Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
SSL, CAs and keeping your stuff safe
Search
Armin Ronacher
May 10, 2014
Programming
1.1k
7
Share
SSL, CAs and keeping your stuff safe
A capitalistic and system conformant talk about encryption.
Armin Ronacher
May 10, 2014
More Decks by Armin Ronacher
See All by Armin Ronacher
Agentic Coding: The Future of Software Development with Agents
mitsuhiko
0
710
Do Dumb Things
mitsuhiko
0
930
No Assumptions
mitsuhiko
0
400
The Complexity Genie
mitsuhiko
0
320
The Catch in Rye: Seeding Change and Lessons Learned
mitsuhiko
0
410
Runtime Objects in Rust
mitsuhiko
0
400
Rust at Sentry
mitsuhiko
0
580
Overcoming Variable Payloads to Optimize for Performance
mitsuhiko
0
290
Rust API Design Learnings
mitsuhiko
0
650
Other Decks in Programming
See All in Programming
Claude Codeをカスタムして自分だけのClaude Codeを作ろう
terisuke
0
150
t *testing.T は どこからやってくるの?
otakakot
1
840
AI時代のPhpStorm最新事情 #phpcon_odawara
yusuke
0
240
Spec-driven Development: How AI Changes Everything (And Nothing)
simas
PRO
0
460
Going Multiplatform with Your Android App (Android Makers 2026)
zsmb
2
460
[RubyKaigi 2026] Require Hooks
palkan
1
260
Claude CodeでETLジョブ実行テストを自動化してみた
yoshikikasama
0
1.1k
mruby on C#: From VM Implementation to Game Scripting (RubyKaigi 2026)
hadashia
2
1.2k
🦞OpenClaw works with AWS
licux
1
310
AIと共に生きる技術選定 2026
sgash708
0
110
感情を設計する
ichimichi
5
1.6k
GNU Makeの使い方 / How to use GNU Make
kaityo256
PRO
16
5.6k
Featured
See All Featured
Building an army of robots
kneath
306
46k
Building Flexible Design Systems
yeseniaperezcruz
330
40k
Design in an AI World
tapps
1
200
Rebuilding a faster, lazier Slack
samanthasiow
85
9.5k
Future Trends and Review - Lecture 12 - Web Technologies (1019888BNR)
signer
PRO
0
3.5k
Unlocking the hidden potential of vector embeddings in international SEO
frankvandijk
0
780
Building a A Zero-Code AI SEO Workflow
portentint
PRO
0
480
Practical Orchestrator
shlominoach
191
11k
Learning to Love Humans: Emotional Interface Design
aarron
275
41k
Cheating the UX When There Is Nothing More to Optimize - PixelPioneers
stephaniewalter
287
14k
Jamie Indigo - Trashchat’s Guide to Black Boxes: Technical SEO Tactics for LLMs
techseoconnect
PRO
0
120
Exploring the Power of Turbo Streams & Action Cable | RailsConf2023
kevinliebholz
37
6.4k
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]