im trying to get a call to amazon web service and im stuck on getting the signature, looked at this but i still have a question on it. using this example what is the NSData *keyData; NSData *clearTextData ? what do i need to pass for these two values? /* inputs: NSData *keyData; NSData *clearTextData */ uint8_t digest[CC_SHA1_DIGEST_LENGTH] = {0}; CCHmacContext hmacContext; CCHmacInit(&hmacContext