Security/libsecurity_apple_csp/lib/YarrowConnection.cpp

   1 /*
   2  * Copyright (c) 2000-2001,2011,2014 Apple Inc. All Rights Reserved.
   3  *
   4  * The contents of this file constitute Original Code as defined in and are
   5  * subject to the Apple Public Source License Version 1.2 (the 'License').
   6  * You may not use this file except in compliance with the License. Please obtain
   7  * a copy of the License at http://www.apple.com/publicsource and read it before
   8  * using this file.
   9  *
  10  * This Original Code and all software distributed under the License are
  11  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESS
  12  * OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, INCLUDING WITHOUT
  13  * LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
  14  * PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. Please see the License for the
  15  * specific language governing rights and limitations under the License.
  16  */
  17
  18
  19 /*
  20  * YarrowConnection.cpp - single, process-wide, thread-safe Yarrow client
  21  */
  22 #include "YarrowConnection.h"
  23 #include <security_utilities/globalizer.h>
  24 #include <security_utilities/devrandom.h>
  25 #include <Security/cssmtype.h>
  26
  27 /* instantiated by C++ runtime at library load/init time */
  28 class YarrowConnection : public DevRandomGenerator {
  29 public:
  30     YarrowConnection() : DevRandomGenerator(getuid() == 0), writable(getuid() == 0) { }
  31     const bool writable;
  32 };
  33
  34 /* the single global thing */
  35 static ModuleNexus<YarrowConnection> yarrowConnection;
  36
  37
  38 /* and the exported functions */
  39 void cspGetRandomBytes(void *buf, unsigned len)
  40 {
  41         yarrowConnection().random(buf, len);
  42 }
  43
  44 void cspAddEntropy(const void *buf, unsigned len)
  45 {
  46     if (yarrowConnection().writable)
  47         yarrowConnection().addEntropy(buf, len);
  48 }