Develop Reference

Add certificates to global Java truststore in code (programatically)

I have a Kubernetes Deployment of my Spring Boot application where I used to update global Java cacerts using keytool at the bootstrap:
keytool -noprompt -import -trustcacerts -cacerts -alias $ALIAS -storepass $PASSWORD
However, I need to make the container immutable using the readOnlyRootFilesystem: true in the securityContext of the image in my Deployment. Therefore, I cannot update the cacert like that with additional certificates to be trusted.
Additional certificates that should be trusted are provided as environment variable CERTS.
I assume that the only proper way would be to do this programmatically, for example during #PostConstruct in the Spring Boot component.
I was looking into some examples how to set the global truststore in code, but all of them refer to update the cacerts and then save it to filesystem, which does not work for me.
Some examples use System.setProperty("javax.net.ssl.trustStore", fileName);, but this does not work either on the read-only filesystem, where I cannot update file.
Another examples suggest to use X509TrustManager, but if I understood correctly, this does not work globally.
Is there any way in Java or Spring Boot to update global truststore in general programmatically so every operation in the code will use and I do not have to implement something like TrustManager to every connection? My goal is to have it imported at the begging (similar like it is done using shell and keytool). Without touching the filesystem, as it is read-only.

You can use the following approach to update the Java truststore programmatically without modifying the read-only filesystem:
Create a KeyStore object in your code.
Load the existing truststore into the KeyStore object using the
truststore password.
Parse the environment variable CERTS and add the certificates to the
KeyStore object.
Use the javax.net.ssl.TrustManagerFactory to create a
TrustManagerFactory with the KeyStore.
Use the TrustManagerFactory to initialize a SSLContext with the
trustmanager.
Use the SSLContext.init() method to set the SSL context as the
default for all SSL connections.
You can achieve this in a Spring Boot component:
#PostConstruct
public void configureGlobalTrustStore() throws KeyStoreException, NoSuchAlgorithmException, CertificateException, IOException, KeyManagementException {
KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
InputStream inputStream = getClass().getResourceAsStream("/cacerts");
trustStore.load(inputStream, "changeit".toCharArray());
inputStream.close();
String certString = System.getenv("CERTS");
if (certString != null) {
String[] certArray = certString.split(" ");
for (int i = 0; i < certArray.length; i++) {
InputStream certInput = new ByteArrayInputStream(Base64.getDecoder().decode(certArray[i]));
CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
X509Certificate cert = (X509Certificate) certificateFactory.generateCertificate(certInput);
certInput.close();
trustStore.setCertificateEntry("cert-" + i, cert);
}
}
TrustManagerFactory trustManagerFactory = TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
trustManagerFactory.init(trustStore);
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, trustManagerFactory.getTrustManagers(), null);
SSLContext.setDefault(sslContext);
}
This way, every SSL connection in your code will use the updated truststore, without having to configure it for each individual connection.

Convert Program to use Secure Socket Connection via java-websockets library

I am attempting to convert an existing application that uses the org.java-websocket library to allow the webserver to communicate using https instead of the previous http. After researching, the only example I was able to find is here:
https://github.com/TooTallNate/Java-WebSocket/blob/master/src/main/example/SSLServerExample.java
public static void main(String[] args) throws Exception {
ChatServer chatserver = new ChatServer(
8887); // Firefox does allow multible ssl connection only via port 443 //tested on FF16
// load up the key store
String STORETYPE = "JKS";
String KEYSTORE = Paths.get("src", "test", "java", "org", "java_websocket", "keystore.jks")
.toString();
String STOREPASSWORD = "storepassword";
String KEYPASSWORD = "keypassword";
KeyStore ks = KeyStore.getInstance(STORETYPE);
File kf = new File(KEYSTORE);
ks.load(new FileInputStream(kf), STOREPASSWORD.toCharArray());
KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
kmf.init(ks, KEYPASSWORD.toCharArray());
TrustManagerFactory tmf = TrustManagerFactory.getInstance("SunX509");
tmf.init(ks);
SSLContext sslContext = null;
sslContext = SSLContext.getInstance("TLS");
sslContext.init(kmf.getKeyManagers(), tmf.getTrustManagers(), null);
chatserver.setWebSocketFactory(new DefaultSSLWebSocketServerFactory(sslContext));
chatserver.start();
}
The only problem with this is that I'm hesitant because it seems to be wanting you to access the keystore.jks and provide to the store password + keypassword and also seems to expect the KeyStore file to be on the running computer (or somewhere released with the software). Isn't this a security risk?
I already have the jar signed with the keystore, perhaps there is nothing more that I need to do? Can someone point me to a different example if this is not the way to do this?
This keystore I'm using is the one provided to us by an external company to our company to sign our java applications. Perhaps this is not the keystore I should be using and need to make one for this single app independently of that one?

