背景
今天集成JWT的時候，選用了PS256算法，在用使用PGP KEY作為私鑰JWT進行簽名的時候，報了如下錯誤：
"C:\Program Files\Java\jdk1.8.0_161\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 "-javaagent:D:\Program Files\JetBrains\IntelliJ IDEA 2019.1.3\lib\idea_rt.jar=9784:D:\Program Files\JetBrains\IntelliJ IDEA 2019.1.3\bin" -Dfile.encoding=UTF-8 -classpath "D:\Program Files\JetBrains\IntelliJ IDEA 2019.1.3\lib\idea_rt.jar;D:\Program Files\JetBrains\IntelliJ IDEA 2019.1.3\plugins\junit\lib\junit-rt.jar;D:\Program Files\JetBrains\IntelliJ IDEA 2019.1.3\plugins\junit\lib\junit5-rt.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\charsets.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\deploy.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\access-bridge-64.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\cldrdata.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\dnsns.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\jaccess.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\jfxrt.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\localedata.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\nashorn.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\sunec.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\sunjce_provider.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\sunmscapi.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\sunpkcs11.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\ext\zipfs.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\javaws.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\jce.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\jfr.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\jfxswt.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\jsse.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\management-agent.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\plugin.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\resources.jar;C:\Program Files\Java\jdk1.8.0_161\jre\lib\rt.jar;D:\Repository\project\eshare-openpgp-examples\target\test-classes;D:\Repository\project\eshare-openpgp-examples\target\classes;D:\Users\10856214\.m2\org\springframework\boot\spring-boot-starter\2.1.6.RELEASE\spring-boot-starter-2.1.6.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\boot\spring-boot\2.1.6.RELEASE\spring-boot-2.1.6.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\spring-context\5.1.8.RELEASE\spring-context-5.1.8.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\boot\spring-boot-autoconfigure\2.1.6.RELEASE\spring-boot-autoconfigure-2.1.6.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\boot\spring-boot-starter-logging\2.1.6.RELEASE\spring-boot-starter-logging-2.1.6.RELEASE.jar;D:\Users\10856214\.m2\ch\qos\logback\logback-classic\1.2.3\logback-classic-1.2.3.jar;D:\Users\10856214\.m2\ch\qos\logback\logback-core\1.2.3\logback-core-1.2.3.jar;D:\Users\10856214\.m2\org\apache\logging\log4j\log4j-to-slf4j\2.11.2\log4j-to-slf4j-2.11.2.jar;D:\Users\10856214\.m2\org\apache\logging\log4j\log4j-api\2.11.2\log4j-api-2.11.2.jar;D:\Users\10856214\.m2\org\slf4j\jul-to-slf4j\1.7.26\jul-to-slf4j-1.7.26.jar;D:\Users\10856214\.m2\javax\annotation\javax.annotation-api\1.3.2\javax.annotation-api-1.3.2.jar;D:\Users\10856214\.m2\org\springframework\spring-core\5.1.8.RELEASE\spring-core-5.1.8.