re PR libgcj/19729 (libgcj DSASignature.java null pointer exception)

2005-05-18  Thomas Fitzsimmons  <fitzsim@redhat.com>

	PR libgcj/19729
	* gnu/java/security/provider/DSASignature.java: Import updates
	from GNU Crypto.

From-SVN: r99904

libjava/ChangeLog

@@ -1,3 +1,9 @@
+2005-05-18  Thomas Fitzsimmons  <fitzsim@redhat.com>
+
+	PR libgcj/19729
+	* gnu/java/security/provider/DSASignature.java: Import updates
+	from GNU Crypto.
+
 2005-05-18  Anthony Green  <green@redhat.com>
 
 	* jni/gtk-peer/gtk_jawt.c (classpath_jawt_object_lock,

libjava/gnu/java/security/provider/DSASignature.java

@@ -51,7 +51,6 @@ import java.security.InvalidKeyException;
 import java.security.InvalidParameterException;
 import java.security.MessageDigest;
 import java.security.NoSuchAlgorithmException;
-import java.security.NoSuchProviderException;
 import java.security.PrivateKey;
 import java.security.PublicKey;
 import java.security.SecureRandom;
@@ -67,22 +66,17 @@ public class DSASignature extends SignatureSpi
 {
   private DSAPublicKey publicKey;
   private DSAPrivateKey privateKey;
-  private MessageDigest digest = null;
+  private final MessageDigest digest;
+  private final SecureRandom random;
 
-  public DSASignature()
+  public DSASignature() throws NoSuchAlgorithmException
-  {}
+  {
+    random = new SecureRandom();
+    digest = MessageDigest.getInstance ("SHA1");
+  }
 
   private void init()
   {
-    if( digest == null ) {
-      try {
-	digest = MessageDigest.getInstance( "SHA1", "GNU" );
-      } catch ( NoSuchAlgorithmException nsae ) {
-	digest = null;
-      } catch ( NoSuchProviderException nspe ) {
-	digest = null;
-      }
-    }
     digest.reset();
   }
 
@@ -102,7 +96,7 @@ public class DSASignature extends SignatureSpi
     if (privateKey instanceof DSAPrivateKey)
       this.privateKey = (DSAPrivateKey) privateKey;
     else
-      throw new InvalidKeyException();
+      throw new InvalidKeyException ("not a DSA private key");
 
     init();
   }
@@ -114,7 +108,7 @@ public class DSASignature extends SignatureSpi
     if (privateKey instanceof DSAPrivateKey)
       this.privateKey = (DSAPrivateKey) privateKey;
     else
-      throw new InvalidKeyException();
+      throw new InvalidKeyException ("not a DSA private key");
 
     appRandom = random;
     init();
@@ -123,38 +117,29 @@ public class DSASignature extends SignatureSpi
   public void engineUpdate(byte b)
     throws SignatureException
   {
-    if( digest == null )
-      throw new SignatureException();		
-
     digest.update (b);
   }
 
   public void engineUpdate (byte[] b, int off, int len)
     throws SignatureException
   {
-    if( digest == null )
-      throw new SignatureException();		
-
     digest.update (b, off, len);
   }
 
-  public byte[] engineSign()
+  public byte[] engineSign() throws SignatureException
-    throws SignatureException
   {
-    if( digest == null )
-      throw new SignatureException();		
     if (privateKey == null)
-      throw new SignatureException();		
+      throw new SignatureException ("not initialized for signing");
-
-    try {
 
+    try
+      {
         BigInteger g = privateKey.getParams().getG();
         BigInteger p = privateKey.getParams().getP();
         BigInteger q = privateKey.getParams().getQ();
 
         BigInteger x = privateKey.getX();
 
-      BigInteger k = new BigInteger( 159, (Random)appRandom );
+        BigInteger k = new BigInteger (159, appRandom != null ? appRandom : random);
 
         BigInteger r = g.modPow(k, p);
         r = r.mod(q);
@@ -167,14 +152,22 @@ public class DSASignature extends SignatureSpi
 
         ByteArrayOutputStream bout = new ByteArrayOutputStream();
         ArrayList seq = new ArrayList (2);
-      seq.set(0, new DERValue(DER.INTEGER, r));
+        seq.add(0, new DERValue (DER.INTEGER, r));
-      seq.set(1, new DERValue(DER.INTEGER, s));
+        seq.add(1, new DERValue (DER.INTEGER, s));
         DERWriter.write (bout, new DERValue (DER.CONSTRUCTED | DER.SEQUENCE, seq));
         return bout.toByteArray();
-    } catch (IOException ioe) {
+      }
-      throw new SignatureException();
+    catch (IOException ioe)
-    } catch ( ArithmeticException ae ) {
+      {
-      throw new SignatureException();
+        SignatureException se = new SignatureException();
+        se.initCause (ioe);
+        throw se;
+      }
+    catch (ArithmeticException ae)
+      {
+        SignatureException se = new SignatureException();
+        se.initCause (ae);
+        throw se;
       }
   }
 
@@ -183,7 +176,7 @@ public class DSASignature extends SignatureSpi
   {
     byte tmp[] = engineSign();
     if (tmp.length > len)
-      throw new SignatureException();
+      throw new SignatureException ("output buffer too short");
     System.arraycopy (tmp, 0, outbuf, offset, tmp.length);
     return tmp.length;
   }
@@ -192,7 +185,8 @@ public class DSASignature extends SignatureSpi
     throws SignatureException
   {
     // Decode sigBytes from ASN.1 DER encoding
-    try {
+    try
+      {
         DERReader in = new DERReader (sigBytes);
         DERValue val = in.read();
         if (!val.isConstructed())
@@ -215,15 +209,18 @@ public class DSASignature extends SignatureSpi
 
         BigInteger u2 = r.multiply (w).mod(q);
 
-      //This should test the compiler :)
         BigInteger v = g.modPow (u1, p).multiply (y.modPow (u2, p)).mod (p).mod (q);
 
         if (v.equals (r))
           return true;
         else
           return false;
-    } catch (IOException ioe) {
+      }
-      throw new SignatureException("badly formed signature");
+    catch (IOException ioe)
+      {
+        SignatureException se = new SignatureException ("badly formed signature");
+        se.initCause (ioe);
+        throw se;
       }
   }
 
@@ -247,17 +244,8 @@ public class DSASignature extends SignatureSpi
     throw new InvalidParameterException();
   }
 
-  public Object clone()
+  public Object clone() throws CloneNotSupportedException
-    //throws CloneNotSupportedException
   {
-    return new DSASignature( this );
+    return super.clone();
-  }
-
-  private DSASignature( DSASignature copy )
-  {
-    this();
-    this.publicKey = copy.publicKey;
-    this.privateKey = copy.privateKey;
-    this.digest = copy.digest;
   }
 }