microsoft azure table authentication stringtosign error - azure

Question

I am having a problem with stringtosign authentication for azure table pagination query.
This is the current stringtosign im using :
GET\n\n\nFri, 05 Sep 2014 03:57:11 GMT\n/mystorageaccount/mytablename\nNextPartitionKey:1!20!UmFjZSBNZW1iZXJfNA--\nNextRowKey:1!12!TmFtZV85ODE-
Is there anything wrong with this stringtosign authentication?
The rest of the Headers are exactly the same as Fiddle.
Example
GET /mytablename?NextPartitionKey=1%2120%21UmFjZSBNZW1iZXJfNA--&NextRowKey=1%2112%21TmFtZV85ODE- HTTP/1.1
Host: mystorageaccount.table.core.windows.net
x-ms-version: 2014-02-14
x-ms-date: Fri, 05 Sep 2014 05:49:19 GMT
Authorization: SharedKey mystorageaccount:GD2w4pqsllzIOixNF/AfFqLkZhYzLpjK67a8OI7j6Go=
Accept: application/atom+xml
Accept-Charset: UTF-8
DataServiceVersion: 3.0;NetFx
MaxDataServiceVersion: 3.0;NetFx
I have read through both
http://msdn.microsoft.com/library/azure/dd179428.aspx
http://msdn.microsoft.com/en-us/library/azure/dd135718.aspx
Hi Gaurav Mantri,
It still did not work. I'll paste the request, my stringtosign and the response below:
GET /mytablename?NextPartitionKey=1%2120%21UmFjZSBNZW1iZXJfNA--&NextRowKey=1%2112%21TmFtZV85ODE- HTTP/1.1
Host: mystorageaccount.table.core.windows.net
x-ms-version: 2014-02-14
x-ms-date: Fri, 05 Sep 2014 07:05:12 GMT
Authorization: SharedKey mystorageaccount:HSYfO1Baadqcd4bQO5Q6uN1hrr2aXtLcQbFPkWgIXuw=
Accept: application/atom+xml
Accept-Charset: UTF-8
DataServiceVersion: 3.0;NetFx
MaxDataServiceVersion: 3.0;NetFx
String to sign:
GET\n\n\nFri, 05 Sep 2014 07:05:12 GMT\n/mystorageaccount/mytablename\nnextpartitionkey:1!20!UmFjZSBNZW1iZXJfNA--\nnextrowkey:1!12!TmFtZV85ODE-
Response:
<?xml version=\"1.0\" encoding=\"utf-8\"?><m:error xmlns:m=\"http://schemas.microsoft.com/ado/2007/08/dataservices/metadata\"><m:code>AuthenticationFailed</m:code><m:message xml:lang=\"en-US\">Server failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the signature.
RequestId:37272f11-0002-0014-5aa7-f7dd1c000000
Time:2014-09-05T07:05:09.5720897Z</m:message></m:error>

Answer 1

I had an opportunity to actually write the code and try it out. Basically when creating CanonicalizedResource string for table resources, you need not include the query string parameters other than comp querystring parameter. Essentially this is what you would need to follow from the documentation (http://msdn.microsoft.com/library/azure/dd179428.aspx):
2009-09-19 Shared Key Lite and Table Service Format
This format supports Shared Key and Shared Key Lite for all versions
of the Table service, and Shared Key Lite for the 2009-09-19 version
of the Blob and Queue services and 2014-02-14 of the File service.
This format is identical to that used with previous versions of the
storage services. Construct the CanonicalizedResource string in this
format as follows:
Beginning with an empty string (""), append a forward slash (/), followed by the name of the account that owns the resource being
accessed.
Append the resource's encoded URI path. If the request URI addresses a component of the resource, append the appropriate query
string. The query string should include the question mark and the comp
parameter (for example, ?comp=metadata). No other parameters should be
included on the query string.
Once you do that, your code should run just fine. Here's the sample code I wrote:
static void QueryTable()
{
var requestMethod = "GET";
var storageServiceVersion = "2014-02-14";
var date = DateTime.UtcNow.ToString("R");
var canonicalizedResource = string.Format("/{0}/{1}", StorageAccount, TableName);
var stringToSign = string.Format("{0}\n\n\n{1}\n{2}", requestMethod, date, canonicalizedResource);
var authorizationHeader = GetAuthorizationHeader(stringToSign);
using (var httpClient = new HttpClient())
{
httpClient.BaseAddress = new Uri(TableEndpoint);
httpClient.DefaultRequestHeaders.Clear();
httpClient.DefaultRequestHeaders.Add("x-ms-date", date);
httpClient.DefaultRequestHeaders.Add("x-ms-version", storageServiceVersion);
httpClient.DefaultRequestHeaders.Add("Authorization", authorizationHeader);
var result = httpClient.GetAsync(TableName + "?NextPartitionKey=1!48!VXwzMzg0MDAzOWYzMjQ0ZDgxOWZjZmM5M2EyMzNkM2IxOA--&NextRowKey=1!0!");
result.Wait();
}
}
static string GetAuthorizationHeader(string canonicalizedString)
{
var signature = string.Empty;
using (var hash = new HMACSHA256(Convert.FromBase64String(StorageAccountKey)))
{
var data = Encoding.UTF8.GetBytes(canonicalizedString);
signature = Convert.ToBase64String(hash.ComputeHash(data));
}
return string.Format(CultureInfo.InvariantCulture, "{0} {1}:{2}", "SharedKey", StorageAccount, signature);
}
Based on the documentation here: http://msdn.microsoft.com/library/azure/dd179428.aspx (2009-09-19 Shared Key Format Section, point #4), you would need to convert all query parameters to lowercase. So your canonicalized resource string should be:
GET\n\n\nFri, 05 Sep 2014 03:57:11 GMT\n/mystorageaccount/mytablename\nnextpartitionkey:1!20!UmFjZSBNZW1iZXJfNA--\nnextrowkey:1!12!TmFtZV85ODE-
Give it a try. That should take care of the problem.