Difference between revisions of "Security Overview"
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=Endpoints= | =Endpoints= | ||
early security: mainframes, protecting users from each other | |||
* how a computer works | * how a computer works | ||
** picture a vast table of index cards - that is memory, it is addressable | ** picture a vast table of index cards - that is memory, it is addressable | ||
Line 52: | Line 48: | ||
*** interact with images, html, javascript, emails | *** interact with images, html, javascript, emails | ||
*** buffer overflows, bad code, bad runtime, bad languages | *** buffer overflows, bad code, bad runtime, bad languages | ||
*** difference between code & data is arbitrary, enforced by software! this is what makes computers powerful, but is also very dangerous | |||
*** if remote attacker can run code directly on your CPU, that's an execution bug | *** if remote attacker can run code directly on your CPU, that's an execution bug | ||
*** this is how the NSA defeated TBB: bug in firefox xml library | *** this is how the NSA defeated TBB: bug in firefox xml library | ||
Line 57: | Line 54: | ||
* arms race: who wants to break in? | * arms race: who wants to break in? | ||
** govts, spies | ** govts, spies | ||
** vandals | ** vandals, trolls, syrian electronic army | ||
** botnets: send spam, mine bitcoin, steal your identity | ** botnets: send spam, mine bitcoin, steal your identity | ||
** black market for pwnd computers, amazon accounts, etc | ** black market for pwnd computers, amazon accounts, etc | ||
** backdoors, CVEs, foxacid | |||
** because exploits are valuable, they use sparingly to avoid discovery | ** because exploits are valuable, they use sparingly to avoid discovery | ||
** updates | |||
*** always update! | |||
*** package managers are the only way | |||
*** app stores add complications: paywalls, "permission creep" | |||
** nonfree software | |||
*** microsoft, apple, google: all evil | |||
*** hall of shame: skype, silverlight, flash are all evil | |||
*** http://www.wired.co.uk/news/archive/2013-10/21/googles-iron-grip-on-android | |||
* defense in depth | * defense in depth | ||
** antivirus | ** antivirus | ||
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*** prevents propagation, phoning home, so no payload for attacker | *** prevents propagation, phoning home, so no payload for attacker | ||
*** NAT is not security, ipv6 is coming, "internet of things" *shiver* | *** NAT is not security, ipv6 is coming, "internet of things" *shiver* | ||
* | |||
** | ==Developer Security== | ||
** package signing | * source control | ||
** | ** http://www.git-scm.com/about/info-assurance | ||
** https://www.kernel.org/ | |||
** http://www.linuxfoundation.org/news-media/blogs/browse/2011/08/cracking-kernelorg | |||
* secret backdoors submitted openly? https://www.nsa.gov/research/selinux/ | |||
* package signing, opsec | |||
* deterministic builds are the future | |||
** https://blog.torproject.org/blog/deterministic-builds-part-one-cyberwar-and-global-compromise | |||
** https://blog.torproject.org/blog/deterministic-builds-part-two-technical-details | |||
** multiple compiler ecosystems (gcc, llvm/clang) | ** multiple compiler ecosystems (gcc, llvm/clang) | ||
==Disk Encryption== | ==Disk Encryption== | ||
* "rubber hose cryptanalysis" https://xkcd.com/538/ | * "rubber hose cryptanalysis" https://xkcd.com/538/ | ||
* adds security at rest, but not while running | * adds security at rest, but not while running | ||
Line 87: | Line 97: | ||
* always keep backups - data loss is DoS | * always keep backups - data loss is DoS | ||
* deniability is very hard | * deniability is very hard | ||
* steganography: hiding in plain sight | ** much easier to avoid being a suspect | ||
** having TBB on your disk is a red flag, especially with particular extensions | |||
** ideal solution is steganography: hiding in plain sight | |||
=Networks= | =Networks= | ||
Line 123: | Line 135: | ||
* SSL | * SSL | ||
