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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+
+/*
+** 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 */