Develop Reference

Android Paho SSL with server sent CA certificate, including Hostname Verification

Duplication: There are a few similar questions (How Can I Access an SSL Connection Through Android?, "Trust anchor for certification path not found" in Android SSL Socket client, Trust anchor for certification path not found using SSL)
with no applicable answers to my issue. I try to give a specific context (e.g. paho and specific test sites) and problem.
Main Issue: I'm using Android Paho, as client, and everything's fine. Now I want to add SSL connection. The broker is the certified entity, and sends its CA-issued certificate during handshake.
(Please note that I'm a security newbie, I just read a few tutorials on the subject.)
Most Java and Paho examples I can find deal with having a local certificate (self-issued, or less known CA, etc.), while I need instead to manage CA-issued certificates sent to my app by the broker server during handshake.
From Android documentation (https://developer.android.com/training/articles/security-ssl.html), the idea seems to be that you just have to use SSLSocketFactory.getDefault(), since root CA certifications for well-known CAs are included with the system. So, simply:
MqttConnectOptions options;
// ...
options.setSocketFactory(SSLSocketFactory.getDefault());
But I tested on both:
ssl://iot.eclipse.org:8883
ssl://test.mosquitto.org:8883
and I always got the dreaded javax.net.ssl.SSLHandshakeException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.
The possible reasons given by the aforementioned android documentation, and Stack Overflow answers, presumably don't apply to such well-known and used test sites. I presume that both sites have updated certificates, issued by well-known Certification Authorities, with no lesser known CAs in the chain. (While I cannot find clear confirmation, usage examples around the net do seem to imply it.)
Any pointers? I really have no idea where to go from here (and I presume I'm missing something obvious that it's not clearly stated.)
Secondary Issue: Furthermore, the Android documentation warns that SSLSocket doesn't do any Hostname Verification: https://developer.android.com/training/articles/security-ssl.html#WarningsSslSocket
And hence it suggests:
SocketFactory sf = SSLSocketFactory.getDefault();
SSLSocket socket = (SSLSocket) sf.createSocket("gmail.com", 443);
HostnameVerifier hv = HttpsURLConnection.getDefaultHostnameVerifier();
SSLSession s = socket.getSession();
// Verify that the certicate hostname is for mail.google.com
// This is due to lack of SNI support in the current SSLSocket.
if (!hv.verify("mail.google.com", s)) {
throw new SSLHandshakeException("Expected mail.google.com, "
"found " + s.getPeerPrincipal());
}
Please note that you need a reference to the actual socket to pass to verify() (no overloaded alternative), you cannot just configure the SSLSocketFactory.
Paho doesn't seem to expose access to the socket it's using, not to set a custom verifier. You can only set the SSLSocketFactory.
If I understand correctly, there seem to be a Paho bug reported about it: https://bugs.eclipse.org/bugs/show_bug.cgi?id=425195
Is it actually the same issue?
Finally, if so, is there any way to work around this and actually have Android Paho over SSL with Hostname Verification?
EDIT, Partial answer / findings: I record here my partial provisional findings.
My assumption about iot.eclipse.org:8883 and test.mosquitto.org:8883 seems to be wrong: I found doc for both that provide certificates to explicitly be used by the clients (I presume self-signed, it's not specified). Some examples omitting this misled me.
ssl://iot.eclipse.org:8883 : iot.eclipse.org.crt as indicated by http://iot.eclipse.org/getting-started
ssl://test.mosquitto.org:8883 : mosquitto.org.crt as indicated by http://test.mosquitto.org/
Loading the certificates in a custom TrustManager, everything work. Mystery solved on this point. Our own broker with CA certificates isn't ready yet to be tested.

HttpClient generates SSLException after acquiring new domain name

Recently I acquired a new domain name to use with an existing Android application. I also bought SSL certificate from a trusted CA (Comodo). When I browse to the new domain with a web browser, everything works as expected - no errors about SSL certificate. Same with HttpUrlConnection, but for some reason Apaches HttpClient generates an SSLException:
javax.net.ssl.SSLException: hostname in certificate didn't match: my.new.domain != my.old.domain OR my.old.domain
What's more interesting, some of the devices that I tried with worked fine for about a week after the change, and stopped working after that. Other devices stopped working right away.
If I use the old domain name in client code, everything works correctly.
I'm using version 4.3.3 from here of the HttpClient for Android. I realize that converting to HttpUrlConnection would indeed solve my problem, but I'm interested in WHY this is happening - from where does the HttpClient pick up the old domain name? Is it some misconfiguration on the server, or does Apaches HttpClient have some sort of internal dns cache? Testing with a fresh emulator instance raised the same exception, so the problem is not related to caching.
My own investigations got stuck - all I could find was instructions for disabling hostname verification completely, or instructions for self-signed certificates.

That's probably because Apache HttpClient does not support SNI (server name indication), where you can have multiple certificates behind the same IP address. This means, that it does not send the target hostname inside the SSL handshake and thus the server has only the target IP address to decide which certificate it should use and just uses the default certificate for the IP - which is probably the wrong one.

