Danny Al-Gaaf (Deutsche Telekom) Sage Weil (Red Hat) Security is essential for critical enterprise OpenStack installations like telco NFV clouds. This includes the often-ignored issue of security for storage of images, objects, and shared file systems (e.g., user data or mission critical configurations like firewall rules). This talk will provide insight into requirements for a secure setup and potential issues, pitfalls, and attack vectors against storage technologies used with an cloud based on OpenStack. The Ceph distributed storage system has become very popular in OpenStack deployments, and is currently the most commonly deployed solution for block storage. It provides an object store, block devices, and a shared file system. However, distributed systems in particular make it much more complex to achieve robust security compared e.g. to local storage on compute nodes. By using Ceph as an example, this talk will present what Deutsche Telekom and Red Hat/Inktank, together with the community, are working on to build a security critical cloud with OpenStack and Ceph. This talk will cover: - the security requirements for telco clouds - the security issues associated with multi-tenant clouds with a range of security zones sharing a single storage system - how to secure the storage setup in an OpenStack cloud - the current state of security in Ceph - current Ceph development efforts that are underway - the security roadmap for Ceph

1. Storage security in a critical
enterprise OpenStack environment
Danny Al-Gaaf (Deutsche Telekom AG), Sage Weil (Red Hat)
OpenStack Summit 2015 - Vancouver

2. ● Secure NFV cloud at DT
● Attack surface
● Proactive countermeasures
○ Setup
○ Vulnerability prevention
○ Breach mitigation
● Reactive countermeasures
○ 0-days, CVEs
○ Security support SLA and lifecycle
● Conclusions
Overview
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3. Secure NFV Cloud @ DT

4. NFV Cloud @ Deutsche Telekom
● Datacenter design
○ BDCs
■ few but classic DCs
■ high SLAs for infrastructure and services
■ for private/customer data and services
○ FDCs
■ small but many
■ near to the customer
■ lower SLAs, can fail at any time
■ services:
● spread over many FDCs
● failures are handled by services and not the infrastructure
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5. High Security Requirements
● Multiple security placement zones (PZ)
○ e.g. EHD, DMZ, MZ, SEC, Management
○ TelcoWG “Security Segregation” use case
● Separation required for:
○ compute
○ networks
○ storage
● Protect against many attack vectors
● Enforced and reviewed by security department
● Run telco core services @ OpenStack/KVM/Ceph
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6. Ceph and OpenStack
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7. Ceph Architecture
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8. Solutions for telco services
● Separation between security zones needed
● Physical separation
○ Large number of clusters (>100)
○ Large hardware demand (compute and storage)
○ High maintenance effort
○ Less flexibility
● RADOS pool separation
○ Much more flexible
○ Efficient use of hardware
● Question:
○ Can we get the same security as physical separation?
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9. Placement Zones
● Separate RADOS pool(s) for each security zone
○ Limit access using Ceph capabilities
● OpenStack AZs as PZs
● Cinder
○ Configure one backend/volume type per pool (with own key)
○ Need to map between AZs and volume types via policy
● Glance
○ Lacks separation between control and compute/storage layer
○ Separate read-only vs management endpoints
● Manila
○ Currently not planned to use in production with CephFS
○ May use RBD via NFS
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10. Attack Surface

11. RadosGW attack surface
● S3/Swift
○ Network access to gateway
only
○ No direct access for consumer
to other Ceph daemons
● Single API attack surface
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12. RBD attack surface
● Protection from hypervisor
block layer
○ No network access or CephX
keys needed at guest level
● Issue:
○ hypervisor is software and
therefore not 100% secure…
■ e.g., Venom!
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13. Host attack surface
● If KVM is compromised, the attacker ...
○ has access to neighbor VMs
○ has access to local Ceph keys
○ has access to Ceph public network and Ceph daemons
● Firewalls, deep packet inspection (DPI), ...
○ partly impractical due to used protocols
○ implications to performance and cost
● Bottom line: Ceph daemons must resist attack
○ C/C++ is harder to secure than e.g. Python
○ Homogenous: if one daemon is vulnerable, all in the cluster are!
○ Risk of denial-of-service
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14. Network attack surface
● Client/cluster sessions are not encrypted
○ Sniffer can recover any data read or written
● Sessions are authenticated
○ Attacker cannot impersonate clients or servers
○ Attacker cannot mount man-in-the-middle attacks
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15. Denial of Service
● Scenarios
○ Submit many / large / expensive IOs
■ use qemu IO throttling!
○ Open many connections
○ Use flaws to crash Ceph daemons
○ Identify non-obvious but expensive features of client/OSD interface
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16. Proactive Countermeasures

17. Deployment and Setup
● Network
○ Always use separated cluster and public net
○ Always separate your control nodes from other networks
○ Don’t expose to the open internet
○ Encrypt inter-datacenter traffic
● Avoid hyper-converged infrastructure
○ Isolate compute and storage resources
○ Scale them independently
○ Risk mitigation if daemons are compromised or DoS’d
○ Don’t mix
■ compute and storage
■ control nodes (OpenStack and Ceph)
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18. Deploying RadosGW
● Big and easy target through
HTTP(S) protocol
● Small appliance per tenant with
○ Separate network
○ SSL terminated proxy forwarding
requests to radosgw
○ WAF (mod_security) to filter
○ Placed in secure/managed zone
● Don’t share buckets/users
between tenants
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19. Ceph security: CephX
● Monitors are trusted key servers
○ Store copies of all entity keys
○ Each key has an associated “capability”
■ Plaintext description of what the key user is
allowed to do
● What you get
○ Mutual authentication of client + server
○ Extensible authorization w/ “capabilities”
○ Protection from man-in-the-middle, TCP
session hijacking
● What you don’t get
○ Secrecy (encryption over the wire)
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20. Ceph security: CephX take-aways
● Monitors must be secured
○ Protect the key database
● Key management is important
○ Separate key for each Cinder backend/AZ
○ Restrict capabilities associated with each key
○ Limit administrators’ power
■ use ‘allow profile admin’ and ‘allow profile readonly’
■ restrict role-definer or ‘allow *’ keys
○ Careful key distribution (Ceph and OpenStack nodes)
● To do:
○ Thorough CephX code review by security experts
○ Audit OpenStack deployment tools’ key distribution
○ Improve security documentation20

