org.apache.shiro.crypto.CryptoException: Unable to execute 'doFinal' with cipher instance [javax.crypto.Cipher@77a2823e].    at org.apache.shiro.crypto.JcaCipherService.crypt(JcaCipherService.java:462) ~[shiro-core-1.4.0.jar:1.4.0]    at org.apache.shiro.crypto.JcaCipherService.crypt(JcaCipherService.java:445) ~[shiro-core-1.4.0.jar:1.4.0]    at org.apache.shiro.crypto.JcaCipherService.decrypt(JcaCipherService.java:390) ~[shiro-core-1.4.0.jar:1.4.0]    at org.apache.shiro.crypto.JcaCipherService.decrypt(JcaCipherService.java:382) ~[shiro-core-1.4.0.jar:1.4.0]    at org.apache.shiro.mgt.AbstractRememberMeManager.decrypt(AbstractRememberMeManager.java:482) ~[shiro-core-1.4.0.jar:1.4.0]    at org.apache.shiro.mgt.AbstractRememberMeManager.convertBytesToPrincipals(AbstractRememberMeManager.java:419) ~[shiro-core-1.4.0.jar:1.4.0]    at org.apache.shiro.mgt.AbstractRememberMeManager.getRememberedPrincipals(AbstractRememberMeManager.java:386) ~[shiro-core-1.4.0.jar:1.4.0]    at org.apache.shiro.mgt.DefaultSecurityManager.getRememberedIdentity(DefaultSecurityManager.java:612) [shiro-core-1.4.0.jar:1.4.0]    at org.apache.shiro.mgt.DefaultSecurityManager.resolvePrincipals(DefaultSecurityManager.java:500) [shiro-core-1.4.0.jar:1.4.0]    at org.apache.shiro.mgt.DefaultSecurityManager.createSubject(DefaultSecurityManager.java:346) [shiro-core-1.4.0.jar:1.4.0]    at org.apache.shiro.subject.Subject$Builder.buildSubject(Subject.java:845) [shiro-core-1.4.0.jar:1.4.0]    at org.apache.shiro.web.subject.WebSubject$Builder.buildWebSubject(WebSubject.java:148) [shiro-web-1.4.0.jar:1.4.0]    at org.apache.shiro.web.servlet.AbstractShiroFilter.createSubject(AbstractShiroFilter.java:292) [shiro-web-1.4.0.jar:1.4.0]    at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:359) [shiro-web-1.4.0.jar:1.4.0]    at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:125) [shiro-web-1.4.0.jar:1.4.0]    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) [spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-5.1.5.RELEASE.jar:5.1.5.RELEASE]    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:200) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:834) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1415) [tomcat-embed-core-9.0.16.jar:9.0.16]    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.16.jar:9.0.16]    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_201]    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_201]    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.16.jar:9.0.16]    at java.lang.Thread.run(Thread.java:748) [na:1.8.0_201]Caused by: javax.crypto.BadPaddingException: Given final block not properly padded. Such issues can arise if a bad key is used during decryption.    at com.sun.crypto.provider.CipherCore.unpad(CipherCore.java:975) ~[sunjce_provider.jar:1.8.0_201]    at com.sun.crypto.provider.CipherCore.fillOutputBuffer(CipherCore.java:1056) ~[sunjce_provider.jar:1.8.0_201]    at com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:853) ~[sunjce_provider.jar:1.8.0_201]    at com.sun.crypto.provider.AESCipher.engineDoFinal(AESCipher.java:446) ~[sunjce_provider.jar:1.8.0_201]    at javax.crypto.Cipher.doFinal(Cipher.java:2164) ~[na:1.8.0_191]    at org.apache.shiro.crypto.JcaCipherService.crypt(JcaCipherService.java:459) ~[shiro-core-1.4.0.jar:1.4.0]    ... 36 common frames omitted

　每次登陆都会报这个错误，尝试了很多次都没解决，代码重编译后清除浏览器cookie登陆就会出现这个报错，虽然不影响登陆但是看着很不爽！！！！

问题产生的原因是rememberMe的cookie在第二次打开页面后shiro无法解密，经过查询资料以及代码跟踪

发现了原因所在

先附上rememberMe管理器配置

@Beanpublic CookieRememberMeManager cookieRememberMeManager() {    CookieRememberMeManager cookieRememberMeManager = new CookieRememberMeManager();    SimpleCookie simpleCookie = new SimpleCookie("rememberMe");    simpleCookie.setMaxAge(259200000);    cookieRememberMeManager.setCookie(simpleCookie);    return cookieRememberMeManager;}

然后跟踪管理器源码发现，rememberMeManager继承了AbstractRememberMeManager，然而AbstractRememberMeManager的构造方法中每次都会重新生成对称加密密钥！！！！意味着每次重启程序都会重新生成一对加解密密钥！！！

public AbstractRememberMeManager() {　　this.serializer = new DefaultSerializer
     
      ();　　AesCipherService cipherService = new AesCipherService();　　this.cipherService = cipherService;　　setCipherKey(cipherService.generateNewKey().getEncoded());}public void setCipherKey(byte[] cipherKey) {　　//Since this method should only be used in symmetric ciphers　　//(where the enc and dec keys are the same), set it on both:　　setEncryptionCipherKey(cipherKey);　　setDecryptionCipherKey(cipherKey);}
     

这就会导致了，第一次启动程序shiro使用A密钥加密了cookie，第二次启动程序shiro重新生成了密钥B，当用户访问页面时，shiro会用密钥B去解密上一次用密钥A加密的cookie，导致解密失败，导致报错，所以这不影响用户登录操作(rememberMe失效罢了)，所以这种异常只会在程序重启(shiro清除session)第一次打开页面的时候出现

解决办法：

既然每次重启都会重新生成一对密钥，那我们就手动设置一个加解密密钥

主动设置cipherkey！！

xml配置方式

springboot代码配置方式

@Beanpublic CookieRememberMeManager cookieRememberMeManager() {　　CookieRememberMeManager cookieRememberMeManager = new CookieRememberMeManager();　　SimpleCookie simpleCookie = new SimpleCookie("rememberMe");　　simpleCookie.setMaxAge(259200000);　　cookieRememberMeManager.setCookie(simpleCookie);　　cookieRememberMeManager.setCipherKey(Base64.decode("6ZmI6I2j5Y+R5aSn5ZOlAA=="));return cookieRememberMeManager;