Secure Sockets in Java without CA [duplicate]

A module I'm adding to our large Java application has to converse with another company's SSL-secured website. The problem is that the site uses a self-signed certificate. I have a copy of the certificate to verify that I'm not encountering a man-in-the-middle attack, and I need to incorporate this certificate into our code in such a way that the connection to the server will be successful.
Here's the basic code:
void sendRequest(String dataPacket) {
String urlStr = "https://host.example.com/";
URL url = new URL(urlStr);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setMethod("POST");
conn.setRequestProperty("Content-Length", data.length());
conn.setDoOutput(true);
OutputStreamWriter o = new OutputStreamWriter(conn.getOutputStream());
o.write(data);
o.flush();
}
Without any additional handling in place for the self-signed certificate, this dies at conn.getOutputStream() with the following exception:
Exception in thread "main" javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
....
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
....
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Ideally, my code needs to teach Java to accept this one self-signed certificate, for this one spot in the application, and nowhere else.
I know that I can import the certificate into the JRE's certificate authority store, and that will allow Java to accept it. That's not an approach I want to take if I can help; it seems very invasive to do on all of our customer's machines for one module they may not use; it would affect all other Java applications using the same JRE, and I don't like that even though the odds of any other Java application ever accessing this site are nil. It's also not a trivial operation: on UNIX I have to obtain access rights to modify the JRE in this way.
I've also seen that I can create a TrustManager instance that does some custom checking. It looks like I might even be able to create a TrustManager that delegates to the real TrustManager in all instances except this one certificate. But it looks like that TrustManager gets installed globally, and I presume would affect all other connections from our application, and that doesn't smell quite right to me, either.
What is the preferred, standard, or best way to set up a Java application to accept a self-signed certificate? Can I accomplish all of the goals I have in mind above, or am I going to have to compromise? Is there an option involving files and directories and configuration settings, and little-to-no code?

Create an SSLSocket factory yourself, and set it on the HttpsURLConnection before connecting.
...
HttpsURLConnection conn = (HttpsURLConnection)url.openConnection();
conn.setSSLSocketFactory(sslFactory);
conn.setMethod("POST");
...
You'll want to create one SSLSocketFactory and keep it around. Here's a sketch of how to initialize it:
/* Load the keyStore that includes self-signed cert as a "trusted" entry. */
KeyStore keyStore = ...
TrustManagerFactory tmf =
TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
tmf.init(keyStore);
SSLContext ctx = SSLContext.getInstance("TLS");
ctx.init(null, tmf.getTrustManagers(), null);
sslFactory = ctx.getSocketFactory();
If you need help creating the key store, please comment.
Here's an example of loading the key store:
KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
keyStore.load(trustStore, trustStorePassword);
trustStore.close();
To create the key store with a PEM format certificate, you can write your own code using CertificateFactory, or just import it with keytool from the JDK (keytool won't work for a "key entry", but is just fine for a "trusted entry").
keytool -import -file selfsigned.pem -alias server -keystore server.jks

