iOS-Upload image to OneDrive using REST API

Question

I am trying to upload image from my app to onedrive using the REST api they provided. But missing some formating for PST method, please help to work out. I am doing as,

NSString *urlString = [NSString stringWithFormat:@"https://apis.live.net/v5.0/me/skydrive/files?access_token=%@",oneDriveAccessToken];
NSMutableURLRequest *request =[[NSMutableURLRequest alloc] init];
[request setURL:[NSURL URLWithString:urlString]];
[request setHTTPMethod:@"POST"];

NSString *boundary = @"A300x";
NSString *contentType = [NSString stringWithFormat:@"multipart/form-data; boundary=%@",boundary];
[request addValue:contentType forHTTPHeaderField: @"Content-Type"];

//-- Append data into post url using following method
NSMutableData *body = [NSMutableData data];

//-- "image_name" is file name of the image (we can set custom name)
[body appendData:[[NSString stringWithFormat:@"\r\n--%@\r\n",boundary] dataUsingEncoding:NSUTF8StringEncoding]];

[body appendData:[[NSString stringWithFormat:@"Content-Disposition:form-data; name=\"file\"; filename=\"%@\"\n",@"name.JPG"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[@"Content-Type: application/octet-stream\n\r\n\n" dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[NSData dataWithData:data]];
[body appendData:[[NSString stringWithFormat:@"--%@--",boundary] dataUsingEncoding:NSUTF8StringEncoding]];


//-- Sending data into server through URL
[request setHTTPBody:body];

//-- Getting response form server
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:nil];

//-- JSON Parsing with response data
NSDictionary *result = [NSJSONSerialization JSONObjectWithData:responseData options:NSJSONReadingMutableContainers error:nil];
NSLog(@"Result = %@",result);

I am getting response as:

Result = {
    error =     {
        code = "request_body_invalid";
        message = "The request entity body for multipart form-data POST isn't valid. The expected format is:
\n--[boundary]
\nContent-Disposition: form-data; name=\"file\"; filename=\"[FileName]\"
\nContent-Type: application/octet-stream
\n[CR][LF]
\n[file contents]
\n--[boundary]--[CR][LF]";
    };
}

I am following this http://msdn.microsoft.com/en-us/library/hh826531.aspx#uploading_files

After suggestions of Jeffery, error message as,

Result = { error = { code = "request_body_invalid"; message = "The 
request entity body has an incorrect value in the 'Content-Disposition' 
header. The expected format for this value is 'Content-Disposition: form-
data; name=\"file\"; filename=\"[FileName]\"'."; }; } 

Answer 1

As a guess, you are mangling the line endings. Sometimes you are using \n sometimes \r\n. You must always use \r\n. As a side note, you shouldn't need the initial \r\n on your first -appendData call. Finally, check your boundary string: they are usually longer to avoid the having those exact same bytes in the content.

NSString *boundary = @"A300x-make-it-longer-to-reduce-risk-12345";

…

[body appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];

[body appendData:[[NSString stringWithFormat:@"Content-Disposition:form-data; name=\"file\"; filename=\"%@\"\r\n", @"name.JPG"] dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[@"Content-Type: application/octet-stream\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
[body appendData:[NSData dataWithData:data]];

[body appendData:[[NSString stringWithFormat:@"--%@--", boundary] dataUsingEncoding:NSUTF8StringEncoding]];