python3 計算rsa私鑰 已知n e計算d

 

 

# 分解模數n
def rsa_moder(n):
    base = 2
    while base < n:
        if n % base == 0:
            return base, n // base
        base += 1


# 求歐拉函數f(n)
def rsa_get_euler(prime1, prime2):
    return (prime1 - 1) * (prime2 - 1)


# 求私鑰
def rsa_get_key(e, euler):
    k = 1
    while True:
        if (((euler * k) + 1) % e) == 0:
            return (euler * k + 1) // e
        k += 1


# 根據n,e計算d(或根據n,d計算e)
def get_rsa_e_d(n, e=None, d=None):
    if e is None and d is None:
        return

    arg = e
    if arg is None:
        arg = d

    primes = rsa_moder(n)
    p = primes[0]
    q = primes[1]

    d = rsa_get_key(arg, rsa_get_euler(p, q))

    return d


def test():
    str_fmt = 'n: {:<10} e: {:<10} d: {:<10}'

    # 導入rsa庫
    import rsa as rsa
    key = rsa.newkeys(24)

    # 產生rsa密鑰對
    if isinstance(key[1], rsa.PrivateKey):
        print(str_fmt.format(key[1].n, key[1].e, key[1].d))

    # 解密
    n = 14666299
    d = 2101153
    e = get_rsa_e_d(n, None, d)
    print(str_fmt.format(n, e, d))

    n = 12748507
    e = 65537
    d = get_rsa_e_d(n, e, None)
    print(str_fmt.format(n, e, d))


if __name__ == '__main__':
    test()