I read through LOTS of places online to solve this thing.
This is the code I wrote to make it work:
ByteArrayInputStream derInputStream = new ByteArrayInputStream(app.certificateString.getBytes());
CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
X509Certificate cert = (X509Certificate) certificateFactory.generateCertificate(derInputStream);
String alias = "alias";//cert.getSubjectX500Principal().getName();
KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
trustStore.load(null);
trustStore.setCertificateEntry(alias, cert);
KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
kmf.init(trustStore, null);
KeyManager[] keyManagers = kmf.getKeyManagers();
TrustManagerFactory tmf = TrustManagerFactory.getInstance("X509");
tmf.init(trustStore);
TrustManager[] trustManagers = tmf.getTrustManagers();
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(keyManagers, trustManagers, null);
URL url = new URL(someURL);
conn = (HttpsURLConnection) url.openConnection();
conn.setSSLSocketFactory(sslContext.getSocketFactory());
app.certificateString is a String that contains the Certificate, for example:
static public String certificateString=
"-----BEGIN CERTIFICATE-----\n" +
"MIIGQTCCBSmgAwIBAgIHBcg1dAivUzANBgkqhkiG9w0BAQsFADCBjDELMAkGA1UE" +
"BhMCSUwxFjAUBgNVBAoTDVN0YXJ0Q29tIEx0ZC4xKzApBgNVBAsTIlNlY3VyZSBE" +
... a bunch of characters...
"5126sfeEJMRV4Fl2E5W1gDHoOd6V==\n" +
"-----END CERTIFICATE-----";
I have tested that you can put any characters in the certificate string, if it is self signed, as long as you keep the exact structure above. I obtained the certificate string with my laptop's Terminal command line.

If creating a SSLSocketFactory is not an option, just import the key into the JVM
Retrieve the public key:
$openssl s_client -connect dev-server:443, then create a file dev-server.pem that looks like
-----BEGIN CERTIFICATE-----
lklkkkllklklklklllkllklkl
lklkkkllklklklklllkllklkl
lklkkkllklk....
-----END CERTIFICATE-----
Import the key: #keytool -import -alias dev-server -keystore $JAVA_HOME/jre/lib/security/cacerts -file dev-server.pem.
Password: changeit
Restart JVM
Source: How to solve javax.net.ssl.SSLHandshakeException?

We copy the JRE's truststore and add our custom certificates to that truststore, then tell the application to use the custom truststore with a system property. This way we leave the default JRE truststore alone.
The downside is that when you update the JRE you don't get its new truststore automatically merged with your custom one.
You could maybe handle this scenario by having an installer or startup routine that verifies the truststore/jdk and checks for a mismatch or automatically updates the truststore. I don't know what happens if you update the truststore while the application is running.
This solution isn't 100% elegant or foolproof but it's simple, works, and requires no code.

I've had to do something like this when using commons-httpclient to access an internal https server with a self-signed certificate. Yes, our solution was to create a custom TrustManager that simply passed everything (logging a debug message).
This comes down to having our own SSLSocketFactory that creates SSL sockets from our local SSLContext, which is set up to have only our local TrustManager associated with it. You don't need to go near a keystore/certstore at all.
So this is in our LocalSSLSocketFactory:
static {
try {
SSL_CONTEXT = SSLContext.getInstance("SSL");
SSL_CONTEXT.init(null, new TrustManager[] { new LocalSSLTrustManager() }, null);
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException("Unable to initialise SSL context", e);
} catch (KeyManagementException e) {
throw new RuntimeException("Unable to initialise SSL context", e);
}
}
public Socket createSocket(String host, int port) throws IOException, UnknownHostException {
LOG.trace("createSocket(host => {}, port => {})", new Object[] { host, new Integer(port) });
return SSL_CONTEXT.getSocketFactory().createSocket(host, port);
}
Along with other methods implementing SecureProtocolSocketFactory. LocalSSLTrustManager is the aforementioned dummy trust manager implementation.

