Blog Posts from December 16, 2008 (page 1 of 1)
One of the cool things about the Live Framework is that while there’s a convenient .NET library available, you can use the raw HTTP interface from any platform. LiveFX data is served up over HTTP and is available in ATOM, RSS, JSON or POX formats. As I’ve already shown, you can easily use the .NET library from IronPython, but I wanted to try working with the raw HTTP interface to get a feel for that as well.
Unfortunately, it was harder than I expected it to be. The big issue is that the documentation on how to LiveFX authorization tokens via raw HTTP is fairly sparse and occasionally contradictory. For example, there’s a whole section on Authentication and Live Framework, but it doesn’t cover this scenario. Luckily, I was able to figure it out with the help of AtomPub Project Manager LiveFX Sample, a post on Alex Feinman’s blog, a post on Emmanuel Mesas’ blog and a little groveling around with Reflector. It does appear that the auth docs are in flux –Emmanuel refers to this MSDN article as being about RPS Soap requests, but it’s actually about delegated authority. (Is MSDN reusing URLs? Bad idea.) Also, the sample code has a comment that reads “to be replaced by delegated authorization” so it looks like changes are coming. In other words, no promises on how long this code will work!
If you look at the AtomPub Project Manager sample, there’s a WindowsLiveIdentity.cs file that implements static GetTicket method that looks similar to both the code on Alex’s blog as well as the implementation of GetWindowsLiveAuthenticationToken. The upshot is that there’s a WS-Trust endpoint for Windows Live at https://dev.login.live.com/wstlogin.srf. You send it a RequestSecurityToken (aka RST) message (with a couple of extra WL specific extensions) and it responds with the security token you’ll need for accessing the LiveFx HTTP endpoints.
I ported the GetTicket function over to IronPython. I’m using .NET classes like WebRequest and XmlReader, but there’s nothing fancy here so I would expect it to be easy enough to port over to the standard Python library.
def get_WL_ticket(username, password, compactTicket): req = WebRequest.Create(_LoginEndPoint) req.Method = "POST" req.ContentType = "application/soap+xml; charset=UTF-8" req.Timeout = 30 * 10000 rst = get_RST_message(username, password, compactTicket) rstbytes = Encoding.UTF8.GetBytes(rst) with req.GetRequestStream() as reqstm: reqstm.Write(rstbytes, 0, rstbytes.Length) with req.GetResponse() as resp: with resp.GetResponseStream() as respstm: with XmlReader.Create(respstm) as reader: if compactTicket: name = "BinarySecurityToken" namespace = "http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" else: name = "RequestedSecurityToken" namespace = "http://schemas.xmlsoap.org/ws/2005/02/trust" if not reader.ReadToDescendant(name, namespace): raise "couldn't find security token element" reader.ReadStartElement(name, namespace) token = reader.ReadContentAsString() reader.ReadEndElement() return Convert.ToBase64String(Encoding.UTF8.GetBytes(token))
This code simply uses a WebRequest object to post the RST message to the WS-Trust enpoint then parses the result to find the token. get_RST_message uses standard Python string formatting to generate the RST message that gets posted to the WS-Trust endpoint. I’m not exactly sure why you need to convert the token value to a byte array and then Base64 encode it, but that’s what the sample code does so I did it to.
Once you have the authentication ticket, you need to download root service endpoint document in order to get the base URL and the profiles link. Then you can download all the profiles or you can download a specific one if you know it’s leet-speak identifier. LiveFX data can be downloaded in a variety of formats: ATOM, JSON, RSS or POX. You choose your format by setting the Accept and Content-Type headers.
I wrote the following functions, the generic boilerplate download function as well a specific versions for downloading JSON and POX:
def download(url, contentType, authToken): req = WebRequest.Create(url) req.Accept = contentType req.ContentType = contentType req.Headers.Add(HttpRequestHeader.Authorization, authToken) return req.GetResponse() def download_json(url, authToken): resp = download(url, 'application/json', authToken) with StreamReader(resp.GetResponseStream()) as reader: data = reader.ReadToEnd() return eval(data) def download_pox(url, authToken): resp = download(url, 'text/xml', authToken) return XmlReader.Create(resp.GetResponseStream())
Here’s some code that uses the get_WL_ticket and download_json functions above to retrieve the the user’s Personal Status Message
#Get user's WL ticket uid = raw_input("enter WL ID: ") pwd = raw_input("enter password: ") authToken = livefx_http.get_WL_ticket(uid, pwd, True) #download root service document service = livefx_http.download_json(_LiveFxUri, authToken) #download general profile document url = service['BaseUri'] + service['ProfilesLink'] + "/G3N3RaL" genprofile = livefx_http.download_json(url, authToken) print genprofile['ProfileBase']['PersonalStatusMessage']
POX is also fairly easy, though a bit more verbose than JSON. The sample code, which I have stuck on my SkyDrive, includes both POX and JSON code, so you can compare and contrast the differences.
Ori Amiga is a Group Program Manager over in the Live Framework team whom you might have seen at PDC08 delivering the Lap Around LiveFX & Mesh Services and LiveFX Programming Model Architecture and Insights talks. And apparently, he’s an IronPython fan as posted a small LiveFX Python module to his blog. It’s pretty simple – it only wraps Connect and ConnectLocal – but it does cut about ten lines of path appending, reference adding and module importing code into a single import statement. Here’s the profile access script from my last post rewritten to use Ori’s LiveOE module.
import LiveOE from devhawk import linq uid = raw_input("Enter Windows Live ID: ") pwd = raw_input("Enter Password: ") loe = LiveOE.Connect(uid, pwd) general = linq.Single(loe.Profiles.Entries, lambda e: e.Resource.Type == LiveOE.ProfileResource.ProfileType.General) print loe.Mesh.ProvisionedUser.Name print loe.Mesh.ProvisionedUser.Email print general.Resource.ProfileInfo.PersonalStatusMessage print linq.Count(loe.Contacts.Entries)
FYI, make sure you update the sdkLibsPath in LiveOE.py – I’m not sure where Ori has installed the LiveFX SDK, but it’s *not* in the location suggested by the read me file.
BTW, it turns out the WL Profile information is read only which answers a question I had. However, reading the thread it sounds like they will eventually get around to making it read-write at some point.