base/SecRandom.h

   1 /*
   2  * Copyright (c) 2007-2009,2011-2013,2016 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      @header SecRandom
  26      The functions provided in SecRandom.h implement high-level accessors
  27      to cryptographically secure random numbers.
  28 */
  29
  30 #ifndef _SECURITY_SECRANDOM_H_
  31 #define _SECURITY_SECRANDOM_H_
  32
  33 #include <Security/SecBase.h>
  34 #include <stdint.h>
  35 #include <sys/types.h>
  36
  37 __BEGIN_DECLS
  38
  39 CF_ASSUME_NONNULL_BEGIN
  40 CF_IMPLICIT_BRIDGING_ENABLED
  41
  42 /*!
  43     @typedef SecRandomRef
  44     @abstract Reference to a (pseudo) random number generator.
  45 */
  46 typedef const struct __SecRandom * SecRandomRef;
  47
  48 /* This is a synonym for NULL, if you'd rather use a named constant.   This
  49    refers to a cryptographically secure random number generator.  */
  50 extern const SecRandomRef kSecRandomDefault
  51     __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_2_0);
  52
  53 /*!
  54      @function SecRandomCopyBytes
  55
  56      @abstract
  57      Return count random bytes in *bytes, allocated by the caller. It
  58      is critical to check the return value for error.
  59
  60      @param rnd
  61      Only @p kSecRandomDefault is supported.
  62
  63      @param count
  64      The number of bytes to generate.
  65
  66      @param bytes
  67      A buffer to fill with random output.
  68
  69      @result Return 0 on success, any other value on failure.
  70
  71      @discussion
  72      If @p rnd is unrecognized or unsupported, @p kSecRandomDefault is
  73      used.
  74 */
  75 int SecRandomCopyBytes(SecRandomRef __nullable rnd, size_t count, void *bytes)
  76     __attribute__ ((warn_unused_result))
  77     __OSX_AVAILABLE_STARTING(__MAC_10_7, __IPHONE_2_0);
  78
  79 CF_IMPLICIT_BRIDGING_DISABLED
  80 CF_ASSUME_NONNULL_END
  81
  82 __END_DECLS
  83
  84 #endif /* !_SECURITY_SECRANDOM_H_ */