cryptotools/Cryptotools/Numbers/primeNumber.py
2026-01-11 09:19:22 +01:00

289 lines
7.3 KiB
Python

#!/usr/bin/env python3
from random import randint, seed, getrandbits
from math import log2
from Cryptotools.Utils.utils import gcd
def isPrimeNumber(p):
"""
Check if the number p is a prime number or not. The function iterate until p is achieve.
This function is not the efficient way to determine if p is prime or a composite.
To identify if p is prime or not, the function check the result of the Euclidean Division has a remainder. If yes, it's means it's not a prime number
Args:
p (Integer): number if possible prime or not
Returns:
Return a boolean if the number p is a prime number or not. True if yes
"""
for i in range(2, p):
if p % i == 0:
return False
return True
# https://people.csail.mit.edu/rivest/Rsapaper.pdf
# https://arxiv.org/pdf/1912.11546
# https://link.springer.com/content/pdf/10.1007/3-540-44499-8_27.pdf
# https://link.springer.com/article/10.1007/BF00202269
# https://www.geeksforgeeks.org/dsa/how-to-generate-large-prime-numbers-for-rsa-algorithm/
# https://crypto.stackexchange.com/questions/20548/generation-of-strong-primes
# https://crypto.stackexchange.com/questions/71/how-can-i-generate-large-prime-numbers-for-rsa
def getPrimeNumber(n, safe=True):
"""
This function generate a large prime number
based on "A method for Obtaining Digital Signatures
and Public-Key Cryptosystems"
Section B. How to Find Large Prime Numbers
https://dl.acm.org/doi/pdf/10.1145/359340.359342
Args:
n (Integer): The size of the prime number. Must be a multiple of 64
safe (Boolean): When generating the prime number, the function must find a safe prime number, based on the Germain primes (2p + 1 is also a prime number)
Returns:
Return the prime number
"""
if n % 64 != 0:
print("Must be multiple of 64")
return
# from sys import getsizeof
upper = getrandbits(n)
lower = upper >> 7
r = randint(lower, upper)
while r % 2 == 0:
r += 1
# Now, we are going to compute r as prime number
i = 100
while 1:
# Check if it's a prime number
if _millerRabinTest(r):
break
# TODO: it's dirty, need to change that
# i = int(log2(r))
# i *= randint(2, 50)
r += i
# print(f"{i} {r}")
i += 1
# print(_fermatLittleTheorem(r))
# print(getsizeof(r))
return r
def getSmallPrimeNumber(n) -> int:
"""
This function is deprecated
Args:
n (Integer): Get the small prime number until n
Returns:
Return the first prime number found
"""
is_prime = True
while True:
for i in range(2, n):
# If n is divisible by i, it's not a prime, we break the loop
if n % i == 0:
is_prime = False
break
if is_prime:
break
is_prime = True
n = n + 1
p = n
return p
def get_prime_numbers(n) -> list:
"""
This function get all prime number of the n
Args:
n (Integer): find all prime number until n is achieves
Returns:
Return a list of prime numbers
"""
l = list()
for i in range(2, n):
if n % i == 0:
l.append(i)
return l
def get_n_prime_numbers(n) -> list:
"""
This function return a list of n prime numbers
Args:
n (Integer): the range, must be an integer
Returns:
Return a list of n prime numbers
"""
l = list()
count = 2
index = 0
while index < n:
is_prime = True
for x in range(2, count):
if count % x == 0:
is_prime = False
break
if is_prime:
l.append(count)
index += 1
count += 1
return l
def are_coprime(p1, p2):
"""
This function check if p1 and p2 are coprime
Args:
p1 (list): list of prime numbers of the first number
p2 (list): list of prime number of the second number
Returns:
Return a boolean result
"""
r = True
for entry in p1:
if entry in p2:
r = False
break
return r
def sieveOfEratosthenes(n) -> list:
"""
This function build a list of prime number based on the Sieve of Erastosthenes
Args:
n (Integer): Interate until n is achives
Returns:
Return a list of all prime numbers to n
"""
if n < 1:
return list()
eratost = dict()
for i in range(2, n):
eratost[i] = True
for i in range(2, n):
if eratost[i]:
for j in range(i*i, n, i):
eratost[j] = False
sieve = list()
for i in range(2, n):
if eratost[i]:
sieve.append(i)
return sieve
def _fermatLittleTheorem(n) -> bool:
"""
The Fermat's little theorem. if n is a prime number, any number from 0 to n- 1 is a multiple of n
Args:
n (Integer): Check if n is prime or not
Returns:
Return True if the number a is a multiple of n, otherwise it's False
"""
a = randint(1, n - 1)
# We compute a ** (n - 1) % n
if pow(a, n - 1, n) == 1:
return True
return False
def _millerRabinTest(n) -> bool:
"""
This function execute a Miller Rabin test
For the algorithm, it's based on the pseudo-algo provided by this document:
* https://www.cs.cornell.edu/courses/cs4820/2010sp/handouts/MillerRabin.pdf
The Mille-Rabin test is an efficient way to determine if n is prime or not
Args:
n (Integer): Check if n is a prime number
Returns:
Return a boolean. True for a prime otherwise, it's a composite number
"""
if n < 2 or (n > 2 and n % 2 == 0): # If n is even, it's a composite
return False
k = 0
q = n - 1
#while (q & 1) == 0:
# k += 1
# q >>= 1
while q % 2 == 0:
k += 1
q //= 2
# We choose a: a < n - 1
for _ in range(40):
a = randint(2, n - 1)
# We compute a ** q % n
x = pow(a, q, n)
# If it's a composite number
if x == 1 or x == n - 1:
continue
for _ in range(k):
z = pow(x, 2, n)
if z == 1 or z == n - 1:
return False
else:
return False
return True
def sophieGermainPrime(p) -> bool:
"""
Check if the number p is a safe prime number: 2p + 1 is also a prime
Args:
p (Integer): Possible prime number
Returns:
Return True if p is a safe prime number, otherwise it's False
"""
pp = 2 * p + 1
return _millerRabinTest(pp)
def isSafePrime(n) -> bool:
"""
This function has not been implemented yet, but check if the number n is a safe prime number. This function will test different properties of the possible prime number n
Args:
n (Integer): the prime number to check
Returns:
Return a Boolean if the prime number n is safe or not. True if yes, otherwise it's False
"""
if n.bit_length() >= 256:
return True
# Do Sophie Germain's test
return False