Extracted ASN.1/DER encoding to method (#368)

src/main/java/net/schmizz/sshj/signature/SignatureDSA.java

@@ -82,21 +82,10 @@ public class SignatureDSA
     }
 
     @Override
-    public boolean verify(byte[] incomingSig) {
+    public boolean verify(byte[] sig) {
-        byte[] extractSig = extractSig(incomingSig, "ssh-dss");
         try {
-            // ASN.1
+            byte[] sigBlob = extractSig(sig, "ssh-dss");
-            ByteArrayOutputStream os = new ByteArrayOutputStream();
+            return signature.verify(asnEncode(sigBlob));
-            ASN1OutputStream asn1OutputStream = new ASN1OutputStream(os);
-            ASN1EncodableVector vector = new ASN1EncodableVector();
-            BigInteger bigInteger = new BigInteger(1, Arrays.copyOfRange(extractSig, 0, 20));
-            vector.add(new ASN1Integer(bigInteger));
-            BigInteger bigInteger2 = new BigInteger(1, Arrays.copyOfRange(extractSig, 20, 40));
-            vector.add(new ASN1Integer(bigInteger2));
-            asn1OutputStream.writeObject(new DERSequence(vector));
-            asn1OutputStream.close();
-            byte[] finalSig = os.toByteArray();
-            return signature.verify(finalSig);
         } catch (SignatureException e) {
             throw new SSHRuntimeException(e);
         } catch (IOException e) {
@@ -104,4 +93,23 @@ public class SignatureDSA
         }
     }
 
+    /**
+     * Encodes the signature as a DER sequence (ASN.1 format).
+     */
+    private byte[] asnEncode(byte[] sigBlob) throws IOException {
+        byte[] r = new BigInteger(1, Arrays.copyOfRange(sigBlob, 0, 20)).toByteArray();
+        byte[] s = new BigInteger(1, Arrays.copyOfRange(sigBlob, 20, 40)).toByteArray();
+
+        ASN1EncodableVector vector = new ASN1EncodableVector();
+        vector.add(new ASN1Integer(r));
+        vector.add(new ASN1Integer(s));
+
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        ASN1OutputStream asnOS = new ASN1OutputStream(baos);
+
+        asnOS.writeObject(new DERSequence(vector));
+        asnOS.flush();
+
+        return baos.toByteArray();
+    }
 }

src/main/java/net/schmizz/sshj/signature/SignatureECDSA.java

@@ -98,7 +98,7 @@ public class SignatureECDSA extends AbstractSignature {
         System.arraycopy(sig, 4, r, 0, rLen);
         System.arraycopy(sig, 6 + rLen, s, 0, sLen);
 
-        Buffer buf = new Buffer.PlainBuffer();
+        Buffer.PlainBuffer buf = new Buffer.PlainBuffer();
         buf.putMPInt(new BigInteger(r));
         buf.putMPInt(new BigInteger(s));
 
@@ -107,18 +107,9 @@ public class SignatureECDSA extends AbstractSignature {
 
     @Override
     public boolean verify(byte[] sig) {
-        byte[] r;
-        byte[] s;
         try {
-            Buffer sigbuf = new Buffer.PlainBuffer(extractSig(sig, keyTypeName));
+            byte[] sigBlob = extractSig(sig, keyTypeName);
-            r = sigbuf.readBytes();
+            return signature.verify(asnEncode(sigBlob));
-            s = sigbuf.readBytes();
-        } catch (Exception e) {
-            throw new SSHRuntimeException(e);
-        }
-
-        try {
-            return signature.verify(asnEncode(r, s));
         } catch (SignatureException e) {
             throw new SSHRuntimeException(e);
         } catch (IOException e) {
@@ -126,7 +117,14 @@ public class SignatureECDSA extends AbstractSignature {
         }
     }
 
-    private byte[] asnEncode(byte[] r, byte[] s) throws IOException {
+    /**
+     * Encodes the signature as a DER sequence (ASN.1 format).
+     */
+    private byte[] asnEncode(byte[] sigBlob) throws IOException {
+        Buffer.PlainBuffer sigbuf = new Buffer.PlainBuffer(sigBlob);
+        byte[] r = sigbuf.readBytes();
+        byte[] s = sigbuf.readBytes();
+
         ASN1EncodableVector vector = new ASN1EncodableVector();
         vector.add(new ASN1Integer(r));
         vector.add(new ASN1Integer(s));

