reverted some changes to get ml-kem working (passes acvp test, not sure if ACVP is up to date)

Author: royb

core/src/main/java/org/bouncycastle/pqc/crypto/crystals/kyber/KyberIndCpa.java

@@ -55,7 +55,11 @@ byte[][] generateKeyPair(byte[] d)
         // (p, sigma) <- G(d || k)
 
         byte[] buf = new byte[64];
-        symmetric.hash_g(buf, Arrays.concatenate(d, Pack.intToLittleEndian(kyberK)));
+        //TODO: specs specifies K to be concatenated to with d but acvp tests says otherwise
+        symmetric.hash_g(buf, d);
+//        byte[] k = new byte[1];
+//        k[0] = (byte)kyberK;
+//        symmetric.hash_g(buf, Arrays.concatenate(d, k));
 
         byte[] publicSeed = new byte[32]; // p in docs
         byte[] noiseSeed = new byte[32]; // sigma in docs
@@ -177,7 +181,7 @@ public byte[] encrypt(byte[] publicKeyInput, byte[] msg, byte[] coins)
             aMatrixTranspose[i] = new PolyVec(engine);
         }
 
-        generateMatrix(aMatrixTranspose, seed, false);
+        generateMatrix(aMatrixTranspose, seed, true);
 
         // System.out.print("matrix transposed = ");
         // for (i = 0; i < kyberK; i++) {

core/src/main/java/org/bouncycastle/pqc/crypto/crystals/kyber/KyberKEMGenerator.java

@@ -30,4 +30,13 @@ public SecretWithEncapsulation generateEncapsulated(AsymmetricKeyParameter recip
         byte[][] kemEncrypt = engine.kemEncrypt(key.getEncoded(), randBytes);
         return new SecretWithEncapsulationImpl(kemEncrypt[0], kemEncrypt[1]);
     }
+    public SecretWithEncapsulation internalGenerateEncapsulated(AsymmetricKeyParameter recipientKey, byte[] randBytes)
+    {
+        KyberPublicKeyParameters key = (KyberPublicKeyParameters)recipientKey;
+        KyberEngine engine = key.getParameters().getEngine();
+        engine.init(sr);
+
+        byte[][] kemEncrypt = engine.kemEncryptInternal(key.getEncoded(), randBytes);
+        return new SecretWithEncapsulationImpl(kemEncrypt[0], kemEncrypt[1]);
+    }
 }

core/src/main/java/org/bouncycastle/pqc/crypto/crystals/kyber/KyberKeyPairGenerator.java

@@ -45,4 +45,14 @@ public AsymmetricCipherKeyPair generateKeyPair()
         return genKeyPair();
     }
 
+    public AsymmetricCipherKeyPair internalGenerateKeyPair(byte[] d, byte[] z)
+    {
+        byte[][] keyPair = kyberParams.getEngine().generateKemKeyPairInternal(d, z);
+
+        KyberPublicKeyParameters pubKey = new KyberPublicKeyParameters(kyberParams, keyPair[0], keyPair[1]);
+        KyberPrivateKeyParameters privKey = new KyberPrivateKeyParameters(kyberParams,  keyPair[2], keyPair[3], keyPair[4], keyPair[0], keyPair[1]);
+
+        return new AsymmetricCipherKeyPair(pubKey, privKey);
+    }
+
 }

core/src/main/java/org/bouncycastle/pqc/crypto/crystals/kyber/KyberParameters.java

@@ -32,7 +32,7 @@ public String getName()
         return name;
     }
 
-    KyberEngine getEngine()
+    public KyberEngine getEngine()
     {
         return new KyberEngine(k, usingAes);
     }