Signing jar in Java, I have followed these three step to sign
keytool -genkey -keystore myKeyStore -alias me
keytool -selfcert -keystore myKeyStore -alias me
jarsigner -keystore myKeyStore jarfile.jar me
My questions are as follows :
After that I have run my applet, why it shows author is unknown?
I can able to give -validity no of days for my jar, what is the maximum days I can give?
The certificate you have created is a self-signed one. Only certificates that has been signed by one of the trust centers marked as trusted in the Java settings are shown as "verified author".
The validity does not have anything to to how long your JAR file will work. The validity period only marks the time you can use the certificate (or better the private key that belongs to the certificate) for signing
As noted in the keytool Validity Period,
Each certificate is valid only for a limited amount of time. This period is described by a start date and time and an end date and time, and can be as short as a few seconds or almost as long as a century.
As Both #Andrew and #Robert note, professional software requires a professionally signed certificate. For casual use, a self-signed certificate can be used among people who share another channel of trust. It can also aid in rejecting a false claim of misprision.
A writes an open source program, signed A.
B adds malware and, unable to sign A, signs B.
C mistakenly obtains B's version and accuses A of the crime.
A can verify that tampering has occurred.
It shows as 'Author unknown' unless the digital certificate is certified by a key chain back to a CA (certification authority) such as Verisign. The problem with the 'self signed' certificate is that while you can create a certificate that claims you are who you are, other people can also make certificates that claim they are who you are. Since one 'self-signed' certificate is as good as the next to positively identify you (I.E. worthless), the JRE states 'author unknown'.
I am not sure, though I recall using 5000 days in previous certificates. Perhaps the real question is, how long is it worth claiming you are who you are, on a certificate that the JRE will never trust enough to even show the identity? If this is for a commercial product, I strongly recommend getting the verification done (it can be expensive). It would not hurt even for a widely distributed free product.
Related
UPDATE: After I have found a solution, I edited the question to be more clear for future reference.
I've got a corporate (ie not well known) CA certificate from a company which provides us a web services to be called from Java. I added this CA certificate to default cacerts trust store (keytool -import -file cert.cer -alias myca -keystore jre/lib/security/cacerts), but connection to the service still fails with the dreaded "PKIX path building failed" message. I have checked that issuer field of the end server certificate is the same as in the CA certificate and also validity dates is ok.
I don't know how to explain this. I can think of the following reasons but I don't know which one is true:
I have noticed that when I add also the end server certificate to trust store, the connection is OK. Maybe cacerts by design don't work as I expect (ie all the certificates signed by an authority added there are considered valid), but instead I have to add all the end server certificates to a trust store including CA certificate of their issuer.
I have to add CA certificate in some other way - by different command, to different file etc.
Maybe the CA certificate is not correct and keytool refuses to consider it a certificate authority.
Maybe PKIX path building fails for other reason.
How can I debug this problem more to find an answer?
Details:
The end server certificate is wildcard certificate
There is no intermediate certificate, just root and the end certificate
I was facing the same problem with "PKIX path building failed" with Let's Encrypt signed certificates at a time Java didn't incorporate the Let's encrypt CA certificate in its default trust store.
My story is written in detail here: http://blog.novoj.net/2016/02/29/how-to-make-apache-httpclient-trust-lets-encrypt-certificate-authority/
At the end I was able to make Java trust "the end of the chain" server certificate by creating internal trust store embedded in my application that contains only root CA certificate (and the backup one).
I much more prefer creating internal application truststore than importing certificate in main Java trust store for two reasons:
you don't need another extra step in install procedure for initializing the global trust store
you limit "the trust" to you application and don't affect another applications running on the same JVM (or better you can even limit the trust to the certain instances of client objects in your application if required)
Maybe I had a different scenario than you're facing, so downvote me if I didn't get the point.
The trust store needs to contain the root certificate (the CA's cert).
I'm not sure if that's what you mean by "the last one I'm the chain", but the CA certificate should be the last one in the certificate chain presented by the server.
If your certificate is signed by a well-known CA, then the CA cert should be in the trust store, and if the server's certificate chain is set up properly, everything should just work.
If yours is a self-signed certificate, then the root certificate will not be in the trust store, and you will have to add it.
Thanks to #pedrofb comment I found out that the reason PKIX path fails is simply that the CA certificate I got is not the CA that signed the end certificate. What made it so complicated is the monstrous incompetence of company that gave me the CA certificate which obviously has two CAs with almost the same description (cn, o, st, c) which differs only in SN and which both issued the same wildcard certificate. Only after I became super paranoid and compared the SNs, I understood the problem.
