eu.europa.ec.eudi.sdjwt.SaltProvider.kt Maven / Gradle / Ivy
/*
* Copyright (c) 2023 European Commission
*
* 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 eu.europa.ec.eudi.sdjwt
import java.security.SecureRandom
/**
* An interface for generating [Salt] values.
*/
fun interface SaltProvider {
/**
* Provides a new [Salt]
* @return a new [Salt] value
*/
fun salt(): Salt
companion object {
/**
* A default implementation of [SaltProvider].
* It produces random [Salt] values of size 16 bytes (128 bits)
*/
val Default: SaltProvider by lazy { randomSaltProvider(16) }
private val secureRandom: SecureRandom = SecureRandom()
/**
* Creates a salt provider which generates random [Salt] values
*
* @param numberOfBytes the size of salt in bytes
*
* @return a salt provider which generates random [Salt] values
*/
fun randomSaltProvider(numberOfBytes: Int): SaltProvider =
SaltProvider {
val randomByteArray: ByteArray = ByteArray(numberOfBytes).also { secureRandom.nextBytes(it) }
JwtBase64.encode(randomByteArray)
}
}
}