1 files changed, 57 insertions, 0 deletions
diff --git a/core/src/main/java/org/bouncycastle/crypto/tls/TlsDSASigner.java b/core/src/main/java/org/bouncycastle/crypto/tls/TlsDSASigner.java
new file mode 100644
index 00000000..b0e89572
--- /dev/null
+++ b/core/src/main/java/org/bouncycastle/crypto/tls/TlsDSASigner.java
@@ -0,0 +1,57 @@
+package org.bouncycastle.crypto.tls;
+
+import org.bouncycastle.crypto.CipherParameters;
+import org.bouncycastle.crypto.CryptoException;
+import org.bouncycastle.crypto.DSA;
+import org.bouncycastle.crypto.Digest;
+import org.bouncycastle.crypto.Signer;
+import org.bouncycastle.crypto.digests.NullDigest;
+import org.bouncycastle.crypto.digests.SHA1Digest;
+import org.bouncycastle.crypto.params.AsymmetricKeyParameter;
+import org.bouncycastle.crypto.params.ParametersWithRandom;
+import org.bouncycastle.crypto.signers.DSADigestSigner;
+
+public abstract class TlsDSASigner
+    extends AbstractTlsSigner
+{
+
+    public byte[] generateRawSignature(AsymmetricKeyParameter privateKey, byte[] md5AndSha1)
+        throws CryptoException
+    {
+
+        // Note: Only use the SHA1 part of the hash
+        Signer signer = makeSigner(new NullDigest(), true,
+            new ParametersWithRandom(privateKey, this.context.getSecureRandom()));
+        signer.update(md5AndSha1, 16, 20);
+        return signer.generateSignature();
+    }
+
+    public boolean verifyRawSignature(byte[] sigBytes, AsymmetricKeyParameter publicKey, byte[] md5AndSha1)
+        throws CryptoException
+    {
+
+        // Note: Only use the SHA1 part of the hash
+        Signer signer = makeSigner(new NullDigest(), false, publicKey);
+        signer.update(md5AndSha1, 16, 20);
+        return signer.verifySignature(sigBytes);
+    }
+
+    public Signer createSigner(AsymmetricKeyParameter privateKey)
+    {
+        return makeSigner(new SHA1Digest(), true, new ParametersWithRandom(privateKey, this.context.getSecureRandom()));
+    }
+
+    public Signer createVerifyer(AsymmetricKeyParameter publicKey)
+    {
+        return makeSigner(new SHA1Digest(), false, publicKey);
+    }
+
+    protected Signer makeSigner(Digest d, boolean forSigning, CipherParameters cp)
+    {
+        Signer s = new DSADigestSigner(createDSAImpl(), d);
+        s.init(forSigning, cp);
+        return s;
+    }
+
+    protected abstract DSA createDSAImpl();
+}