Shiro 的 DefaultPasswordService 线程安全吗？

Question

我可以拥有 DefaultPasswordService 的单个实例并调用它的 encryptPassword() 方法而不用担心线程安全问题吗？

文档没有说明这一点。

Answer 1

是的，你可以。您可以通过 reading the source code:

轻松验证这一点

public String encryptPassword(Object plaintext) {
  Hash hash = hashPassword(plaintext);
  checkHashFormatDurability();
  return this.hashFormat.format(hash);
}

可能发生的最糟糕的事情是 checkHashFormatDurability 方法多次打印警告，但 encryptPassword 方法将始终按预期工作。

但是请注意，DefaultPasswordService 本身不是线程安全的，无论是在构建之后还是在调用 setter 时。因此，在多线程中使用它之前，您需要担心共享实例的safe publication。

Answer 2

很安全。我从以下测试 class:

生成了一个跟踪记录所有方法调用和并发访问的字段

public class TestShiro  implements Runnable {

private static final DefaultPasswordService defaultPasswordService = new DefaultPasswordService();

protected void exec() {
/*  calling 
 * defaultPasswordService.setHashFormat(   new Shiro1CryptFormat() ); 
 * will lead to a data race
 */
    defaultPasswordService.encryptPassword( Thread.currentThread().getName());

}

private AtomicInteger threadCount = new AtomicInteger();

public void test() throws Exception
{
    for(int i = 0; i < 8 ;i++)
    {
        Thread thread = new Thread(this, "First Test Thread " + i);
        this.threadCount.incrementAndGet();
        thread.start();
    }


    while( this.threadCount.get() > 0 )
    {
        Thread.sleep(1000);
    }


    Thread.sleep(10 * 1000);
}


public void run()
{
    exec();
    threadCount.decrementAndGet();

}

public static void main(String[] args) throws Exception
{
     (new TestShiro()).test();
}
}

