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
470
Do Dumb Things
mitsuhiko
0
840
No Assumptions
mitsuhiko
0
320
The Complexity Genie
mitsuhiko
0
280
The Catch in Rye: Seeding Change and Lessons Learned
mitsuhiko
0
390
Runtime Objects in Rust
mitsuhiko
0
370
Rust at Sentry
mitsuhiko
0
540
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
HTTPプロトコル正しく理解していますか? 〜かわいい猫と共に学ぼう。ฅ^•ω•^ฅ ニャ〜
hekuchan
2
650
2025 Reflections on Working with Natural Language
inouehi
0
100
Claude Codeの「Compacting Conversation」を体感50%減! CLAUDE.md + 8 Skills で挑むコンテキスト管理術
kmurahama
1
780
今こそ知るべき耐量子計算機暗号(PQC)入門 / PQC: What You Need to Know Now
mackey0225
3
330
まだ間に合う!Claude Code元年をふりかえる
nogu66
5
940
[AI Engineering Summit Tokyo 2025] LLMは計画業務のゲームチェンジャーか? 最適化業務における活⽤の可能性と限界
terryu16
2
390
re:Invent 2025 トレンドからみる製品開発への AI Agent 活用
yoskoh
0
680
re:Invent 2025 のイケてるサービスを紹介する
maroon1st
0
170
從冷知識到漏洞,你不懂的 Web,駭客懂 - Huli @ WebConf Taiwan 2025
aszx87410
2
3.4k
コントリビューターによるDenoのすゝめ / Deno Recommendations by a Contributor
petamoriken
0
180
Denoのセキュリティに関する仕組みの紹介 (toranoana.deno #23)
uki00a
0
250
インターン生でもAuth0で認証基盤刷新が出来るのか
taku271
0
180
Featured
See All Featured
エンジニアに許された特別な時間の終わり
watany
106
230k
How to train your dragon (web standard)
notwaldorf
97
6.5k
The browser strikes back
jonoalderson
0
320
Sam Torres - BigQuery for SEOs
techseoconnect
PRO
0
170
Imperfection Machines: The Place of Print at Facebook
scottboms
269
13k
Darren the Foodie - Storyboard
khoart
PRO
2
2.2k
AI: The stuff that nobody shows you
jnunemaker
PRO
2
190
The Pragmatic Product Professional
lauravandoore
37
7.1k
Measuring Dark Social's Impact On Conversion and Attribution
stephenakadiri
1
110
How to Align SEO within the Product Triangle To Get Buy-In & Support - #RIMC
aleyda
1
1.4k
YesSQL, Process and Tooling at Scale
rocio
174
15k
Navigating the moral maze — ethical principles for Al-driven product design
skipperchong
2
230
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]