1 files changed, 82 insertions, 0 deletions

diff --git a/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPGPDigestCalculatorProvider.java b/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPGPDigestCalculatorProvider.java
new file mode 100644
index 00000000..50d5fc73
--- /dev/null
+++ b/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPGPDigestCalculatorProvider.java
@@ -0,0 +1,82 @@
+package org.spongycastle.openpgp.operator.bc;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+import org.spongycastle.crypto.Digest;
+import org.spongycastle.openpgp.PGPException;
+import org.spongycastle.openpgp.operator.PGPDigestCalculator;
+import org.spongycastle.openpgp.operator.PGPDigestCalculatorProvider;
+
+public class BcPGPDigestCalculatorProvider
+    implements PGPDigestCalculatorProvider
+{
+    public PGPDigestCalculator get(final int algorithm)
+        throws PGPException
+    {
+        final Digest dig = BcImplProvider.createDigest(algorithm);
+
+        final DigestOutputStream stream = new DigestOutputStream(dig);
+
+        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 Digest dig;
+
+        DigestOutputStream(Digest 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, 0, bytes.length);
+        }
+
+        public void write(int b)
+            throws IOException
+        {
+            dig.update((byte)b);
+        }
+
+        byte[] getDigest()
+        {
+            byte[] d = new byte[dig.getDigestSize()];
+
+            dig.doFinal(d, 0);
+
+            return d;
+        }
+    }
+}
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