** | ** example of site that sells SSL certs: https://www.namecheap.com/ssl-certificates.aspx | ||
** | ** example of who an OS trusts (Arch Linux uses Mozilla's cert list): https://www.archlinux.org/packages/core/any/ca-certificates/ | ||
** any of these orgs can impersonate any website | ** any of these orgs can impersonate any website | ||
** cert authorities don't solve mitm, just narrows down who can do it | ** cert authorities don't solve mitm, just narrows down who can do it | ||
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* https://panopticlick.eff.org/ | * https://panopticlick.eff.org/ | ||
* http://browserspy.dk | * http://browserspy.dk | ||
* tor bug tracker is always thinking of new problems https://trac.torproject.org/projects/tor/query?status=!closed&keywords=~tbb-fingerprinting | |||
* https reduces attack surface but does not solve | * https reduces attack surface but does not solve | ||
** with http you are vulnerable to fingerprinting from EVERYONE EVERYWHERE | ** with http you are vulnerable to fingerprinting from EVERYONE EVERYWHERE |
Latest revision as of 12:36, 17 December 2013
http://does-this-need-to-be-said.tumblr.com/
Social Engineering & Basic Stuff
- doxxing: http://thebot.net/general-tutorials/233339-how-doxing-works-protect-yourself/
- cultivate multiple identities, emails, usernames, etc
- be very wary of facebook, g+, social networks
- always avoid using your legal name, address
- avoid logging in on your phone, or entering your phone #
- you can look up license plates
- "20 questions" metaphor: http://geer.tinho.net/geer.uncc.9x13.txt
Hardware
- cameras, microphones, radios
- facial recognition
- evil chip manufacturers
- keyloggers
- monitors leak radiation
- tracking devices on cars - ride a bicycle, store it indoors
- burner phones - prepaid, kept batteryless
- tin foil houses: http://www.theage.com.au/world/barack-obamas-portable-secrecy-tent-some-assembly-required-20131111-2xb0l.html
Endpoints
early security: mainframes, protecting users from each other
- how a computer works
- picture a vast table of index cards - that is memory, it is addressable
- CPU instructions manipulate the index cards
- I/O devices all have addresses you write to/from (registers, ram, disk, net, keyboard, mouse, monitor)
- how an operating system works
- kernel vs userspace - enforced by CPU
- kernel runs on a CPU, has access to hardware
- CPU time is expensive, so how to multitask?
- kernel invents concept of "users", protects them from each other
- if user figures out how to mess with the kernel, that's an escalation bug
- userspace is often called a "shell"
- trusted boot
- causing kernel escalation bugs to be taken more seriously
- when combined with full-disk encryption, prevents "evil maid"
- sometimes only trusts windows
- attempts at closing this hole on linux: http://www.outflux.net/blog/archives/2013/12/10/live-patching-the-kernel/
- super users
- root on unix, admin on windows
- privilege separation made windows XP unusable
- android uses privilege separation - every app is its own user
- getting super user is also an escalation bug
- sometimes achieved by keyloggers
- Xorg / linux desktop ships with its own keylogger (xev)
- userspace apps are sandboxes
- interact with images, html, javascript, emails
- buffer overflows, bad code, bad runtime, bad languages
- difference between code & data is arbitrary, enforced by software! this is what makes computers powerful, but is also very dangerous
- if remote attacker can run code directly on your CPU, that's an execution bug
- this is how the NSA defeated TBB: bug in firefox xml library
- execution (get shell) then escalation (get root), optionally get kernel (rootkit) == pwnd
- kernel vs userspace - enforced by CPU
- arms race: who wants to break in?
- govts, spies
- vandals, trolls, syrian electronic army
- botnets: send spam, mine bitcoin, steal your identity
- black market for pwnd computers, amazon accounts, etc
- backdoors, CVEs, foxacid
- because exploits are valuable, they use sparingly to avoid discovery
- updates
- always update!
