HTTPS in 2015

Eric Lawrence@ericlaw

Quick Introductions

Eric Lawrence @ericlaw

Why?

• Bad guys• Government snoops• Non-neutral networks (Gogo, corporate)

• “Value adding providers”

Rewards • Increased user trust• Better search ranking• More reliable egress (HTTP2; WebSocket)

The Stack

• Your Client Browser• HTTP• SSL/TLS• TCP• IP

HTTPS Provides…

• Authentication• Confidentiality• Integrity

How?

• Public Key Infrastructure for certificate chains• Public Key Cryptography for key exchanges• Symmetric Cryptography for data transfers

Certificates

Hash Algorithms• MD5 busted• SHA1 heading that way• SHA256 entering mainstream in 2015

Validating the Certificate

• Validate certificate signature• Validate it is within validity period• Validate it chains to trusted root• Validate Subject CN or SubjectAltName

contains hostname of the target…– Wildcards

• Check to see if it was revoked

Extended Validation SSL

BankoftheVVest.com phishing siteDomain validation and the race to the bottom

Ciphers, Hashes, and MACs oh my…

Initial Handshake

SNI Extension

• Break the IPEndpoint->Server mapping• Important to allow HTTPS virtual hosting• Not available on WinXP or Android < v2.3

Forward Secrecy

• If you can record ALL of the traffic…• And you’re using RSA…• And you can ever steal or crack the private key (at

any point in the future…

Achieving Forward SecrecyDo not use the RSA key exchange, which does not provide forward secrecy. Instead, look for the string ECDHE or DHE in the cipher suite name. RSA can be used for key exchange and authentication; there is nothing wrong with the latter.

Popular Ciphers• Triple-DES• RC4• AES• ChaCha (new)

Revocation• CRL (Certificate Revocation List)• OCSP (Online Certificate Status Protocol)• Deployed blocklists

Certificate Pinning• Built-into browser• Distributed with security software

like Microsoft EMET• New HTTP Public Key Pinning

header https://tools.ietf.org/html/draft-ietf-websec-key-pinning-21

Public-Key-Pins: pin-sha256="GHI..."; pin-sha256="JKL..."; max-age=… report-uri=…; includeSubDomains

Certificate Transparencyhttp://www.certificate-transparency.org/

Google Chrome intends to require Certificate Transparency (CT) for all EV certificates issued after 2014. A SCT “Signed Certificate Timestamp” is added to the certificate.

Performance

https://www.youtube.com/watch?v=0EB7zh_7UE4

Session Resumptionhttp://calendar.perfplanet.com/2014/speeding-up-https-with-session-resumption/

ECC Public Keys

ECC certificates offer stronger security and smaller certificates - e.g. a 256-bit ECC key is equivalent to a 3072-bit RSA key.

http://arstechnica.com/security/2013/10/a-relatively-easy-to-understand-primer-on-elliptic-curve-cryptography/

Run Latest Versions

I’m in!

Enabling HTTPS for your site will be as easy as installing a small piece of certificate management software on the server:

https://example.com is immediately live.

The Let’s Encrypt management software will:• Automatically prove to the Let’s Encrypt CA that you control the website• Obtain a browser-trusted certificate and set it up on your web server• Keep track of when your certificate is going to expire, and automatically renew it• Help you revoke the certificate if that ever becomes necessary.

No validation emails, no complicated configuration editing, no expired certificates breaking your website. And of course, because Let’s Encrypt provides certificates for free, no need to arrange payment.

WebDev Errors

• Critical Mistake #1: Non-HTTPS Login pages (even if submitting to a HTTPS page).

WebDev Errors

• Critical Mistake #2: Mixing HTTP Content into a HTTPS page

HSTS

HSTS

http://blogs.msdn.com/b/ieinternals/archive/2014/08/18/hsts-strict-transport-security-attacks-mitigations-deployment-https.aspx

• Insecure references are upgraded• Certificate errors are fatal

Use the HTTPS response header: Strict-Transport-Security: max-age=63072000; includeSubDomainsOr get on the browsers’ pre-load list (avoid bootstrapping problem)

Fiddler Visualization

If there’s an exclamation point in the column, you’ve done something wrong!

Migration Guide

https://t.co/0ORIlnp64YChris Palmer @fugueish

• Use STS• Use Secure attribute on cookies• Protocol-relative URLs• Run the Qualys SSLLabs Server test

SSLLabs

HTTPS all the Things!

Best Practice

• Secure everything. It’s very hard to predict future attack scenarios.

• Yes, really.

HTTP Content indicator

HTTP Content indicator

Not Just Browsers…

Hacks

HTTPS Traffic Analysis

• Source IP• Destination IP• Server Name (via SNI)• Higher-level protocol (via ALPN)• Client Certificates (if sent before encryption)

Implementation Issues

• Truncation• Compression• Clickthrough UI

Implementation Issues

• Truncation• Compression• Clickthrough UI

Implementation Issues

• Truncation• Compression• Clickthrough UI

MITM/MITB Attacks

MITM/MITB Attacks

Extended Validation Won’t Help

Heartbleed

http://xkcd.com/1354/

Sometimes, you do attack the crypto

Crypto Deep Dive later this morning…

Book: Bulletproof SSL and TLS

https://www.feistyduck.com/books/bulletproof-ssl-and-tls/

Coupon Code for 25% off

CODEMASH

Valid January 1st to 31st

Free Chapter: https://www.feistyduck.com/books/openssl-cookbook/

Thanks for coming!

Questions?

Find me on Twitter: @ericlawEmail me: e_Lawrence@hotmail.com

Go forth and secure all the things!

See how lightsabers are built…

Combatting breach?