一个线程的 Trace 如下所示：

com.anarsoft.agent.regression.MultiThreadedOneInstanceTemplate.run
com.anarsoft.agent.regression.TestShiro.exec
org.apache.shiro.authc.credential.DefaultPasswordService.encryptPassword
org.apache.shiro.authc.credential.DefaultPasswordService.hashPassword
org.apache.shiro.authc.credential.DefaultPasswordService.createByteSource
org.apache.shiro.util.ByteSource$Util.bytes
org.apache.shiro.util.ByteSource$Util.isCompatible
org.apache.shiro.util.SimpleByteSource.<init>
org.apache.shiro.codec.CodecSupport.toBytes
org.apache.shiro.codec.CodecSupport.toBytes
org.apache.shiro.authc.credential.DefaultPasswordService.createHashRequest
org.apache.shiro.crypto.hash.SimpleHashRequest.<init>
org.apache.shiro.authc.credential.DefaultPasswordService.hashPassword
    read  from field  org.apache.shiro.authc.credential.DefaultPasswordService.hashService from object 861842890
org.apache.shiro.crypto.hash.SimpleHashRequest.<init>
org.apache.shiro.crypto.hash.DefaultHashService.computeHash
org.apache.shiro.crypto.hash.DefaultHashService.getAlgorithmName
org.apache.shiro.crypto.hash.DefaultHashService.getHashAlgorithmName
    read  from field  org.apache.shiro.crypto.hash.DefaultHashService.algorithmName from object 1033490990
org.apache.shiro.crypto.hash.DefaultHashService.getAlgorithmName
org.apache.shiro.crypto.hash.DefaultHashService.getIterations
org.apache.shiro.crypto.hash.DefaultHashService.getHashIterations
    read  from field  org.apache.shiro.crypto.hash.DefaultHashService.iterations from object 1033490990
org.apache.shiro.crypto.hash.DefaultHashService.getIterations
org.apache.shiro.crypto.hash.DefaultHashService.getPublicSalt
org.apache.shiro.crypto.hash.DefaultHashService.getPrivateSalt
    read  from field  org.apache.shiro.crypto.hash.DefaultHashService.privateSalt from object 1033490990
org.apache.shiro.crypto.hash.DefaultHashService.isGeneratePublicSalt
    read  from field  org.apache.shiro.crypto.hash.DefaultHashService.generatePublicSalt from object 1033490990
org.apache.shiro.crypto.hash.DefaultHashService.getRandomNumberGenerator
    read  from field  org.apache.shiro.crypto.hash.DefaultHashService.rng from object 1033490990
org.apache.shiro.crypto.hash.DefaultHashService.getPublicSalt
org.apache.shiro.crypto.SecureRandomNumberGenerator.nextBytes
org.apache.shiro.crypto.SecureRandomNumberGenerator.getDefaultNextBytesSize
    read  from field  org.apache.shiro.crypto.SecureRandomNumberGenerator.defaultNextBytesSize from object 520016214
org.apache.shiro.crypto.SecureRandomNumberGenerator.nextBytes
org.apache.shiro.crypto.SecureRandomNumberGenerator.nextBytes
org.apache.shiro.crypto.SecureRandomNumberGenerator.nextBytes
    read  from field  org.apache.shiro.crypto.SecureRandomNumberGenerator.secureRandom from object 520016214
org.apache.shiro.crypto.hash.DefaultHashService.getPrivateSalt
    read  from field  org.apache.shiro.crypto.hash.DefaultHashService.privateSalt from object 1033490990
org.apache.shiro.crypto.SecureRandomNumberGenerator.nextBytes
org.apache.shiro.crypto.hash.DefaultHashService.combine
org.apache.shiro.crypto.hash.SimpleHash.<init>
org.apache.shiro.util.StringUtils.hasText
org.apache.shiro.util.StringUtils.hasLength
org.apache.shiro.crypto.hash.SimpleHash.convertSaltToBytes
org.apache.shiro.crypto.hash.SimpleHash.toByteSource
org.apache.shiro.crypto.hash.SimpleHash.convertSourceToBytes
org.apache.shiro.crypto.hash.SimpleHash.toByteSource
org.apache.shiro.crypto.hash.SimpleHash.hash
org.apache.shiro.crypto.hash.SimpleHash.hash
org.apache.shiro.crypto.hash.SimpleHash.getDigest
java.util.HashMap.getNode
    read  from field  java.util.HashMap.table from object 832279283
java.util.HashMap.getNode
    read  from field  java.util.HashMap$Node.hash from object 22805895
java.util.HashMap.getNode
    read  from field  java.util.HashMap$Node.key from object 22805895
java.util.LinkedHashMap.get
    read  from field  java.util.LinkedHashMap.accessOrder from object 832279283
java.util.LinkedHashMap.get
    read  from field  java.util.HashMap$Node.value from object 22805895
java.util.HashMap.getNode
    read  from field  java.util.HashMap.table from object 1924582348
java.util.HashMap.getNode
    read  from field  java.util.HashMap$Node.hash from object 2097514481
java.util.HashMap.getNode
    read  from field  java.util.HashMap$Node.key from object 2097514481
java.util.HashMap.get
    read  from field  java.util.HashMap$Node.value from object 2097514481
org.apache.shiro.crypto.hash.SimpleHash.getDigest
org.apache.shiro.crypto.hash.SimpleHash.setIterations
org.apache.shiro.authc.credential.DefaultPasswordService.checkHashFormatDurability
org.apache.shiro.authc.credential.DefaultPasswordService.checkHashFormatDurability
    read  from field  org.apache.shiro.authc.credential.DefaultPasswordService.hashFormatWarned from object 861842890
org.apache.shiro.authc.credential.DefaultPasswordService.checkHashFormatDurability
    read  from field  org.apache.shiro.authc.credential.DefaultPasswordService.hashFormat from object 861842890
org.apache.shiro.authc.credential.DefaultPasswordService.encryptPassword
    read  from field  org.apache.shiro.authc.credential.DefaultPasswordService.hashFormat from object 861842890
org.apache.shiro.authc.credential.DefaultPasswordService.checkHashFormatDurability
org.apache.shiro.crypto.hash.format.Shiro1CryptFormat.format
org.apache.shiro.util.SimpleByteSource.toBase64
org.apache.shiro.codec.Base64.encodeToString
org.apache.shiro.codec.Base64.encode
org.apache.shiro.codec.Base64.encode
org.apache.shiro.codec.CodecSupport.toString
org.apache.shiro.codec.CodecSupport.toString
org.apache.shiro.crypto.hash.SimpleHash.toBase64
org.apache.shiro.codec.Base64.encodeToString
org.apache.shiro.codec.Base64.encode
org.apache.shiro.codec.Base64.encode
org.apache.shiro.codec.CodecSupport.toString
org.apache.shiro.codec.CodecSupport.toString
com.anarsoft.agent.regression.MultiThreadedOneInstanceTemplate.run
    read  from field  com.anarsoft.agent.regression.MultiThreadedOneInstanceTemplate.threadCount from object 1461149300

所以只有读取，来自创建 DefaultPasswordService 写入的字段。在我的测试中，创建发生在主线程中。

Answer 3

它是线程安全的，因为在加密过程中没有写入 class 成员。

从技术上讲，您确实需要确保在执行 encryptPassword(...) 期间没有调用 setHashService 或 setHashFormat。例如，调用 setHashService(null) 会导致 encryptPassword(...) 引发 NPE。

在实践中，这可能不是问题，因为不太可能有理由在服务启动后更改 HashService 或 HashFormat 运行。

Shiro 的 DefaultPasswordService 线程安全吗？

Is Shiro's DefaultPasswordService thread safe?

java

multithreading

thread-safety

shiro