further cleanup work on McEliece

added setting of digest to CCA2 params

core/src/main/java/org/bouncycastle/pqc/crypto/DigestingMessageSigner.java

@@ -89,14 +89,6 @@ public void reset()
         messDigest.reset();
     }
 
-    /**
-     * @deprecated use verifySignature
-     */
-    public boolean verify(byte[] signature)
-    {
-        return verifySignature(signature);
-    }
-
     /**
      * This function verifies the signature of the message that has been
      * updated, with the aid of the public key.

core/src/main/java/org/bouncycastle/pqc/crypto/MessageEncryptor.java

@@ -2,6 +2,7 @@
 
 
 import org.bouncycastle.crypto.CipherParameters;
+import org.bouncycastle.crypto.InvalidCipherTextException;
 
 /**
  * Base interface for a PQC encryption algorithm.
@@ -22,12 +23,13 @@ public interface MessageEncryptor
      * @param message the message to be signed.
      * @throws Exception 
      */
-    public byte[] messageEncrypt(byte[] message) throws Exception;
+    public byte[] messageEncrypt(byte[] message);
 
     /**
      *
      * @param cipher the cipher text of the message
      * @throws Exception 
      */
-    public byte[] messageDecrypt(byte[] cipher) throws Exception;
+    public byte[] messageDecrypt(byte[] cipher)
+        throws InvalidCipherTextException;
 }

core/src/main/java/org/bouncycastle/pqc/crypto/mceliece/McElieceCCA2KeyPairGenerator.java

@@ -5,13 +5,7 @@
 
 import org.bouncycastle.crypto.AsymmetricCipherKeyPair;
 import org.bouncycastle.crypto.AsymmetricCipherKeyPairGenerator;
-import org.bouncycastle.crypto.Digest;
 import org.bouncycastle.crypto.KeyGenerationParameters;
-import org.bouncycastle.crypto.digests.SHA1Digest;
-import org.bouncycastle.crypto.digests.SHA224Digest;
-import org.bouncycastle.crypto.digests.SHA256Digest;
-import org.bouncycastle.crypto.digests.SHA384Digest;
-import org.bouncycastle.crypto.digests.SHA512Digest;
 import org.bouncycastle.pqc.math.linearalgebra.GF2Matrix;
 import org.bouncycastle.pqc.math.linearalgebra.GF2mField;
 import org.bouncycastle.pqc.math.linearalgebra.GoppaCode;
@@ -110,36 +104,10 @@ public AsymmetricCipherKeyPair generateKeyPair()
         int k = shortG.getNumRows();
 
         // generate keys
-        McElieceCCA2PublicKeyParameters pubKey = new McElieceCCA2PublicKeyParameters(n, t, shortG, getDigest(mcElieceCCA2Params.getParameters().getDigest().getAlgorithmName()));
-        McElieceCCA2PrivateKeyParameters privKey = new McElieceCCA2PrivateKeyParameters(n, k, field, gp, p, getDigest(mcElieceCCA2Params.getParameters().getDigest().getAlgorithmName()));
+        McElieceCCA2PublicKeyParameters pubKey = new McElieceCCA2PublicKeyParameters(n, t, shortG, mcElieceCCA2Params.getParameters().getDigest());
+        McElieceCCA2PrivateKeyParameters privKey = new McElieceCCA2PrivateKeyParameters(n, k, field, gp, p, mcElieceCCA2Params.getParameters().getDigest());
 
         // return key pair
         return new AsymmetricCipherKeyPair(pubKey, privKey);
     }
-
-    static Digest getDigest(String digestName)
-    {
-        if (digestName.equals("SHA-1"))
-        {
-            return new SHA1Digest();
-        }
-        if (digestName.equals("SHA-224"))
-        {
-            return new SHA224Digest();
-        }
-        if (digestName.equals("SHA-256"))
-        {
-            return new SHA256Digest();
-        }
-        if (digestName.equals("SHA-384"))
-        {
-            return new SHA384Digest();
-        }
-        if (digestName.equals("SHA-512"))
-        {
-            return new SHA512Digest();
-        }
-
-        throw new IllegalArgumentException("unrecognised digest algorithm: " + digestName);
-    }
 }

core/src/main/java/org/bouncycastle/pqc/crypto/mceliece/McElieceCCA2KeyParameters.java

@@ -1,24 +1,23 @@
 package org.bouncycastle.pqc.crypto.mceliece;
 
-import org.bouncycastle.crypto.Digest;
 import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
 
 
 public class McElieceCCA2KeyParameters
     extends AsymmetricKeyParameter
 {
-    private Digest params;
+    private String params;
 
     public McElieceCCA2KeyParameters(
         boolean isPrivate,
-        Digest params)
+        String params)
     {
         super(isPrivate);
         this.params = params;
     }
 
