HTTPS Adoption & Security Indicators

7/24/2018

This post details the development and launch of the 'SSL Test Tool' (internally codenamed HelperBot-External) and the proactive email campaign to customers regarding Mixed Content errors and Redirect Loops. It explains the use of a custom NLP model and Search Based Software Engineering strategies to automate debugging and present relevant information to support agents and, in A/B tests, directly to users. The SSL Test Tool is presented as a public-facing application of these internal capabilities to help website owners enable HTTPS.

7/24/2018

This post details the significance of Chrome flagging all non-secure connections as 'Not Secure' and discusses the broader trend of browser vendors driving HTTPS adoption. It highlights the historical challenges of HTTPS adoption (cost, complexity, performance) and how these have been overcome. The post references Scott Helme's Alexa Top 1M reports to show the rapid growth of HTTPS adoption, noting that while larger sites have adopted it more quickly, the effort for smaller sites is now negligible. It also addresses the argument that static sites don't need HTTPS by listing potential attacks like script injection, cryptomining, DDoS amplification, and malware/phishing delivery. The post concludes by noting that this is one of many steps towards a more secure-by-default web, with multiple browser vendors driving this change.

6/28/2018

This post details the upcoming Chrome change to flag HTTP sites as 'Not Secure' and argues against common misconceptions about HTTPS difficulty, necessity, and performance. It highlights Cloudflare's free SSL offering, automatic renewal, and edge deployment for performance. It also mentions SSL for SaaS providers and the use of Cloudflare Workers for edge logic. The post provides a tool to check site readiness and offers guidance on avoiding the 'Not Secure' flag, including using 'Always use HTTPS' and 'Automatic HTTPS Rewrites'.

5/16/2018

This post announces the official release of TLS 1.3 from beta on Cloudflare's platform. It details the default enablement for new zones and existing Business customers, and explains the technical work done to address middlebox compatibility issues by reintroducing handshake messages like ChangeCipherSpec and manipulating the session_id field in ClientHello. It also presents adoption metrics showing a significant increase in TLS 1.3 usage and discusses browser adoption trends.

2/14/2018

This post details Google's plan to mark all HTTP sites as "not secure" in Chrome 68, a significant step towards deprecating HTTP. It also provides a historical timeline of milestones towards HTTPS ubiquity, including Cloudflare's Universal SSL announcement and the launch of Let's Encrypt. The post predicts Google will remove the lock icon entirely in Chrome 72 (January 2019) when HTTPS page loads are expected to exceed 85%.

10/20/2017

This post explains SSL stripping attacks and introduces HTTP Strict Transport Security (HSTS) as a defense mechanism. It details how HSTS works via the `Strict-Transport-Security` header and discusses its limitations, such as the need for an initial connection and susceptibility to time synchronization attacks. It also introduces HSTS Preloading as a solution to mitigate these shortcomings by hardcoding HTTPS-only sites into browser lists.

3/15/2017

Introduced Zero Round Trip Time (0-RTT) resumption for TLS 1.3, which eliminates one round trip for resumed connections, speeding up subsequent visits to websites. This feature is available for paid customers and is experimental.

10/12/2016

This post details the evolution of nonce management in TLS, from early vulnerable implementations like RC4 and CBC in TLS 1.0 to the more secure AEAD ciphers in TLS 1.2 and the robust scheme in TLS 1.3. It explains the security implications of nonce reuse, including the BEAST and Nonce-Disrespecting Adversaries attacks, and highlights how TLS 1.3's approach of XORing a fixed IV with the sequence number provides a secure and efficient solution.

9/30/2016

Introduced Dedicated SSL Certificates and Dedicated SSL Certificates with Custom Hostnames. These new offerings provide customers with non-shared, customizable SSL certificates for their domains, addressing requests for more control over issuance, subdomain protection, and SSL/TLS version/encryption options. The process involves ordering through the Cloudflare Dashboard, with costs of $5/month for Dedicated Certificates and $10/month for Dedicated Certificates with Custom Hostnames. The post also details the priority order for serving certificates (Uploaded > Dedicated with Custom Hostnames > Dedicated > Universal) and clarifies the differences from Let's Encrypt.

