Loading a self-signed SSL certificate .crt file and packaging it into a SSLSocketFactory for use with a HttpsURLConnection.

SelfSignedCrtCertificate.java

// Usage example...
HttpsURLConnection connection = (HttpsURLConnection) new URL("https://someurl.com").openConnection();
connection.setSSLSocketFactory(buildSslSocketFactory());

private static SSLSocketFactory buildSslSocketFactory(Context context) {
	// Add support for self-signed (local) SSL certificates
	// Based on http://developer.android.com/training/articles/security-ssl.html#UnknownCa
	try {
	  
		// 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 is = context.getResources().getAssets().openAsset("somefolder/somecertificate.crt");
		InputStream caInput = new BufferedInputStream(is);
		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);
		return context.getSocketFactory();

	} catch (NoSuchAlgorithmException e) {
		e.printStackTrace();
	} catch (KeyStoreException e) {
		e.printStackTrace();
	} catch (KeyManagementException e) {
		e.printStackTrace();
	} catch (CertificateException e) {
		e.printStackTrace();
	} catch (IOException e) {
		e.printStackTrace();
	}
	return null;
	
}

how can you use crt file in swift code?

Usage says: connection.setSSLSocketFactory(buildSslSocketFactory());

private static SSLSocketFactory buildSslSocketFactory(Context context) {

what is Context ?