How to Block SSH password Dialog.

[jsulm]

@moyin You can avoid using passwords if you use public key authentication, see: https://kb.iu.edu/d/aews

[JonB]

@moyin
I believe you can -B on the command-line to scp to prevent it prompting for a password. (It's worth a try just to see if the dialog goes away.) You will of course then get an error about "no password" instead. As @jsulm says, you could use public key auth instead. But scp does not allow password on command-line.

For an alternative to scp, https://stackoverflow.com/a/47328516/489865 says curl does accept a command-line password.

[jsulm]

@JNBarchan I'm wondering what password dialog is shown as scp is a pure command line tool and does not show any dialogs.
I'm still waiting for more information on how exactly @moyin starts scp.

[JonB]

@jsulm
I agree, but whatever the case if OP is not going to use key-gen and wants to supply password via command-line he's going to be stymied with scp.

I have no idea whether there is any relation here, but I have a "password prompting dialog" that I don't understand where it's coming from under Ubuntu: when I go into MySQL Workbench first time in a session, it always says "my password has not been saved in the keyring and I need to enter it". It does not look like the dialog is coming from Workbench, more like it's coming from "Ubuntu/the desktop". Dunno if that could be related to his scp, or whether this only comes out of Workbench...

[moyin]

@jsulm
How do you start scp? Using QProcess? Can you show the code?
yeh! i'm using QProc, Here is my code

void Transfer::on_pushButton_Go_clicked()
{
    //proc = new QProcess() ;
    QString command = "scp" ;
    QString ip = ui->lineEdit_IP_Address->text() ;
    QString username = ui->lineEdit_SSH_username->text() ;
    QString dest_path = ui->lineEdit_TransferToTarget_DestinationFolder->text() ;
    QString source_path = ui->lineEdit_TransferToTarget_SourcePath->text() ;
    std::stringstream s ;
    s << username.toStdString() << "@" << ip.toStdString() << ":" << dest_path.toStdString();
    std::cout << s.str() << std::endl ;
    QStringList params ;
    params.append(source_path) ;
    params.append(QString::fromStdString(s.str())) ;
    qDebug() << params ;
    //    params.append("/home/span51/Desktop/readme.txt");
    //    params.append("spanidea@192.168.1.26:/home/spanidea/test" );
    qDebug() << connect(&proc, SIGNAL(readyReadStandardError()), this, SLOT(readOutput()));
    qDebug() << connect(&proc, SIGNAL(readyReadStandardOutput()), this, SLOT(readOutput()));
    //    connect(&proc, SIGNAL(errorOccurred(QProcess::ProcessError error)), this, SLOT(readErr()));
    proc.start(command,params) ;

}

[JonB]

@moyin
Since as we've said scp will not accept a command-line argument for a password, what would you like to do about it in that light?

[moyin]

@JNBarchan is there any file_transfer command that accepts password as parameter.

[jsulm]

@moyin Isn't public key authentication an alternative?

[JonB]

@moyin said in How to Block SSH password Dialog.:

@JNBarchan is there any file_transfer command that accepts password as parameter.

But I answered exactly this in my reply to you. Why do you think I wrote:

For an alternative to scp, https://stackoverflow.com/a/47328516/489865 says curl does accept a command-line password.

?

Or your alternative is @jsulm's public key for scp, as we have said.

[moyin]

how about sshpass?
this will accept the password as argument along with username,ip,etc..,