无法使用从本地文件读取的正确凭据（用户名和密码）对SSH服务器进行身份验证

Question

I'm making a small program that connects into an SSH server, testing multiple usernames and passwords that are inside a .txt file. The problem I'm having is when it get to the correct username and password it doesn't connect, or at least my if statement doesn't properly say it.

If I do pass it as regular variable or just set the username = 'correct user' ,password = 'correct password' , it works. Here's part of the code, I'm testing in a local environment with a Linux VM:

# read files
fs = open('users.txt','r')
users = fs.readlines()
fs.close()
fs = open('passwords.txt','r')
psswds = fs.readlines()
fs.close()

# connect and test the password
for user in users:
    for psswd in psswds:
        try:        
            print(usuario)
            print(senha)
            ssh = paramiko.SSHClient()
            ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
            con = ssh.connect(ip,port,username = user,password = psswd)
            if con is None:
                print ('yes')
                break
            else:
                print ('nop')
            SSHClient.close()
        except paramiko.AuthenticationException:
            print('User and/or password incorrect')

Answer 1

When you use readlines , it keeps trailing new line characters in the lines.

So you are actually connecting with wrong credentials as both your username and password contain new line, which is not a part of the correct credentials.

See Getting rid of \\n when using .readlines() .