1 files changed, 388 insertions, 0 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/pqc/crypto/ntru/NTRUSigningPrivateKeyParameters.java b/bcprov/src/main/java/org/bouncycastle/pqc/crypto/ntru/NTRUSigningPrivateKeyParameters.java
new file mode 100644
index 0000000..451422e
--- /dev/null
+++ b/bcprov/src/main/java/org/bouncycastle/pqc/crypto/ntru/NTRUSigningPrivateKeyParameters.java
@@ -0,0 +1,388 @@
+package org.bouncycastle.pqc.crypto.ntru;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
+import org.bouncycastle.pqc.math.ntru.polynomial.DenseTernaryPolynomial;
+import org.bouncycastle.pqc.math.ntru.polynomial.IntegerPolynomial;
+import org.bouncycastle.pqc.math.ntru.polynomial.Polynomial;
+import org.bouncycastle.pqc.math.ntru.polynomial.ProductFormPolynomial;
+import org.bouncycastle.pqc.math.ntru.polynomial.SparseTernaryPolynomial;
+
+/**
+ * A NtruSign private key comprises one or more {@link NTRUSigningPrivateKeyParameters.Basis} of three polynomials each,
+ * except the zeroth basis for which <code>h</code> is undefined.
+ */
+public class NTRUSigningPrivateKeyParameters
+    extends AsymmetricKeyParameter
+{
+    private List<Basis> bases;
+    private NTRUSigningPublicKeyParameters publicKey;
+
+    /**
+     * Constructs a new private key from a byte array
+     *
+     * @param b      an encoded private key
+     * @param params the NtruSign parameters to use
+     */
+    public NTRUSigningPrivateKeyParameters(byte[] b, NTRUSigningKeyGenerationParameters params)
+        throws IOException
+    {
+        this(new ByteArrayInputStream(b), params);
+    }
+
+    /**
+     * Constructs a new private key from an input stream
+     *
+     * @param is     an input stream
+     * @param params the NtruSign parameters to use
+     */
+    public NTRUSigningPrivateKeyParameters(InputStream is, NTRUSigningKeyGenerationParameters params)
+        throws IOException
+    {
+        super(true);
+        bases = new ArrayList<Basis>();
+        for (int i = 0; i <= params.B; i++)
+        // include a public key h[i] in all bases except for the first one
+        {
+            add(new Basis(is, params, i != 0));
+        }
+        publicKey = new NTRUSigningPublicKeyParameters(is, params.getSigningParameters());
+    }
+
+    public NTRUSigningPrivateKeyParameters(List<Basis> bases, NTRUSigningPublicKeyParameters publicKey)
+    {
+        super(true);
+        this.bases = new ArrayList<Basis>(bases);
+        this.publicKey = publicKey;
+    }
+
+    /**
+     * Adds a basis to the key.
+     *
+     * @param b a NtruSign basis
+     */
+    private void add(Basis b)
+    {
+        bases.add(b);
+    }
+
+    /**
+     * Returns the <code>i</code>-th basis
+     *
+     * @param i the index
+     * @return the basis at index <code>i</code>
+     */
+    public Basis getBasis(int i)
+    {
+        return bases.get(i);
+    }
+
+    public NTRUSigningPublicKeyParameters getPublicKey()
+    {
+        return publicKey;
+    }
+
+    /**
+     * Converts the key to a byte array
+     *
+     * @return the encoded key
+     */
+    public byte[] getEncoded()
+        throws IOException
+    {
+        ByteArrayOutputStream os = new ByteArrayOutputStream();
+        for (int i = 0; i < bases.size(); i++)
+        {
+            // all bases except for the first one contain a public key
+            bases.get(i).encode(os, i != 0);
+        }
+
+        os.write(publicKey.getEncoded());
+
+        return os.toByteArray();
+    }
+
+    /**
+     * Writes the key to an output stream
+     *
+     * @param os an output stream
+     * @throws IOException
+     */
+    public void writeTo(OutputStream os)
+        throws IOException
+    {
+        os.write(getEncoded());
+    }
+
+    @Override
+    public int hashCode()
+    {
+        final int prime = 31;
+        int result = 1;
+        result = prime * result;
+        if (bases==null) return result;
+        result += bases.hashCode();
+        for (Basis basis : bases)
+        {
+            result += basis.hashCode();
+        }
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj)
+    {
+        if (this == obj)
+        {
+            return true;
+        }
+        if (obj == null)
+        {
+            return false;
+        }
+        if (getClass() != obj.getClass())
+        {
+            return false;
+        }
+        NTRUSigningPrivateKeyParameters other = (NTRUSigningPrivateKeyParameters)obj;
+        if ((bases == null) != (other.bases == null))
+        {
+            return false;
+        }
+        if (bases == null)
+        {
+            return true;
+        }
+        if (bases.size() != other.bases.size())
+        {
+            return false;
+        }
+        for (int i = 0; i < bases.size(); i++)
+        {
+            Basis basis1 = bases.get(i);
+            Basis basis2 = other.bases.get(i);
+            if (!basis1.f.equals(basis2.f))
+            {
+                return false;
+            }
+            if (!basis1.fPrime.equals(basis2.fPrime))
+            {
+                return false;
+            }
+            if (i != 0 && !basis1.h.equals(basis2.h))   // don't compare h for the 0th basis
+            {
+                return false;
+            }
+            if (!basis1.params.equals(basis2.params))
+            {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * A NtruSign basis. Contains three polynomials <code>f, f', h</code>.