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\spring-jcl\5.1.8.RELEASE\spring-jcl-5.1.8.RELEASE.jar;D:\Users\10856214\.m2\org\yaml\snakeyaml\1.23\snakeyaml-1.23.jar;D:\Users\10856214\.m2\org\springframework\boot\spring-boot-starter-test\2.1.6.RELEASE\spring-boot-starter-test-2.1.6.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\boot\spring-boot-test\2.1.6.RELEASE\spring-boot-test-2.1.6.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\boot\spring-boot-test-autoconfigure\2.1.6.RELEASE\spring-boot-test-autoconfigure-2.1.6.RELEASE.jar;D:\Users\10856214\.m2\com\jayway\jsonpath\json-path\2.4.0\json-path-2.4.0.jar;D:\Users\10856214\.m2\net\minidev\json-smart\2.3\json-smart-2.3.jar;D:\Users\10856214\.m2\net\minidev\accessors-smart\1.2\accessors-smart-1.2.jar;D:\Users\10856214\.m2\org\ow2\asm\asm\5.0.4\asm-5.0.4.jar;D:\Users\10856214\.m2\org\slf4j\slf4j-api\1.7.26\slf4j-api-1.7.26.jar;D:\Users\10856214\.m2\junit\junit\4.12\junit-4.12.jar;D:\Users\10856214\.m2\org\assertj\assertj-core\3.11.1\assertj-core-3.11.1.jar;D:\Users\10856214\.m2\org\mockito\mockito-core\2.23.4\mockito-core-2.23.4.jar;D:\Users\10856214\.m2\net\bytebuddy\byte-buddy\1.9.13\byte-buddy-1.9.13.jar;D:\Users\10856214\.m2\net\bytebuddy\byte-buddy-agent\1.9.13\byte-buddy-agent-1.9.13.jar;D:\Users\10856214\.m2\org\objenesis\objenesis\2.6\objenesis-2.6.jar;D:\Users\10856214\.m2\org\hamcrest\hamcrest-core\1.3\hamcrest-core-1.3.jar;D:\Users\10856214\.m2\org\hamcrest\hamcrest-library\1.3\hamcrest-library-1.3.jar;D:\Users\10856214\.m2\org\skyscreamer\jsonassert\1.5.0\jsonassert-1.5.0.jar;D:\Users\10856214\.m2\com\vaadin\external\google\android-json\0.0.20131108.vaadin1\android-json-0.0.20131108.vaadin1.jar;D:\Users\10856214\.m2\org\springframework\spring-test\5.1.8.RELEASE\spring-test-5.1.8.RELEASE.jar;D:\Users\10856214\.m2\org\xmlunit\xmlunit-core\2.6.2\xmlunit-core-2.6.2.jar;D:\Users\10856214\.m2\org\springframework\boot\spring-boot-devtools\2.1.6.RELEASE\spring-boot-devtools-2.1.6.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\boot\spring-boot-starter-web\2.1.6.RELEASE\spring-boot-starter-web-2.1.6.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\boot\spring-boot-starter-json\2.1.6.RELEASE\spring-boot-starter-json-2.1.6.RELEASE.jar;D:\Users\10856214\.m2\com\fasterxml\jackson\datatype\jackson-datatype-jdk8\2.9.9\jackson-datatype-jdk8-2.9.9.jar;D:\Users\10856214\.m2\com\fasterxml\jackson\datatype\jackson-datatype-jsr310\2.9.9\jackson-datatype-jsr310-2.9.9.jar;D:\Users\10856214\.m2\com\fasterxml\jackson\module\jackson-module-parameter-names\2.9.9\jackson-module-parameter-names-2.9.9.jar;D:\Users\10856214\.m2\org\springframework\boot\spring-boot-starter-tomcat\2.1.6.RELEASE\spring-boot-starter-tomcat-2.1.6.RELEASE.jar;D:\Users\10856214\.m2\org\apache\tomcat\embed\tomcat-embed-core\9.0.21\tomcat-embed-core-9.0.21.jar;D:\Users\10856214\.m2\org\apache\tomcat\embed\tomcat-embed-el\9.0.21\tomcat-embed-el-9.0.21.jar;D:\Users\10856214\.m2\org\apache\tomcat\embed\tomcat-embed-websocket\9.0.21\tomcat-embed-websocket-9.0.21.jar;D:\Users\10856214\.m2\org\hibernate\validator\hibernate-validator\6.0.17.Final\hibernate-validator-6.0.17.Final.jar;D:\Users\10856214\.m2\javax\validation\validation-api\2.0.1.Final\validation-api-2.0.1.Final.jar;D:\Users\10856214\.m2\org\jboss\logging\jboss-logging\3.3.2.Final\jboss-logging-3.3.2.Final.jar;D:\Users\10856214\.m2\com\fasterxml\classmate\1.4.0\classmate-1.4.0.jar;D:\Users\10856214\.m2\org\springframework\spring-web\5.1.8.RELEASE\spring-web-5.1.8.