src/test/java/net/schmizz/sshj/signature/SignatureDSATest.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright (C)2009 - SSHJ Contributors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package net.schmizz.sshj.signature;
+
+import java.math.BigInteger;
+import java.security.KeyFactory;
+import java.security.NoSuchAlgorithmException;
+import java.security.spec.DSAPrivateKeySpec;
+import java.security.spec.DSAPublicKeySpec;
+import java.util.Arrays;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+
+import net.schmizz.sshj.common.Buffer;
+import net.schmizz.sshj.common.IOUtils;
+
+public class SignatureDSATest {
+
+    private KeyFactory keyFactory;
+
+    @Before
+    public void setUp() throws NoSuchAlgorithmException {
+        keyFactory = KeyFactory.getInstance("DSA");
+    }
+
+    @Test
+    public void testSignAndVerify() throws Exception {
+        BigInteger x = new BigInteger(new byte[] { 58, 19, -71, -30, 89, -111, 75, 98, 110, 38, -56, -23, 68, 74, -40, 17, -30, 37, 50, 35 });
+        BigInteger y = new BigInteger(new byte[] { 32, -91, -39, 54, 19, 14, 26, 113, -109, -92, -45, 83, -86, 23, -103, 108, 102, 86, 110, 78, -45, -41, -37, 38, -94, -92, -124, -36, -93, 92, 127, 113, 97, -119, -10, -73, -41, -45, 98, -104, -54, -9, -92, 66, 15, 31, 68, -32, 32, -121, -51, 68, 29, 100, 59, 60, 109, 111, -81, 80, 7, 127, 116, -107, 88, -114, -114, -69, 41, -15, 59, 81, 70, 9, -113, 36, 119, 28, 16, -127, -65, 32, -19, 109, -27, 24, -48, -80, 84, 47, 119, 25, 57, -118, -66, -22, -105, -11, 112, 16, -91, -127, 62, 23, 89, -17, -43, -105, -4, -43, 60, 42, -81, -95, -27, -8, 98, -37, 120, 80, -76, 93, -24, -104, -117, 38, -56, -68 });
+        BigInteger p = new BigInteger(new byte[] { 0, -3, 127, 83, -127, 29, 117, 18, 41, 82, -33, 74, -100, 46, -20, -28, -25, -10, 17, -73, 82, 60, -17, 68, 0, -61, 30, 63, -128, -74, 81, 38, 105, 69, 93, 64, 34, 81, -5, 89, 61, -115, 88, -6, -65, -59, -11, -70, 48, -10, -53, -101, 85, 108, -41, -127, 59, -128, 29, 52, 111, -14, 102, 96, -73, 107, -103, 80, -91, -92, -97, -97, -24, 4, 123, 16, 34, -62, 79, -69, -87, -41, -2, -73, -58, 27, -8, 59, 87, -25, -58, -88, -90, 21, 15, 4, -5, -125, -10, -45, -59, 30, -61, 2, 53, 84, 19, 90, 22, -111, 50, -10, 117, -13, -82, 43, 97, -41, 42, -17, -14, 34, 3, 25, -99, -47, 72, 1, -57 });
+        BigInteger q = new BigInteger(new byte[] { 0, -105, 96, 80, -113, 21, 35, 11, -52, -78, -110, -71, -126, -94, -21, -124, 11, -16, 88, 28, -11 });
+        BigInteger g = new BigInteger(new byte[] { 0, -9, -31, -96, -123, -42, -101, 61, -34, -53, -68, -85, 92, 54, -72, 87, -71, 121, -108, -81, -69, -6, 58, -22, -126, -7, 87, 76, 11, 61, 7, -126, 103, 81, 89, 87, -114, -70, -44, 89, 79, -26, 113, 7, 16, -127, -128, -76, 73, 22, 113, 35, -24, 76, 40, 22, 19, -73, -49, 9, 50, -116, -56, -90, -31, 60, 22, 122, -117, 84, 124, -115, 40, -32, -93, -82, 30, 43, -77, -90, 117, -111, 110, -93, 127, 11, -6, 33, 53, 98, -15, -5, 98, 122, 1, 36, 59, -52, -92, -15, -66, -88, 81, -112, -119, -88, -125, -33, -31, 90, -27, -97, 6, -110, -117, 102, 94, -128, 123, 85, 37, 100, 1, 76, 59, -2, -49, 73, 42 });
+
+        byte[] data = "The Magic Words are Squeamish Ossifrage".getBytes(IOUtils.UTF8);
+
+        // A previously signed and verified signature using the data and DSA key parameters above.
+        byte[] dataSig = new byte[] { 0, 0, 0, 7, 115, 115, 104, 45, 100, 115, 115, 0, 0, 0, 40, 40, -71, 33, 105, -89, -107, 8, 26, -13, -90, 73, -103, 105, 112, 7, -59, -66, 46, 85, -27, 20, 82, 22, -113, -75, -86, -121, -42, -73, 78, 66, 93, -34, 39, -50, -93, 27, -5, 37, -92 };
+
+        SignatureDSA signatureForSigning = new SignatureDSA();
+        signatureForSigning.initSign(keyFactory.generatePrivate(new DSAPrivateKeySpec(x, p, q, g)));
+        signatureForSigning.update(data);
+        byte[] sigBlob = signatureForSigning.encode(signatureForSigning.sign());
+        byte[] sigFull = new Buffer.PlainBuffer().putString("ssh-dss").putBytes(sigBlob).getCompactData();
+
+        SignatureDSA signatureForVerifying = new SignatureDSA();
+        signatureForVerifying.initVerify(keyFactory.generatePublic(new DSAPublicKeySpec(y, p, q, g)));
+        signatureForVerifying.update(data);
+        Assert.assertTrue("Failed to verify signature: " + Arrays.toString(sigFull), signatureForVerifying.verify(sigFull));
+        signatureForVerifying.update(data);
+        Assert.assertTrue("Failed to verify signature: " + Arrays.toString(dataSig), signatureForVerifying.verify(dataSig));
+    }
+
+}

src/test/java/net/schmizz/sshj/signature/SignatureECDSATest.java

@@ -22,7 +22,7 @@ import org.junit.Test;
 
 import java.security.PublicKey;
 
-public class VerificationTest {
+public class SignatureECDSATest {
 
     @Test
     public void testECDSA256Verifies() throws BufferException {