| Security | |
| ======== | |
| We take the security of ``cryptography`` seriously. The following are a set of | |
| policies we have adopted to ensure that security issues are addressed in a | |
| timely fashion. | |
| Infrastructure | |
| -------------- | |
| In addition to ``cryptography``'s code, we're also concerned with the security | |
| of the infrastructure we run (primarily ``cryptography.io`` and | |
| ``ci.cryptography.io``). If you discover a security vulnerability in our | |
| infrastructure, we ask you to report it using the same procedure. | |
| What is a security issue? | |
| ------------------------- | |
| Anytime it's possible to write code using ``cryptography``'s public API which | |
| does not provide the guarantees that a reasonable developer would expect it to | |
| based on our documentation. | |
| That's a bit academic, but basically it means the scope of what we consider a | |
| vulnerability is broad, and we do not require a proof of concept or even a | |
| specific exploit, merely a reasonable threat model under which ``cryptography`` | |
| could be attacked. | |
| To give a few examples of things we would consider security issues: | |
| * If a recipe, such as Fernet, made it easy for a user to bypass | |
| confidentiality or integrity with the public API (e.g. if the API let a user | |
| reuse nonces). | |
| * If, under any circumstances, we used a CSPRNG which wasn't fork-safe. | |
| * If ``cryptography`` used an API in an underlying C library and failed to | |
| handle error conditions safely. | |
| Examples of things we wouldn't consider security issues: | |
| * Offering ECB mode for symmetric encryption in the *Hazmat* layer. Though ECB | |
| is critically weak, it is documented as being weak in our documentation. | |
| * Using a variable time comparison somewhere, if it's not possible to | |
| articulate any particular program in which this would result in problematic | |
| information disclosure. | |
| In general, if you're unsure, we request that you to default to treating things | |
| as security issues and handling them sensitively, the worst thing that can | |
| happen is that we'll ask you to file a public issue. | |
| Reporting a security issue | |
| -------------------------- | |
| We ask that you do not report security issues to our normal GitHub issue | |
| tracker. | |
| If you believe you've identified a security issue with ``cryptography``, please | |
| report it to ``alex.gaynor@gmail.com``. Messages may be optionally encrypted | |
| with PGP using key fingerprint | |
| ``F7FC 698F AAE2 D2EF BECD E98E D1B3 ADC0 E023 8CA6`` (this public key is | |
| available from most commonly-used key servers). | |
| Once you've submitted an issue via email, you should receive an acknowledgment | |
| within 48 hours, and depending on the action to be taken, you may receive | |
| further follow-up emails. | |
| Supported Versions | |
| ------------------ | |
| At any given time, we will provide security support for the `master`_ branch | |
| as well as the most recent release. | |
| New releases for OpenSSL updates | |
| -------------------------------- | |
| As of versions 0.5, 1.0.1, and 2.0.0, ``cryptography`` statically links OpenSSL | |
| on Windows, macOS, and Linux respectively, to ease installation. Due to this, | |
| ``cryptography`` will release a new version whenever OpenSSL has a security or | |
| bug fix release to avoid shipping insecure software. | |
| Like all our other releases, this will be announced on the mailing list and we | |
| strongly recommend that you upgrade as soon as possible. | |
| Disclosure Process | |
| ------------------ | |
| When we become aware of a security bug in ``cryptography``, we will endeavor to | |
| fix it and issue a release as quickly as possible. We will generally issue a new | |
| release for any security issue. | |
| The steps for issuing a security release are described in our | |
| :doc:`/doing-a-release` documentation. | |
| .. _`master`: https://github.com/pyca/cryptography |