http:///challenges#hide

#python3运行
from subprocess import *

def foo():
    stegoFile='hide.jpg'#source pic path
    extractFile='flag.txt'#steghide extract result
    passFile='english.dic'#dist path

    errors=['could not extract','steghide --help','Syntax error']
    cmdFormat='steghide extract -sf "%s" -xf "%s" -p "%s"'
    f=open(passFile,'r')

    for line in f.readlines():
        cmd=cmdFormat %(stegoFile,extractFile,line.strip())
        p=Popen(cmd,shell=True,stdout=PIPE,stderr=STDOUT)
        content=str(p.stdout.read(),'gbk')
        for err in errors:
            if err in content:
                break
        else:
            print (content),
            print ('the passphrase is %s' %(line.strip()))
            f.close()
            return

if __name__ == '__main__':
    foo()
    print ('ok')
    pass

flag{St3gh1d3_1s_N1u_B1}