github.com/dorkamotorka/go/src@v0.0.0-20230614113921-187095f0e316/crypto/rand/rand_windows.go (about)

     1  // Copyright 2010 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Windows cryptographically secure pseudorandom number
     6  // generator.
     7  
     8  package rand
     9  
    10  import (
    11  	"internal/syscall/windows"
    12  )
    13  
    14  func init() { Reader = &rngReader{} }
    15  
    16  type rngReader struct{}
    17  
    18  func (r *rngReader) Read(b []byte) (n int, err error) {
    19  	// RtlGenRandom only returns 1<<32-1 bytes at a time. We only read at
    20  	// most 1<<31-1 bytes at a time so that  this works the same on 32-bit
    21  	// and 64-bit systems.
    22  	if err := batched(windows.RtlGenRandom, 1<<31-1)(b); err != nil {
    23  		return 0, err
    24  	}
    25  	return len(b), nil
    26  }