How to extract the username and password from a jenkins "username with password" parameter?

withCredentials([[$class: 'UsernamePasswordMultiBinding', credentialsId: credentialsId, usernameVariable: 'USERNAME', passwordVariable: 'PASSWORD']]) {     // use USERNAME and PASSWORD as envs - ${USERNAME}    // credentialId is the credential id from Credentials tab }

Generally speaking if you are using ssh/scp the ssh-agent is what you want. (And usually you also want public key authentication instead of the password, but that is another story)

node {    sshagent (credentials: ['your-credential-id']) {        sh 'ssh blaa blaa'    }}

As mentioned by @jil it would make things a lot easier if you'd use ssh keys for the authentication at your SSH server - assuming your jenkins server is running on a linux / unix machine. You can add the keys to the system user jenkins which runs Jenkins and copy it to the machine to which you want to connect for your scp / ssh steps. Afterwards you can directly use any ssh / scp command without providing a password.

There are some security considerations though: adding the SSH key to the jenkins user enables every job on the Jenkins server to access your SSH server.

If this is not a problem for you - this is a good article on how to use ssh keys.