java - SecureRandom.getInstanceStrong() 何时抛出 NoSuchAlgorithmException？

Question

方法SecureRandom.getInstanceStrong()声明它可以抛出 NoSuchAlgorithmException，但是文档说:

Every implementation of the Java platform is required to support at least one strong SecureRandom implementation.

什么情况下会抛出这个异常？仅当属性 securerandom.strongAlgorithms 是用户定义且未列出算法时才会发生这种情况吗？

Answer 1

如果 securerandom.strongAlgorithms 配置不正确，似乎确实会引发此异常。未经检查的异常可能是更好的选择。

http://hg.openjdk.java.net/jdk/jdk/file/ac56154f0b9e/src/java.base/share/classes/java/security/SecureRandom.java

if (property == null || property.isEmpty()) {
    throw new NoSuchAlgorithmException(
        "Null/empty securerandom.strongAlgorithms Security Property");
}

...

throw new NoSuchAlgorithmException(
            "No strong SecureRandom impls available: " + property);