1 files changed, 43 insertions, 0 deletions
diff --git a/libraries/spongycastle/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPBESecretKeyDecryptorBuilder.java b/libraries/spongycastle/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPBESecretKeyDecryptorBuilder.java
new file mode 100644
index 000000000..bf0a0db9a
--- /dev/null
+++ b/libraries/spongycastle/pg/src/main/java/org/spongycastle/openpgp/operator/bc/BcPBESecretKeyDecryptorBuilder.java
@@ -0,0 +1,43 @@
+package org.spongycastle.openpgp.operator.bc;
+
+import org.spongycastle.crypto.BufferedBlockCipher;
+import org.spongycastle.crypto.InvalidCipherTextException;
+import org.spongycastle.openpgp.PGPException;
+import org.spongycastle.openpgp.operator.PBESecretKeyDecryptor;
+import org.spongycastle.openpgp.operator.PGPDigestCalculatorProvider;
+
+public class BcPBESecretKeyDecryptorBuilder
+{
+    private PGPDigestCalculatorProvider calculatorProvider;
+
+    public BcPBESecretKeyDecryptorBuilder(PGPDigestCalculatorProvider calculatorProvider)
+    {
+        this.calculatorProvider = calculatorProvider;
+    }
+
+    public PBESecretKeyDecryptor build(char[] passPhrase)
+    {
+        return new PBESecretKeyDecryptor(passPhrase, calculatorProvider)
+        {
+            public byte[] recoverKeyData(int encAlgorithm, byte[] key, byte[] iv, byte[] keyData, int keyOff, int keyLen)
+                throws PGPException
+            {
+                try
+                {
+                    BufferedBlockCipher c = BcUtil.createSymmetricKeyWrapper(false, BcImplProvider.createBlockCipher(encAlgorithm), key, iv);
+
+                    byte[] out = new byte[keyLen];
+                    int    outLen = c.processBytes(keyData, keyOff, keyLen, out, 0);
+
+                    outLen += c.doFinal(out, outLen);
+
+                    return out;
+                }
+                catch (InvalidCipherTextException e)
+                {
+                    throw new PGPException("decryption failed: " + e.getMessage(), e);
+                }
+            }
+        };
+    }
+}