Verifying a Signature

 

Verifying a Signature

First

Alice：

alice  Creates a keystore, alice.certs, and generates a key pair with alias alice：

keytool -genkeypair -keystore alice.certs -alias alice

export a certificate file:

keytool -exportcert -keystore alice.certs -alias alice -file alice.cer

Bob：

When Bob receives the certificate, he can print it:

keytool -printcert -file alice.cer

he can import it into his keystore

       keytool -importcert -keystore bob.certs -alias alice -file alice.cer

Second

Now Alice can start sending signed documents to Bob. The jarsigner tool signs and verifies JAR files. Alice simply adds the document to be signed into a JAR file.

jar cvf document.jar document.txt

Then she uses the jarsigner tool to add the signature to the file. She needs to specify the keystore, the JAR file, and the alias of the key to use

       jarsigner -keystore alice.certs document.jar alice

When Bob receives the file, he uses the -verify option of the jarsigner program

       jarsigner -verify -keystore bob.certs document.jar