prrng.h
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- /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
- /* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- * http://www.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is the Netscape Portable Runtime (NSPR).
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 1999-2000
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either the GNU General Public License Version 2 or later (the "GPL"), or
- * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
- /*
- ** prrng.h -- NSPR Random Number Generator
- **
- **
- ** lth. 29-Oct-1999.
- */
- #ifndef prrng_h___
- #define prrng_h___
- #include "prtypes.h"
- PR_BEGIN_EXTERN_C
- /*
- ** PR_GetRandomNoise() -- Get random noise from the host platform
- **
- ** Description:
- ** PR_GetRandomNoise() provides, depending on platform, a random value.
- ** The length of the random value is dependent on platform and the
- ** platform's ability to provide a random value at that moment.
- **
- ** The intent of PR_GetRandomNoise() is to provide a "seed" value for a
- ** another random number generator that may be suitable for
- ** cryptographic operations. This implies that the random value
- ** provided may not be, by itself, cryptographically secure. The value
- ** generated by PR_GetRandomNoise() is at best, extremely difficult to
- ** predict and is as non-deterministic as the underlying platfrom can
- ** provide.
- **
- ** Inputs:
- ** buf -- pointer to a caller supplied buffer to contain the
- ** generated random number. buf must be at least as large as
- ** is specified in the 'size' argument.
- **
- ** size -- the requested size of the generated random number
- **
- ** Outputs:
- ** a random number provided in 'buf'.
- **
- ** Returns:
- ** PRSize value equal to the size of the random number actually
- ** generated, or zero. The generated size may be less than the size
- ** requested. A return value of zero means that PR_GetRandomNoise() is
- ** not implemented on this platform, or there is no available noise
- ** available to be returned at the time of the call.
- **
- ** Restrictions:
- ** Calls to PR_GetRandomNoise() may use a lot of CPU on some platforms.
- ** Some platforms may block for up to a few seconds while they
- ** accumulate some noise. Busy machines generate lots of noise, but
- ** care is advised when using PR_GetRandomNoise() frequently in your
- ** application.
- **
- ** History:
- ** Parts of the model dependent implementation for PR_GetRandomNoise()
- ** were taken in whole or part from code previously in Netscape's NSS
- ** component.
- **
- */
- NSPR_API(PRSize) PR_GetRandomNoise(
- void *buf,
- PRSize size
- );
- PR_END_EXTERN_C
- #endif /* prrng_h___ */
- /* end prrng.h */