Java Keystore reload whilst in runtime [duplicate]

A module I'm adding to our large Java application has to converse with another company's SSL-secured website. The problem is that the site uses a self-signed certificate. I have a copy of the certificate to verify that I'm not encountering a man-in-the-middle attack, and I need to incorporate this certificate into our code in such a way that the connection to the server will be successful.
Here's the basic code:
void sendRequest(String dataPacket) {
String urlStr = "https://host.example.com/";
URL url = new URL(urlStr);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setMethod("POST");
conn.setRequestProperty("Content-Length", data.length());
conn.setDoOutput(true);
OutputStreamWriter o = new OutputStreamWriter(conn.getOutputStream());
o.write(data);
o.flush();
}
Without any additional handling in place for the self-signed certificate, this dies at conn.getOutputStream() with the following exception:
Exception in thread "main" javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
....
Caused by: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
....
Caused by: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Ideally, my code needs to teach Java to accept this one self-signed certificate, for this one spot in the application, and nowhere else.
I know that I can import the certificate into the JRE's certificate authority store, and that will allow Java to accept it. That's not an approach I want to take if I can help; it seems very invasive to do on all of our customer's machines for one module they may not use; it would affect all other Java applications using the same JRE, and I don't like that even though the odds of any other Java application ever accessing this site are nil. It's also not a trivial operation: on UNIX I have to obtain access rights to modify the JRE in this way.
I've also seen that I can create a TrustManager instance that does some custom checking. It looks like I might even be able to create a TrustManager that delegates to the real TrustManager in all instances except this one certificate. But it looks like that TrustManager gets installed globally, and I presume would affect all other connections from our application, and that doesn't smell quite right to me, either.
What is the preferred, standard, or best way to set up a Java application to accept a self-signed certificate? Can I accomplish all of the goals I have in mind above, or am I going to have to compromise? Is there an option involving files and directories and configuration settings, and little-to-no code?

Create an SSLSocket factory yourself, and set it on the HttpsURLConnection before connecting.
...
HttpsURLConnection conn = (HttpsURLConnection)url.openConnection();
conn.setSSLSocketFactory(sslFactory);
conn.setMethod("POST");
...
You'll want to create one SSLSocketFactory and keep it around. Here's a sketch of how to initialize it:
/* Load the keyStore that includes self-signed cert as a "trusted" entry. */
KeyStore keyStore = ...
TrustManagerFactory tmf =
TrustManagerFactory.getInstance(TrustManagerFactory.getDefaultAlgorithm());
tmf.init(keyStore);
SSLContext ctx = SSLContext.getInstance("TLS");
ctx.init(null, tmf.getTrustManagers(), null);
sslFactory = ctx.getSocketFactory();
If you need help creating the key store, please comment.
Here's an example of loading the key store:
KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
keyStore.load(trustStore, trustStorePassword);
trustStore.close();
To create the key store with a PEM format certificate, you can write your own code using CertificateFactory, or just import it with keytool from the JDK (keytool won't work for a "key entry", but is just fine for a "trusted entry").
keytool -import -file selfsigned.pem -alias server -keystore server.jks

I read through LOTS of places online to solve this thing.
This is the code I wrote to make it work:
ByteArrayInputStream derInputStream = new ByteArrayInputStream(app.certificateString.getBytes());
CertificateFactory certificateFactory = CertificateFactory.getInstance("X.509");
X509Certificate cert = (X509Certificate) certificateFactory.generateCertificate(derInputStream);
String alias = "alias";//cert.getSubjectX500Principal().getName();
KeyStore trustStore = KeyStore.getInstance(KeyStore.getDefaultType());
trustStore.load(null);
trustStore.setCertificateEntry(alias, cert);
KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
kmf.init(trustStore, null);
KeyManager[] keyManagers = kmf.getKeyManagers();
TrustManagerFactory tmf = TrustManagerFactory.getInstance("X509");
tmf.init(trustStore);
TrustManager[] trustManagers = tmf.getTrustManagers();
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(keyManagers, trustManagers, null);
URL url = new URL(someURL);
conn = (HttpsURLConnection) url.openConnection();
conn.setSSLSocketFactory(sslContext.getSocketFactory());
app.certificateString is a String that contains the Certificate, for example:
static public String certificateString=
"-----BEGIN CERTIFICATE-----\n" +
"MIIGQTCCBSmgAwIBAgIHBcg1dAivUzANBgkqhkiG9w0BAQsFADCBjDELMAkGA1UE" +
"BhMCSUwxFjAUBgNVBAoTDVN0YXJ0Q29tIEx0ZC4xKzApBgNVBAsTIlNlY3VyZSBE" +
... a bunch of characters...
"5126sfeEJMRV4Fl2E5W1gDHoOd6V==\n" +
"-----END CERTIFICATE-----";
I have tested that you can put any characters in the certificate string, if it is self signed, as long as you keep the exact structure above. I obtained the certificate string with my laptop's Terminal command line.