The server has changed from http to https. Instead of modifying client code (of course the host which was http is now https), we use keytool to save server CA. When I used keytool, I see a list of all stored CA (about 100 pieces).
So how does JRE know which CA to use? And what is the story behind this, like why when JRE is configured with a CA the client code could remain the same?
Thanks.
I'm trying to answer the basic questions you pose.
Java and Keytool know which CAs to trust by consulting a special file named cacerts which is shipped with the JRE and it's placed in <JRE_HOME>/lib/security.
This kind of file is usually called KeyStore or TrustStore.
This file is shipped by default by the "creator" of the JRE (e.g. Oracle) and contains list of Certificate Authority certificates to be trusted (usually updated at every release).
It's not that different from the same process for browsers.
As for the story behind this, if I understand correctly, we are talking about PKI (Public Key Infrastructure) which, in you case, very roughly, means that when your JRE keystore gets updated with the new CA certificate, then entities (such as SSL Sites, applets,etc) presenting a certificate provided (usually sold) by that CA are now basically valid and trusted, since now a trusted third party (the new CA) can guarantee (by means of encryption and digital signature) that "you are effectively you" in a digital scenario.
Also worth noting that, Keytool can be instructed to use a user-defined keystore with the -keystore <keystore_path> command line option (and even the JVM can configure a specific non-default truststore for SSL connection via a system property like this)
I developed an application that uses Java Webstart. It needs write access to the disk so it has to be signed, but it would only be used by a limited group of users so I don't want to pay for a trusted certificate.
What is the easiest option to let the users trust my application/self signed certificate? I don't want them to use keytool because it is not really user friendly. I though about creating a certificate that can be imported via the Java Control Panel and first tried creating an importable certificate using the following commands:
keytool -genkeypair -keystore patrickgotthard.jks -alias patrickgotthard
keytool -exportcert -keystore patrickgotthard.jks -alias patrickgotthard -file patrickgotthard.cer
But it is not possible to import the generated .cer file. Then I found Cannot import certificate into java control panel and used the following command:
keytool -genkey -alias patrickgotthard -keystore patrickgotthard.p12 -storetype pkcs12
But as far as I understand, the .p12 file also contains my private key - I don't think that the private key should be shared?! Can you tell me how to create a self signed certificate that can be imported via Java Control Panel but does not contain my private key? Or do you know a better solution for my problem?
In this scenario, it may be sufficient to check the SHA1 fingerprint associated with the self-signed certificate used to sign the JAR:
Sign the JAR with your self-signed certificate.
Use keytool -v -list to determine your certificate's fingerprint.
Communicate the certificate's fingerprint in a mutually agreed way.
Instruct user's to add your secure site to the Exception Site List in the Security tab of the Java Control Panel; this allows the user to retain the minimum recommended security level setting, High.
At the security prompt, click on More Information to compare the communicated fingerprint with the one received.
This approach does not confer trust, but it reduces the risk of the user accepting an altered JAR.
Addendum: The article Self-signed certificates for a known community discusses how to export a self-signed certificate. Members of the community can then import the certificate as warranted.
I was developing Java Web Start app years ago with NetBeans. It did everything for me automatically.
You just have to put permissions tags in JNLP file.
Also 6 month after I had problems to create a new self-signed certificate.
But self signed app still works. (many years after, no modification, certs to install)
Clients do not have to install any certificates.
It just warns everytime when it starts that is signed with self signed cert.
Another option is to have this "limited group of users" lower the security level for Java. In Windows, you go to the Control Panel->Java and then one of the tabs is for Security (sorry on my mac right now and it is not quite the same). I believe that if you push that security level lower to Medium, you can get away with the self-signed certificate.
I have a small javafx2 application that is used in the office. Some guys run it from Firefox, some run it as a desktop app. Webstart is great.
The current approach is that I have added this to the jnlp file:
<security>
<all-permissions/>
</security>
Then created a key in a keystore using the keytool:
keytool -genkey -keystore yourKeystore -alias keyname
And I sign all jar files that are to be on the user's PC using jarsigner:
jarsigner -keystore ./myapp.keystore -storepass xxx -keypass yyy <path to jar file> keyname
So the user either starts the app using the shortcut file (the jnlp file) on their desktop, or they browse to the app in Firefox. This works great, except nowadays we get this dialog that says:
Running applications by UNKNOWN publishers will be blocked in a future
release
and I am worried about what will happen when that future release is out.
