Newbie question: I'm sending a large text string in the form of a byte array using the WebClient.UploadData method to a web site but I'm not sure exactly where to retrieve that data from on the server. I've read posts that say it is in the request object which I already know but how exactly do I retrieve the specific byte array I sent like in the following c# pseudo code:
byte[] dataSent = request.GettheByteArrayISentFromWebClientUploadDataMethod;
I understand that it may not be as simple as this and that I may need to do some other processing but can anyone post a code snippet that shows how I can get at the byte array that was sent?
Mucho Thank-you
Try reading it from the request stream Request.InputStream:
var bytes = new byte[request.InputStream.Length];
Request.InputStream.Read(bytes, 0, bytes.Length);
If you are sending key/value pairs then you could use the UploadValues method and read them simply as request paraneters:
string value = Request["someKey"];
Related
I'm currently writing an ASP.NET Core web API that has an action with a encrypted value as a parameter.
I'm trying to test this action and the URL won't even submit in the web browser, at first I thought it could be due to the URL being too long but I've found this answer and my URL is well below the 2000 character limit. I've changed the parameter to a trivial string ("hello") and it submits fine and runs the code. I've tried in both Edge and IE11 whilst debugging my application, in Edge nothing happens at all, in IE11 I get a message saying:
Windows cannot find 'http://localhost:5000/api/...' Check the spelling and try again
In either case the code in the application doesn't execute (I've put a breakpoint on the first line of the controllers constructor which isn't being hit).
I've included an example of one of the URLs that isn't working below, as well as the code I'm using to generate the encrypted string, it uses HttpUtility.UrlEncode to convert the encrypted byte[] array to a string.
Example URL (one that doesn't work):
http://localhost:5000/api/testcontroller/doaction/%95%d6%f8%97%84K%1f%d4%40P%f0%8d%de%27%19%ed%ffAR%9c%c6%d4%b1%83%1e%9fX%ce%9b%ca%0e%d4j%d3Rlz%89%19%96%5dL%b1%16%e9V%14u%c7W%ee%89p%3f%f7%e6d%60%13%e5%ca%00%e9%a2%27%cb%d3J%94%a6%e1%b9%9c%914%06y%7e%0bn%ce%00%e5%7d%98b%85c%fa6m%7d%f7%f1%7b8%26%22%5e%1et%5e%10%0c%05%dd%deFAR%bb%93L%b9-W%e1K%82%d8%cc8%ce%e0%0c%2b%bc%19
Action:
[HttpGet("[action]/{encrypted}")]
public string DoAction(string encrypted)
{
return "Executed";
}
Generate encrypted string:
private string GenerateEncryptedString()
{
RSACryptoServiceProvider rsaProvider = new RSACryptoServiceProvider();
byte[] data = HttpUtility.UrlDecodeToBytes("AHMW9GMXQZXYL04EYBIW");
byte[] encryptedData = rsaProvider.Encrypt(data, true);
string encryptedString = HttpUtility.UrlEncode(encryptedData);
return encryptedString;
}
Not sure if I'm going wrong in my methodology for converting the encrypted data to a string but I would appreciate any feedback on how to fix this issue.
I think you should try to pass this data in the query string and not in the location (path) part of the url (some characters may be forbidden in paths as a security layer), so add a ?data= before the encoded data.
http://localhost:5000/api/testcontroller/doaction/?data=%95%d6%f8%97%84K%1f%d4%40P%f0%8d%de%27%19%ed%ffAR%9c%c6%d4%b1%83%1e%9fX%ce%9b%ca%0e%d4j%d3Rlz%89%19%96%5dL%b1%16%e9V%14u%c7W%ee%89p%3f%f7%e6d%60%13%e5%ca%00%e9%a2%27%cb%d3J%94%a6%e1%b9%9c%914%06y%7e%0bn%ce%00%e5%7d%98b%85c%fa6m%7d%f7%f1%7b8%26%22%5e%1et%5e%10%0c%05%dd%deFAR%bb%93L%b9-W%e1K%82%d8%cc8%ce%e0%0c%2b%bc%19
I want to upload an image from IOS device to Google datastore.