9/23/2016

This post details the technical advancements of TLS 1.3 over TLS 1.2, focusing on reducing handshake round-trips from two to one for initial connections and enabling 0-RTT for subsequent connections. It explains the mechanics of the TLS 1.2 and TLS 1.3 handshakes, including key exchange mechanisms like ECDHE. The post also discusses the security implications of 0-RTT, such as the lack of forward secrecy against Session Ticket key compromise and the risk of replay attacks, proposing solutions like using idempotent operations for 0-RTT data. Furthermore, it highlights the removal of insecure and complex features from TLS 1.3, such as static RSA handshake, CBC MAC-then-Encrypt modes, and weak primitives like RC4 and SHA1, emphasizing a shift towards more robust and secure cryptographic primitives and a simplified protocol design.

9/20/2016

This post announces the availability of TLS 1.3 to all Cloudflare customers, highlighting its benefits for both security and speed. It details the removal of legacy, vulnerable cryptographic features from TLS 1.2 in TLS 1.3, enhancing overall security. It also explains how TLS 1.3 reduces handshake round-trips from two to one, significantly improving latency and page load times, especially for mobile and geographically distant users. The post also mentions upcoming support for 0-RTT mode for even faster load times.

9/20/2016

This post announces and details three new features: TLS 1.3 for faster and more secure connections, Automatic HTTPS Rewrites to fix mixed content issues by rewriting HTTP sub-resource URLs to HTTPS, and Opportunistic Encryption to enable HTTP/2 over encrypted connections for sites that cannot fully upgrade to HTTPS. It explains the technical benefits and implications of each feature for website security and performance.

5/10/2016

Introduced Cloudflare Origin CA, enabling customers to obtain certificates for encrypting connections between Cloudflare and their origin servers. This feature utilizes client-side key generation in the browser via the Web Crypto API and PKI.js library for CSR creation, ensuring private keys are never exposed to Cloudflare's servers. This approach enhances usability and security by simplifying the certificate acquisition process and eliminating the need for users to manage private keys directly or install cryptographic software.

5/3/2016

Introduced Cloudflare Origin CA, a new Certificate Authority specifically designed for encrypting traffic between Cloudflare's edge and customer origin servers. This CA offers benefits over public certificates including simplified issuance and renewal, wildcard certificate support for multiple hostnames, faster and more reliable revocation, and optimized certificates that reduce handshake size and origin bandwidth consumption. The post details the technical rationale behind these optimizations, such as removing intermediate CAs and SCTs, and provides instructions for installation and usage.

3/23/2016

This post details the technical implementation of optimizing TLS certificate selection between SHA-1, SHA-2, RSA, and ECDSA to accommodate varying client capabilities, ensuring secure and performant connections. It outlines the TLS handshake process and presents a logic tree for determining the optimal certificate based on the ClientHello message, specifically for paid plans, differentiating from the free plan's default SHA-256/ECDSA certificate.

12/9/2015

This post details the deprecation of SHA-1 certificates due to security vulnerabilities and the challenges of global SHA-2 adoption. Cloudflare implements a SHA-1 fallback mechanism for paid customers to support legacy browsers, ensuring continued access for users in regions with lower SHA-2 support. The post analyzes global SHA-2 support data, identifies countries with low adoption, and highlights the importance of this fallback for vulnerable populations. It also discusses the chicken-and-egg problem faced by Mozilla in transitioning to SHA-2 and Cloudflare's collaboration with them.

9/29/2014

Introduced Universal SSL, enabling SSL connections for all Cloudflare customers, including those on the free plan. This involved automatically provisioning SSL certificates on Cloudflare's network, supporting root domains and wildcard subdomains. Addressed challenges of CPU load and IPv4 exhaustion by leveraging ECDSA cipher suites and Server Name Indication (SNI) for modern browsers, allowing shared IP addresses. Enabled Flexible SSL mode by default for new SSL configurations, with recommendations for Full or Strict SSL. Enabled SPDY protocol by default for all customers. Introduced the 'A Better Browser' app to encourage upgrades to modern browsers.

8/6/2014

Introduced a new method for dynamically loading SSL certificates on demand, enabling Cloudflare to manage millions of domains and shift traffic dynamically while supporting HTTPS. This technical advancement paved the way for offering free SSL to all customers.