I do not have a deep understanding about all this code signing thing. I know that it works by embedding some binary data into files that is used to prove that the releaser of the app is a company/individual that is recognized by the Certificate Authority (and this is what jarsigner does AFAIK). Certificates are recognized by OSes like Windows and Linux, by webbrowsers like Firefox and Safari and Java also recognizes certificates at 2 levels, user and system. There are widely accepted Certificate Authorities (like Verisign) that are recognized by default in OSes like Windows and Linux. I know that webbrowsers also recognize some Certificate Authorities, but I think the list they recognize can be different from the list the OS recognizes. I guess Java also recognizes some but I do not know what. I also know that I can have system level configured keystores in Java by specifying the keystore in ~/.java/deployment/deployment.properties, deployment.system.security.trusted.certs. If I do not want to pay for a certificate, I can create my own (this is what I was doing) so my certificate is from an UNKNOWN publisher. What I was hoping for that if I specify my keystore via deployment.system.security.trusted.certs then it will solve this problem for the office but apparently it does not, which I do not understand because in this case the system administrator says that he recognizes this certificate. So now I am thinking about making a certificate using makecert in windows which can then be pushed down to client PCs via GPO. My understanding is that this will create certificates that are recognized by the OS, but I do not know if makecert made certificates would be treated the same way as e.g. verisign certificates in Windows, in Firefox and also in Java. And I do not know if UNKNOWN refers to a list within java or it refers to the fact that the Certificate Authority is not recognized by the OS.
My questions:
If someone could fix the mistakes I made in the above description I would appreciate it. I believe I am misunderstanding something, but I do not know what.
I just cannot believe that Webstart won't work unless we pay for a certificate. I guess what we need is a mechanism that a sysadmin can say that he wants the office PCs to recognize a given certificate. Does anyone have an idea how to do this in the future?
If we have to purchase a certificate, could someone please let me know what to watch out for or how that works in general? Can I use jarsigner the same way?
If we have to purchase a certificate, is there a list of Certificate Authorities out there that we can pick from? Obviously I want to go for the cheapest as I find this an administrative overhead.
Thank you for your help.
My setup that works with JRE7u40 and JRE8 is this:
I have a self-signed cert for my certificate authority (CA). This cert must be trusted by the system (e.g. add it to Java Control Panel / Security / Certificates / Signer CA, but there may be other ways to make your CA trusted).
Then I have a code publisher certificate, signed by my CA. I use this cert to sign all my code (jars).
Furthermore, if you want all permissions for your code, I suggest these MANIFEST.MF attributes as QDH minimum (since JRE7u40, if I remember):
Permissions: all-permissions
Codebase: *
Trusted-Library: true
Trusted-Only: true
First time you run such application, you will still see the security warning because runtime is unable to ensure that code signer certificate was not revoked by its CA.
However, now you have the option to permanently accept this publisher (code signer certificate), and if you do, the code signer certificate will be added to trusted publishers (Java Control Panel / Security / Certificates / Trusted Certificates) and you won't see such warning again.
If you want to avoid this step, I guess you have to setup your CA infrastructure properly to support certificate revocation verification. I assume that includes some extra attributes in your CA certificate and availability of special certificate revocation service. For intranet deployment, you may skip that.
Is it possible to use a server certificate to sign a java web start app? What I want to know is if will it work. I have a trusted certificate for my server, and I would like to reuse the same certificate to sign an app.
Right now, I have this warning:
This jar contains entries whose signer certificate's ExtendedKeyUsage
extension doesn't allow code signing. This jar contains entries whose
signer certificate's NetscapeCertType extension doesn't allow code
signing.
Will I be able to launch my app without the warning that the certificate is not trusted?
You will get warning if you don't use a code signing certificate. For most CA, code signing cert costs more than the server cert. In my opinion, this is just a marketing scheme to make you to pay for another cert. There is no technical difference between two certs. Some CA may provide combo deals with usage for both.
I assume you have created the JKS file using the KEY and CRT of your SSL and hence you get the error..
I have a simple solution here:
As you know you can create a JKS using the following command
keytool -genkey -v -keystore my-release-key.jks -keyalg RSA -keysize 2048 -validity 10000 -alias my-alias
and when you use this JKS you get self signed certification message which is absolutely fine to make the app live at Google play store.. But buying code signing certificate is good if you can afford it ..