Building Encrypted APIswith

HTTPS and Paillier

Nick Doiron - @mapmeld~30 min + questions

About meTraveling web dev and mapmaker

Some useful things:

One Laptop per Child, Code for America,Myanmar 2015 election API

Some useless things:

Fortran.io, GitJK

(can answer Qs in Spanish… maybe)

What’s so special about HTTPS?HTTP is easy to track, intercept, modify, or forge

HTTPS encrypts page’s

- URL (beyond subdomain.domain.com)- content

An HTTPS certificate shows that the content was encrypted by the domain(no modifying / forgery)

Forward secrecy: compromised key can’t decode old sessions (iOS mandatory)

HTTPS critical for news, political sites: https://securethe.news/sites/

Some JS won’t run without HTTPS

Web crypto API (OpenPGP.js)

getUserMedia (camera/mic)

Where do certs come from?

Certificate Authorities (and uber-authorities)

Team started in 2012: FREE HTTPS ON DEMAND

Public beta in December 2015 - over 24 million in one year!

LetsEncrypt: can I do it?- github.com/certbot/certbot, written in Python, maintained with EFF

- you could have a big impact on online security, by helping out this repo

- ./certbot-auto CLI- No wildcard domains- Easier if you run in sudo- Apache or Nginx auto-setups (you should be using one already)- Also does renewals

Checking your HTTPS settingsSSL Labs: grades your HTTPS security on several settings

OverEncrypt

Hacker News bait - Security beyond LetsEncrypt Defaults

Apache/Nginx config

- Is this necessary?- ‘Stormchaser’

- Steps reviewableon SSL Labs

Must-Staple

OCSP Stapling = standard to publicly notify when revoking certificates

Must-Staple tells browser to always check that the cert has not been revoked

LetsEncrypt supports it, but does not auto-enable

Certificate Transparency

Mostly forward-thinking and not fully used today

LetsEncrypt posts every cert issued, on https://crt.sh

Goal is to notice unusual and distrust non-public certs

More info: https://certificate-transparency.org

Public Key Pinning

WARNING: this can brick your entire domain

Tells browsers to only allow certs with a certain SHA256 hash

I recommend current cert + root cert (renewal gives you a brand new cert and hash)But then you are tied to LetsEncrypt :-\

Allow Preload

Used on major websites, governments, etc

Most major browsers have a list of expected certs for these websites, you can apply

Avoids attacks on cert authorities, first-time users

OverEncrypt CLI

I’m developing a CLI to recommend or make these changes automatically

https://github.com/mapmeld/overencrypt

Python Nginx-config-parser broke on my settings (?)

General Tips

and future notes

And you can start

living in the future NOW

UUID - don’t use sequential IDs

Future: Quantum Computers and BoringSSL

BoringSSL:

- initially created by Google to avoid sketchy OpenSSL code

- recently testing ‘A New Hope’- Ring Learning With Errors > Lattice-based

Encryption > Post-Quantum Encryption

Future: Homomorphic Encryption

What if I could send you encrypted data and numbers,

and you could run code / operations on it,

without ever decrypting it?

1st fully-homomorphic algorithm in 2009

Potential for e-voting, private medical data, exchange rates, searching encrypted data

Crypto-GeoFence project

Uses partially-homomorphic encryption called Paillier cryptosystem

Check if client’s latitude / longitude is in the target area

- don’t reveal client location to server- don’t reveal target area to client

github.com/Georeactor/crypto-geofence

Crypto-GeoFence

pip install phe (partially-homomorphic encryption)

X > Left_Border&&X > Right_Border

X > Left_Border&&X < Right_Border

Crypto-GeoFence

Calculate distance to sides

Randomize

Client can decrypt if it is inside the box

Thank you - Muchas gracias - Questions?Nick Doiron - @mapmeld