+     */
+    public static class Basis
+    {
+        public Polynomial f;
+        public Polynomial fPrime;
+        public IntegerPolynomial h;
+        NTRUSigningKeyGenerationParameters params;
+
+        /**
+         * Constructs a new basis from polynomials <code>f, f', h</code>.
+         *
+         * @param f
+         * @param fPrime
+         * @param h
+         * @param params NtruSign parameters
+         */
+        protected Basis(Polynomial f, Polynomial fPrime, IntegerPolynomial h, NTRUSigningKeyGenerationParameters params)
+        {
+            this.f = f;
+            this.fPrime = fPrime;
+            this.h = h;
+            this.params = params;
+        }
+
+        /**
+         * Reads a basis from an input stream and constructs a new basis.
+         *
+         * @param is        an input stream
+         * @param params    NtruSign parameters
+         * @param include_h whether to read the polynomial <code>h</code> (<code>true</code>) or only <code>f</code> and <code>f'</code> (<code>false</code>)
+         */
+        Basis(InputStream is, NTRUSigningKeyGenerationParameters params, boolean include_h)
+            throws IOException
+        {
+            int N = params.N;
+            int q = params.q;
+            int d1 = params.d1;
+            int d2 = params.d2;
+            int d3 = params.d3;
+            boolean sparse = params.sparse;
+            this.params = params;
+
+            if (params.polyType == NTRUParameters.TERNARY_POLYNOMIAL_TYPE_PRODUCT)
+            {
+                f = ProductFormPolynomial.fromBinary(is, N, d1, d2, d3 + 1, d3);
+            }
+            else
+            {
+                IntegerPolynomial fInt = IntegerPolynomial.fromBinary3Tight(is, N);
+                f = sparse ? new SparseTernaryPolynomial(fInt) : new DenseTernaryPolynomial(fInt);
+            }
+
+            if (params.basisType == NTRUSigningKeyGenerationParameters.BASIS_TYPE_STANDARD)
+            {
+                IntegerPolynomial fPrimeInt = IntegerPolynomial.fromBinary(is, N, q);
+                for (int i = 0; i < fPrimeInt.coeffs.length; i++)
+                {
+                    fPrimeInt.coeffs[i] -= q / 2;
+                }
+                fPrime = fPrimeInt;
+            }
+            else if (params.polyType == NTRUParameters.TERNARY_POLYNOMIAL_TYPE_PRODUCT)
+            {
+                fPrime = ProductFormPolynomial.fromBinary(is, N, d1, d2, d3 + 1, d3);
+            }
+            else
+            {
+                fPrime = IntegerPolynomial.fromBinary3Tight(is, N);
+            }
+
+            if (include_h)
+            {
+                h = IntegerPolynomial.fromBinary(is, N, q);
+            }
+        }
+
+        /**
+         * Writes the basis to an output stream
+         *
+         * @param os        an output stream
+         * @param include_h whether to write the polynomial <code>h</code> (<code>true</code>) or only <code>f</code> and <code>f'</code> (<code>false</code>)
+         * @throws IOException
+         */
+        void encode(OutputStream os, boolean include_h)
+            throws IOException
+        {
+            int q = params.q;
+
+            os.write(getEncoded(f));
+            if (params.basisType == NTRUSigningKeyGenerationParameters.BASIS_TYPE_STANDARD)
+            {
+                IntegerPolynomial fPrimeInt = fPrime.toIntegerPolynomial();
+                for (int i = 0; i < fPrimeInt.coeffs.length; i++)
+                {
+                    fPrimeInt.coeffs[i] += q / 2;
+                }
+                os.write(fPrimeInt.toBinary(q));
+            }
+            else
+            {
+                os.write(getEncoded(fPrime));
+            }
+            if (include_h)
+            {
+                os.write(h.toBinary(q));
+            }
+        }
+
+        private byte[] getEncoded(Polynomial p)
+        {
+            if (p instanceof ProductFormPolynomial)
+            {
+                return ((ProductFormPolynomial)p).toBinary();
+            }
+            else
+            {
+                return p.toIntegerPolynomial().toBinary3Tight();
+            }
+        }
+
+        @Override
+        public int hashCode()
+        {
+            final int prime = 31;
+            int result = 1;
+            result = prime * result + ((f == null) ? 0 : f.hashCode());
+            result = prime * result + ((fPrime == null) ? 0 : fPrime.hashCode());
+            result = prime * result + ((h == null) ? 0 : h.hashCode());
+            result = prime * result + ((params == null) ? 0 : params.hashCode());
+            return result;
+        }
+
+        @Override
+        public boolean equals(Object obj)
+        {
+            if (this == obj)
+            {
+                return true;
+            }
+            if (obj == null)
+            {
+                return false;
+            }
+            if (!(obj instanceof Basis))
+            {
+                return false;
+            }
+            Basis other = (Basis)obj;
+            if (f == null)
+            {
+                if (other.f != null)
+                {
+                    return false;
+                }
+            }
+            else if (!f.equals(other.f))
+            {
+                return false;
+            }
+            if (fPrime == null)
+            {
+                if (other.fPrime != null)
+                {
+                    return false;
+                }
+            }
+            else if (!fPrime.equals(other.fPrime))
+            {
+                return false;
+            }
+            if (h == null)
+            {
+                if (other.h != null)
+                {
+                    return false;
+                }
+            }
+            else if (!h.equals(other.h))
+            {
+                return false;
+            }
+            if (params == null)
+            {
+                if (other.params != null)
+                {
+                    return false;
+                }
+            }
+            else if (!params.equals(other.params))
+            {
+                return false;
+            }
+            return true;
+        }
+    }
+}