1. 01 Sep, 2004 1 commit
    • Leigh Stoller's avatar
      SSL version of the XMLRPC server. · a9c1045e
      Leigh Stoller authored
      * SSL based server (sslxmlrpc_server.py) that wraps the existing Python
        classes (what we export via the existing ssh XMLRPC server). I also have a
        demo client that is analogous the ssh demo client (sslxmlrpc_client.py).
        This client looks for an ssl cert in the user's .ssl directory, or you can
        specify one on the command line. The demo client is installed on ops, and
        is in the downloads directory with the rest of the xmlrpc stuff we export
        to users. The server runs as root, forking a child for each connection and
        logs connections to /usr/testbed/log/sslxmlrpc.log via syslog.
      
      * New script (mkusercert) generates SSL certs for users. Two modes of
        operation; when called from the account creation path, generates a
        unencrypted private key and certificate for use on Emulab nodes (this is
        analagous to the unencrypted SSH key we generate for users). The other mode
        of operation is used to generate an encrypted private key so that the user
        can drag a certificate to their home/desktop machine.
      
      * New webpage (gensslcert.php3) linked in from the My Emulab page that
        allows users to create a certificate. The user is prompted for a pass
        phrase to encrypt the private key, as well as the user's current Emulab
        login password. mkusercert is called to generate the certificate, and the
        result is stored in the user's ~/.ssl directory, and spit back to the user
        as a text file that can be downloaded and placed in the users homedir on
        their local machine.
      
      * The server needs to associate a certificate with a user so that it can
        flip to that user in the child after it forks. To do that, I have stored
        the uid of the user in the certificate. When a connection comes in, I grab
        the uid out of the certificate and check it against the DB. If there is a
        match (see below) the child does the usual setgid,setgroups,setuid to the
        user, instantiates the Emulab server class, and dispatches the method. At
        the moment, only one request per connection is dispatched. I'm not sure
        how to do a persistant connection on the SSL path, but probably not a big
        deal right now.
      
      * New DB table user_sslcerts that stores the PEM formatted certificates and
        private keys, as well as the serial number of the certificate, for each
        user. I also mark if the private key is encrypted or not, although not
        making any use of this data. At the moment, each user is allowed to get
        one unencrypted cert/key pair and one encrypted cert/key pair. No real
        reason except that I do not want to spend too much time on this until we
        see how/if it gets used. Anyway, the serial number is used as a crude form
        of certificate revocation. When the connection is made, I suck the serial
        number and uid out of the certificate, and look for a match in the table.
        If cert serial number does not match, the connection is rejected. In other
        words, revoking a certificate just means removing its entry from the DB
        for that user. I could also compare the certificate itself, but I am not
        sure what purpose that would serve since that is what the SSL handshake is
        supposed to take of, right?
      
      * Updated the documentation for the XMLRPC server to mention the existence
        of the SSL server and client, with a pointer into the downloads directory
        where users can pick up the client.
      a9c1045e
  2. 09 Aug, 2004 1 commit
    • Leigh Stoller's avatar
      Major rework of the script interface to Emulab. Up to now we have been · 5ef8f70a
      Leigh Stoller authored
      supporting both a shell script driven interface, plus the newer XMLRPC
      interface. This change removes the script driven interface from boss,
      replacing it with just the XMLRPC interface. Since we like to maintain
      backwards compatability with interfaces we have advertised to users (and
      which we know are being used), I have implemented a script wrapper that
      exports the same interface, but which converts the operations into XMLRPC
      requests to the server. This wrapper is written in python and uses our
      locally grown xmlrpc-over-ssh library. Like the current "demonstation"
      client, you can take this wrapper to your machine that has python and ssh
      installed, and use it there; you do not need to use these services from
      just users.emulab.net. Other things to note:
      
      * The wrapper is a single python script that has a "class" for each wrapped
        script. Running the wrapper without any arguments will list all of the
        operations it supports. You can invoke the wrapper with the operation as
        its argument:
      
          {987} stoller$ script_wrapper.py swapexp --help
          swapexp -e pid,eid in|out
          swapexp pid eid in|out
          where:
               -w   - Wait for experiment to finish swapping
               -e   - Project and Experiment ID
               in   - Swap experiment in  (must currently be swapped out)
              out   - Swap experiment out (must currently be swapped in)
      
          Wrapper Options:
              --help      Display this help message
              --server    Set the server hostname
              --login     Set the login id (defaults to $USER)
              --debug     Turn on semi-useful debugging
      
         But more convenient is to create a set of symlinks so that you can just
         invoke the operation by its familiar scriptname. This is what I have
         done on users.emulab.net.
      
          {987} stoller$ /usr/tesbed/bin/swapexp --help
          swapexp -e pid,eid in|out
          swapexp pid eid in|out
      
      
      * For those of you talking directly to the RPC server from python, I have
        added a wrapper class so that you can issue requests to any of the
        modules from a single connection. Instead using /xmlrpc/modulename, you
        can use just /xmlrpc, and use method names of the form experiment.swapexp,
        node.reboot, etc.
      
        Tim this should be useful for the netlab client which I think opens up
        multiple ssh connections?
      
      * I have replaced the paperbag shell with a stripped down xmlrpcbag shell
        that is quite a bit simpler since we no longer allow access to anything
        but the RPC server. No interactive mode, no argument processing, no
        directory changing, etc. My main reason for reworking the bag is to make
        it easier to understand, maintain, and verify that it is secure. The new
        bag also logs all connections to syslog (something we should have done in
        the orginal). I also added some setrlimit calls (core, maxcpu). I also
        thought about niceing the server down, but that would put RPC users at a
        disadvantage relative to web interface users. When we switch the web
        interface to use the XMLRPC backend, we can add this (reniceing from the
        web server would be a pain cause of its scattered implementation).
      5ef8f70a
  3. 19 Mar, 2004 1 commit