Following is the code:
- (IBAction)postBtnTapped:(id)sender {
NSString *accessKey = @"SERVER_ACCESS_KEY";
NSString *secretKey=@"SERVER_SECRET_KEY";
UIImage *img =[[UIImage alloc] initWithContentsOfFile:@"stones.png"];
NSData *data = UIImagePNGRepresentation(img);
NSString *imageDataString = [data base64Encoding]; //// I have used the Category to find out the base64encoded String
NSString *imgWidth = [[NSNumber numberWithFloat:img.size.width] stringValue];
NSDictionary * postDictionary = [NSDictionary dictionaryWithObjectsAndKeys:@"ASW_Image",@"name", img.size.width,@"width" , imageDataString,@"image", nil];
NSError * error = nil;
NSData * jsonData = [NSJSONSerialization dataWithJSONObject:postDictionary options:NSJSONReadingMutableContainers error:&error];
NSMutableURLRequest * urlRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"https://vws.vuforia.com/targets"]];
[urlRequest setHTTPMethod:@"POST"];
[urlRequest setHTTPBody:jsonData];
NSDate *currDate = [NSDate date];
NSString *dateStr = [self getUTCFormateDate:currDate];
NSLog(@"DateFormat: %@",dateStr);
[urlRequest setValue: dateStr forHTTPHeaderField:@"Date"];
[urlRequest setValue:@"application/json" forHTTPHeaderField:@"Content-Type"];
NSString *contentmd5 =@"I am having trouble to find this String in Objective-C"
NSString *dataValue =[NSString stringWithFormat:@"%@\n%@\n%@\n%@\n%@",urlRequest.HTTPMethod,contentmd5,@"application/json",dateStr,urlRequest.URL.path];
NSString *hmacStr = [self HMAC:secretKey :dataValue];
NSString *authStr = [NSString stringWithFormat:@"VWS %@:%@",accessKey,hmacStr];
[urlRequest setValue:authStr forHTTPHeaderField:@"Authorization"];
NSURLConnection * myConnection = [[NSURLConnection alloc] initWithRequest:urlRequest delegate:self startImmediately:YES];
}
-(NSString*)HMAC:(NSString*)key:(NSString*)data{
const char *cKey = [key cStringUsingEncoding:NSASCIIStringEncoding];
const char *cData = [data cStringUsingEncoding:NSASCIIStringEncoding];
unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH];
CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC);
NSData *HMAC = [[NSData alloc] initWithBytes:cHMAC length:sizeof(cHMAC)];
NSString *hash = [HMAC base64Encoding]; //// I have used the Category to find out the base64encoded String
return hash;
}
-(NSString *)getUTCFormateDate:(NSDate *)localDate
{
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:@"UTC"];
[dateFormatter setTimeZone:timeZone];
[dateFormatter setDateFormat:@"EEE',' dd MMM yyyy HH':'mm':'ss 'GMT'"];
NSString *dateString = [dateFormatter stringFromDate:localDate];
return dateString;
}
Please give some time to see the code.Am I doing wrong anything? Also I want to ask what will be the input to find out the contentMD5 string?
DId you guys ever find a solution here?
I've got similar code to above, however I am trying with a GET approach, and therefore remove an chance it is the objective-c MD5 algorithm. As such, I believe that this must be due to the HMAC routine?
If there is anyone on this forum, that knows enough objective-c to validate the signing approach here, that would be of huge assistance. My code is as follows:
- (void) getCloudTargetSummary{ NSDateFormatter *df = [[NSDateFormatter alloc] init]; df.timeZone = [NSTimeZone timeZoneWithAbbreviation:@"GMT"]; df.dateFormat = @"EEE',' dd MMM yyyy HH':'mm':'ss 'GMT'"; NSString *date = [df stringFromDate:[NSDate date]]; NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"%@%@", urlSource, @"/summary"]]; NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration]; NSURLSession *session = [NSURLSession sessionWithConfiguration:config]; NSMutableURLRequest *request = [[NSMutableURLRequest alloc] initWithURL:url]; request.HTTPMethod = @"GET"; [request addValue:date forHTTPHeaderField:@"Date"]; NSString *signature = [self buildSignature: request : secretKey : date]; NSString *signingString = [NSString stringWithFormat:@"VWS %@:%@",accessKey, signature]; NSLog(@"Signing Key = %@",signingString); [request setValue:signingString forHTTPHeaderField:@"Authorization"]; NSURLSessionDataTask *getTask = [session dataTaskWithRequest:request completionHandler:^(NSData *data, NSURLResponse *response, NSError *error) { NSLog(@"Response %@", response); NSLog(@"error %@", error); NSDictionary * json = [NSJSONSerialization JSONObjectWithData:data options:0 error:nil]; NSLog(@"%@",json); }]; [getTask resume]; } - (NSString *) buildSignature : (NSMutableURLRequest *) request : (NSString *) secretKey : (NSString *) date{ NSString *method = [request HTTPMethod]; NSString *contentType = @""; NSString *hexDigest = @"d41d8cd98f00b204e9800998ecf8427e"; // Hex digest of an empty string if ([method isEqualToString:@"GET"] || [method isEqualToString: @"DELETE"]) { // Do nothing because the strings are already set correctly hexDigest = @"d41d8cd98f00b204e9800998ecf8427e"; } else if( [method isEqualToString:@"POST"] || [method isEqualToString:@"PUT"]) { contentType = @"application/json"; NSString *bodyString = [[NSString alloc] initWithData:[request HTTPBody] encoding:NSASCIIStringEncoding]; hexDigest = [self md5HexDigest:bodyString]; NSLog(@"hexDigest%@", hexDigest); } else { NSLog(@"ERROR: Invalid content type passed to Sig Builder"); } NSString *toDigest = [NSString stringWithFormat:@"%@\n%@\n%@\n%@\n%@",method,hexDigest,contentType,date, [request URL].path]; NSLog(@"To Digest: %@", toDigest); return [self getBase64HMAC:toDigest withKey:secretKey]; // return [self HMAC:secretKey :toDigest]; } // NOT BEING USED FOR GET - (NSString*)md5HexDigest:(NSString*)input { const char* str = [input UTF8String]; unsigned char result[CC_MD5_DIGEST_LENGTH]; CC_MD5(str, (int)strlen(str), result); NSMutableString *ret = [NSMutableString stringWithCapacity:CC_MD5_DIGEST_LENGTH*2]; for(int i = 0; i<CC_MD5_DIGEST_LENGTH; i++) { [ret appendFormat:@"%02x",result[i]]; } return ret; } - (NSString*)getBase64HMAC:(NSString*)data withKey:(NSString*)secret { const char *cKey = [secret cStringUsingEncoding:NSASCIIStringEncoding]; const char *cData = [data cStringUsingEncoding:NSASCIIStringEncoding]; unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH]; CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC); NSData *HMAC = [[NSData alloc] initWithBytes:cHMAC length:sizeof(cHMAC)]; // Get NSString from NSData object in Base64 NSString *base64Encoded = [HMAC base64EncodedStringWithOptions:0]; return base64Encoded; }