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SSL, CAs and keeping your stuff safe
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Armin Ronacher
May 10, 2014
Programming
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SSL, CAs and keeping your stuff safe
A capitalistic and system conformant talk about encryption.
Armin Ronacher
May 10, 2014
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Transcript
SSL, CAs and keeping your stuff safe BQSFTFOUBUJPOCZBSNJOSPOBDIFSGPSQZHSVOO http://lucumr.pocoo.org/ —
@mitsuhiko
SSL, CAs and keeping your stuff safe BQSFTFOUBUJPOCZBSNJOSPOBDIFSGPSQZHSVOO http://lucumr.pocoo.org/ —
@mitsuhiko a capitalistic and system conformant talk about encryption
Armin Ronacher Independent Contractor for Splash Damage / Fireteam Doing
Online Infrastructure for Computer Games
… The Problem with Programmers ~ Epilogue ~
Programmers think everything is a technical problem
Fraud ~ Chapter 1 ~
XXXX-XXXX-XXXX-1234 What is the worst that can happen?
What makes Credit Card Numbers “secure”?
theft ere will always be criminals
prevented But what damage can they do?
Bitcoin A Credit Card Strong Encryption Potentially No Encryption 256
bit private key 16 digit number + checksum decentralized centralized √ x
But I'd rather lose my credit card …
Never
LOL
We Accept Stolen Creditcards
e Protocol e Process is insecure is secure
If the aud percentage is smaller than the transaction fees
we're all good.
It's too easy to forget the bigger picture
of Lock Symbols and Encryption ~ Chapter 2 ~
the lock symbol is a lie
the lock stands for secure
but so is encryption 8 7
such security
such buzzwords CRIME BEAST Heartbleed BREACH PFS
users need to understand how to keep good om bad
lock symbols / good om bad encryption. = -
but even developers are not sure yet …
remember why you encrypt (NSA
Why do we Encrypt Traffic? ~ Chapter 3 ~
None
public WiFi the unencrypted browser session kilLed
? Who is the Attacker?
om secret agents to idiots
om targeted to untargeted
om low to high probability
What You Need for Encryption ~ Chapter 4 ~
passive vs active eavesdropping encryption authentication
$ ssh pocoo.org The authenticity of host 'pocoo.org (148.251.50.164)' can't
be established. RSA key fingerprint is 14:23:83:02:45:f9:9c:d0:eb:39:c7:14:42:f5:9f:9c. Are you sure you want to continue connecting (yes/no)?
your user does not check ngerprints (your
e Certificate Authorities thus:
CAs are worthless for securing APIs let it be known
that
Protecting APIs and Services ~ Chapter 5 ~ (non
The Only Rule to Follow
run your own CA issue certi cates for 24 hours
trust your own CA only screw re ocations
You trust your own CA by distributing the certi cate
to everybody.
If your root gets compromised, distribute new root certi cates.
If an individual key gets compromised, in less than 24
hours everything is ne.
from requests import get resp = get('https://api.yourserver.com/', verify='your/certificate.bundle')
“But my awesome AntiVirus says your certi cate is not
trusted.” — Windows User
Certificate Authorities Again ~ Chapter 6 ~
Hardly news: CAs are Broken
But why are the broken?
I Trust “TÜRKTRUST Elektronik Serti ka Hizmet Sağlayıcısı” to ouch
for the identity of any domain on the planet. Trusting a CA:
trusting half the world: one shitty employee in one shitty
CA is enough to break your security.
I Trust “Comodo” to ouch for the identity of “Foo
Owner” foo.com. I only trust “Foo Owner” to ouch for the identity of api.foo.com What we actually want:
if you have seen google.com being from Verisign and all
the sudden google.com becomes a StartSSL certificate you know something might be wrong.
Soon: Certificate Pinning?
Frack OpenSSL and Question “Best Practices” ~ Chapter 7 ~
Self-Signed Certificates are not bad. Just in browsers.
Never. Ever. Look at OpenSSL's Source.
OpenSSL's "patches" are even worse: Apple's OpenSSL always trusts system
store :-/
Requests by default trusts it's own bundle :-/ (And does
not even properly document how to use custom ones)
With Heartbleed SSL was less secure than no SSL :-/
Growing SSL ~ Chapter 8 ~
Credit Cards were made for thousands of people Certificate Authorities
were made for hundreds of sites
OpenSSL was probably improperly audited
See “OpenSSL Valhalla Rampage” :-( “i give up. reuse problem
is unixable. dlg says puppet crashes” — tedu
Plan for Failure ~ Chapter 9 ~
what
what happens to your user if he gets hacked? (food
for thought: keyloggers are still a thing)
what happens to your data
what happens to your company
encryption is hardened security it must not be your only
defense
? Feel Free To Ask Questions Talk slides will be
online on lucumr.pocoo.org/talks You can find me on Twitter: @mitsuhiko And gittip: gittip.com/mitsuhiko Or hire me:
[email protected]