DH Secret Key Space Calc

# Chris M. Thomasson


import math;
import random;


def is_prime(n):
    if (not (n % 2)): return (n == 2);
    if (not (n % 3)): return (n == 3);

    m = int(math.sqrt(n));

    for i in range(5, m + 1, 6):
        if (not (n % i) or not (n % (i + 2))):
            return False;

    return True;


def get_primes(nmin, nmax):
    c = nmin;
    p = [];
    for i in range(nmax):
        while (not is_prime(c)):
            c = c + 1;
        p.append(c);
        c = c + 2;
    return p;

def dh_get_primes(p):
    dh_p = [];
    for i in p:
        c = i*2 + 1;
        if (is_prime(c)):
            dh_p.append(c);
    return dh_p;


def dh_gen_mbase(p, g):
    return (p, g);

def dh_gen_rand_mbase(dh_p):
    p = random.randint(0, len(dh_p) - 1);
    g = random.randint(2, p - 2);
    return dh_gen_mbase(p, g);


def dh_gen(mbase, r_n):
    p = mbase[1]**r_n % mbase[0];
    return (r_n, p);

def dh_gen_rand(mbase, nmin, nmax):
    r_n = random.randint(nmin, nmax);
    return dh_gen(mbase, r_n);

def dh_get(mbase, gen, p):
    return p**gen[0] % mbase[0];


def dh_calc_range(mbase, n):
    h = [];
    for y in range(1, n + 1):
        for x in range(1, n + 1):
            alice = dh_gen(mbase, x);
            bob = dh_gen(mbase, y);

            a_s = dh_get(mbase, alice, bob[1]);
            b_s = dh_get(mbase, bob, alice[1]);

            try:
                i = h.index(a_s);
            except ValueError:
                if (a_s != b_s):
                    print("******** SECRET KEY ERROR! *********");
                h.append(a_s);

            #print("(%s, %s):s:%s" % (x, y, a_s));
    return (h, len(h) / mbase[0]);

def dh_calc_display(mbase, calc):
    n = len(calc[0]);
    print("mbase:%s" % (str(mbase)));
    print("\n\n%s Unique Secret Values" % (n));
    print("__________________________________________");
    a = "";
    for i in range(n):
        a = a + "%s\t" % (calc[0][i]);
        if (not ((i + 1) % 6)): a = a + "\n";
    print(a);
    print("\n%s of %s used, %s" % (n, mbase[0], calc[1]));



# Main Program
primes = dh_get_primes(get_primes(256, 1024));
mbase = dh_gen_mbase(23, 5);
calc = dh_calc_range(mbase, mbase[0] + 1);
dh_calc_display(mbase, calc);