I am currently attempting to connect to a server which has no domain name and is only reachable by its ip address. I previously attempted to do it by using the library volley, but after spending a day of research I couldn't figure out why the ssl handshake wouldn't work. after switching to Okhttp I got the warning:
javax.net.ssl.SSLPeerUnverifiedException: Hostname 185.101.92.193 not verified:
certificate: sha256/QMgPlAslWrBi1dd/P17AKxJCniO2RfHQ5MufVO5Xji4=
DN: 1.2.840.113549.1.9.1=#1619626c61636b6a61636b34323636323440676d61696c2e636f6d,CN=185.101.92.193,O=Internet Widgits Pty Ltd,L=Berlin,ST=Berlin,C=DE
subjectAltNames: []
Now this problem has already been addressed on github: https://github.com/square/okhttp/issues/1467
I have "resolved" the problem with the following code (look at HostnameVerifier at the bottom):
// loading CAs from an InputStream
try {
CertificateFactory cf = CertificateFactory.getInstance("X.509");
InputStream cert = context.getResources().openRawResource(R.raw.servercert);
Certificate ca;
try {
ca = cf.generateCertificate(cert);
} finally {
cert.close();
}
// creating a KeyStore containing our trusted CAs
String keyStoreType = KeyStore.getDefaultType();
KeyStore keyStore = KeyStore.getInstance(keyStoreType);
keyStore.load(null, null);
keyStore.setCertificateEntry("ca", ca);
// creating a TrustManager that trusts the CAs in our KeyStore
String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
TrustManagerFactory tmf = TrustManagerFactory.getInstance(tmfAlgorithm);
tmf.init(keyStore);
// creating an SSLSocketFactory that uses our TrustManager
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, tmf.getTrustManagers(), null);
client = new OkHttpClient.Builder().sslSocketFactory(sslContext.getSocketFactory())
.hostnameVerifier(new HostnameVerifier() {
#Override
public boolean verify(String s, SSLSession sslSession) {
if(s.equals(myIPAddress)){
return true;
}else{
return false;
}
}
})
.build();
}catch (Exception e){
e.printStackTrace();
}
Now this kinda looks like bad practice to me and my actual question is: what problems could arise from implementing the HostnameVerifier like this (security-wise) and how could I solve this matter in a more sophisticated way?
There is nothing to do with the domain name, the only issue is that your application (android) can't verify the certificate because it's private (self signed certificate). What you did in your code is just trying to bypass the validation process by overriding the SSLFactory and created a new one that uses your CAs.
Check android documentation below:
https://developer.android.com/training/articles/security-ssl.html#CommonProblems
You can continue of what you have. or buy a certificate and then there is no need for this code at all.
Related
i have implemented the certificate and keystore to my app and succeeded in making request to my server , but now i want to accept another server's HTTPS (for online payment) to be able to integrate it in my app but volley says that it doesn't accept it , can i accept this domain without their keystore
and this is my code for accepting my server's certificate
private SSLSocketFactory newSslSocketFactory() {
try {
// Get an instance of the Bouncy Castle KeyStore format
KeyStore trusted = KeyStore.getInstance("BKS");
// Get the raw resource, which contains the keystore with
// your trusted certificates (root and any intermediate certs)
InputStream in = getApplicationContext().getResources().openRawResource(R.raw.keystore);
try {
// Initialize the keystore with the provided trusted certificates
// Provide the password of the keystore
trusted.load(in, KEYSTORE_PASSWORD);
} finally {
in.close();
}
String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
TrustManagerFactory tmf = TrustManagerFactory.getInstance(tmfAlgorithm);
tmf.init(trusted);
SSLContext context = SSLContext.getInstance("TLS");
context.init(null, tmf.getTrustManagers(), null);
SSLSocketFactory sf = context.getSocketFactory();
return sf;
} catch (Exception e) {
throw new AssertionError(e);
}
}
I have a website which I want to open in an Android Webview. The website uses a certificate emitted by COMODO RSA Domain Validation Secure Server CA. The problem is that I get an Unkown Certificate Error for devices all running a version less than (including) Android 5.
I serched in the documentation and as far as I understood the problem is that the CA was created before the release of Android 5.
I could do a handler.proceed(); on onReceivedSslError but I want to keep the app secure and I think Google can reject the app on play store anyway.
I found that I cound do something like this
// Load CAs from an InputStream
// (could be from a resource or ByteArrayInputStream or ...)