Why does android get the wrong ssl certificate? (two domains, one server)

I have two domains: foo.net and bar.com. They both have SSL certificates, and they work well in all desktop and mobile browsers. They are hosted on the same server configured with nginx.
However, when I make a request to a domain from within a native android app, it somehow gets the certificate from the wrong domain! This results in an IO Exception:
request = new HttpPost("https://foo.net/api/v1/baz");
request.setHeader("Authorization", "user:pass");
response = httpClient.execute(request);
...
javax.net.ssl.SSLException: hostname in certificate didn't match: <foo.net> != <bar.com> OR <bar.com> OR <www.bar.com>
What would cause android/java to try using the certificate from bar.com when every other measure seems to indicate that the server is correctly configured? Nothing appears in the nginx access or error log. There is no mention of bar.com anywhere in my android project.
Edit: I'm not sure why, but it appears that the server is using the certificate for bar.com for the server IP https://198.245.xx.xxx

The most likely cause for this problem is that the server uses Server Name Indication to choose which certificate to send. If the client doesn't support SNI, the server cannot choose which certificate to send during the SSL/TLS handshake (before any HTTP traffic is sent). SNI is required when you want to use multiple certificates on the same IP address and port, but not all clients support it (notoriously, IE on any version of Windows XP, and a number of mobile browsers).
You're also visibly using the Apache HTTP Client library (not HttpsURLConnection, for which there can be SNI support with some Android versions.
Support for SNI in the Apache HTTP Client library is quite recent, and certainly hasn't made it into the Android stack.
You may find the workaround described in this article useful (although it seems only to work for Android 4.2+).
Another two options would be:
to use a distinct IP address for each host (so as not to need SNI), if you're in control of server, or
to use another HTTP Client library (e.g. HttpsURLConnection).

A solution for Apache, more like a trick:
the SSL certificates are loaded based on the vhost name from /etc/apache2/sites-enabled. So, to trick that check make sure the problematic certificate is loaded first (remember that the vhosts are loaded by name).

It looks like the certificate of foo.net is misconfigured, and is using the same hostname as bar.com
Try to run an online certificate validation tool, like https://www.digicert.com/help/ on foo.net, just to be sure.
I think that you need to regenerate the certificate of foo.net with the right hostname, or reconfigure ngix to make sure that nginx serve the right certificate for the right host.

Using UnboundID SDK with an SSL certificate file to connect to LDAP server in Android app

I'm trying to make a connection to an LDAP server in my Android app, and am using the UnboundID SDK. Recently, a change was made from unsecured to secured LDAP, and I have to change the app accordingly. I have been given the SSL certificates file to validate against. I've already used the file to make a keystore as described here. I've got this keystore file in the assets folder of my app, and am pulling from that. The code below does not currently work, and throws the exception:
LDAPException(resultCode=01 (connect error), errorMessage=('An error occurred while attempting to connect to server place.myserver.com:636: javax.net.ssl.SSLHandShakeException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found
// code from above link
AssetManager assetManager = getApplicationContext().getAssets();
InputStream keyStoreInputStream = assetManager.open("yourapp.store");
KeyStore trustStore = KeyStore.getInstance("BKS");
trustStore.load(keyStoreInputStream, "myPassword".toCharArray());
TrustManagerFactory tmf = TrustManagerFactory.getInstance("X509");
tmf.init(trustStore);
// my code
SSLUtil sslUtil = new SSLUtil(tmf.getTrustManagers());
LDAPConnection connection = new LDAPConnection(sslUtil.createSSLSocketFactory());
connection.connect("place.myserver.com", 636);
However, the code segment:
SSLUtil sslUtil = new SSLUtil(new TrustAllTrustManager());
LDAPConnection connection = new LDAPConnection(sslUtil.createSSLSocketFactory());
connection.connect("place.myserver.com", 636);
does work (although I was informed by the higher-ups that this would be insecure).
I'm not quite sure as to what exactly I'm doing wrong here, so any help would be appreciated. Also, if there is a better way of accomplishing this than what I'm attempting to do above, feel free to let me know :) I would like to stick with the UnboundID library though, since the rest of the code is already written using that as well, and everything works if I use the TrustAllTrustManager.

It's true that the trust all trust manager isn't secure. It's convenient for testing purposes, but it will allow a bad guy to set up his own server with a certificate he generates for himself and use it to impersonate the real server, or to operate as a man in the middle, intercepting and potentially alerting any communication between the client and the real server. With a more strict trust manager in place, the client should reject the bogus certificate that the fake server will present.
Unfortunately, though, it looks like the trust manager you're trying to use in this case doesn't like the certificate that your server is presenting to it. Because the trust all trust manager allows you to establish the connection, that means that your server does have a certificate and is capable of performing SSL communication, but there's something about that certificate that your trust manager doesn't like. It's almost certainly not an issue with the LDAP SDK, since the same problem should arise with any other LDAP API if you're using the same trust store.
If you look at the result, it has a message of "Trust anchor for certification path not found". This implies that neither the certificate the server is using nor those of any of its issuers was found in the trust store. You'll need to import the server certificate (or the certificate of one of its issuers) into the trust store that you're using. It sounds like you've tried to do that, but since it's not working then something must not be quite right with the way it was done. I'd recommend working wit the directory server administrator to ensure that you're trying to import the right certificate based on the server configuration.

Android - Custom SSL certificate chain checking without bundling keystore with the app

I am after a solution which would enable me to use the in-build keystore and StrictHostnameVerifier but would allow me to obtain the X590CertificateChain (either once connected or post handshake) so I can perform some additional checks (specifically I want to verify the root public key is the one I expected).
The examples I have investigated are mainly around overriding the behaviour (i.e. by replacing the socket factory or hostname checker with ones which don't do anything) and I am struggling with the differences between the android and other java implementations.
The reason I don't want to bundle a keystore (aside from having to use bouncycastle instead of jks) is that I don't want to package the intermediate CA cert with the app as this will create a certificate management problem sooner.
Many thanks in advance for any comments.

Ideally, this should be done at runtime. Bundling the certificate might be redundant as well, when some devices might already have that certificate installed.
Normally, your approach should be this.
Try connecting to the server.
If certificate is not installed, you will get a certificate exception. Catch it, extract the public certificate, save it, by creating a keystore on the fly.
While making new connections, use this keystore to initialize your SSL context.