小指数rsa 多线程版writeup

下载flag.enc 和pubkey.pem文件

将pem文件拖入openssl得到n(modulus)和e(exponent)

 openssl rsa -pubin -text -modulus -in pubkey.pem

需从github下载libnum,gmpy

from multiprocessing import Pool
from libnum import s2n
import gmpy
workerCount=4
n=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
e=3
f=open('exp/flag.enc','rb')
c=f.read()
c=s2n(c)
f.close()
def worker(workerID):
    global workerCount
    print("[%d] " % workerID, "Worker start, workerID =", workerID, ",workerCount =", workerCount)
    ibase = 0
    i = ibase + workerID
    while True:
        gTempC = gmpy.mpz(c + i * n)
        (M, flag) = gmpy.root(gTempC, e)
        if flag == True :
            print("[%d] " % workerID, "Found! i =", i, "; M = ", M)
            break
        ibase = ibase + workerCount
        i = ibase + workerID


    

if __name__ == '__main__':
    pool = Pool(workerCount)
    pool.map(worker, range(workerCount))
    pool.close()
    pool.join()