NSMutableString *boundary = [NSMutableString new];
    [boundary appendString:@"__-----------------------"];
    [boundary appendFormat:@"%ld", arc4random() % 2147483648];
    [boundary appendFormat:@"%ld", (long) ([[NSDate new] timeIntervalSince1970] * 1000)];

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

//    [request setHTTPBody:imageData];
//    [request setValue:@"image/jpeg" forHTTPHeaderField:@"Content-Type"]

    NSMutableData *bodyData = [[NSMutableData alloc] init];
    NSMutableDictionary *paramsDictionary = [NSMutableDictionary new];
    [paramsDictionary setObject:preSignedPost.fileName forKey:@"key"];
    [paramsDictionary setObject:@"public-read" forKey:@"acl"];
    [paramsDictionary setObject:preSignedPost.contentType forKey:@"Content-Type"];
    [paramsDictionary setObject:preSignedPost.amzCredential forKey:@"X-Amz-Credential"];
    [paramsDictionary setObject:@"AWS4-HMAC-SHA256" forKey:@"X-Amz-Algorithm"];
    [paramsDictionary setObject:preSignedPost.amzDate forKey:@"X-Amz-Date"];
    [paramsDictionary setObject:preSignedPost.amzSignature forKey:@"X-Amz-Signature"];
    [paramsDictionary setObject:preSignedPost.encodedPolicy forKey:@"Policy"];
    NSString *str;

    for (NSString *key in paramsDictionary) {
        [bodyData appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
        [bodyData appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=\"%@\"\r\n\r\n", key] dataUsingEncoding:NSUTF8StringEncoding]];
        [bodyData appendData:[[NSString stringWithFormat:@"%@\r\n", [paramsDictionary objectForKey:key]] dataUsingEncoding:NSUTF8StringEncoding]];
    }

    [bodyData appendData:[[NSString stringWithFormat:@"--%@\r\n", boundary] dataUsingEncoding:NSUTF8StringEncoding]];
    [bodyData appendData:[[NSString stringWithFormat:@"Content-Disposition: form-data; name=%@; filename=%@\r\n", preSignedPost.fileName] dataUsingEncoding:NSUTF8StringEncoding]];
    [bodyData appendData:[@"Content-Type: image/jpeg\r\n\r\n" dataUsingEncoding:NSUTF8StringEncoding]];
    [bodyData appendData:imageData];
    [bodyData appendData:[[NSString stringWithFormat:@"\r\n"] dataUsingEncoding:NSUTF8StringEncoding]];

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