amazon.py 文件源码

def getSignedUrl(base_url, params, timestamp = None):
    global HMAC
    hmac = HMAC.copy()

    # Add a ISO 8601 compliant timestamp (in GMT)
    if timestamp:
        params['Timestamp'] = timestamp
    else:
        params['Timestamp'] = time.strftime("%Y-%m-%dT%H:%M:%S", time.gmtime())
    #params['SignatureVersion']='1'

    # Sort the URL parameters by key
    keys = params.keys()
    #keys.sort(cmp = lambda x, y: cmp(x.lower(), y.lower()))
    keys.sort()

    # Reconstruct the URL parameters and encode them
    pairs = []
    for key in keys:
        #val = urllib.quote(params[key])
        val = params[key]
        pairs.append(key + '=' + val)
    url_string = '&'.join(pairs)
    url_string = url_string.replace('+', "%20")
    url_string = url_string.replace(':', "%3A")

    #Construct the string to sign
    urlparts = base_url.split('/')
    string_to_sign = """GET
%s
/%s/%s
%s""" % (urlparts[2], urlparts[3], urlparts[4], url_string)
    url_string = url_string.replace(';', urllib.quote(';'))

    # Sign the request
    hmac.update(string_to_sign)
    signature = hmac.digest()

    # Base64 encode the signature
    signature = base64.encodestring(signature).strip()
    signature = signature.replace('+','%2B');
    signature = signature.replace('=','%3D');
    signature = signature.replace('/','%2F');

    # Make the signature URL safe
    url_string += "&Signature=%s" % signature
    return "%s?%s" % (base_url, url_string)


## main functions