1 files changed, 96 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/crypto/params/KDFFeedbackParameters.java b/core/src/main/java/org/spongycastle/crypto/params/KDFFeedbackParameters.java
new file mode 100644
index 00000000..44d1e964
--- /dev/null
+++ b/core/src/main/java/org/spongycastle/crypto/params/KDFFeedbackParameters.java
@@ -0,0 +1,96 @@
+package org.spongycastle.crypto.params;
+
+import org.spongycastle.crypto.DerivationParameters;
+import org.spongycastle.util.Arrays;
+
+/**
+ * Note that counter is only supported at the location presented in the
+ * NIST SP 800-108 specification, not in the additional locations present
+ * in the CAVP test vectors.
+ */
+public final class KDFFeedbackParameters
+    implements DerivationParameters
+{
+
+    // could be any valid value, using 32, don't know why
+    private static final int UNUSED_R = -1;
+
+    private final byte[] ki;
+    private final byte[] iv;
+    private final boolean useCounter;
+    private final int r;
+    private final byte[] fixedInputData;
+
+    private KDFFeedbackParameters(byte[] ki, byte[] iv, byte[] fixedInputData, int r, boolean useCounter)
+    {
+        if (ki == null)
+        {
+            throw new IllegalArgumentException("A KDF requires Ki (a seed) as input");
+        }
+        this.ki = Arrays.clone(ki);
+
+        if (fixedInputData == null)
+        {
+            this.fixedInputData = new byte[0];
+        }
+        else
+        {
+            this.fixedInputData = Arrays.clone(fixedInputData);
+        }
+
+        this.r = r;
+
+        if (iv == null)
+        {
+            this.iv = new byte[0];
+        }
+        else
+        {
+            this.iv = Arrays.clone(iv);
+        }
+
+        this.useCounter = useCounter;
+    }
+
+    public static KDFFeedbackParameters createWithCounter(
+        byte[] ki, final byte[] iv, byte[] fixedInputData, int r)
+    {
+        if (r != 8 && r != 16 && r != 24 && r != 32)
+        {
+            throw new IllegalArgumentException("Length of counter should be 8, 16, 24 or 32");
+        }
+
+        return new KDFFeedbackParameters(ki, iv, fixedInputData, r, true);
+    }
+
+    public static KDFFeedbackParameters createWithoutCounter(
+        byte[] ki, final byte[] iv, byte[] fixedInputData)
+    {
+        return new KDFFeedbackParameters(ki, iv, fixedInputData, UNUSED_R, false);
+    }
+
+    public byte[] getKI()
+    {
+        return ki;
+    }
+
+    public byte[] getIV()
+    {
+        return iv;
+    }
+
+    public boolean useCounter()
+    {
+        return useCounter;
+    }
+
+    public int getR()
+    {
+        return r;
+    }
+
+    public byte[] getFixedInputData()
+    {
+        return Arrays.clone(fixedInputData);
+    }
+}