Improve the secure random function and fix issue #12

Author: Ale32bit

common/src/main/java/me/alexdevs/classicPeripherals/core/Crypto.java

@@ -114,6 +114,20 @@ public static double secureRandom() {
         return random.nextDouble();
     }
 
+    public static double secureRandom(double max) {
+        var random = new SecureRandom();
+        if (max == 0d) {
+            // mimics the behavior of the Lua random function
+            return random.nextDouble(Long.MIN_VALUE, Long.MAX_VALUE);
+        }
+        return random.nextDouble(max);
+    }
+
+    public static double secureRandom(double min, double max) {
+        var random = new SecureRandom();
+        return random.nextDouble(min, max);
+    }
+
     public static byte[] secureRandomBuffer(int length) {
         var random = new SecureRandom();
         var bytes = new byte[length];

common/src/main/java/me/alexdevs/classicPeripherals/peripherals/crypto/AbstractCryptographicAcceleratorPeripheral.java

@@ -3,6 +3,7 @@
 import dan200.computercraft.api.lua.IArguments;
 import dan200.computercraft.api.lua.LuaException;
 import dan200.computercraft.api.lua.LuaFunction;
+import dan200.computercraft.api.lua.LuaValues;
 import dan200.computercraft.api.peripheral.IPeripheral;
 import me.alexdevs.classicPeripherals.core.Crypto;
 import me.alexdevs.classicPeripherals.utils.CryptoUtils;
@@ -62,17 +63,25 @@ public final String hmacSha512(String key, String data, Optional<Boolean> hex) {
 
     @LuaFunction
     public final double random(IArguments args) throws LuaException {
-        var value = Crypto.secureRandom();
-
         if (args.count() == 0) { // 0.0 - 1.0
-            return value;
+            return Crypto.secureRandom();
         } else if (args.count() == 1) { // 0.0 - max
-            var max = args.getInt(0);
-            return Math.floor(value * max);
+            var max = args.getFiniteDouble(0);
+
+            if (max < 0) {
+                throw new LuaException("bad argument #1 (interval is empty)");
+            }
+
+            return Crypto.secureRandom(max);
         } else { // min - max
-            var min = args.getInt(0);
-            var max = args.getInt(1);
-            return Math.floor(value * max) + min;
+            var min = args.getFiniteDouble(0);
+            var max = args.getFiniteDouble(1);
+
+            if (max - min <= 0) {
+                throw new LuaException("bad argument #1 (interval is empty)");
+            }
+
+            return Crypto.secureRandom(min, max);
         }
     }