Initial Commit

iTechSharp/srcbc/cms/RecipientInformation.cs

@@ -0,0 +1,137 @@
+using System;
+using System.IO;
+
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Asn1.Nist;
+using Org.BouncyCastle.Asn1.Pkcs;
+using Org.BouncyCastle.Asn1.X509;
+using Org.BouncyCastle.Crypto;
+using Org.BouncyCastle.Crypto.IO;
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Security;
+using Org.BouncyCastle.Utilities.Collections;
+
+namespace Org.BouncyCastle.Cms
+{
+    public abstract class RecipientInformation
+    {
+		internal RecipientID _rid = new RecipientID();
+        internal AlgorithmIdentifier _encAlg;
+        internal AlgorithmIdentifier _keyEncAlg;
+        internal Stream _data;
+
+		internal RecipientInformation(
+            AlgorithmIdentifier	encAlg,
+            AlgorithmIdentifier	keyEncAlg,
+            Stream				data)
+        {
+			if (!data.CanRead)
+				throw new ArgumentException("Expected input stream", "data");
+
+			this._encAlg = encAlg;
+            this._keyEncAlg = keyEncAlg;
+            this._data = data;
+        }
+
+		public RecipientID RecipientID
+        {
+			get { return _rid; }
+        }
+
+		public AlgorithmIdentifier KeyEncryptionAlgorithmID
+		{
+			get { return _keyEncAlg; }
+		}
+
+		/**
+        * return the object identifier for the key encryption algorithm.
+		* @return OID for key encryption algorithm.
+        */
+        public string KeyEncryptionAlgOid
+        {
+			get { return _keyEncAlg.ObjectID.Id; }
+        }
+
+		/**
+        * return the ASN.1 encoded key encryption algorithm parameters, or null if
+        * there aren't any.
+		* @return ASN.1 encoding of key encryption algorithm parameters.
+        */
+		public Asn1Object KeyEncryptionAlgParams
+		{
+			get
+			{
+				Asn1Encodable ae = _keyEncAlg.Parameters;
+
+				return ae == null ? null : ae.ToAsn1Object();
+			}
+		}
+
+		internal CmsTypedStream GetContentFromSessionKey(
+            KeyParameter sKey)
+        {
+			try
+            {
+				IBufferedCipher cipher =  CipherUtilities.GetCipher(_encAlg.ObjectID);
+
+				Asn1Encodable asn1Enc = _encAlg.Parameters;
+				Asn1Object asn1Params = asn1Enc == null ? null : asn1Enc.ToAsn1Object();
+
+				ICipherParameters cipherParameters = sKey;
+
+				if (asn1Params != null && !(asn1Params is Asn1Null))
+                {
+					cipherParameters = ParameterUtilities.GetCipherParameters(
+						_encAlg.ObjectID, cipherParameters, asn1Params);
+                }
+                else
+                {
+					string alg = _encAlg.ObjectID.Id;
+					if (alg.Equals(CmsEnvelopedDataGenerator.DesEde3Cbc)
+                        || alg.Equals(CmsEnvelopedDataGenerator.IdeaCbc)
+                        || alg.Equals(CmsEnvelopedDataGenerator.Cast5Cbc))
+                    {
+                        cipherParameters = new ParametersWithIV(cipherParameters, new byte[8]);
+                    }
+                }
+
+				cipher.Init(false, cipherParameters);
+
+				return new CmsTypedStream(new CipherStream(_data, cipher, null));
+            }
+			catch (SecurityUtilityException e)
+			{
+				throw new CmsException("couldn't create cipher.", e);
+			}
+			catch (InvalidKeyException e)
+            {
+                throw new CmsException("key invalid in message.", e);
+            }
+            catch (IOException e)
+            {
+                throw new CmsException("error decoding algorithm parameters.", e);
+            }
+        }
+
+		public byte[] GetContent(
+            ICipherParameters key)
+        {
+            try
+            {
+                if (_data is MemoryStream)
+                {
+//					_data.Reset();
+					_data.Seek(0L, SeekOrigin.Begin);
+                }
+
+				return CmsUtilities.StreamToByteArray(GetContentStream(key).ContentStream);
+            }
+            catch (IOException e)
+            {
+                throw new Exception("unable to parse internal stream: " + e);
+            }
+        }
+
+		public abstract CmsTypedStream GetContentStream(ICipherParameters key);
+    }
+}