CertificateFactory cf = CertificateFactory.getInstance("X.509");
// From https://www.washington.edu/itconnect/security/ca/load-der.crt
InputStream caInput = new BufferedInputStream(new FileInputStream("load-der.crt"));
Certificate ca;
try {
ca = cf.generateCertificate(caInput);
System.out.println("ca=" + ((X509Certificate) ca).getSubjectDN());
} finally {
caInput.close();
}
// Create a KeyStore containing our trusted CAs
String keyStoreType = KeyStore.getDefaultType();
KeyStore keyStore = KeyStore.getInstance(keyStoreType);
keyStore.load(null, null);
keyStore.setCertificateEntry("ca", ca);
// Create a TrustManager that trusts the CAs in our KeyStore
String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
TrustManagerFactory tmf = TrustManagerFactory.getInstance(tmfAlgorithm);
tmf.init(keyStore);
// Create an SSLContext that uses our TrustManager
SSLContext context = SSLContext.getInstance("TLS");
context.init(null, tmf.getTrustManagers(), null);
// Tell the URLConnection to use a SocketFactory from our SSLContext
URL url = new URL("https://certs.cac.washington.edu/CAtest/");
HttpsURLConnection urlConnection =
(HttpsURLConnection)url.openConnection();
urlConnection.setSSLSocketFactory(context.getSocketFactory());
InputStream in = urlConnection.getInputStream();
copyInputStreamToOutputStream(in, System.out);
but the problem is that my code is like so
myWebView.loadUrl("https://site.domain.com")
How can I install the certificate of the CA within my Webview?
Thanks
You need to override method to your WebViewClient implementation. Try this:
public void onReceivedSslError(WebView view, SslErrorHandler handler,
SslError error) { handler.proceed(); }
Also, it could be with the SSL certificate installed on the website that you wish to run on webview. The SSL certificate provided by the authority is not supported on mobile, assuming if there's no error viewing the website on a desktop.
My Android project (OkHttp 3.3.1) currently works with my HTTPS web service (my PC, IIS web server, Asp.Net Web API, self-signed certificate)
Helper methods:
private SSLSocketFactory getSSLSocketFactory()
throws CertificateException, KeyStoreException, IOException,
NoSuchAlgorithmException, KeyManagementException {
CertificateFactory cf = CertificateFactory.getInstance("X.509");
InputStream caInput = getResources().openRawResource(R.raw.iis_cert);
Certificate ca = cf.generateCertificate(caInput);
caInput.close();
KeyStore keyStore = KeyStore.getInstance("BKS");
keyStore.load(null, null);
keyStore.setCertificateEntry("ca", ca);
String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
TrustManagerFactory tmf = TrustManagerFactory.getInstance(tmfAlgorithm);
tmf.init(keyStore);
SSLContext sslContext = SSLContext.getInstance("TLS");
sslContext.init(null, tmf.getTrustManagers(), null);
return sslContext.getSocketFactory();
}
private HostnameVerifier getHostnameVerifier() {
return new HostnameVerifier() {
#Override
public boolean verify(String hostname, SSLSession session) {
HostnameVerifier hv = HttpsURLConnection.getDefaultHostnameVerifier();
return hv.verify("BNK-PC.LOCALHOST.COM", session);
}
};
}
Code A:
OkHttpClient client = new OkHttpClient.Builder()
.sslSocketFactory(getSSLSocketFactory())
.hostnameVerifier(getHostnameVerifier())
.build();
After reading this CertificatePinner guide, my project also works well when adding .certificatePinner(certificatePinner) as below:
Code B:
OkHttpClient client = new OkHttpClient.Builder()
.sslSocketFactory(getSSLSocketFactory())
.certificatePinner(certificatePinner)
.hostnameVerifier(getHostnameVerifier())
.build();
According to this Wiki, certificate pinning increases security.
However, actually I have not clearly understood this idea. So my question is that whether I need to or have to use certificatePinner or not when my app still works with the Code A. In other words, does Code B have better security than Code A?
Certificate Pinning should help with certain classes of attacks
Any trusted certificate authority gets hacked and generates valid certificates for your domain which a MITM attack e.g. by an invasive government.
Your app is running on a device with additional trusted certificates e.g. installed by the Corporation that supplied the phone.
