1 files changed, 74 insertions, 0 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/prng/SP800SecureRandom.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/prng/SP800SecureRandom.java
new file mode 100644
index 000000000..1a452f9ef
--- /dev/null
+++ b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/prng/SP800SecureRandom.java
@@ -0,0 +1,74 @@
+package org.spongycastle.crypto.prng;
+
+import java.security.SecureRandom;
+
+import org.spongycastle.crypto.prng.drbg.SP80090DRBG;
+
+public class SP800SecureRandom
+    extends SecureRandom
+{
+    private final DRBGProvider drbgProvider;
+    private final boolean predictionResistant;
+    private final SecureRandom randomSource;
+    private final EntropySource entropySource;
+
+    private SP80090DRBG drbg;
+
+    SP800SecureRandom(SecureRandom randomSource, EntropySource entropySource, DRBGProvider drbgProvider, boolean predictionResistant)
+    {
+        this.randomSource = randomSource;
+        this.entropySource = entropySource;
+        this.drbgProvider = drbgProvider;
+        this.predictionResistant = predictionResistant;
+    }
+
+    public void setSeed(byte[] seed)
+    {
+        synchronized (this)
+        {
+            if (randomSource != null)
+            {
+                this.randomSource.setSeed(seed);
+            }
+        }
+    }
+
+    public void setSeed(long seed)
+    {
+        synchronized (this)
+        {
+            // this will happen when SecureRandom() is created
+            if (randomSource != null)
+            {
+                this.randomSource.setSeed(seed);
+            }
+        }
+    }
+
+    public void nextBytes(byte[] bytes)
+    {
+        synchronized (this)
+        {
+            if (drbg == null)
+            {
+                drbg = drbgProvider.get(entropySource);
+            }
+
+            // check if a reseed is required...
+            if (drbg.generate(bytes, null, predictionResistant) < 0)
+            {
+                drbg.reseed(entropySource.getEntropy());
+                drbg.generate(bytes, null, predictionResistant);
+            }
+        }
+    }
+
+    public byte[] generateSeed(int numBytes)
+    {
+        byte[] bytes = new byte[numBytes];
+
+        this.nextBytes(bytes);
+
+        return bytes;
+    }
+}