Sending a password over SSH or SCP with subprocess.Popen

Question

I\'m trying to run an scp (secure copy) command using subprocess.Popen. The login requires that I send a password:

from subprocess import Popen         


        

Answer 1

Here is my scp function based on pexpect. It can handle wildcards (i.e. multiple file transfer), in addition to the password. To handle multiple file transfer (i.e. wildcards), we need to issue a command via a shell. Refer to pexpect FAQ.

import pexpect

def scp(src,user2,host2,tgt,pwd,opts='',timeout=30):
    ''' Performs the scp command. Transfers file(s) from local host to remote host '''
    cmd = f'''/bin/bash -c "scp {opts} {src} {user2}@{host2}:{tgt}"'''
    print("Executing the following cmd:",cmd,sep='\n')

    tmpFl = '/tmp/scp.log'
    fp = open(tmpFl,'wb')
    childP = pexpect.spawn(cmd,timeout=timeout)
    try:
        childP.sendline(cmd)
        childP.expect([f"{user2}@{host2}'s password:"])
        childP.sendline(pwd)
        childP.logfile = fp
        childP.expect(pexpect.EOF)
        childP.close()
        fp.close()

        fp = open(tmpFl,'r')
        stdout = fp.read()
        fp.close()

        if childP.exitstatus != 0:
            raise Exception(stdout)
    except KeyboardInterrupt:
        childP.close()
        fp.close()
        return

    print(stdout)

It can be used this way:

params = {
    'src': '/home/src/*.txt',
    'user2': 'userName',
    'host2': '192.168.1.300',
    'tgt': '/home/userName/',
    'pwd': myPwd(),
    'opts': '',
}

scp(**params)