https://wechatpay-api.gitbook.io/wechatpay-api-v3/qian-ming-zhi-nan-1/zheng-shu-he-hui-tiao-bao-wen-jie-mi

解密的代码是文档中的代码，一字未改，密文也是之前的密文，没换过，微信支付后台显示的apiv3更新时间也是最早的更新时间，目前无法解密，是为什么，只有以下报错信息

java.lang.IllegalArgumentException: java.security.InvalidKeyException: Illegal key size

at cn.xxxx.util.AesUtil.decryptToString(AesUtil.java:41)

at cn.xxxx.util.WechatTest.testTousu(WechatTest.java:23)

at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)

at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)

at java.lang.reflect.Method.invoke(Method.java:498)

at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50)

at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)

at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47)

at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)

at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78)

at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57)

at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290)

at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71)

at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288)

at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58)

at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268)

at org.junit.runners.ParentRunner.run(ParentRunner.java:363)

at org.junit.runner.JUnitCore.run(JUnitCore.java:137)

at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)

at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)

at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:230)

at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:58)

Caused by: java.security.InvalidKeyException: Illegal key size

at javax.crypto.Cipher.checkCryptoPerm(Cipher.java:1039)

at javax.crypto.Cipher.implInit(Cipher.java:805)

at javax.crypto.Cipher.chooseProvider(Cipher.java:864)

at javax.crypto.Cipher.init(Cipher.java:1396)

at javax.crypto.Cipher.init(Cipher.java:1327)

at cn.fangline.ant.util.AesUtil.decryptToString(AesUtil.java:34)

... 23 more