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
Embed
Copy iframe code
Copy JS code
Copy link
Start on current slide
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
800
Do Dumb Things
mitsuhiko
0
950
No Assumptions
mitsuhiko
0
410
The Complexity Genie
mitsuhiko
0
330
The Catch in Rye: Seeding Change and Lessons Learned
mitsuhiko
0
440
Runtime Objects in Rust
mitsuhiko
0
420
Rust at Sentry
mitsuhiko
0
590
Overcoming Variable Payloads to Optimize for Performance
mitsuhiko
0
300
Rust API Design Learnings
mitsuhiko
0
670
Other Decks in Programming
See All in Programming
コンテキストの使い捨てをやめる — ビジネスルール駆動開発と miko —
ioki
0
200
Signal Forms: Details & Live Coding @enterJS 2026 in Mannheim
manfredsteyer
PRO
0
130
Agentic UI
manfredsteyer
PRO
0
160
Observability in Practice:Grafana 與 Edge Device SRE 的那些事
blueswen
0
160
TypeScript+Orvalで実現する型安全かつ堅牢でスケーラブルなマルチチャネル通知基盤 / TSKaigi Night talks ~after conference~
d0riven
0
340
LLM本来の能力を解き放つサンドボックス技術とAI民主化への適用
yukukotani
3
4k
ECSアプリログをFireLensでコスト削減しようとしたけど諦めた話 in Fargate×Node.js
akihisaikeda
2
4.2k
The NotImplementedError Problem in Ruby
koic
1
790
OSもどきOS
arkw
0
560
ローカルLLMを使ってB2Bサービスを作っていての学び
yaotti
0
170
AI 時代のソフトウェア設計の学び方
masuda220
PRO
29
12k
Javaの型とAI時代に型が大事な理由 / java types and type in AI era
kishida
2
140
Featured
See All Featured
Collaborative Software Design: How to facilitate domain modelling decisions
baasie
1
250
世界の人気アプリ100個を分析して見えたペイウォール設計の心得
akihiro_kokubo
PRO
71
40k
Mobile First: as difficult as doing things right
swwweet
225
10k
The Art of Programming - Codeland 2020
erikaheidi
57
14k
Learning to Love Humans: Emotional Interface Design
aarron
275
41k
Mozcon NYC 2025: Stop Losing SEO Traffic
samtorres
1
250
First, design no harm
axbom
PRO
2
1.2k
Bridging the Design Gap: How Collaborative Modelling removes blockers to flow between stakeholders and teams @FastFlow conf
baasie
0
580
SERP Conf. Vienna - Web Accessibility: Optimizing for Inclusivity and SEO
sarafernandez
2
1.5k
The Curious Case for Waylosing
cassininazir
1
390
Agile Leadership in an Agile Organization
kimpetersen
PRO
0
160
Gemini Prompt Engineering: Practical Techniques for Tangible AI Outcomes
mfonobong
2
430
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]