How to sign a JAR file

Talking about certificates is beyond the scope of this page. Here we present a brief example using the tools keytool and jarsigner included in the Java SDK.

More and better information about these tools can be:

• How to Sign Applets Using RSA-Signed Certificates.
• Signing Code and Granting It Permissions.

Assuming both tools are in the PATH environment variable, the basic steps are:

• Create a certificate, it can be done only once.
• Export the certificate to a file.
• Sign your files with the certificate.

> keytool -genkey -keyalg rsa -alias somename
 Enter pw : ******

> keytool -export -alias somename -file somename.crt

> jarsigner file.jar yourname