Initial Commit

iTechSharp/srcbc/asn1/cms/SignedDataParser.cs

@@ -0,0 +1,112 @@
+using System;
+using System.IO;
+
+namespace Org.BouncyCastle.Asn1.Cms
+{
+	/**
+	* <pre>
+	* SignedData ::= SEQUENCE {
+	*     version CMSVersion,
+	*     digestAlgorithms DigestAlgorithmIdentifiers,
+	*     encapContentInfo EncapsulatedContentInfo,
+	*     certificates [0] IMPLICIT CertificateSet OPTIONAL,
+	*     crls [1] IMPLICIT CertificateRevocationLists OPTIONAL,
+	*     signerInfos SignerInfos
+	*   }
+	* </pre>
+	*/
+	public class SignedDataParser
+	{
+		private Asn1SequenceParser	_seq;
+		private DerInteger			_version;
+		private object				_nextObject;
+		private bool				_certsCalled;
+		private bool				_crlsCalled;
+
+		public static SignedDataParser GetInstance(
+			object o)
+		{
+			if (o is Asn1Sequence)
+				return new SignedDataParser(((Asn1Sequence)o).Parser);
+
+			if (o is Asn1SequenceParser)
+				return new SignedDataParser((Asn1SequenceParser)o);
+
+			throw new IOException("unknown object encountered: " + o.GetType().Name);
+		}
+
+		public SignedDataParser(
+			Asn1SequenceParser seq)
+		{
+			this._seq = seq;
+			this._version = (DerInteger)seq.ReadObject();
+		}
+
+		public DerInteger Version
+		{
+			get { return _version; }
+		}
+
+		public Asn1SetParser GetDigestAlgorithms()
+		{
+			return (Asn1SetParser)_seq.ReadObject();
+		}
+
+		public ContentInfoParser GetEncapContentInfo()
+		{
+			return new ContentInfoParser((Asn1SequenceParser)_seq.ReadObject());
+		}
+
+		public Asn1SetParser GetCertificates()
+		{
+			_certsCalled = true;
+			_nextObject = _seq.ReadObject();
+
+			if (_nextObject is Asn1TaggedObjectParser && ((Asn1TaggedObjectParser)_nextObject).TagNo == 0)
+			{
+				Asn1SetParser certs = (Asn1SetParser)((Asn1TaggedObjectParser)_nextObject).GetObjectParser(Asn1Tags.Set, false);
+				_nextObject = null;
+
+				return certs;
+			}
+
+			return null;
+		}
+
+		public Asn1SetParser GetCrls()
+		{
+			if (!_certsCalled)
+				throw new IOException("GetCerts() has not been called.");
+
+			_crlsCalled = true;
+
+			if (_nextObject == null)
+			{
+				_nextObject = _seq.ReadObject();
+			}
+
+			if (_nextObject is Asn1TaggedObjectParser && ((Asn1TaggedObjectParser)_nextObject).TagNo == 1)
+			{
+				Asn1SetParser crls = (Asn1SetParser)((Asn1TaggedObjectParser)_nextObject).GetObjectParser(Asn1Tags.Set, false);
+				_nextObject = null;
+
+				return crls;
+			}
+
+			return null;
+		}
+
+		public Asn1SetParser GetSignerInfos()
+		{
+			if (!_certsCalled || !_crlsCalled)
+				throw new IOException("GetCerts() and/or GetCrls() has not been called.");
+
+			if (_nextObject == null)
+			{
+				_nextObject = _seq.ReadObject();
+			}
+
+			return (Asn1SetParser)_nextObject;
+		}
+	}
+}