Issues with Python hashlib.sha256 (2.4.3)

Question

So I have some code:

signature = hmac.new(
    key=AWS_SECRET_ACCESS_KEY,
    msg=string_to_sign,
    digestmod=hashlib.sha256).digest()

That runs perfectly on my own computer (has python 2.6.1). However, when I run this code on my server (Python 2.4.3) I get the following:

 /home/MYUSERNAME/public_html/Foo.com/cgi-bin/foo.py
   66     key=AWS_SECRET_ACCESS_KEY,
   67     msg=string_to_sign,
   68     digestmod=hashlib.sha1).digest()
   69  
   70 # Base64 encode the signature
digestmod = <built-in function openssl_sha256>, hashlib = <module 'hashlib' from '/usr/lib/python2.4/site-...shlib-20081119-py2.4-linux-i686.egg/hashlib.pyc'>, hashlib.sha1 = <built-in function openssl_sha1>, ).digest undefined
 /usr/lib/python2.4/hmac.py in new(key='xR6MsC/+Vc2xkd0YYbER0meR/IkWEU', msg='GET\necs.amazonaws.com\n/onca/xml\nAWSAccessKeyId=A...CommerceService&Timestamp=2010-07-03T18%3A56%3A48', digestmod=<built-in function openssl_sha1>)
  103     You can now feed arbitrary strings into the object using its update()
  104     method, and can ask for the hash value at any time by calling its digest()
  105     method.
  106     """
  107     return HMAC(key, msg, digestmod)
global HMAC = <class hmac.HMAC>, key = 'xR6MsC/+Vc2xkd0YYbER0meR/IkWEU', msg = 'GET\necs.amazonaws.com\n/onca/xml\nAWSAccessKeyId=A...CommerceService&Timestamp=2010-07-03T18%3A56%3A48', digestmod = <built-in function openssl_sha1>
 /usr/lib/python2.4/hmac.py in __init__(self=<hmac.HMAC instance>, key='xR6MsC/+Vc2xkd0YYbER0meR/IkWEU', msg='GET\necs.amazonaws.com\n/onca/xml\nAWSAccessKeyId=A...CommerceService&Timestamp=2010-07-03T18%3A56%3A48', digestmod=<built-in function openssl_sha1>)
   40 
   41         self.digestmod = digestmod
   42         self.outer = digestmod.new()
   43         self.inner = digestmod.new()
   44         self.digest_size = digestmod.digest_size
self = <hmac.HMAC instance>, self.outer undefined, digestmod = <built-in function openssl_sha1>, digestmod.new undefined

AttributeError: 'builtin_function_or_method' object has no attribute 'new'
      args = ("'builtin_function_or_method' object has no attribute 'new'",) 

I know the obvious response is to just update Python on my server, but my host has to do that and I don;t know how long it'll take. I'm just curious if this is a common/known issue on 2.4.3 or if something else is going on.

Thanks

Answer 1

hashlib is new in 2.5. You'll need the backport for older versions of Python.