1 files changed, 68 insertions, 0 deletions
diff --git a/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPBEDataDecryptorFactory.java b/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPBEDataDecryptorFactory.java
new file mode 100644
index 00000000..b9a1c189
--- /dev/null
+++ b/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPBEDataDecryptorFactory.java
@@ -0,0 +1,68 @@
+package org.spongycastle.openpgp.operator.bc;
+
+import org.spongycastle.crypto.BlockCipher;
+import org.spongycastle.crypto.BufferedBlockCipher;
+import org.spongycastle.openpgp.PGPException;
+import org.spongycastle.openpgp.operator.PBEDataDecryptorFactory;
+import org.spongycastle.openpgp.operator.PGPDataDecryptor;
+
+/**
+ * A {@link PBEDataDecryptorFactory} for handling PBE decryption operations using the Bouncy Castle
+ * lightweight API to implement cryptographic primitives.
+ */
+public class BcPBEDataDecryptorFactory
+    extends PBEDataDecryptorFactory
+{
+    /**
+     * Base constructor.
+     *
+     * @param pass  the passphrase to use as the primary source of key material.
+     * @param calculatorProvider   a digest calculator provider to provide calculators to support the key generation calculation required.
+     */
+    public BcPBEDataDecryptorFactory(char[] pass, BcPGPDigestCalculatorProvider calculatorProvider)
+    {
+        super(pass, calculatorProvider);
+    }
+
+    public byte[] recoverSessionData(int keyAlgorithm, byte[] key, byte[] secKeyData)
+        throws PGPException
+    {
+        try
+        {
+            if (secKeyData != null && secKeyData.length > 0)
+            {
+                BlockCipher engine = BcImplProvider.createBlockCipher(keyAlgorithm);
+                BufferedBlockCipher cipher = BcUtil.createSymmetricKeyWrapper(false, engine, key, new byte[engine.getBlockSize()]);
+
+                byte[] out = new byte[secKeyData.length];
+
+                int len = cipher.processBytes(secKeyData, 0, secKeyData.length, out, 0);
+
+                len += cipher.doFinal(out, len);
+
+                return out;
+            }
+            else
+            {
+                byte[] keyBytes = new byte[key.length + 1];
+
+                keyBytes[0] = (byte)keyAlgorithm;
+                System.arraycopy(key, 0, keyBytes, 1, key.length);
+
+                return keyBytes;
+            }
+        }
+        catch (Exception e)
+        {
+            throw new PGPException("Exception recovering session info", e);
+        }
+    }
+
+    public PGPDataDecryptor createDataDecryptor(boolean withIntegrityPacket, int encAlgorithm, byte[] key)
+        throws PGPException
+    {
+        BlockCipher engine = BcImplProvider.createBlockCipher(encAlgorithm);
+
+        return BcUtil.createDataDecryptor(withIntegrityPacket, engine, key);
+    }
+}