Two commercial vendors competing for LSST business have been awarded contracts for a set of preliminary devices. Before shipment, each device will undergo a series of tests by the vendor, producing ~25 GB of data. These data must be transferred to SLAC, analyzed, archived and distributed to other LSST laboratories prior to a "pre-ship review". Only after successfully passing this review will a device be authorized for shipment. It is expected that SLAC will receive multiple data deliveries per month although they are not precisely scheduled and deliveries may be bundled.
- Vendors must be able to control the timing of the data delivery.
- The intranet within the company as well as their connection with the internet can be overwhelmed by these deliveries
- Vendors insist on controlling the exact timing for the electronic data transfers
- Vendors must be able to restart an aborted data delivery.
- The internet connection between SLAC and the two vendors is subject to intermittent instability.
- The internet connection to at least one of the vendors is quite slow (100 Mbps)
- The need to restart a large and time-consuming delivery from scratch would cause an unacceptable delay
- Vendors must be able to create, modify, or delete files in their FTP areas
- A simple solution: vendors have very limited IT expertise and are unwilling or unable to perform software installations or complex configuration changes to their systems
- The transfer buffer must be able to hold multiple data deliveries per vendor, so at least 200 GB
- LSST must do its best to prevent data from Vendor A from being visible to Vendor B, and vice versa
- LSST operated advanced FTP service
- vsftp server software: very secure; high performance; restartable transfers; virtual ftp-only accounts
- installed and running on LSST service VM (VM is "SCS Standard")
- access to /nfs/farm/g/lsst/u2
- New lsst-ftp account to have ownership privs on a single NFS partition: /nfs/farm/g/lsst/u2 (which will be a short-term buffer from which a permanent archive will be made)
- Individual virtual vsftp accounts for Vendors A and B.
- This FTP area would be considered a "vendor playpen" from which copies would be archived to permanent LSST storage
Potential Security Issues and Mitigations (not complete!!)
- Hacking into a vendor account
- Possible consequences
- loss or corruption of vendor data
- use of storage for illicit purposes
- interruption of vendor data deliveries
- load on "u2" server (currently wain006)
- Possible mitigations
- configure vsftpd to recognize only certain IP addresses to log in
- vendors must agree with the level of security and the risk
- monitor disk usage with ganglia and look for abnormalities
- configure vsftpd for secure userid/pwd transfer, e.g., tls
- Possible consequences
- Hacking into the vsftp server
- Is this likely? This server is generally considered "very secure" as its name suggests. No hard data on this claim.
- Hacking into the lsstlnx VM
- Independent of vsftp and, therefore, no different from other VMs at SLAC with externally visible ports. Server restricts login to a small set of authorized SLAC users.
Suggestions from the Cyber Security Group
- Ask vendors to send MD5 checksum via a separate channel than FTP. Response: ask them to send it via email in their announcement message
- Employ and IP filter (or virtual IP addresses), preferred would be to add this filter to the perimeter router. Response: request sent to net-admin
Why Existing FTP Service is Unacceptable
- Non-anonymous (s)FTP requires a SLAC unix account and that has been deemed unacceptable by LSST project team
- Anonymous FTP server suffers from several shortcomings:
- The server software cannot restart an interrupted data transfer
- The AFS-backed store is possibly not scalable to the hundreds of GB needed
- The 3-day dwell period is too risky for the data
- The AFS permissions combined with the 3-day dwell do not allow for the type of permissions that would allow for a convincing separation between the two vendor's data
- The dropbox paradigm does not allow for vendors to manage its data once at SLAC, i.e., to replace faulty data files.
We are using vsftpd daemon running on a dedicated virtual machine. The machine is running a standard SLAC RHEL6 installation, with taylor and NFS access. Login is restricted to members of the sca-admin group.
Modifications to standard installation:
sudo yum install vsftpd
create file virtual_users.txt:
sudo db_load -T -t hash -f /etc/vsftpd/virtual_users.txt /etc/vsftpd/virtual_users.db
Modify standard /etc/vsftpd/vsftpd.conf as follows
< # Virtual user setup
Add a new file, /etc/pam.d/vsftpd_virtual
auth required pam_userdb.so db=/etc/vsftpd/virtual_users
account required pam_userdb.so db=/etc/vsftpd/virtual_users
session required pam_loginuid.so
sudo /etc/init.d/vsftpd restart