}
}
// This could be a goto, but trying to stay away from that.
if(!keybits || !mod){
free(text);
return 0;
}
sprintf(text, "%s", argv[txtpos]);
if((keybits != 1024) && (keybits != 2048) && (keybits != 8192)){
printf("Keybit length of %d is invalid.\n", keybits);
return 0;
}
if((MODULO != 26) && (MODULO != 52) && (MODULO != 94)){
printf("Modulo value %d is invalid.\n", MODULO);
return 0;
} else
MODULO = mod;
gen_p(keybits);
free(text);
return 0;
}
