WSuppose that you are Ruth and have received from Stan Smith
- The signed JAR file
sContract.jar
containing a contract
- The file
StanSmith.cer
containing the public key certificate for the public key corresponding to the private key used to sign the JAR fileBefore you can use the
jarsigner
tool to check the authenticity of the JAR file's signature, you need to import Stan's certificate into your keystore.Even though you (acting as Stan) created these files and they haven't actually been transported anywhere, you can simulate being someone other than the creater and sender, Stan. Acting as Ruth, type the following command to create a keystore named
ruthstore
and import the certificate into an entry with an alias ofstan
.Since the keystore doesn't yet exist,keytool -import -alias stan -file StanSmith.cer -keystore ruthstorekeytool
will create it for you. It will prompt you for a keystore password.The
keytool
prints the certificate information and asks you to verify it; For example, by comparing the displayed certificate fingerprints with those obtained from another (trusted) source of information. (Each fingerprint is a relatively short number that uniquely and reliably identifies the certificate.) For example, in the real world you can phone Stan and ask him what the fingerprints should be. He can get the fingerprints of theStanSmith.cer
file he created by executing the commandIf the fingerprints he sees are the same as the ones reported to you bykeytool -printcert -file StanSmith.cerkeytool
, then you both can assume that the certificate has not been modified in transit. You can safely letkeytool
procede to place a "trusted certificate" entry into your keystore. This entry contains the public key certificate data from the fileStanSmith.cer
.keytool
assigns the aliasstan
to this new entry.