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Diffstat (limited to 'nsprpub/pr/include/prrng.h')
-rw-r--r-- | nsprpub/pr/include/prrng.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/nsprpub/pr/include/prrng.h b/nsprpub/pr/include/prrng.h new file mode 100644 index 0000000000..db7dc68c66 --- /dev/null +++ b/nsprpub/pr/include/prrng.h @@ -0,0 +1,75 @@ +/* -*- 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 */ |