- package managers are the only way
- app stores add complications: paywalls, "permission creep"
- nonfree software
- microsoft, apple, google: all evil
- hall of shame: skype, silverlight, flash are all evil
- http://www.wired.co.uk/news/archive/2013-10/21/googles-iron-grip-on-android
- defense in depth
- antivirus
- helps slow mass infections
- does not protect you personally
- it's too late, wipe & restore
- cannot remove all rootkits, kernel exploits, firmware worms
- firewalls
- reduce attack surface
- prevents propagation, phoning home, so no payload for attacker
- NAT is not security, ipv6 is coming, "internet of things" *shiver*
- antivirus
Developer Security
- source control
- secret backdoors submitted openly? https://www.nsa.gov/research/selinux/
- package signing, opsec
- deterministic builds are the future
- https://blog.torproject.org/blog/deterministic-builds-part-one-cyberwar-and-global-compromise
- https://blog.torproject.org/blog/deterministic-builds-part-two-technical-details
- multiple compiler ecosystems (gcc, llvm/clang)
Disk Encryption
- "rubber hose cryptanalysis" https://xkcd.com/538/
- adds security at rest, but not while running
- android makes this easy
- your mugger probably won't dump the RAM, but cops can
- always keep backups - data loss is DoS
- deniability is very hard
- much easier to avoid being a suspect
- having TBB on your disk is a red flag, especially with particular extensions
- ideal solution is steganography: hiding in plain sight
Networks
- evil
- ISPs spy on you
- assume all cables are tapped, intercepted
- routers & modems are vulnerable
- NSA suppresses openwrt to keep them that way
- closed hardware drivers are the other culprit - patents, binary blobs
- some things need old kernels: more work for kernel devs
- #1 reason some hardware needs dd-wrt, not openwrt
- cell phones especially, even with cyanogenmod
Mesh
- harder to wiretap individuals
- but ideally should not be trusted either - end-to-end encryption
- can do location analysis, enable stalkers (seattle)
- mac address randomization: unsupported, not foolproof, easy to block
Tor, VPNs, Proxies
- protect you from your own ISP/network hardware
- provider or exit node still can spy on you
- much VPN software/protocols are not audited
- local traffic analysis & timestamps could give you less deniability
- they can tell WHEN you are using tor/vpn
- tor only hides/obfuscates your IP address - NOTHING ELSE (unless you use tbb)
- flash is evil: poor sandboxing, disrespects proxies
MITM
- anyone controlling the pipes can do it
- Tor can make this WORSE, not better, so router-level Tor is also bad
Crypto
- SSL
- example of site that sells SSL certs: https://www.namecheap.com/ssl-certificates.aspx
- example of who an OS trusts (Arch Linux uses Mozilla's cert list): https://www.archlinux.org/packages/core/any/ca-certificates/
- any of these orgs can impersonate any website
- cert authorities don't solve mitm, just narrows down who can do it
- US & UK govt: FLYING PIG?
- bootstrap problem
- HSTS preloading
- https://www.eff.org/https-everywhere
- ipsec + dnssec + dane
- metadata
- even with SSL, they can see who you're talking to
- traffic analysis, packet size gives away a lot: google maps tiles, for example
- tor hidden services
- the address is the certificate
- solves the mitm problem
- solves the metadata problem
- solves the auth problem
- are not user-friendly by today's standards
- this is what securedrop uses
- in the future we will all memorize hashes like phone #s
- similarly: hashed.im
- OTR approximates this
- this means that access to truly random numbers is very important
- specialized crypto hardware
- PRNGs: android fail
- freebsd no longer trusts intel http://arstechnica.com/security/2013/12/we-cannot-trust-intel-and-vias-chip-based-crypto-freebsd-developers-say/
Datamining
Cookies
- ad networks: google, etc
- analytics: google, etc
- CDNs: google, amazon, akamai
- social networks: facebook "like" button, twitter, etc
- session cookies partially solves
- but how long is your session?
- what did you do in your session?
- persistence - anything on disk: flash cookies, DOM objects, cache
- deleting flash cookies deletes security settings. flash is evil!
- disk encryption does not solve this - it is still a disk!
- private / incognito mode partially solves, makes false promises
- bugs, leaks, plugins: https://trac.torproject.org/projects/tor/wiki/doc/ImportantGoogleChromeBugs
- TAILS solves this - defense in depth
Fingerprinting
- https://panopticlick.eff.org/
- http://browserspy.dk
- tor bug tracker is always thinking of new problems https://trac.torproject.org/projects/tor/query?status=!closed&keywords=~tbb-fingerprinting
- https reduces attack surface but does not solve
- with http you are vulnerable to fingerprinting from EVERYONE EVERYWHERE
- with https you are vulnerable to fingerprinting from sites you visit & 3rd party networks
- in active use at major sites
- worst offenders: javascript, plugins, user agents
- TBB does its best, not perfect
- TAILS mostly solves - but webrtc
- still leaves: your language, timezone (country), window size, timestamps, things you say & do, textual analysis
Other
- referers
- geolocation
- URL shorteners: t.co, bit.ly
- if you're not paying, you're the product