Contentstack has upgraded its TLS to version 1.2, and therefore, TLS 1.0 and 1.1 has been deprecated.
What You Need to Know
Our CDN/API services now use the upgraded TLS version and no longer support TLS 1.0 or TLS 1.1 over HTTPS on the “api/cdn/images/assets.contentstack.io” domain. We will now only accept requests made by browsers or API clients that have TLS version 1.2 or higher. Here's a comprehensive support matrix that you can access.
Why Did We Make This Change
The TLS 1.2 protocol was defined in RFC 5246 in August 2008. It is an improvement over TLS 1.1 standard, and is more secure. Among other items, it provides protection against Cipher Block Chaining (CBC) attacks. One of the major reasons for this revision from TLS 1.1 to TLS 1.2 is to remove the protocol's dependency on the MD5 and SHA-1 digest algorithms. TLS 1.2 supports expansion of support for authenticated encryption ciphers with AES-GCM cipher suites that are not prone to these attacks.
What You Should Do Now
Most browsers have supported TLS 1.2 for at least the last few years. So, end users are unlikely to be affected by this change. The impact is likely only going to be felt by API users with very old libraries
Api Library Support
If you have code that connects with the Contentstack APIs, it is important to ensure that it will continue to work after August 23, 2019. While each language and library is different, we have identified some of the popular ones as a starting reference.
Here's the list of languages that will need significant changes/upgrades in order to continue operating uninterrupted:
- Java 6u45 / 7u45
- .NET before 4.5 (does not support TLS 1.2)
- .NET 4.5 (setting must be changed to explicitly enable TLS 1.2)
- OpenSSL 0.9.8
Most dynamic languages such as Ruby, PHP, and Python rely on the underlying operating system's OpenSSL version. You can check it by running openssl version. Version 1.0.1 is the minimum requirement.
Most browsers support TLS 1.2, and have been supporting it for several years. The following are the browser versions (including lower versions) that DO NOT support TLS 1.2:
- Google Chrome 29
- Mozilla Firefox 26
- Internet Explorer 10
- Safari 8
- iOS 4
- Android 4