 
-    public Digest getDigest()
+    public String getDigest()
     {
         return params;
     }

core/src/main/java/org/bouncycastle/pqc/crypto/mceliece/McElieceCCA2Parameters.java

@@ -1,22 +1,19 @@
 package org.bouncycastle.pqc.crypto.mceliece;
 
-import org.bouncycastle.crypto.Digest;
-import org.bouncycastle.crypto.digests.SHA256Digest;
-
 public class McElieceCCA2Parameters
     extends McElieceParameters
 {
-    private Digest digest;
+    private final String digest;
 
     /**
      * Constructor. Set the default parameters: extension degree.
      */
     public McElieceCCA2Parameters()
     {
-        this(DEFAULT_M, DEFAULT_T, new SHA256Digest());
+        this(DEFAULT_M, DEFAULT_T, "SHA-256");
     }
 
-    public McElieceCCA2Parameters(Digest digest)
+    public McElieceCCA2Parameters(String digest)
     {
         this(DEFAULT_M, DEFAULT_T, digest);
     }
@@ -29,7 +26,7 @@ public McElieceCCA2Parameters(Digest digest)
      */
     public McElieceCCA2Parameters(int keysize)
     {
-        this(keysize, new SHA256Digest());
+        this(keysize, "SHA-256");
     }
 
     /**
@@ -39,7 +36,7 @@ public McElieceCCA2Parameters(int keysize)
      * @param digest CCA2 mode digest
      * @throws IllegalArgumentException if <tt>keysize &lt; 1</tt>.
      */
-    public McElieceCCA2Parameters(int keysize, Digest digest)
+    public McElieceCCA2Parameters(int keysize, String digest)
     {
         super(keysize);
         this.digest = digest;
@@ -55,7 +52,7 @@ public McElieceCCA2Parameters(int keysize, Digest digest)
      */
     public McElieceCCA2Parameters(int m, int t)
     {
-        this(m, t, new SHA256Digest());
+        this(m, t, "SHA-256");
     }
 
     /**
@@ -66,7 +63,7 @@ public McElieceCCA2Parameters(int m, int t)
      * @throws IllegalArgumentException if <tt>m &lt; 1</tt> or <tt>m &gt; 32</tt> or
      * <tt>t &lt; 0</tt> or <tt>t &gt; n</tt>.
      */
-    public McElieceCCA2Parameters(int m, int t, Digest digest)
+    public McElieceCCA2Parameters(int m, int t, String digest)
     {
         super(m, t);
         this.digest = digest;
@@ -84,7 +81,7 @@ public McElieceCCA2Parameters(int m, int t, Digest digest)
      */
     public McElieceCCA2Parameters(int m, int t, int poly)
     {
-        this(m, t, poly, new SHA256Digest());
+        this(m, t, poly, "SHA-256");
     }
 
     /**
@@ -98,7 +95,7 @@ public McElieceCCA2Parameters(int m, int t, int poly)
      * <tt>t &lt; 0</tt> or <tt>t &gt; n</tt> or
      * <tt>poly</tt> is not an irreducible field polynomial.
      */
-    public McElieceCCA2Parameters(int m, int t, int poly, Digest digest)
+    public McElieceCCA2Parameters(int m, int t, int poly, String digest)
     {
         super(m, t, poly);
         this.digest = digest;
@@ -109,7 +106,7 @@ public McElieceCCA2Parameters(int m, int t, int poly, Digest digest)
      *
      * @return the CCA2 digest to use, null if not present.
      */
-    public Digest getDigest()
+    public String getDigest()
     {
         return digest;
     }

core/src/main/java/org/bouncycastle/pqc/crypto/mceliece/McElieceCCA2PrivateKeyParameters.java

@@ -1,7 +1,6 @@
 package org.bouncycastle.pqc.crypto.mceliece;
 
 
-import org.bouncycastle.crypto.Digest;
 import org.bouncycastle.pqc.math.linearalgebra.GF2Matrix;
 import org.bouncycastle.pqc.math.linearalgebra.GF2mField;
 import org.bouncycastle.pqc.math.linearalgebra.GoppaCode;
@@ -49,7 +48,7 @@ public class McElieceCCA2PrivateKeyParameters
      * @param digest McElieceCCA2Parameters
      */
     public McElieceCCA2PrivateKeyParameters(int n, int k, GF2mField field,
-                                            PolynomialGF2mSmallM gp, Permutation p, Digest digest)
+                                            PolynomialGF2mSmallM gp, Permutation p, String digest)
     {
         super(true, digest);
         this.n = n;

core/src/main/java/org/bouncycastle/pqc/crypto/mceliece/McElieceCCA2PublicKeyParameters.java

