1 files changed, 119 insertions, 0 deletions
diff --git a/libraries/spongycastle/pg/src/main/java/org/spongycastle/openpgp/operator/jcajce/JcaPGPDigestCalculatorProviderBuilder.java b/libraries/spongycastle/pg/src/main/java/org/spongycastle/openpgp/operator/jcajce/JcaPGPDigestCalculatorProviderBuilder.java
new file mode 100644
index 000000000..a70919cb8
--- /dev/null
+++ b/libraries/spongycastle/pg/src/main/java/org/spongycastle/openpgp/operator/jcajce/JcaPGPDigestCalculatorProviderBuilder.java
@@ -0,0 +1,119 @@
+package org.spongycastle.openpgp.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.jcajce.DefaultJcaJceHelper;
+import org.spongycastle.jcajce.NamedJcaJceHelper;
+import org.spongycastle.jcajce.ProviderJcaJceHelper;
+import org.spongycastle.openpgp.PGPException;
+import org.spongycastle.openpgp.operator.PGPDigestCalculator;
+import org.spongycastle.openpgp.operator.PGPDigestCalculatorProvider;
+
+public class JcaPGPDigestCalculatorProviderBuilder
+{
+    private OperatorHelper helper = new OperatorHelper(new DefaultJcaJceHelper());
+
+    public JcaPGPDigestCalculatorProviderBuilder()
+    {
+    }
+
+    public JcaPGPDigestCalculatorProviderBuilder setProvider(Provider provider)
+    {
+        this.helper = new OperatorHelper(new ProviderJcaJceHelper(provider));
+
+        return this;
+    }
+
+    public JcaPGPDigestCalculatorProviderBuilder setProvider(String providerName)
+    {
+        this.helper = new OperatorHelper(new NamedJcaJceHelper(providerName));
+
+        return this;
+    }
+
+    public PGPDigestCalculatorProvider build()
+        throws PGPException
+    {
+        return new PGPDigestCalculatorProvider()
+        {
+            public PGPDigestCalculator get(final int algorithm)
+                throws PGPException
+            {
+                final DigestOutputStream stream;
+                final MessageDigest dig;
+
+                try
+                {
+                    dig = helper.createDigest(algorithm);
+
+                    stream = new DigestOutputStream(dig);
+                }
+                catch (GeneralSecurityException e)
+                {
+                    throw new PGPException("exception on setup: " + e, e);
+                }
+
+                return new PGPDigestCalculator()
+                {
+                    public int getAlgorithm()
+                    {
+                        return algorithm;
+                    }
+
+                    public OutputStream getOutputStream()
+                    {
+                        return stream;
+                    }
+
+                    public byte[] getDigest()
+                    {
+                        return stream.getDigest();
+                    }
+
+                    public void reset()
+                    {
+                        dig.reset();
+                    }
+                };
+            }
+        };
+    }
+
+    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();
+        }
+    }
+}