This is an example of how to list all the available Encryption/Decryption algorithms. In order to do so we have created a method, Set<String> getAlgorithms(String serviceType). The method gets a String parameter that is the serviceType for which it will return the algorithms. The steps of the method are the ones below:
- Create a new Set of String elements, to hold the algorithms.
- Use
getProviders()API method of Security to get an array of the Providers. - For every Provider get a view of the property keys contained in this provider, using
keySet()API method of Provider. - Iterate over the keys. For every key check if it starts with the specified String
serviceTypeor if it starts with the"Alg.Alias."String followed by the StringserviceType. If so, add the rest of the key to the Set of the algorithms.
Let’s take a look at the code snippet that follows:
package com.javacodegeeks.snippets.core;
import java.security.Provider;
import java.security.Security;
import java.util.Iterator;
import java.util.Set;
import java.util.TreeSet;
public class ListAvailableEncryptionDecryptionAlgorithms {
public static void main(String[] args) {
// get an array containing all the installed providers
Provider[] providers = Security.getProviders();
for (int i=0; i<providers.length; i++) {
// get a view of the property keys contained in this provider
Set<Object> keys = providers[i].keySet();
for (Iterator<Object> it=keys.iterator(); it.hasNext();) {
String key = it.next().toString();
key = key.split(" ")[0];
if (key.startsWith("Alg.Alias.")) {
// strip the alias
key = key.substring(10);
}
int index = key.indexOf('.');
String serviceType = key.substring(0, index);
Set<String> algorithms = getAlgorithms(serviceType);
System.out.println(serviceType);
for (Iterator<String> iter=algorithms.iterator(); iter.hasNext();) {
System.out.println("t" + iter.next());
}
}
}
}
private static Set<String> getAlgorithms(String serviceType) {
Set<String> algorithms = new TreeSet<String>();
// get an array containing all the installed providers
Provider[] providers = Security.getProviders();
for (int i=0; i<providers.length; i++) {
// get a view of the property keys contained in this provider
Set<Object> keys = providers[i].keySet();
for (Iterator<Object> it=keys.iterator(); it.hasNext();) {
String key = it.next().toString();
key = key.split(" ")[0];
if (key.startsWith(serviceType+".")) {
algorithms.add(key.substring(serviceType.length()+1));
}
else if (key.startsWith("Alg.Alias."+serviceType+".")) {
algorithms.add(key.substring(serviceType.length()+11));
}
}
}
return algorithms;
}
}
This was an example of how to list all the available Encryption/Decryption algorithms in Java.
