1Security 2======== 3 4We take the security of ``cryptography`` seriously. The following are a set of 5policies we have adopted to ensure that security issues are addressed in a 6timely fashion. 7 8Infrastructure 9-------------- 10 11In addition to ``cryptography``'s code, we're also concerned with the security 12of the infrastructure we run (primarily ``cryptography.io`` and 13``ci.cryptography.io``). If you discover a security vulnerability in our 14infrastructure, we ask you to report it using the same procedure. 15 16What is a security issue? 17------------------------- 18 19Anytime it's possible to write code using ``cryptography``'s public API which 20does not provide the guarantees that a reasonable developer would expect it to 21based on our documentation. 22 23That's a bit academic, but basically it means the scope of what we consider a 24vulnerability is broad, and we do not require a proof of concept or even a 25specific exploit, merely a reasonable threat model under which ``cryptography`` 26could be attacked. 27 28To give a few examples of things we would consider security issues: 29 30* If a recipe, such as Fernet, made it easy for a user to bypass 31 confidentiality or integrity with the public API (e.g. if the API let a user 32 reuse nonces). 33* If, under any circumstances, we used a CSPRNG which wasn't fork-safe. 34* If ``cryptography`` used an API in an underlying C library and failed to 35 handle error conditions safely. 36 37Examples of things we wouldn't consider security issues: 38 39* Offering ECB mode for symmetric encryption in the *Hazmat* layer. Though ECB 40 is critically weak, it is documented as being weak in our documentation. 41* Using a variable time comparison somewhere, if it's not possible to 42 articulate any particular program in which this would result in problematic 43 information disclosure. 44 45In general, if you're unsure, we request that you to default to treating things 46as security issues and handling them sensitively, the worst thing that can 47happen is that we'll ask you to file a public issue. 48 49Reporting a security issue 50-------------------------- 51 52We ask that you do not report security issues to our normal GitHub issue 53tracker. 54 55If you believe you've identified a security issue with ``cryptography``, please 56report it to ``alex.gaynor@gmail.com``. Messages may be optionally encrypted 57with PGP using key fingerprint 58``F7FC 698F AAE2 D2EF BECD E98E D1B3 ADC0 E023 8CA6`` (this public key is 59available from most commonly-used key servers). 60 61Once you've submitted an issue via email, you should receive an acknowledgment 62within 48 hours, and depending on the action to be taken, you may receive 63further follow-up emails. 64 65Supported Versions 66------------------ 67 68At any given time, we will provide security support for the `master`_ branch 69as well as the most recent release. 70 71New releases for OpenSSL updates 72-------------------------------- 73 74As of versions 0.5, 1.0.1, and 2.0.0, ``cryptography`` statically links OpenSSL 75on Windows, macOS, and Linux respectively, to ease installation. Due to this, 76``cryptography`` will release a new version whenever OpenSSL has a security or 77bug fix release to avoid shipping insecure software. 78 79Like all our other releases, this will be announced on the mailing list and we 80strongly recommend that you upgrade as soon as possible. 81 82Disclosure Process 83------------------ 84 85When we become aware of a security bug in ``cryptography``, we will endeavor to 86fix it and issue a release as quickly as possible. We will generally issue a new 87release for any security issue. 88 89The steps for issuing a security release are described in our 90:doc:`/doing-a-release` documentation. 91 92 93.. _`master`: https://github.com/pyca/cryptography 94