forgot to push new Symmetric class in SABER

Author: royb

core/src/main/java/org/bouncycastle/pqc/crypto/saber/Symmetric.java

@@ -0,0 +1,102 @@
+package org.bouncycastle.pqc.crypto.saber;
+
+import org.bouncycastle.crypto.Digest;
+import org.bouncycastle.crypto.Xof;
+import org.bouncycastle.crypto.digests.SHA256Digest;
+import org.bouncycastle.crypto.digests.SHA3Digest;
+import org.bouncycastle.crypto.digests.SHA512Digest;
+import org.bouncycastle.crypto.digests.SHAKEDigest;
+import org.bouncycastle.crypto.engines.AESEngine;
+import org.bouncycastle.crypto.modes.SICBlockCipher;
+import org.bouncycastle.crypto.params.KeyParameter;
+import org.bouncycastle.crypto.params.ParametersWithIV;
+import sun.security.provider.SHA;
+
+abstract class Symmetric
+{
+    abstract void hash_h(byte[] out, byte[] in, int outOffset);
+
+    abstract void hash_g(byte[] out, byte[] in);
+
+    abstract void prf(byte[] out, byte[] in, int inLen, int outLen);
+
+    static class ShakeSymmetric
+        extends Symmetric
+    {
+
+        private final SHA3Digest sha3Digest256;
+        private final SHA3Digest sha3Digest512;
+        private final Xof shakeDigest;
+        ShakeSymmetric()
+        {
+            shakeDigest = new SHAKEDigest(128);
+            sha3Digest256 = new SHA3Digest(256);
+            sha3Digest512 = new SHA3Digest(512);
+        }
+
+        @Override
+        void hash_h(byte[] out, byte[] in, int outOffset)
+        {
+            sha3Digest256.update(in, 0, in.length);
+            sha3Digest256.doFinal(out, outOffset);
+        }
+
+        @Override
+        void hash_g(byte[] out, byte[] in)
+        {
+            sha3Digest512.update(in, 0, in.length);
+            sha3Digest512.doFinal(out, 0);
+        }
+
+        @Override
+        void prf(byte[] out, byte[] in, int inLen, int outLen)
+        {
+            shakeDigest.reset();
+            shakeDigest.update(in, 0, inLen);
+            shakeDigest.doFinal(out, 0, outLen);
+        }
+
+
+    }
+    static class AesSymmetric
+        extends Symmetric
+    {
+
+        private final SHA256Digest sha256Digest;
+        private final SHA512Digest sha512Digest;
+
+        private final SICBlockCipher cipher;
+
+
+        AesSymmetric()
+        {
+            sha256Digest = new SHA256Digest();
+            sha512Digest = new SHA512Digest();
+            this.cipher = new SICBlockCipher(new AESEngine());
+        }
+        @Override
+        void hash_h(byte[] out, byte[] in, int outOffset)
+        {
+            sha256Digest.update(in, 0, in.length);
+            sha256Digest.doFinal(out, outOffset);
+        }
+
+        @Override
+        void hash_g(byte[] out, byte[] in)
+        {
+            sha512Digest.update(in, 0, in.length);
+            sha512Digest.doFinal(out, 0);
+        }
+
+        @Override
+        void prf(byte[] out, byte[] in, int inLen, int outLen)
+        {
+            ParametersWithIV kp = new ParametersWithIV(new KeyParameter(in, 0, 32 ), new byte[16]);
+            cipher.init(true, kp);
+            byte[] buf = new byte[outLen];   // TODO: there might be a more efficient way of doing this...
+            cipher.processBytes(buf, 0, outLen, out, 0);
+        }
+
+
+    }
+}