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
7
1.1k
SSL, CAs and keeping your stuff safe
A capitalistic and system conformant talk about encryption.
Armin Ronacher
May 10, 2014
Tweet
Share
More Decks by Armin Ronacher
See All by Armin Ronacher
Agentic Coding: The Future of Software Development with Agents
mitsuhiko
0
540
Do Dumb Things
mitsuhiko
0
870
No Assumptions
mitsuhiko
0
340
The Complexity Genie
mitsuhiko
0
290
The Catch in Rye: Seeding Change and Lessons Learned
mitsuhiko
0
390
Runtime Objects in Rust
mitsuhiko
0
380
Rust at Sentry
mitsuhiko
0
550
Overcoming Variable Payloads to Optimize for Performance
mitsuhiko
0
260
Rust API Design Learnings
mitsuhiko
0
630
Other Decks in Programming
See All in Programming
AIと一緒にレガシーに向き合ってみた
nyafunta9858
0
260
LLM Observabilityによる 対話型音声AIアプリケーションの安定運用
gekko0114
2
440
CSC307 Lecture 10
javiergs
PRO
1
660
AIによる高速開発をどう制御するか? ガードレール設置で開発速度と品質を両立させたチームの事例
tonkotsuboy_com
7
2.4k
360° Signals in Angular: Signal Forms with SignalStore & Resources @ngLondon 01/2026
manfredsteyer
PRO
0
140
Unicodeどうしてる? PHPから見たUnicode対応と他言語での対応についてのお伺い
youkidearitai
PRO
1
2.6k
そのAIレビュー、レビューしてますか? / Are you reviewing those AI reviews?
rkaga
6
4.6k
なぜSQLはAIぽく見えるのか/why does SQL look AI like
florets1
0
480
React 19でつくる「気持ちいいUI」- 楽観的UIのすすめ
himorishige
11
7.5k
Claude Codeと2つの巻き戻し戦略 / Two Rewind Strategies with Claude Code
fruitriin
0
150
並行開発のためのコードレビュー
miyukiw
0
1.2k
ノイジーネイバー問題を解決する 公平なキューイング
occhi
0
110
Featured
See All Featured
Designing Dashboards & Data Visualisations in Web Apps
destraynor
231
54k
Balancing Empowerment & Direction
lara
5
900
Sharpening the Axe: The Primacy of Toolmaking
bcantrill
46
2.7k
Responsive Adventures: Dirty Tricks From The Dark Corners of Front-End
smashingmag
254
22k
A brief & incomplete history of UX Design for the World Wide Web: 1989–2019
jct
1
300
Visual Storytelling: How to be a Superhuman Communicator
reverentgeek
2
440
30 Presentation Tips
portentint
PRO
1
220
Thoughts on Productivity
jonyablonski
74
5k
Optimizing for Happiness
mojombo
379
71k
What’s in a name? Adding method to the madness
productmarketing
PRO
24
3.9k
The Myth of the Modular Monolith - Day 2 Keynote - Rails World 2024
eileencodes
26
3.3k
Game over? The fight for quality and originality in the time of robots
wayneb77
1
120
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]