# PR_GetRandomNoise

Produces a random value for use as a seed value for another random
number generator.

## Syntax

```{code}
#include <prrng.h>

NSPR_API(PRSize) PR_GetRandomNoise(
   void    *buf,
   PRSize  size
);
```

### Parameters

The function has these parameters:

`buf`

: A pointer to a caller-supplied buffer to contain the generated random
  number. `buf` must be at least as large as specified in `size`.

`size`

: The size, in bytes, of the requested random number.

### Returns

{ref}`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 {ref}`PR_GetRandomNoise` is
not implemented on this platform, or there is no available noise to be
returned at the time of the call.

## Description

{ref}`PR_GetRandomNoise` provides a random value, depending on platform.
The length of the random value is dependent on the platform and its
ability to provide a random value at that moment.

{ref}`PR_GetRandomNoise` is intended 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
{ref}`PR_GetRandomNoise` is at best, extremely difficult to predict and is
as nondeterministic as the underlying platform permits.