AWSSignature.py

#!/usr/bin/env python
# encoding: utf-8

import hmac
import hashlib
from uuid import uuid1 as uuid
from base64 import b64encode
from urllib import urlencode
from functools import wraps

def main():
    secretkey = 'ExampleSecretKey'

    data = {
        'SignatureVersion': '2',
        'AWSAccessKeyId': 'ExampleAPIKey',
        'Version': '2013-10-15',
        'Timestamp': '2014-02-19T23:34:43.868347',
        'SignatureMethod': 'HmacSHA256',
        'KeyName': 'Test',
        'Action': 'DeleteKeyPair'
    }

    request_string = _get_request_string(data)
    print _generate_signature(secretkey, request_string)


def _generate_signature(secretkey, request_string):

    signature = hmac.new(
        key=secretkey,
        msg=bytes(request_string),
        digestmod=hashlib.sha256
    ).digest()

    signature = b64encode(signature)

    return signature


def _get_request_string(data):
    query_string = _get_query_string(data)

    request_string = '\n'.join(
        ['POST', 'localhost', '/', query_string]
    )

    return request_string.encode('utf-8')


def _get_query_string(data):
    params = {}
    for param in data:
        if param != 'Signature':
            params[param] = data[param]

    keys = sorted(params.keys())
    values = map(params.get, keys)

    query_string = urlencode(
        list(
            zip(keys, values)
        )
    )

    return query_string

if __name__ == "__main__":
    main()