利用rsa对文本加密的python实现

以下是一个简单的RSA加密和解密的Python实现：

import random
import math

def gcd(a, b):
    while b != 0:
        a, b = b, a % b
    return a

def mod_inverse(a, m):
    if gcd(a, m) != 1:
        return None
    u1, u2, u3 = 1, 0, a
    v1, v2, v3 = 0, 1, m
    while v3 != 0:
        q = u3 // v3
        v1, v2, v3, u1, u2, u3 = (u1 - q * v1), (u2 - q * v2), (u3 - q * v3), v1, v2, v3
    return u1 % m

def is_prime(n):
    if n <= 1:
        return False
    for i in range(2, int(math.sqrt(n)) + 1):
        if n % i == 0:
            return False
    return True

def generate_keypair(p, q):
    if not (is_prime(p) and is_prime(q)):
        raise ValueError("Both numbers must be prime.")
    elif p == q:
        raise ValueError("p and q cannot be equal")
    # n = pq
    n = p * q
    # phi(n) = (p-1)(q-1)
    phi = (p - 1) * (q - 1)
    # Choose an integer e such that e and phi(n) are coprime
    e = random.randrange(1, phi)
    g = gcd(e, phi)
    while g != 1:
        e = random.randrange(1, phi)
        g = gcd(e, phi)
    # Calculate d such that ed = 1 (mod phi(n))
    d = mod_inverse(e, phi)
    # Return public and private keypair
    # Public key is (e, n)
    # Private key is (d, n)
    return ((e, n), (d, n))

def encrypt(public_key, plaintext):
    # Unpack the key into its components
    key, n = public_key
    # Convert each letter in the plaintext to numbers based on the character using a^b mod m
    cipher = [pow(ord(char), key, n) for char in plaintext]
    # Return the array of bytes
    return cipher

def decrypt(private_key, ciphertext):
    # Unpack the key into its components
    key, n = private_key
    # Generate the plaintext based on the ciphertext and key using a^b mod m
    plain = [chr(pow(char, key, n)) for char in ciphertext]
    # Return the array of bytes as a string
    return ''.join(plain)

# Example usage
p = 61
q = 53
public, private = generate_keypair(p, q)
print("Public key:", public)
print("Private key:", private)
message = "hello, world"
encrypted_msg = encrypt(public, message)
print("Encrypted message:", ''.join(map(str, encrypted_msg)))
decrypted_msg = decrypt(private, encrypted_msg)
print("Decrypted message:", decrypted_msg)

在此示例中，我们使用generate_keypair函数生成RSA公钥和私钥。然后，我们使用encrypt函数将文本加密为数字数组，使用decrypt函数将加密的数字数组解密为文本。在此示例中，我们使用61和53作为p和q的值，但您可以使用不同的值来生成不同的密钥