@@ -1,6 +1,5 @@
 package org.bouncycastle.pqc.crypto.mceliece;
 
-import org.bouncycastle.crypto.Digest;
 import org.bouncycastle.pqc.math.linearalgebra.GF2Matrix;
 
 /**
@@ -27,7 +26,7 @@ public class McElieceCCA2PublicKeyParameters
      * @param matrix generator matrix
      * @param digest McElieceCCA2Parameters
      */
-    public McElieceCCA2PublicKeyParameters(int n, int t, GF2Matrix matrix, Digest digest)
+    public McElieceCCA2PublicKeyParameters(int n, int t, GF2Matrix matrix, String digest)
     {
         super(false, digest);
 

core/src/main/java/org/bouncycastle/pqc/crypto/mceliece/McElieceCipher.java

@@ -44,14 +44,15 @@ public class McElieceCipher
     // The maximum number of bytes the cipher can encrypt
     public int cipherTextSize;
 
-    McElieceKeyParameters key;
+    private McElieceKeyParameters key;
+    private boolean forEncryption;
 
 
-    public void init(boolean forSigning,
+    public void init(boolean forEncryption,
                      CipherParameters param)
     {
-
-        if (forSigning)
+        this.forEncryption = forEncryption;
+        if (forEncryption)
         {
             if (param instanceof ParametersWithRandom)
             {
@@ -77,7 +78,6 @@ public void init(boolean forSigning,
 
     }
 
-
     /**
      * Return the key size of the given key object.
      *
@@ -130,6 +130,10 @@ public void initCipherDecrypt(McEliecePrivateKeyParameters privKey)
      */
     public byte[] messageEncrypt(byte[] input)
     {
+        if (!forEncryption)
+        {
+            throw new IllegalStateException("cipher initialised for decryption");
+        }
         GF2Vector m = computeMessageRepresentative(input);
         GF2Vector z = new GF2Vector(n, t, sr);
 
@@ -158,6 +162,11 @@ private GF2Vector computeMessageRepresentative(byte[] input)
     public byte[] messageDecrypt(byte[] input)
         throws InvalidCipherTextException
     {
+        if (forEncryption)
+        {
+            throw new IllegalStateException("cipher initialised for decryption");
+        }
+
         GF2Vector vec = GF2Vector.OS2VP(n, input);
         McEliecePrivateKeyParameters privKey = (McEliecePrivateKeyParameters)key;
         GF2mField field = privKey.getField();

core/src/main/java/org/bouncycastle/pqc/crypto/mceliece/McElieceFujisakiCipher.java

@@ -41,13 +41,14 @@ public class McElieceFujisakiCipher
     private int n, k, t;
 
     McElieceCCA2KeyParameters key;
+    private boolean forEncryption;
 
 
-    public void init(boolean forEncrypting,
+    public void init(boolean forEncryption,
                      CipherParameters param)
     {
-
-        if (forEncrypting)
+        this.forEncryption = forEncryption;
+        if (forEncryption)
         {
             if (param instanceof ParametersWithRandom)
             {
@@ -93,7 +94,7 @@ public int getKeySize(McElieceCCA2KeyParameters key)
     private void initCipherEncrypt(McElieceCCA2PublicKeyParameters pubKey)
     {
         this.sr = sr != null ? sr : new SecureRandom();
-        this.messDigest = pubKey.getDigest();
+        this.messDigest = Utils.getDigest(pubKey.getDigest());
         n = pubKey.getN();
         k = pubKey.getK();
         t = pubKey.getT();
@@ -102,14 +103,19 @@ private void initCipherEncrypt(McElieceCCA2PublicKeyParameters pubKey)
 
     public void initCipherDecrypt(McElieceCCA2PrivateKeyParameters privKey)
     {
-        this.messDigest = privKey.getDigest();
+        this.messDigest = Utils.getDigest(privKey.getDigest());
         n = privKey.getN();
         t = privKey.getT();
     }
 
 
     public byte[] messageEncrypt(byte[] input)
     {
+        if (!forEncryption)
+        {
+            throw new IllegalStateException("cipher initialised for decryption");
+        }
+
         // generate random vector r of length k bits
         GF2Vector r = new GF2Vector(k, sr);
 
@@ -154,6 +160,11 @@ public byte[] messageEncrypt(byte[] input)
     public byte[] messageDecrypt(byte[] input)
         throws InvalidCipherTextException
     {
+        if (forEncryption)
+        {
+            throw new IllegalStateException("cipher initialised for decryption");
+        }
+
         int c1Len = (n + 7) >> 3;
         int c2Len = input.length - c1Len;