1 files changed, 161 insertions, 0 deletions
diff --git a/Crypto/src/cms/CMSEnvelopedDataParser.cs b/Crypto/src/cms/CMSEnvelopedDataParser.cs
new file mode 100644
index 000000000..01a949d47
--- /dev/null
+++ b/Crypto/src/cms/CMSEnvelopedDataParser.cs
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+using System;
+using System.Collections;
+using System.IO;
+
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Asn1.Cms;
+using Org.BouncyCastle.Asn1.X509;
+using Org.BouncyCastle.Crypto;
+
+namespace Org.BouncyCastle.Cms
+{
+ /**
+ * Parsing class for an CMS Enveloped Data object from an input stream.
+ * <p>
+ * Note: that because we are in a streaming mode only one recipient can be tried and it is important
+ * that the methods on the parser are called in the appropriate order.
+ * </p>
+ * <p>
+ * Example of use - assuming the first recipient matches the private key we have.
+ * <pre>
+ * CmsEnvelopedDataParser ep = new CmsEnvelopedDataParser(inputStream);
+ *
+ * RecipientInformationStore recipients = ep.GetRecipientInfos();
+ *
+ * Collection c = recipients.getRecipients();
+ * Iterator it = c.iterator();
+ *
+ * if (it.hasNext())
+ * {
+ * RecipientInformation recipient = (RecipientInformation)it.next();
+ *
+ * CMSTypedStream recData = recipient.getContentStream(privateKey);
+ *
+ * processDataStream(recData.getContentStream());
+ * }
+ * </pre>
+ * Note: this class does not introduce buffering - if you are processing large files you should create
+ * the parser with:
+ * <pre>
+ * CmsEnvelopedDataParser ep = new CmsEnvelopedDataParser(new BufferedInputStream(inputStream, bufSize));
+ * </pre>
+ * where bufSize is a suitably large buffer size.
+ * </p>
+ */
+ public class CmsEnvelopedDataParser
+ : CmsContentInfoParser
+ {
+ internal RecipientInformationStore recipientInfoStore;
+ internal EnvelopedDataParser envelopedData;
+
+ private AlgorithmIdentifier _encAlg;
+ private Asn1.Cms.AttributeTable _unprotectedAttributes;
+ private bool _attrNotRead;
+
+ public CmsEnvelopedDataParser(
+ byte[] envelopedData)
+ : this(new MemoryStream(envelopedData, false))
+ {
+ }
+
+ public CmsEnvelopedDataParser(
+ Stream envelopedData)
+ : base(envelopedData)
+ {
+ this._attrNotRead = true;
+ this.envelopedData = new EnvelopedDataParser(
+ (Asn1SequenceParser)this.contentInfo.GetContent(Asn1Tags.Sequence));
+
+ // TODO Validate version?
+ //DerInteger version = this.envelopedData.Version;
+
+ //
+ // read the recipients
+ //
+ Asn1Set recipientInfos = Asn1Set.GetInstance(this.envelopedData.GetRecipientInfos().ToAsn1Object());
+
+ //
+ // read the encrypted content info
+ //
+ EncryptedContentInfoParser encInfo = this.envelopedData.GetEncryptedContentInfo();
+ this._encAlg = encInfo.ContentEncryptionAlgorithm;
+ CmsReadable readable = new CmsProcessableInputStream(
+ ((Asn1OctetStringParser)encInfo.GetEncryptedContent(Asn1Tags.OctetString)).GetOctetStream());
+ CmsSecureReadable secureReadable = new CmsEnvelopedHelper.CmsEnvelopedSecureReadable(
+ this._encAlg, readable);
+
+ //
+ // build the RecipientInformationStore
+ //
+ this.recipientInfoStore = CmsEnvelopedHelper.BuildRecipientInformationStore(
+ recipientInfos, secureReadable);
+ }
+
+ public AlgorithmIdentifier EncryptionAlgorithmID
+ {
+ get { return _encAlg; }
+ }
+
+ /**
+ * return the object identifier for the content encryption algorithm.
+ */
+ public string EncryptionAlgOid
+ {
+ get { return _encAlg.ObjectID.Id; }
+ }
+
+ /**
+ * return the ASN.1 encoded encryption algorithm parameters, or null if
+ * there aren't any.
+ */
+ public Asn1Object EncryptionAlgParams
+ {
+ get
+ {
+ Asn1Encodable ae = _encAlg.Parameters;
+
+ return ae == null ? null : ae.ToAsn1Object();
+ }
+ }
+
+ /**
+ * return a store of the intended recipients for this message
+ */
+ public RecipientInformationStore GetRecipientInfos()
+ {
+ return this.recipientInfoStore;
+ }
+
+ /**
+ * return a table of the unprotected attributes indexed by
+ * the OID of the attribute.
+ * @throws IOException
+ */
+ public Asn1.Cms.AttributeTable GetUnprotectedAttributes()
+ {
+ if (_unprotectedAttributes == null && _attrNotRead)
+ {
+ Asn1SetParser asn1Set = this.envelopedData.GetUnprotectedAttrs();
+
+ _attrNotRead = false;
+
+ if (asn1Set != null)
+ {
+ Asn1EncodableVector v = new Asn1EncodableVector();
+ IAsn1Convertible o;
+
+ while ((o = asn1Set.ReadObject()) != null)
+ {
+ Asn1SequenceParser seq = (Asn1SequenceParser)o;
+
+ v.Add(seq.ToAsn1Object());
+ }
+
+ _unprotectedAttributes = new Asn1.Cms.AttributeTable(new DerSet(v));
+ }
+ }
+
+ return _unprotectedAttributes;
+ }
+ }
+}
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