This is how I did it:
On client side, I use cocos2d to get image raw data. image->getData(), which returns an (unsigned char*) type. I guess it's in base64.
I set, std::string postdata = "image=" + (char *)(image->getData());.
I use cocos2d HttpClient to send the postdata to a servlet.
On the servlet, I use request.getParameter("image"); to get the image data. But I got an java.lang.IllegalArgumentException: !utf8 ERROR!
However, if I just set postdata = "image=XXXX", the servlet is able to return me "XXXX", which is what I want. So I guess the problem is:
"image=" is in UTF8, but image data is in base64.
Then servlet does not know how to decode the string and returns me !UTF8 error.
I don't know if my understanding is correct?
All I want is to let servlet receive image data and send it back to client.
Is any one know how to do it?
Thanks in advance.
Regards
I solved the problem. It's just I need to encode the image data to base64, then post it to the servlet. Thanks any way.
I am creating a web site in .Net 3.5 , I am converting the string into Base64String to send it through querystring. The Response.Redirect works fine for smaller string. But if the original string size is 1670, the response.redirect results in error "Page can not be found".
item is the string in below code snippet.
byte[] data = Encoding.Default.GetBytes(item);
return Convert.ToBase64String(data)
Can any one please help in resolving this?
A query string shouldn't be used for long values - while it depends on the browser and web server exactly what the maximum safe length is, it's certainly not safe above about 2000 characters, and I'd be wary about relying on it above 255. The solution is to use a POST request instead, or possibly to save the data on the server and pass a key to it in the query string.
There is a limit on characters sent as a query string - it varies from browser to browser:
http://support.microsoft.com/kb/q208427/
I'd save it to a DB and retrieve it on the other end with a key.
I have silverlight app that post some data to another web application ,the data to post is converted to base 64 using code
byte[] byteArray = Encoding.UTF8.GetBytes(sDataToPost);
sDataToPost = Convert.ToBase64String(byteArray);
Another webapplication
get the data using the code
strText = System.Text.Encoding.ASCII.GetString(System.Convert.FromBase64String(postedData));
But it gives the exception invalid length for a base-64 char array
Thanks in Advance
DNM
Depending on how you post the data its quite possible that the Base64 string is being munged a little more. For example URL encoders may do odd things with the + and = symbols in the Base64 string.
I am working on an app where we have to pass specific web api parameters to a web app using HTTP POST.
eg:
apimethod name
parameter1 value
parameter2 value
So do I use a string or URLEncodedPostData to send that data?
It would be good if u help me with a code eg.
I am using something like this but it doesnt post the data to the server.
Though the response code is ok/200 and I also get get a parsed html response when i read the httpresponse input stream. But the code doesnt post anything. So unable to get the expected response.
_postData.append("method", "session.getToken");
_postData.append( "developerKey", "value");
_postData.append( "clientID", "value");
_httpConnection = (HttpConnection) Connector.open(URL, Connector.READ_WRITE);
String encodedData = _postData.toString();
_httpConnection.setRequestMethod(HttpConnection.POST);
_httpConnection.setRequestProperty("User-Agent", "BlackBerry/3.2.1");
_httpConnection.setRequestProperty("Content-Language", "en-US");
_httpConnection.setRequestProperty("Content-Type","application/x-www-form-urlencoded");
_httpConnection.setRequestProperty("Content-Length",(new Integer(encodedData.length())).toString());
os = _httpConnection.openOutputStream();
os.write(requeststring.getBytes());`
The code you posted above looks correct - although you'll want to do a few more things (maybe you did this already but didn't include it in your code):
Close the outputstream once you've written all the bytes to it
Call getResponseCode() on the connection so that it actually sends the request
POSTed parameters are usually sent in the response BODY, which means URL-encoding them is inappropriate. Quote from the HTTP/1.1 protocol:
Note: The "multipart/form-data" type has been specifically defined
for carrying form data suitable for processing via the POST
request method, as described in RFC 1867 [15].
The post method allows you to use pretty arbitrary message bodies — so it is whatever format the server wants.