1 files changed, 98 insertions, 0 deletions
diff --git a/libraries/spongycastle/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPGPContentSignerBuilder.java b/libraries/spongycastle/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPGPContentSignerBuilder.java
new file mode 100644
index 000000000..cd98ef38c
--- /dev/null
+++ b/libraries/spongycastle/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPGPContentSignerBuilder.java
@@ -0,0 +1,98 @@
+package org.spongycastle.openpgp.operator.bc;
+
+import java.io.OutputStream;
+import java.security.SecureRandom;
+
+import org.spongycastle.crypto.CryptoException;
+import org.spongycastle.crypto.Signer;
+import org.spongycastle.crypto.params.ParametersWithRandom;
+import org.spongycastle.openpgp.PGPException;
+import org.spongycastle.openpgp.PGPPrivateKey;
+import org.spongycastle.openpgp.operator.PGPContentSigner;
+import org.spongycastle.openpgp.operator.PGPContentSignerBuilder;
+import org.spongycastle.openpgp.operator.PGPDigestCalculator;
+import org.spongycastle.util.io.TeeOutputStream;
+
+public class BcPGPContentSignerBuilder
+    implements PGPContentSignerBuilder
+{
+    private BcPGPDigestCalculatorProvider digestCalculatorProvider = new BcPGPDigestCalculatorProvider();
+    private BcPGPKeyConverter           keyConverter = new BcPGPKeyConverter();
+    private int                         hashAlgorithm;
+    private SecureRandom                random;
+    private int keyAlgorithm;
+
+    public BcPGPContentSignerBuilder(int keyAlgorithm, int hashAlgorithm)
+    {
+        this.keyAlgorithm = keyAlgorithm;
+        this.hashAlgorithm = hashAlgorithm;
+    }
+
+    public BcPGPContentSignerBuilder setSecureRandom(SecureRandom random)
+    {
+        this.random = random;
+
+        return this;
+    }
+
+    public PGPContentSigner build(final int signatureType, final PGPPrivateKey privateKey)
+        throws PGPException
+    {
+        final PGPDigestCalculator digestCalculator = digestCalculatorProvider.get(hashAlgorithm);
+        final Signer signer = BcImplProvider.createSigner(keyAlgorithm, hashAlgorithm);
+
+        if (random != null)
+        {
+            signer.init(true, new ParametersWithRandom(keyConverter.getPrivateKey(privateKey), random));
+        }
+        else
+        {
+            signer.init(true, keyConverter.getPrivateKey(privateKey));
+        }
+
+        return new PGPContentSigner()
+        {
+            public int getType()
+            {
+                return signatureType;
+            }
+
+            public int getHashAlgorithm()
+            {
+                return hashAlgorithm;
+            }
+
+            public int getKeyAlgorithm()
+            {
+                return keyAlgorithm;
+            }
+
+            public long getKeyID()
+            {
+                return privateKey.getKeyID();
+            }
+
+            public OutputStream getOutputStream()
+            {
+                return new TeeOutputStream(new SignerOutputStream(signer), digestCalculator.getOutputStream());
+            }
+
+            public byte[] getSignature()
+            {
+                try
+                {
+                    return signer.generateSignature();
+                }
+                catch (CryptoException e)
+                {    // TODO: need a specific runtime exception for PGP operators.
+                    throw new IllegalStateException("unable to create signature");
+                }
+            }
+
+            public byte[] getDigest()
+            {
+                return digestCalculator.getDigest();
+            }
+        };
+    }
+}