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\spring-beans\5.1.8.RELEASE\spring-beans-5.1.8.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\spring-webmvc\5.1.8.RELEASE\spring-webmvc-5.1.8.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\spring-aop\5.1.8.RELEASE\spring-aop-5.1.8.RELEASE.jar;D:\Users\10856214\.m2\org\springframework\spring-expression\5.1.8.RELEASE\spring-expression-5.1.8.RELEASE.jar;D:\Users\10856214\.m2\org\bouncycastle\bcpg-jdk15on\1.62\bcpg-jdk15on-1.62.jar;D:\Users\10856214\.m2\org\bouncycastle\bcprov-jdk15on\1.62\bcprov-jdk15on-1.62.jar;D:\Users\10856214\.m2\commons-io\commons-io\2.4\commons-io-2.4.jar;D:\Users\10856214\.m2\org\apache\commons\commons-lang3\3.4\commons-lang3-3.4.jar;D:\Users\10856214\.m2\io\jsonwebtoken\jjwt-api\0.10.7\jjwt-api-0.10.7.jar;D:\Users\10856214\.m2\io\jsonwebtoken\jjwt-impl\0.10.7\jjwt-impl-0.10.7.jar;D:\Users\10856214\.m2\io\jsonwebtoken\jjwt-jackson\0.10.7\jjwt-jackson-0.10.7.jar;D:\Users\10856214\.m2\com\fasterxml\jackson\core\jackson-databind\2.9.9\jackson-databind-2.9.9.jar;D:\Users\10856214\.m2\com\fasterxml\jackson\core\jackson-annotations\2.9.0\jackson-annotations-2.9.0.jar;D:\Users\10856214\.m2\com\fasterxml\jackson\core\jackson-core\2.9.9\jackson-core-2.9.9.jar" com.intellij.rt.execution.junit.JUnitStarter -ideVersion5 -junit4 com.eshare.examples.JwtExampleTest,testJWTSigningAndVerify
io.jsonwebtoken.security.WeakKeyException: The signing key's size is 1024 bits which is not secure enough for the PS256 algorithm. The JWT JWA Specification (RFC 7518, Section 3.5) states that keys used with PS256 MUST have a size >= 2048 bits. Consider using the io.jsonwebtoken.security.Keys class's 'keyPairFor(SignatureAlgorithm.PS256)' method to create a key pair guaranteed to be secure enough for PS256. See https://tools.ietf.org/html/rfc7518#section-3.5 for more information.
at io.jsonwebtoken.SignatureAlgorithm.assertValid(SignatureAlgorithm.java:424)
at io.jsonwebtoken.SignatureAlgorithm.assertValidSigningKey(SignatureAlgorithm.java:302)
at io.jsonwebtoken.impl.DefaultJwtBuilder.signWith(DefaultJwtBuilder.java:123)
at com.eshare.examples.JwtExampleTest.testJWTSigningAndVerify(JwtExampleTest.java:64)
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$2.evaluate(ParentRunner.java:268)
at org.junit.runners.ParentRunner.run(ParentRunner.java:363)
at org.junit.runner.JUnitCore.run(JUnitCore.java:137)
at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)
Process finished with exit code -1
代碼如下:
//Generate jwt token
String jwtToken = Jwts.builder()
.setIssuer("me")
.setSubject("Bob")
.setAudience("you").signWith(privateKey,
SignatureAlgorithm.PS256)
.setId(UUID.randomUUID().toString()).compact();
//Verify singing
Jwts.parser()
.setSigningKey(publicKey) // <---- publicKey, not privateKey
.parseClaimsJws(jwtToken);
解決方案
經排查，這問題是因為選用了PS256算法后，對安全要求更高了，原有的RSA算法私鑰長度1024已經不符合要求，因此假如要使用該算法進行加密，需要重新更換秘鑰長度，在生成RSA密鑰對的時候，把keySize改為2048或者更高。
