diff options
Diffstat (limited to 'gnu/java/security/provider/DSASignature.java')
| -rw-r--r-- | gnu/java/security/provider/DSASignature.java | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/gnu/java/security/provider/DSASignature.java b/gnu/java/security/provider/DSASignature.java new file mode 100644 index 000000000..5665ad9fd --- /dev/null +++ b/gnu/java/security/provider/DSASignature.java @@ -0,0 +1,211 @@ +package gnu.java.security.provider;
+
+import java.math.BigInteger;
+import java.security.InvalidAlgorithmParameterException;
+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;
+import java.security.SignatureException;
+import java.security.SignatureSpi;
+import java.security.interfaces.DSAPrivateKey;
+import java.security.interfaces.DSAPublicKey;
+import java.security.spec.AlgorithmParameterSpec;
+import java.util.Random;
+import gnu.java.security.der.DEREncodingException;
+
+public class DSASignature extends SignatureSpi
+{
+private DSAPublicKey publicKey;
+private DSAPrivateKey privateKey;
+private MessageDigest digest = null;
+
+public DSASignature()
+{}
+
+private void init()
+{
+ if( digest == null ) {
+ try {
+ digest = MessageDigest.getInstance( "SHA1", "GNU" );
+ } catch ( NoSuchAlgorithmException nsae ) {
+ digest = null;
+ } catch ( NoSuchProviderException nspe ) {
+ digest = null;
+ }
+ }
+ digest.reset();
+}
+
+public void engineInitVerify(PublicKey publicKey)
+ throws InvalidKeyException
+{
+ if( publicKey instanceof DSAPublicKey )
+ this.publicKey = (DSAPublicKey)publicKey;
+ else
+ throw new InvalidKeyException();
+ init();
+}
+
+public void engineInitSign(PrivateKey privateKey)
+ throws InvalidKeyException
+{
+ if( privateKey instanceof DSAPrivateKey )
+ this.privateKey = (DSAPrivateKey)privateKey;
+ else
+ throw new InvalidKeyException();
+
+ init();
+}
+
+public void engineInitSign(PrivateKey privateKey,
+ SecureRandom random)
+ throws InvalidKeyException
+{
+ if( privateKey instanceof DSAPrivateKey )
+ this.privateKey = (DSAPrivateKey)privateKey;
+ else
+ throw new InvalidKeyException();
+
+ appRandom = random;
+ init();
+}
+
+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()
+ throws SignatureException
+{
+ if( digest == null )
+ throw new SignatureException();
+ if( privateKey == null)
+ throw new SignatureException();
+
+ 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 r = g.modPow(k, p);
+ r = r.mod(q);
+
+ byte bytes[] = digest.digest();
+ BigInteger sha = new BigInteger(1, bytes);
+
+ BigInteger s = sha.add( x.multiply( r ) );
+ s = s.multiply( k.modInverse(q) ).mod( q );
+
+ DERWriter writer = new DERWriter();
+ return writer.joinarrays( writer.writeBigInteger( r ), writer.writeBigInteger( s ) );
+
+ } catch ( ArithmeticException ae ) {
+ throw new SignatureException();
+ }
+}
+
+public int engineSign(byte[] outbuf, int offset, int len)
+ throws SignatureException
+{
+ byte tmp[] = engineSign();
+ if( tmp.length > len )
+ throw new SignatureException();
+ System.arraycopy( tmp, 0, outbuf, offset, tmp.length );
+ return tmp.length;
+}
+
+public boolean engineVerify(byte[] sigBytes)
+ throws SignatureException
+{
+ //Decode sigBytes from ASN.1 DER encoding
+ try {
+ DERReader reader = new DERReader( sigBytes );
+ BigInteger r = reader.getBigInteger();
+ BigInteger s = reader.getBigInteger();
+
+ BigInteger g = publicKey.getParams().getG();
+ BigInteger p = publicKey.getParams().getP();
+ BigInteger q = publicKey.getParams().getQ();
+
+ BigInteger y = publicKey.getY();
+
+ BigInteger w = s.modInverse( q );
+
+ byte bytes[] = digest.digest();
+ BigInteger sha = new BigInteger(1, bytes);
+
+ BigInteger u1 = w.multiply( sha ).mod( q );
+
+ 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 ( DEREncodingException deree ) {
+ throw new SignatureException();
+ }
+}
+
+public void engineSetParameter(String param,
+ Object value)
+ throws InvalidParameterException
+{
+ throw new InvalidParameterException();
+}
+
+public void engineSetParameter(AlgorithmParameterSpec params)
+ throws InvalidAlgorithmParameterException
+{
+ throw new InvalidParameterException();
+
+}
+
+public Object engineGetParameter(String param)
+ throws InvalidParameterException
+{
+ throw new InvalidParameterException();
+}
+
+public Object clone()
+ //throws CloneNotSupportedException
+{
+ return new DSASignature( this );
+}
+
+private DSASignature( DSASignature copy )
+{
+ this();
+ this.publicKey = copy.publicKey;
+ this.privateKey = copy.privateKey;
+ this.digest = copy.digest;
+}
+
+}
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