1 files changed, 114 insertions, 0 deletions
diff --git a/pkix/src/main/java/org/spongycastle/operator/jcajce/JcaDigestCalculatorProviderBuilder.java b/pkix/src/main/java/org/spongycastle/operator/jcajce/JcaDigestCalculatorProviderBuilder.java
new file mode 100644
index 00000000..c734b866
--- /dev/null
+++ b/pkix/src/main/java/org/spongycastle/operator/jcajce/JcaDigestCalculatorProviderBuilder.java
@@ -0,0 +1,114 @@
+package org.spongycastle.operator.jcajce;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.security.GeneralSecurityException;
+import java.security.MessageDigest;
+import java.security.Provider;
+
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.jcajce.util.DefaultJcaJceHelper;
+import org.spongycastle.jcajce.util.NamedJcaJceHelper;
+import org.spongycastle.jcajce.util.ProviderJcaJceHelper;
+import org.spongycastle.operator.DigestCalculator;
+import org.spongycastle.operator.DigestCalculatorProvider;
+import org.spongycastle.operator.OperatorCreationException;
+
+public class JcaDigestCalculatorProviderBuilder
+{
+    private OperatorHelper helper = new OperatorHelper(new DefaultJcaJceHelper());
+
+    public JcaDigestCalculatorProviderBuilder()
+    {
+    }
+
+    public JcaDigestCalculatorProviderBuilder setProvider(Provider provider)
+    {
+        this.helper = new OperatorHelper(new ProviderJcaJceHelper(provider));
+
+        return this;
+    }
+
+    public JcaDigestCalculatorProviderBuilder setProvider(String providerName)
+    {
+        this.helper = new OperatorHelper(new NamedJcaJceHelper(providerName));
+
+        return this;
+    }
+
+    public DigestCalculatorProvider build()
+        throws OperatorCreationException
+    {
+        return new DigestCalculatorProvider()
+        {
+            public DigestCalculator get(final AlgorithmIdentifier algorithm)
+                throws OperatorCreationException
+            {
+                final DigestOutputStream stream;
+
+                try
+                {
+                    MessageDigest dig = helper.createDigest(algorithm);
+
+                    stream = new DigestOutputStream(dig);
+                }
+                catch (GeneralSecurityException e)
+                {
+                    throw new OperatorCreationException("exception on setup: " + e, e);
+                }
+
+                return new DigestCalculator()
+                {
+                    public AlgorithmIdentifier getAlgorithmIdentifier()
+                    {
+                        return algorithm;
+                    }
+                    
+                    public OutputStream getOutputStream()
+                    {
+                        return stream;
+                    }
+
+                    public byte[] getDigest()
+                    {
+                        return stream.getDigest();
+                    }
+                };
+            }
+        };
+    }
+
+    private class DigestOutputStream
+        extends OutputStream
+    {
+        private MessageDigest dig;
+
+        DigestOutputStream(MessageDigest dig)
+        {
+            this.dig = dig;
+        }
+
+        public void write(byte[] bytes, int off, int len)
+            throws IOException
+        {
+            dig.update(bytes, off, len);
+        }
+
+        public void write(byte[] bytes)
+            throws IOException
+        {
+           dig.update(bytes);
+        }
+
+        public void write(int b)
+            throws IOException
+        {
+           dig.update((byte)b);
+        }
+
+        byte[] getDigest()
+        {
+            return dig.digest();
+        }
+    }
+}
+\ No newline at end of file