1 files changed, 62 insertions, 0 deletions
diff --git a/crypto/src/cms/KEKRecipientInformation.cs b/crypto/src/cms/KEKRecipientInformation.cs
new file mode 100644
index 000000000..f960197d6
--- /dev/null
+++ b/crypto/src/cms/KEKRecipientInformation.cs
@@ -0,0 +1,62 @@
+using System;
+using System.IO;
+
+using Org.BouncyCastle.Asn1.Cms;
+using Org.BouncyCastle.Asn1.X509;
+using Org.BouncyCastle.Crypto;
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Security;
+
+namespace Org.BouncyCastle.Cms
+{
+    /**
+    * the RecipientInfo class for a recipient who has been sent a message
+    * encrypted using a secret key known to the other side.
+    */
+    public class KekRecipientInformation
+        : RecipientInformation
+    {
+        private KekRecipientInfo info;
+
+		internal KekRecipientInformation(
+			KekRecipientInfo	info,
+			CmsSecureReadable	secureReadable)
+			: base(info.KeyEncryptionAlgorithm, secureReadable)
+		{
+            this.info = info;
+            this.rid = new RecipientID();
+
+			KekIdentifier kekId = info.KekID;
+
+			rid.KeyIdentifier = kekId.KeyIdentifier.GetOctets();
+        }
+
+		/**
+        * decrypt the content and return an input stream.
+        */
+        public override CmsTypedStream GetContentStream(
+            ICipherParameters key)
+        {
+			try
+			{
+				byte[] encryptedKey = info.EncryptedKey.GetOctets();
+				IWrapper keyWrapper = WrapperUtilities.GetWrapper(keyEncAlg.ObjectID.Id);
+
+				keyWrapper.Init(false, key);
+
+				KeyParameter sKey = ParameterUtilities.CreateKeyParameter(
+					GetContentAlgorithmName(), keyWrapper.Unwrap(encryptedKey, 0, encryptedKey.Length));
+
+				return GetContentFromSessionKey(sKey);
+			}
+			catch (SecurityUtilityException e)
+			{
+				throw new CmsException("couldn't create cipher.", e);
+			}
+			catch (InvalidKeyException e)
+			{
+				throw new CmsException("key invalid in message.", e);
+			}
+        }
+    }
+}