1 files changed, 36 insertions, 0 deletions
diff --git a/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/bc/BcKeyTransRecipient.java b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/bc/BcKeyTransRecipient.java
new file mode 100644
index 000000000..ab50269d7
--- /dev/null
+++ b/libraries/spongycastle/pkix/src/main/java/org/spongycastle/cms/bc/BcKeyTransRecipient.java
@@ -0,0 +1,36 @@
+package org.spongycastle.cms.bc;
+
+import org.spongycastle.asn1.x509.AlgorithmIdentifier;
+import org.spongycastle.cms.CMSException;
+import org.spongycastle.cms.KeyTransRecipient;
+import org.spongycastle.crypto.CipherParameters;
+import org.spongycastle.crypto.params.AsymmetricKeyParameter;
+import org.spongycastle.operator.AsymmetricKeyUnwrapper;
+import org.spongycastle.operator.OperatorException;
+import org.spongycastle.operator.bc.BcRSAAsymmetricKeyUnwrapper;
+
+public abstract class BcKeyTransRecipient
+    implements KeyTransRecipient
+{
+    private AsymmetricKeyParameter recipientKey;
+
+    public BcKeyTransRecipient(AsymmetricKeyParameter recipientKey)
+    {
+        this.recipientKey = recipientKey;
+    }
+
+    protected CipherParameters extractSecretKey(AlgorithmIdentifier keyEncryptionAlgorithm, AlgorithmIdentifier encryptedKeyAlgorithm, byte[] encryptedEncryptionKey)
+        throws CMSException
+    {
+        AsymmetricKeyUnwrapper unwrapper = new BcRSAAsymmetricKeyUnwrapper(keyEncryptionAlgorithm, recipientKey);
+
+        try
+        {
+            return CMSUtils.getBcKey(unwrapper.generateUnwrappedKey(encryptedKeyAlgorithm, encryptedEncryptionKey));
+        }
+        catch (OperatorException e)
+        {
+            throw new CMSException("exception unwrapping key: " + e.getMessage(), e);
+        }
+    }
+}