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SecureRandom.scala
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SecureRandom.scala
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/*
* Copyright 2021 Typelevel
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package bobcats.unsafe
import bobcats.facade
import java.util.Random
import scala.scalajs.js
import scodec.bits.ByteVector
final class SecureRandom extends Random {
private def nextBytes(numBytes: Int): js.typedarray.Uint8Array =
if (facade.isNodeJSRuntime)
facade.node.crypto.randomBytes(numBytes)
else
facade.browser.crypto.getRandomValues(new js.typedarray.Uint8Array(numBytes))
override def nextBytes(bytes: Array[Byte]): Unit =
ByteVector.view(nextBytes(bytes.length)).copyToArray(bytes, 0)
// Java's SecureRandom overrides this and thus so do we
override protected final def next(numBits: Int): Int = {
val numBytes = (numBits + 7) / 8;
val b = new js.typedarray.Int8Array(nextBytes(numBytes).buffer);
var next = 0;
var i = 0
while (i < numBytes) {
next = (next << 8) + (b(i) & 0xff)
i += 1
}
next >>> (numBytes * 8 - numBits);
}
}