RSAn分解攻击

题目给出public.key, flag.enc

如果n较小&＃xff0c;可以尝试分解n来进行攻击

# coding:utf8"""
需要安装2个模块&＃xff1a;rsa&＃xff0c;pycrypto
如果有问题&＃xff0c;应该把之前安装的crypto、pycrypto模块卸载掉重新安装一遍
还需要使用 yafu 分解n
"""import rsa
from Crypto.PublicKey import RSAdef egcd(a, b):if a &＃61;&＃61; 0:return (b, 0, 1)else:g, y, x &＃61; egcd(b % a, a)return (g, x - (b // a) * y, y)pub &＃61; RSA.importKey(open(&＃39;pub.key&＃39;).read())
n &＃61; long(pub.n)
e &＃61; long(pub.e)########################################################################################
# 通过yafu分解n,命令行打开yafu,输入factor(n)即可
# 如果可联网&＃xff0c;还可以使用http://www.factordb.com/网站分解
# p &＃61; 28596...
# q &＃61; 30400...if not p an not q:print &＃39;Need get p,q&＃39;exit(0)d &＃61; egcd((p - 1) * (q - 1), e)[2]
if d <0:d &＃43;&＃61; (p - 1) * (q - 1)key &＃61; RSA.construct((n, e, d)) # 如果e较小&＃xff0c;e应转化成long型: e &＃61; long(e)
key.exportKey()
open("private.pem", "w").write(key.exportKey())p &＃61; open("private.pem").read()
privkey &＃61; rsa.PrivateKey.load_pkcs1(p)
crypto &＃61; open("flag.enc").read()
message &＃61; rsa.decrypt(crypto, privkey)
print message