21. ● Static Code Analysis (SCA)
○ Buffer overflows and other code flaws
○ Regular Coverity scans
■ 996 fixed, 284 dismissed; 420 outstanding
■ defect density 0.97
○ cppcheck
○ LLVM: clang/scan-build
● Runtime analysis
○ valgrind memcheck
● Plan
○ Reduce backlog of low-priority issues (e.g., issues in test code)
○ Automated reporting of new SCA issues on pull requests
○ Improve code reviewer awareness of security defects
Preventing Breaches - Defects
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22. ● Pen-testing
○ human attempt to subvert security, generally guided by code review
● Fuzz testing
○ computer attempt to subvert or crash, by feeding garbage input
● Harden build
○ -fpie -fpic
○ -D_FORTIFY_SOURCE=2 -O2 (?)
○ -stack-protector=strong
○ -Wl,-z,relro,-z,now
○ Check for performance regression!
Preventing Breaches - Hardening
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23. Mitigating Breaches
● Run non-root daemons
○ Prevent escalating privileges to get root
○ Run as ‘ceph’ user and group
○ Pending for Infernalis
● MAC
○ SELinux / AppArmor
○ Profiles for daemons and tools planned for Infernalis
● Run (some) daemons in VMs or containers
○ Monitor and RGW - less resource intensive
○ MDS - maybe
○ OSD - prefers direct access to hardware
● Separate mon admin network
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24. Encryption: Data at Rest
● Ceph-disk tool supports dm-crypt
○ Encrypt raw block device (OSD and journal)
○ Allow disks to be safely discarded if key remains secret
● Key management is still very simple
○ Encryption key stored on disk via LUKS
○ LUKS key stored in /etc/ceph/keys
● Plan
○ Petera, a new key escrow project from Red Hat
■ https://github.com/npmccallum/petera
○ Alternative: simple key management via monitor
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25. ● Goal
○ Protect data from someone listening in on network
○ Protect administrator sessions configuring client keys
● Plan
○ Generate per-session keys based on existing tickets
○ Selectively encrypt monitor administrator sessions
Encryption: On Wire
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26. ● Limit load from client
○ Use qemu IO throttling features - set safe upper bound
● To do:
○ Limit max open sockets per OSD
○ Limit max open sockets per source IP
■ handle on Ceph or in the network layer?
○ Throttle operations per-session or per-client (vs just globally)?
Denial of Service attacks
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27. CephFS
● No standard virtualization layer (unlike block)
○ Proxy through gateway (NFS?)
○ Filesystem passthrough (9p/virtfs) to host
○ Allow direct access from tenant VM
● Granularity of access control is harder
○ No simple mapping to RADOS objects
● Work in progress
○ root_squash
○ Restrict mount to subtree
○ Restrict mount to user
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28. Reactive Countermeasures

29. ● Community
○ Single point of contact: security@ceph.com
■ Core development team
■ Red Hat, SUSE, Canonical security teams
○ Security related fixes are prioritized and backported
○ Releases may be accelerated on ad hoc basis
○ Security advisories to ceph-announce@ceph.com
● Red Hat Ceph
○ Strict SLA on issues raised with Red Hat security team
○ Escalation process to Ceph developers
○ Red Hat security team drives CVE process
○ Hot fixes distributed via Red Hat’s CDN
Reactive Security Process
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30. Detecting and Preventing Breaches
● Brute force attacks
○ Good logging of any failed authentication
○ Monitoring easy via existing tools like e.g. Nagios
● To do:
○ Automatic blacklisting IPs/clients after n-failed attempts on Ceph level
● Unauthorized injection of keys
○ Monitor the audit log
■ trigger alerts for auth events -> monitoring
○ Periodic comparison with signed backup of auth database?
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31. Conclusions

32. Summary
● Reactive processes are in place
○ security@ceph.com, CVEs, downstream product updates, etc.
● Proactive measures in progress
○ Code quality improves (SCA, etc.)
○ Unprivileged daemons
○ MAC (SELinux, AppArmor)
○ Encryption
● Progress defining security best-practices
○ Document best practices for security
● Ongoing process
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33. Get involved !
● OpenStack
○ Telco Working Group
■ #openstack-nfv
○ Cinder, Glance, Manila, ...
● Ceph
○ https://ceph.com/community/contribute/
○ ceph-devel@vger.kernel.org
○ IRC: OFTC
■ #ceph,
■ #ceph-devel
○ Ceph Developer Summit
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34. danny.al-gaaf@telekom.de
sage@redhat.com
dalgaaf
sage
Danny Al-Gaaf
Senior Cloud Technologist
Sage Weil
Ceph Principal Architect
IRC
THANK YOU!