hashlib suddenly broken

Larry Martell larry.martell at gmail.com
Thu Sep 18 21:22:04 CEST 2014

On Thu, Sep 18, 2014 at 11:07 AM, Steven D'Aprano
<steve+comp.lang.python at pearwood.info> wrote:
> Larry Martell wrote:
>> I am on a mac running 10.8.5, python 2.7
>> Suddenly, many of my scripts started failing with:
>> ValueError: unsupported hash type sha1
> [...]
>> This just started happening yesterday, and I cannot think of anything
>> that I've done that could cause this.
> Ah, the ol' "I didn't change anything, I swear!" excuse *wink*
> But seriously... did you perhaps upgrade Python prior to yesterday? Or
> possibly an automatic update ran?

No, I did not upgrade or install anything.

> Check the creation/last modified dates on:
> /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/hashlib.py

That was in my original post:

$ ls -l /System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/hashlib.py
-rw-r--r--  1 root  wheel  5013 Apr 12  2013

> but I expect that's probably not where the problem lies. My *wild guess* is
> that your system updated SSL, and removed some underlying SHA-1 library
> needed by hashlib. SHA-1 is pretty old, and there is now a known attack on
> it, so some over-zealous security update may have removed it.
> If that's the case, it really is over-zealous, for although SHA-1 is
> deprecated, the threat is still some years away. Microsoft, Google and
> Mozilla have all announced that they will continue accepting it until 2017.
> I can't imagine why Apple would removed it so soon.

So you know how I could check and see if I have SHA-1 and when my SSL
was updated?

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