1  /*
 2   * Copyright (c) 2010-2011,2014 Apple Inc. All Rights Reserved.
 3   *
 4   * @APPLE_LICENSE_HEADER_START@
 5   * 
 6   * This file contains Original Code and/or Modifications of Original Code
 7   * as defined in and that are subject to the Apple Public Source License
 8   * Version 2.0 (the 'License'). You may not use this file except in
 9   * compliance with the License. Please obtain a copy of the License at
10   * http://www.opensource.apple.com/apsl/ and read it before using this
11   * file.
12   * 
13   * The Original Code and all software distributed under the License are
14   * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
15   * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
16   * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
17   * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
18   * Please see the License for the specific language governing rights and
19   * limitations under the License.
20   * 
21   * @APPLE_LICENSE_HEADER_END@
22   */
23  
24  
25  #include "SecTransform.h"
26  #include "SecCustomTransform.h"
27  #include "SecExternalSourceTransform.h"
28  #include <dispatch/dispatch.h>
29  
30  CFStringRef external_source_name = CFSTR("com.apple.security.external_source");
31  
32  static SecTransformInstanceBlock SecExternalSourceTransformCreateBlock(CFStringRef name, SecTransformRef newTransform, SecTransformImplementationRef ref)
33  {
34  	return Block_copy(^{ 
35  		SecTransformCustomSetAttribute(ref, kSecTransformInputAttributeName, kSecTransformMetaAttributeRequired, kCFBooleanFalse);
36  		
37  		SecTransformAttributeRef out = SecTranformCustomGetAttribute(ref, kSecTransformOutputAttributeName, kSecTransformMetaAttributeRef);
38  		
39  		SecTransformSetAttributeAction(ref, kSecTransformActionAttributeNotification, kSecTransformInputAttributeName, ^(SecTransformAttributeRef attribute, CFTypeRef value) {
40  			SecTransformCustomSetAttribute(ref, out, kSecTransformMetaAttributeValue, value);
41  			return (CFTypeRef)NULL;
42  		});
43  		
44  		return (CFErrorRef)NULL;
45  	});
46  }
47  
48  SecTransformRef SecExternalSourceTransformCreate(CFErrorRef* error)
49  {
50  	static dispatch_once_t once;
51  	dispatch_once(&once, ^{
52  		SecTransformRegister(external_source_name, SecExternalSourceTransformCreateBlock, error);
53  	});
54  	
55  	return SecTransformCreate(external_source_name, error);
56  }