urllib3: Differences between standard SSL and Pyopenssl (ZeroReturnError, SysCallError)

We use urllib3 via requests with pyopenssl so we can have SNI support in python 2.7.3.

Since we switched, we’ve noticed more errors from requests. Specifically:

• ZeroReturnError
• SysCallError: (104, ‘Connection reset by peer’)
• SysCallError: (-1, ‘Unexpected EOF’)

It seems like these should all be caught somehow in contrib/pyopenssl.py so at the requests level, we don’t have to worry about pyopenssl being different than the standard ssl module.

Here’s a few of the ideas I’m considering:

• in fileobject.read, everywhere we are catching WantReadError also catch ZeroReturnError and make sure that data is an empty string and continuing
• In inject_into_urllib3, setting connection.BaseSSLError = OpenSSL.SSL.Error

Based on my limited understanding of pyopenssl (and python’s standard _ssl.c) I’m probably missing something in trying to unify these interfaces. If somebody with more familiarity with this stuff can point me in the right direction I can try to formalize this stuff into a pull request.

Here’s a gist of how I started investigating the ZeroReturnError specifically: https://gist.github.com/mthurman/9963741