// Copyright 2018 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.

//:build js && wasm

// This implementation of crypto/rand takes its entropy from the host's
// cryptographically secure generator (crypto.getRandomValues in the browser),
// reached through crypto/internal/sysrand's wasm implementation.

package rand

import (
	"io"

	"crypto/internal/sysrand"
)

func _reader() io.Reader { return &reader{} }

type reader struct{}

func (r *reader) Read(b []byte) (n int32, err error) {
	if len(b) == 0 {
		return 0, nil
	}
	sysrand.Read(b)
	return int32(len(b)), nil
}