Check the Validity of a Signed JAR File

Use the command jarsigner -verify -verbose -certs *.jar to see the validity and other details of the signed jar files. JDK should be installed on your system and you need to run the command from the JDK bin directory.

Here I have checked the validity of the jar file named pdfwebsigner.jar. Open the command prompt (cmd) as an administrator and go to the bin directory of the installed JDK and run the below command with the jar file.

C:\Program Files (x86)\Java\jdk1.8.0_171\bin>jarsigner -verify -verbose -certs c:\Users\5183\Desktop\Signed_jar_2018\pdfwebsigner.jar

The output of the above command shown below which shows that the jar file was signed on 27.04.2018 and the jar is valid from 27/4/18 5:30 AM to 7/5/21 5:29 AM.

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 [entry was signed on 27/4/18 5:25 PM]
      X.509, CN=eMudhra Limited, OU=Technology, O=eMudhra Limited, L=Bangalore, ST=Karnataka, C=IN
      [certificate is valid from 27/4/18 5:30 AM to 7/5/21 5:29 AM]
      X.509, CN=Symantec Class 3 SHA256 Code Signing CA - G2, OU=Symantec Trust Network, O=Symantec Corporation, C=US
      [certificate is valid from 22/7/14 5:30 AM to 22/7/24 5:29 AM]
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Note: I have checked the validity of the above jar file on Microsoft Windows 10 system with JDK 1.8.