sha1WithRSAEncryption in Python

Can someone recommend a library for calculating SHA1WithRSAEncryption in Python?

Context: I'm trying to do some message authentication. I've looked at PyXMLDSig, but it seemed to expect the certificates as separate files. As a first step to better understanding the problem space, I wanted to calculate the digest values "by hand".

I've looked around and seen Java implementati开发者_如何转开发ons, but not Python ones. (Jython isn't really an option for my environment.)

Thanks in advance.

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Take a look at M2Crypto, it's probably the best and most complete crypto library for Python.