I think generally if you issued your certificates from two major CA e.g. verisign, you would pin to their signing certificates rather than your own. This is because you are likely to generate new certificates for your server as a routine thing.
public static SSLContext getSSL() {
try {
CertificateFactory cf = CertificateFactory.getInstance("X.509");
AssetManager assetManager = App.getAppContext()
.getAssets();
InputStream caInput = assetManager.open("cert.pem");
java.security.cert.X509Certificate ca = null;
try {
ca = (java.security.cert.X509Certificate) cf
.generateCertificate(caInput);
} catch (Exception er) {
} finally {
caInput.close();
}
String keyStoreType = KeyStore.getDefaultType();
KeyStore keyStore = KeyStore.getInstance(keyStoreType);
keyStore.load(null, null);
keyStore.setCertificateEntry("ca",
ca);
String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
TrustManagerFactory tmf = TrustManagerFactory
.getInstance(tmfAlgorithm);
tmf.init(keyStore);
SSLContext context = SSLContext.getInstance("TLS");
context.init(null, tmf.getTrustManagers(), null);
return context;
} catch (Exception e1) {
return null;
}
}
Ok this is how i do SSL Pinning in my Android application, and it all works perfect. So, What is the problem I have? I have cert.pem in my assets folder, what If I want to update my certificate? I will have to publish a new app on the store just for that. I dont want to do that, I want to know whats best way to handle such issue? Shall I download the certificate from somewhere and use it, or is there a way I can specify it via google play store and it can read it from there instead of assets folder? My goal is to avoid publishing new android app everytime i change the certificate.
The point of certificate pinning is to mitigate man-in-the-middle (MITM) attacks. If you download the pinned certificate from a non-pinned source, you're not really any better off preventing MITM as this download source becomes MITM target.
Therefore, just ship your app with the pinnings you want.
Options to mitigate the update issue:
Self-generate or purchase a certificate with a long validity period so you don't have to update that often.
If you are using a purchased CA-backed certificate, don't pin the certificate itself but the CA's root certificate that is valid for decades. Of course this enables MITM with a certificate for your domain signed with that CA, but at least you're reducing the number of CAs you need to trust to only one.
I have my own PKI infrastructure for my web server with a CA and an intermediate CA. Then I have a web certificate signed by the intermediate CA and I want my app to communicate with the server. According to the Developer docs the solution is to create my own keystore. So I bundled the root CA certificate with the app and tried to see if that would work. It didnt, and I got the following error:
javax.net.ssl.SSLHandshakeException: java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.
So my question is this. Since the SSL certificate is signed by my intermediate CA, is that the certificate I should be importing into the custom key store, or do I need both, or is there something else wrong here?
Ultimately, with a SSL certificate signed by a CA not trusted by Android, is this the right way to go about it?
Thanks!
Here's the code that sets up the keystore manager.
public SSLContext getTrusted() throws Exception{
// Load CAs from an InputStream
CertificateFactory cf = CertificateFactory.getInstance("X.509");
AssetManager assManager = context.getAssets();
InputStream is = null;
try {
is = assManager.open("ca.cert.crt");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
InputStream caInput = new BufferedInputStream(is);
Certificate ca;
try {
ca = cf.generateCertificate(caInput);
Log.d("TrustMan", "ca=" + ((X509Certificate) ca).getSubjectDN());
} finally {
caInput.close();
}
// Create a KeyStore containing our trusted CAs
String keyStoreType = KeyStore.getDefaultType();
KeyStore keyStore = KeyStore.getInstance(keyStoreType);
keyStore.load(null, null);
keyStore.setCertificateEntry("ca", ca);
// Create a TrustManager that trusts the CAs in our KeyStore
String tmfAlgorithm = TrustManagerFactory.getDefaultAlgorithm();
TrustManagerFactory tmf = TrustManagerFactory.getInstance(tmfAlgorithm);
tmf.init(keyStore);
// Create an SSLContext that uses our TrustManager
SSLContext context = SSLContext.getInstance("TLS");
context.init(null, tmf.getTrustManagers(), null);
return context;
}
And then I am trying to use it as follows.
HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
TrustMan tm = new TrustMan(context);
SSLContext sslContext;
sslContext = tm.getTrusted();
connection.setSSLSocketFactory(sslContext.getSocketFactory());
The code did actually work, but not when I returned the SSLContext from my class. I adjusted the class to return the TrustManagerFactory instead, and using the intermediate CA certificate works fine now!
Thanks!