1 files changed, 49 insertions, 0 deletions
diff --git a/libraries/spongycastle/pkix/src/main/java/org/spongycastle/operator/bc/BcSymmetricKeyUnwrapper.java b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/operator/bc/BcSymmetricKeyUnwrapper.java
new file mode 100644
index 000000000..da37cf1aa
--- /dev/null
+++ b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/operator/bc/BcSymmetricKeyUnwrapper.java
@@ -0,0 +1,49 @@
+package org.spongycastle.operator.bc;
+
+import java.security.SecureRandom;
+
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.crypto.InvalidCipherTextException;
+import org.spongycastle.crypto.Wrapper;
+import org.spongycastle.crypto.params.KeyParameter;
+import org.spongycastle.operator.GenericKey;
+import org.spongycastle.operator.OperatorException;
+import org.spongycastle.operator.SymmetricKeyUnwrapper;
+
+public class BcSymmetricKeyUnwrapper
+    extends SymmetricKeyUnwrapper
+{
+    private SecureRandom random;
+    private Wrapper wrapper;
+    private KeyParameter wrappingKey;
+
+    public BcSymmetricKeyUnwrapper(AlgorithmIdentifier wrappingAlgorithm, Wrapper wrapper, KeyParameter wrappingKey)
+    {
+        super(wrappingAlgorithm);
+
+        this.wrapper = wrapper;
+        this.wrappingKey = wrappingKey;
+    }
+
+    public BcSymmetricKeyUnwrapper setSecureRandom(SecureRandom random)
+    {
+        this.random = random;
+
+        return this;
+    }
+
+    public GenericKey generateUnwrappedKey(AlgorithmIdentifier encryptedKeyAlgorithm, byte[] encryptedKey)
+        throws OperatorException
+    {
+        wrapper.init(false, wrappingKey);
+
+        try
+        {
+            return new GenericKey(encryptedKeyAlgorithm, wrapper.unwrap(encryptedKey, 0, encryptedKey.length));
+        }
+        catch (InvalidCipherTextException e)
+        {
+            throw new OperatorException("unable to unwrap key: " + e.getMessage(), e);
+        }
+    }
+}