Ukázka podepisování requestů

gistfile1.m

- (NSString *)signatureWithPlainText:(NSString *)plainText key:(NSString *)key {
  const char *charKey = [key cStringUsingEncoding:NSASCIIStringEncoding];
  const char *charData = [plainText cStringUsingEncoding:NSASCIIStringEncoding];

  unsigned char charHMAC[CC_SHA1_DIGEST_LENGTH];

  CCHmac( kCCHmacAlgSHA1, charKey, strlen( charKey ), charData, strlen( charData ), charHMAC);

  NSData *data = [[NSData alloc] initWithBytes:charHMAC length:sizeof( charHMAC )];
  return [data base64EncodedStringWithOptions:0];
}

- (NSMutableURLRequest *)requestWithMethod:(NSString *)method
                                 URLString:(NSString *)URLString
                                parameters:(id)parameters
                                     error:(NSError *__autoreleasing *)error {

  NSMutableURLRequest *request = [super requestWithMethod:method
                                                URLString:URLString
                                               parameters:parameters
                                                    error:error];

  NSString *nonce = [[NSUUID UUID] UUIDString];

  NSMutableString *message = [@"" mutableCopy];

  if ( request.HTTPBody != nil ) {
    NSString *stringBody = [[NSString alloc] initWithData:request.HTTPBody
                                                 encoding:NSUTF8StringEncoding];
    [message appendString:stringBody];
  }

  NSString *path = request.URL.path;
  if ( path.length > 0 ) {
    [message appendString:path];
  }

  [message appendString:nonce];

  NSString *query = request.URL.query;
  if ( query.length > 0 ) {
    [message appendFormat:@"?%@", query];
  }

  NSData *decodedKeyData = [[NSData alloc] initWithBase64EncodedString:@"base64-klíč-známý-appce-a-serveru"
                                                               options:0];
  NSString *key = [[NSString alloc] initWithData:decodedKeyData encoding:NSUTF8StringEncoding];

  NSString *signature = [self signatureWithPlainText:message key:key];

  [request setValue:nonce forHTTPHeaderField:@"nonce"];
  [request setValue:signature forHTTPHeaderField:@"signature"];

  return request;
}