If creating a SSLSocketFactory is not an option, just import the key into the JVM
Retrieve the public key:
$openssl s_client -connect dev-server:443, then create a file dev-server.pem that looks like
-----BEGIN CERTIFICATE-----
lklkkkllklklklklllkllklkl
lklkkkllklklklklllkllklkl
lklkkkllklk....
-----END CERTIFICATE-----
Import the key: #keytool -import -alias dev-server -keystore $JAVA_HOME/jre/lib/security/cacerts -file dev-server.pem.
Password: changeit
Restart JVM
Source: How to solve javax.net.ssl.SSLHandshakeException?

We copy the JRE's truststore and add our custom certificates to that truststore, then tell the application to use the custom truststore with a system property. This way we leave the default JRE truststore alone.
The downside is that when you update the JRE you don't get its new truststore automatically merged with your custom one.
You could maybe handle this scenario by having an installer or startup routine that verifies the truststore/jdk and checks for a mismatch or automatically updates the truststore. I don't know what happens if you update the truststore while the application is running.
This solution isn't 100% elegant or foolproof but it's simple, works, and requires no code.

I've had to do something like this when using commons-httpclient to access an internal https server with a self-signed certificate. Yes, our solution was to create a custom TrustManager that simply passed everything (logging a debug message).
This comes down to having our own SSLSocketFactory that creates SSL sockets from our local SSLContext, which is set up to have only our local TrustManager associated with it. You don't need to go near a keystore/certstore at all.
So this is in our LocalSSLSocketFactory:
static {
try {
SSL_CONTEXT = SSLContext.getInstance("SSL");
SSL_CONTEXT.init(null, new TrustManager[] { new LocalSSLTrustManager() }, null);
} catch (NoSuchAlgorithmException e) {
throw new RuntimeException("Unable to initialise SSL context", e);
} catch (KeyManagementException e) {
throw new RuntimeException("Unable to initialise SSL context", e);
}
}
public Socket createSocket(String host, int port) throws IOException, UnknownHostException {
LOG.trace("createSocket(host => {}, port => {})", new Object[] { host, new Integer(port) });
return SSL_CONTEXT.getSocketFactory().createSocket(host, port);
}
Along with other methods implementing SecureProtocolSocketFactory. LocalSSLTrustManager is the aforementioned dummy trust manager implementation.

using Certificate in https

I write android application.
How can I use Certificate in https connection when I initialize certificate from directory file and not from packages?
When I have packages file with password, this code works:
KeyStore keyStore = KeyStore.getInstance("PKCS12");
keyStore.load(certificateIs, pass.toCharArray());
KeyManagerFactory kmf = KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
kmf.init(keyStore, pass.toCharArray());
SSLContext sc = SSLContext.getInstance("TLS");
sc.init(kmf.getKeyManagers(), trustAllCerts, new java.security.SecureRandom());
HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory());
But I have certificate initialized from der file:
CertificateFactory cf = CertificateFactory.getInstance("X.509");
X509Certificate certificate = (X509Certificate) cf.generateCertificate(certBytes);
I do not know how use this certificate over https connection.

You seem to be talking about client-certificate authentication (where your Android device is the client).
Firstly, you need the client to have the private key matching the public key in the certificate you're trying to use (that's the whole point, otherwise, it wouldn't authenticated anything). PKCS#12 is one of the usual formats for containing the private key and the certificate. If you only have the certificate in a der file, you probably won't have the private key in it, hence it won't work.
It's not quite clear from your question what you do with your certificate variable, with respect to the KeyManagerFactory (if you have a custom X509KeyManager, it should return the private key in its getPrivateKey method, otherwise it won't work).
Secondly, client-certificate authentication is always initiated by the server, so you'd need the server to be set up accordingly too (it seems to be the case already, if your test based on a PKCS#12 keystore works).