RSA篇

代码

库调用

pip install pycryptodome

关于填充的说明

PyCryptodome 库为 RSA 加密提供了 PKCS#1 OAEP 和 PKCS#1 v1.5 两种填充方案

PKCS#1 OAEP

使用哈希函数（如SHA-1、SHA-256）和随机数进行复杂编码

PKCS#1 v1.5 (旧版)

00 || 02 || [至少8字节的非零随机数] || 00 || 明文

留意Bleichenbacher攻击

from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_OAEP
import base64
def generate_rsa_keys():
    # key = RSA.generate(2048)
    key = RSA.generate(1024)
    private_key = key.export_key()
    public_key = key.publickey().export_key()
    return private_key, public_key

def encrypt_rsa(public_key_pem, plaintext):
    rsa_key = RSA.import_key(public_key_pem)
    cipher = PKCS1_OAEP.new(rsa_key) 
    ciphertext = cipher.encrypt(plaintext.encode('utf-8'))
    return base64.b64encode(ciphertext).decode('utf-8')

def decrypt_rsa(private_key_pem, ciphertext_b64):
    rsa_key = RSA.import_key(private_key_pem)
    cipher = PKCS1_OAEP.new(rsa_key)
    encrypted_data = base64.b64decode(ciphertext_b64)
    decrypted_data = cipher.decrypt(encrypted_data)
    return decrypted_data.decode('utf-8')

if __name__ == "__main__":
    private_key_pem, public_key_pem = generate_rsa_keys()
    print("Private Key:\n", private_key_pem.decode())
    print("Public Key:\n", public_key_pem.decode())

    message = "re100dayzhuji"
    print(f"原始消息: {message}")

    encrypted_msg_b64 = encrypt_rsa(public_key_pem, message)
    print(f"加密后的数据 (Base64): {encrypted_msg_b64}")

    decrypted_msg = decrypt_rsa(private_key_pem, encrypted_msg_b64)
    print(f"解密后的消息: {decrypted_msg}")

源码

import math
import random
def prime_init(max_num):
    prime_num=[]
    for i in range(2,max_num):
        tmp=0
        s=int(math.sqrt(i))+1
        for j in range(2,s):
            if i%j==0:
                tmp=1
                break
        if tmp==0:
            prime_num.append(i)
    return prime_num
def key_init():
    prime_num=prime_init(500)
    print(prime_num)
    while True:
        string=input("选择两个素数: ").split(' ')
        p,q=[int(x) for x in string]
        if (p in prime_num) and (q in prime_num):
            break
        else:
            print("输入错误")
    N=p*q
    r=(p-1)*(q-1)
    r_prime=prime_init(r)
    r_len=len(r_prime)
    e=r_prime[random.randint(0,r_len-1)]
    d=0
    for n in range(2,r):   #遍历找私钥
        if(e*n)%r==1:
            d=n
            break
    return (N,e),(N,d)

def encode(pub_key,m):
    N,e=pub_key
    return pow(m,e,N)

def decode(pri_key,m):
    N,d=pri_key
    return pow(m,d,N)

pub_key,pri_key=key_init()
print('公钥：',pub_key,'\n私钥：',pri_key)
m='re100dayzhuji'
enc=[encode(pub_key,ord(i)) for i in m]
print('加密后:')
s1=''.join(f'{x:02x}' for x in enc)
print(s1)
dec=[chr(decode(pri_key,i)) for i in enc]
print('解密后:')
s2=''.join(dec)
print(s2)
# 选择两个素数: 13 43
# 公钥： (559, 257) 
# 私钥： (559, 353)
# 加密后:
# 861fffb1d1d16f917f87ea341721a1
# 解密后:
# re100dayzhuji

解密技巧

https://blog.csdn.net/qq_46145027/article/details/125047313