nmode's Git Repositories - signal-cli/blob - src/main/java/org/asamk/signal/util/RandomUtils.java

   1 package org.asamk.signal.util;
   2
   3 import java.security.NoSuchAlgorithmException;
   4 import java.security.SecureRandom;
   5
   6 public class RandomUtils {
   7
   8     private static final ThreadLocal<SecureRandom> LOCAL_RANDOM = new ThreadLocal<SecureRandom>() {
   9         @Override
  10         protected SecureRandom initialValue() {
  11             SecureRandom rand = getSecureRandomUnseeded();
  12
  13             // Let the SecureRandom seed it self initially
  14             rand.nextBoolean();
  15
  16             return rand;
  17         }
  18     };
  19
  20     private static SecureRandom getSecureRandomUnseeded() {
  21         try {
  22             return SecureRandom.getInstance("NativePRNG");
  23         } catch (NoSuchAlgorithmException e) {
  24             // Fallback to SHA1PRNG if NativePRNG is not available (e.g. on windows)
  25             try {
  26                 return SecureRandom.getInstance("SHA1PRNG");
  27             } catch (NoSuchAlgorithmException e1) {
  28                 // Fallback to default
  29                 return new SecureRandom();
  30             }
  31         }
  32     }
  33
  34     public static SecureRandom getSecureRandom() {
  35         return LOCAL_RANDOM.get();
  36     }
  37 }