| // Copyright 2010 The Go Authors.  All rights reserved. | 
 | // Use of this source code is governed by a BSD-style | 
 | // license that can be found in the LICENSE file. | 
 |  | 
 | // Package rand implements a cryptographically secure | 
 | // pseudorandom number generator. | 
 | package rand | 
 |  | 
 | import "io" | 
 |  | 
 | // Reader is a global, shared instance of a cryptographically | 
 | // strong pseudo-random generator. | 
 | // On Unix-like systems, Reader reads from /dev/urandom. | 
 | // On Windows systems, Reader uses the CryptGenRandom API. | 
 | var Reader io.Reader | 
 |  | 
 | // Read is a helper function that calls Reader.Read using io.ReadFull. | 
 | // On return, n == len(b) if and only if err == nil. | 
 | func Read(b []byte) (n int, err error) { | 
 | 	return io.ReadFull(Reader, b) | 
 | } |